add glfw library

13 files changed, 4305 insertions, 0 deletions

diff --git a/libs/glfw-3.3.8/examples/CMakeLists.txt b/libs/glfw-3.3.8/examples/CMakeLists.txt
new file mode 100644
index 0000000..0eba4e6
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/CMakeLists.txt
@@ -0,0 +1,93 @@
+
+link_libraries(glfw)
+
+include_directories("${GLFW_SOURCE_DIR}/deps")
+
+if (MATH_LIBRARY)
+    link_libraries("${MATH_LIBRARY}")
+endif()
+
+# Workaround for the MS CRT deprecating parts of the standard library
+if (MSVC OR CMAKE_C_SIMULATE_ID STREQUAL "MSVC")
+    add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+endif()
+
+if (WIN32)
+    set(ICON glfw.rc)
+elseif (APPLE)
+    set(ICON glfw.icns)
+endif()
+
+if (${CMAKE_VERSION} VERSION_EQUAL "3.1.0" OR
+    ${CMAKE_VERSION} VERSION_GREATER "3.1.0")
+    set(CMAKE_C_STANDARD 99)
+else()
+    # Remove this fallback when removing support for CMake version less than 3.1
+    add_compile_options("$<$<C_COMPILER_ID:AppleClang>:-std=c99>"
+                        "$<$<C_COMPILER_ID:Clang>:-std=c99>"
+                        "$<$<C_COMPILER_ID:GNU>:-std=c99>")
+
+endif()
+
+set(GLAD_GL "${GLFW_SOURCE_DIR}/deps/glad/gl.h"
+            "${GLFW_SOURCE_DIR}/deps/glad_gl.c")
+set(GETOPT "${GLFW_SOURCE_DIR}/deps/getopt.h"
+           "${GLFW_SOURCE_DIR}/deps/getopt.c")
+set(TINYCTHREAD "${GLFW_SOURCE_DIR}/deps/tinycthread.h"
+                "${GLFW_SOURCE_DIR}/deps/tinycthread.c")
+
+add_executable(boing WIN32 MACOSX_BUNDLE boing.c ${ICON} ${GLAD_GL})
+add_executable(gears WIN32 MACOSX_BUNDLE gears.c ${ICON} ${GLAD_GL})
+add_executable(heightmap WIN32 MACOSX_BUNDLE heightmap.c ${ICON} ${GLAD_GL})
+add_executable(offscreen offscreen.c ${ICON} ${GLAD_GL})
+add_executable(particles WIN32 MACOSX_BUNDLE particles.c ${ICON} ${TINYCTHREAD} ${GETOPT} ${GLAD_GL})
+add_executable(sharing WIN32 MACOSX_BUNDLE sharing.c ${ICON} ${GLAD_GL})
+add_executable(simple WIN32 MACOSX_BUNDLE simple.c ${ICON} ${GLAD_GL})
+add_executable(splitview WIN32 MACOSX_BUNDLE splitview.c ${ICON} ${GLAD_GL})
+add_executable(wave WIN32 MACOSX_BUNDLE wave.c ${ICON} ${GLAD_GL})
+
+target_link_libraries(particles "${CMAKE_THREAD_LIBS_INIT}")
+if (RT_LIBRARY)
+    target_link_libraries(particles "${RT_LIBRARY}")
+endif()
+
+set(GUI_ONLY_BINARIES boing gears heightmap particles sharing simple splitview
+    wave)
+set(CONSOLE_BINARIES offscreen)
+
+set_target_properties(${GUI_ONLY_BINARIES} ${CONSOLE_BINARIES} PROPERTIES
+                      FOLDER "GLFW3/Examples")
+
+if (GLFW_USE_OSMESA)
+    target_compile_definitions(offscreen PRIVATE USE_NATIVE_OSMESA)
+endif()
+
+if (MSVC)
+    # Tell MSVC to use main instead of WinMain
+    set_target_properties(${GUI_ONLY_BINARIES} PROPERTIES
+                          LINK_FLAGS "/ENTRY:mainCRTStartup")
+elseif (CMAKE_C_SIMULATE_ID STREQUAL "MSVC")
+    # Tell Clang using MS CRT to use main instead of WinMain
+    set_target_properties(${GUI_ONLY_BINARIES} PROPERTIES
+                          LINK_FLAGS "-Wl,/entry:mainCRTStartup")
+endif()
+
+if (APPLE)
+    set_target_properties(boing PROPERTIES MACOSX_BUNDLE_BUNDLE_NAME "Boing")
+    set_target_properties(gears PROPERTIES MACOSX_BUNDLE_BUNDLE_NAME "Gears")
+    set_target_properties(heightmap PROPERTIES MACOSX_BUNDLE_BUNDLE_NAME "Heightmap")
+    set_target_properties(particles PROPERTIES MACOSX_BUNDLE_BUNDLE_NAME "Particles")
+    set_target_properties(sharing PROPERTIES MACOSX_BUNDLE_BUNDLE_NAME "Sharing")
+    set_target_properties(simple PROPERTIES MACOSX_BUNDLE_BUNDLE_NAME "Simple")
+    set_target_properties(splitview PROPERTIES MACOSX_BUNDLE_BUNDLE_NAME "SplitView")
+    set_target_properties(wave PROPERTIES MACOSX_BUNDLE_BUNDLE_NAME "Wave")
+
+    set_source_files_properties(glfw.icns PROPERTIES
+                                MACOSX_PACKAGE_LOCATION "Resources")
+    set_target_properties(${GUI_ONLY_BINARIES} PROPERTIES
+                          MACOSX_BUNDLE_SHORT_VERSION_STRING ${GLFW_VERSION}
+                          MACOSX_BUNDLE_LONG_VERSION_STRING ${GLFW_VERSION}
+                          MACOSX_BUNDLE_ICON_FILE glfw.icns
+                          MACOSX_BUNDLE_INFO_PLIST "${GLFW_SOURCE_DIR}/CMake/MacOSXBundleInfo.plist.in")
+endif()
+
diff --git a/libs/glfw-3.3.8/examples/boing.c b/libs/glfw-3.3.8/examples/boing.c
new file mode 100644
index 0000000..ca38908
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/boing.c
@@ -0,0 +1,679 @@
+/*****************************************************************************
+ * Title:   GLBoing
+ * Desc:    Tribute to Amiga Boing.
+ * Author:  Jim Brooks  <gfx@jimbrooks.org>
+ *          Original Amiga authors were R.J. Mical and Dale Luck.
+ *          GLFW conversion by Marcus Geelnard
+ * Notes:   - 360' = 2*PI [radian]
+ *
+ *          - Distances between objects are created by doing a relative
+ *            Z translations.
+ *
+ *          - Although OpenGL enticingly supports alpha-blending,
+ *            the shadow of the original Boing didn't affect the color
+ *            of the grid.
+ *
+ *          - [Marcus] Changed timing scheme from interval driven to frame-
+ *            time based animation steps (which results in much smoother
+ *            movement)
+ *
+ * History of Amiga Boing:
+ *
+ * Boing was demonstrated on the prototype Amiga (codenamed "Lorraine") in
+ * 1985. According to legend, it was written ad-hoc in one night by
+ * R. J. Mical and Dale Luck. Because the bouncing ball animation was so fast
+ * and smooth, attendees did not believe the Amiga prototype was really doing
+ * the rendering. Suspecting a trick, they began looking around the booth for
+ * a hidden computer or VCR.
+ *****************************************************************************/
+
+#if defined(_MSC_VER)
+ // Make MS math.h define M_PI
+ #define _USE_MATH_DEFINES
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+#include <linmath.h>
+
+
+/*****************************************************************************
+ * Various declarations and macros
+ *****************************************************************************/
+
+/* Prototypes */
+void init( void );
+void display( void );
+void reshape( GLFWwindow* window, int w, int h );
+void key_callback( GLFWwindow* window, int key, int scancode, int action, int mods );
+void mouse_button_callback( GLFWwindow* window, int button, int action, int mods );
+void cursor_position_callback( GLFWwindow* window, double x, double y );
+void DrawBoingBall( void );
+void BounceBall( double dt );
+void DrawBoingBallBand( GLfloat long_lo, GLfloat long_hi );
+void DrawGrid( void );
+
+#define RADIUS           70.f
+#define STEP_LONGITUDE   22.5f                   /* 22.5 makes 8 bands like original Boing */
+#define STEP_LATITUDE    22.5f
+
+#define DIST_BALL       (RADIUS * 2.f + RADIUS * 0.1f)
+
+#define VIEW_SCENE_DIST (DIST_BALL * 3.f + 200.f)/* distance from viewer to middle of boing area */
+#define GRID_SIZE       (RADIUS * 4.5f)          /* length (width) of grid */
+#define BOUNCE_HEIGHT   (RADIUS * 2.1f)
+#define BOUNCE_WIDTH    (RADIUS * 2.1f)
+
+#define SHADOW_OFFSET_X -20.f
+#define SHADOW_OFFSET_Y  10.f
+#define SHADOW_OFFSET_Z   0.f
+
+#define WALL_L_OFFSET   0.f
+#define WALL_R_OFFSET   5.f
+
+/* Animation speed (50.0 mimics the original GLUT demo speed) */
+#define ANIMATION_SPEED 50.f
+
+/* Maximum allowed delta time per physics iteration */
+#define MAX_DELTA_T 0.02f
+
+/* Draw ball, or its shadow */
+typedef enum { DRAW_BALL, DRAW_BALL_SHADOW } DRAW_BALL_ENUM;
+
+/* Vertex type */
+typedef struct {float x; float y; float z;} vertex_t;
+
+/* Global vars */
+int windowed_xpos, windowed_ypos, windowed_width, windowed_height;
+int width, height;
+GLfloat deg_rot_y       = 0.f;
+GLfloat deg_rot_y_inc   = 2.f;
+int override_pos        = GLFW_FALSE;
+GLfloat cursor_x        = 0.f;
+GLfloat cursor_y        = 0.f;
+GLfloat ball_x          = -RADIUS;
+GLfloat ball_y          = -RADIUS;
+GLfloat ball_x_inc      = 1.f;
+GLfloat ball_y_inc      = 2.f;
+DRAW_BALL_ENUM drawBallHow;
+double  t;
+double  t_old = 0.f;
+double  dt;
+
+/* Random number generator */
+#ifndef RAND_MAX
+ #define RAND_MAX 4095
+#endif
+
+
+/*****************************************************************************
+ * Truncate a degree.
+ *****************************************************************************/
+GLfloat TruncateDeg( GLfloat deg )
+{
+   if ( deg >= 360.f )
+      return (deg - 360.f);
+   else
+      return deg;
+}
+
+/*****************************************************************************
+ * Convert a degree (360-based) into a radian.
+ * 360' = 2 * PI
+ *****************************************************************************/
+double deg2rad( double deg )
+{
+   return deg / 360 * (2 * M_PI);
+}
+
+/*****************************************************************************
+ * 360' sin().
+ *****************************************************************************/
+double sin_deg( double deg )
+{
+   return sin( deg2rad( deg ) );
+}
+
+/*****************************************************************************
+ * 360' cos().
+ *****************************************************************************/
+double cos_deg( double deg )
+{
+   return cos( deg2rad( deg ) );
+}
+
+/*****************************************************************************
+ * Compute a cross product (for a normal vector).
+ *
+ * c = a x b
+ *****************************************************************************/
+void CrossProduct( vertex_t a, vertex_t b, vertex_t c, vertex_t *n )
+{
+   GLfloat u1, u2, u3;
+   GLfloat v1, v2, v3;
+
+   u1 = b.x - a.x;
+   u2 = b.y - a.y;
+   u3 = b.y - a.z;
+
+   v1 = c.x - a.x;
+   v2 = c.y - a.y;
+   v3 = c.z - a.z;
+
+   n->x = u2 * v3 - v2 * u3;
+   n->y = u3 * v1 - v3 * u1;
+   n->z = u1 * v2 - v1 * u2;
+}
+
+
+#define BOING_DEBUG 0
+
+
+/*****************************************************************************
+ * init()
+ *****************************************************************************/
+void init( void )
+{
+   /*
+    * Clear background.
+    */
+   glClearColor( 0.55f, 0.55f, 0.55f, 0.f );
+
+   glShadeModel( GL_FLAT );
+}
+
+
+/*****************************************************************************
+ * display()
+ *****************************************************************************/
+void display(void)
+{
+   glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+   glPushMatrix();
+
+   drawBallHow = DRAW_BALL_SHADOW;
+   DrawBoingBall();
+
+   DrawGrid();
+
+   drawBallHow = DRAW_BALL;
+   DrawBoingBall();
+
+   glPopMatrix();
+   glFlush();
+}
+
+
+/*****************************************************************************
+ * reshape()
+ *****************************************************************************/
+void reshape( GLFWwindow* window, int w, int h )
+{
+   mat4x4 projection, view;
+
+   glViewport( 0, 0, (GLsizei)w, (GLsizei)h );
+
+   glMatrixMode( GL_PROJECTION );
+   mat4x4_perspective( projection,
+                       2.f * (float) atan2( RADIUS, 200.f ),
+                       (float)w / (float)h,
+                       1.f, VIEW_SCENE_DIST );
+   glLoadMatrixf((const GLfloat*) projection);
+
+   glMatrixMode( GL_MODELVIEW );
+   {
+      vec3 eye = { 0.f, 0.f, VIEW_SCENE_DIST };
+      vec3 center = { 0.f, 0.f, 0.f };
+      vec3 up = { 0.f, -1.f, 0.f };
+      mat4x4_look_at( view, eye, center, up );
+   }
+   glLoadMatrixf((const GLfloat*) view);
+}
+
+void key_callback( GLFWwindow* window, int key, int scancode, int action, int mods )
+{
+    if (action != GLFW_PRESS)
+        return;
+
+    if (key == GLFW_KEY_ESCAPE && mods == 0)
+        glfwSetWindowShouldClose(window, GLFW_TRUE);
+    if ((key == GLFW_KEY_ENTER && mods == GLFW_MOD_ALT) ||
+        (key == GLFW_KEY_F11 && mods == GLFW_MOD_ALT))
+    {
+        if (glfwGetWindowMonitor(window))
+        {
+            glfwSetWindowMonitor(window, NULL,
+                                 windowed_xpos, windowed_ypos,
+                                 windowed_width, windowed_height, 0);
+        }
+        else
+        {
+            GLFWmonitor* monitor = glfwGetPrimaryMonitor();
+            if (monitor)
+            {
+                const GLFWvidmode* mode = glfwGetVideoMode(monitor);
+                glfwGetWindowPos(window, &windowed_xpos, &windowed_ypos);
+                glfwGetWindowSize(window, &windowed_width, &windowed_height);
+                glfwSetWindowMonitor(window, monitor, 0, 0, mode->width, mode->height, mode->refreshRate);
+            }
+        }
+    }
+}
+
+static void set_ball_pos ( GLfloat x, GLfloat y )
+{
+   ball_x = (width / 2) - x;
+   ball_y = y - (height / 2);
+}
+
+void mouse_button_callback( GLFWwindow* window, int button, int action, int mods )
+{
+   if (button != GLFW_MOUSE_BUTTON_LEFT)
+      return;
+
+   if (action == GLFW_PRESS)
+   {
+      override_pos = GLFW_TRUE;
+      set_ball_pos(cursor_x, cursor_y);
+   }
+   else
+   {
+      override_pos = GLFW_FALSE;
+   }
+}
+
+void cursor_position_callback( GLFWwindow* window, double x, double y )
+{
+   cursor_x = (float) x;
+   cursor_y = (float) y;
+
+   if ( override_pos )
+      set_ball_pos(cursor_x, cursor_y);
+}
+
+/*****************************************************************************
+ * Draw the Boing ball.
+ *
+ * The Boing ball is sphere in which each facet is a rectangle.
+ * Facet colors alternate between red and white.
+ * The ball is built by stacking latitudinal circles.  Each circle is composed
+ * of a widely-separated set of points, so that each facet is noticeably large.
+ *****************************************************************************/
+void DrawBoingBall( void )
+{
+   GLfloat lon_deg;     /* degree of longitude */
+   double dt_total, dt2;
+
+   glPushMatrix();
+   glMatrixMode( GL_MODELVIEW );
+
+  /*
+   * Another relative Z translation to separate objects.
+   */
+   glTranslatef( 0.0, 0.0, DIST_BALL );
+
+   /* Update ball position and rotation (iterate if necessary) */
+   dt_total = dt;
+   while( dt_total > 0.0 )
+   {
+       dt2 = dt_total > MAX_DELTA_T ? MAX_DELTA_T : dt_total;
+       dt_total -= dt2;
+       BounceBall( dt2 );
+       deg_rot_y = TruncateDeg( deg_rot_y + deg_rot_y_inc*((float)dt2*ANIMATION_SPEED) );
+   }
+
+   /* Set ball position */
+   glTranslatef( ball_x, ball_y, 0.0 );
+
+  /*
+   * Offset the shadow.
+   */
+   if ( drawBallHow == DRAW_BALL_SHADOW )
+   {
+      glTranslatef( SHADOW_OFFSET_X,
+                    SHADOW_OFFSET_Y,
+                    SHADOW_OFFSET_Z );
+   }
+
+  /*
+   * Tilt the ball.
+   */
+   glRotatef( -20.0, 0.0, 0.0, 1.0 );
+
+  /*
+   * Continually rotate ball around Y axis.
+   */
+   glRotatef( deg_rot_y, 0.0, 1.0, 0.0 );
+
+  /*
+   * Set OpenGL state for Boing ball.
+   */
+   glCullFace( GL_FRONT );
+   glEnable( GL_CULL_FACE );
+   glEnable( GL_NORMALIZE );
+
+  /*
+   * Build a faceted latitude slice of the Boing ball,
+   * stepping same-sized vertical bands of the sphere.
+   */
+   for ( lon_deg = 0;
+         lon_deg < 180;
+         lon_deg += STEP_LONGITUDE )
+   {
+     /*
+      * Draw a latitude circle at this longitude.
+      */
+      DrawBoingBallBand( lon_deg,
+                         lon_deg + STEP_LONGITUDE );
+   }
+
+   glPopMatrix();
+
+   return;
+}
+
+
+/*****************************************************************************
+ * Bounce the ball.
+ *****************************************************************************/
+void BounceBall( double delta_t )
+{
+   GLfloat sign;
+   GLfloat deg;
+
+   if ( override_pos )
+     return;
+
+   /* Bounce on walls */
+   if ( ball_x >  (BOUNCE_WIDTH/2 + WALL_R_OFFSET ) )
+   {
+      ball_x_inc = -0.5f - 0.75f * (GLfloat)rand() / (GLfloat)RAND_MAX;
+      deg_rot_y_inc = -deg_rot_y_inc;
+   }
+   if ( ball_x < -(BOUNCE_HEIGHT/2 + WALL_L_OFFSET) )
+   {
+      ball_x_inc =  0.5f + 0.75f * (GLfloat)rand() / (GLfloat)RAND_MAX;
+      deg_rot_y_inc = -deg_rot_y_inc;
+   }
+
+   /* Bounce on floor / roof */
+   if ( ball_y >  BOUNCE_HEIGHT/2      )
+   {
+      ball_y_inc = -0.75f - 1.f * (GLfloat)rand() / (GLfloat)RAND_MAX;
+   }
+   if ( ball_y < -BOUNCE_HEIGHT/2*0.85 )
+   {
+      ball_y_inc =  0.75f + 1.f * (GLfloat)rand() / (GLfloat)RAND_MAX;
+   }
+
+   /* Update ball position */
+   ball_x += ball_x_inc * ((float)delta_t*ANIMATION_SPEED);
+   ball_y += ball_y_inc * ((float)delta_t*ANIMATION_SPEED);
+
+  /*
+   * Simulate the effects of gravity on Y movement.
+   */
+   if ( ball_y_inc < 0 ) sign = -1.0; else sign = 1.0;
+
+   deg = (ball_y + BOUNCE_HEIGHT/2) * 90 / BOUNCE_HEIGHT;
+   if ( deg > 80 ) deg = 80;
+   if ( deg < 10 ) deg = 10;
+
+   ball_y_inc = sign * 4.f * (float) sin_deg( deg );
+}
+
+
+/*****************************************************************************
+ * Draw a faceted latitude band of the Boing ball.
+ *
+ * Parms:   long_lo, long_hi
+ *          Low and high longitudes of slice, resp.
+ *****************************************************************************/
+void DrawBoingBallBand( GLfloat long_lo,
+                        GLfloat long_hi )
+{
+   vertex_t vert_ne;            /* "ne" means south-east, so on */
+   vertex_t vert_nw;
+   vertex_t vert_sw;
+   vertex_t vert_se;
+   vertex_t vert_norm;
+   GLfloat  lat_deg;
+   static int colorToggle = 0;
+
+  /*
+   * Iterate through the points of a latitude circle.
+   * A latitude circle is a 2D set of X,Z points.
+   */
+   for ( lat_deg = 0;
+         lat_deg <= (360 - STEP_LATITUDE);
+         lat_deg += STEP_LATITUDE )
+   {
+     /*
+      * Color this polygon with red or white.
+      */
+      if ( colorToggle )
+         glColor3f( 0.8f, 0.1f, 0.1f );
+      else
+         glColor3f( 0.95f, 0.95f, 0.95f );
+#if 0
+      if ( lat_deg >= 180 )
+         if ( colorToggle )
+            glColor3f( 0.1f, 0.8f, 0.1f );
+         else
+            glColor3f( 0.5f, 0.5f, 0.95f );
+#endif
+      colorToggle = ! colorToggle;
+
+     /*
+      * Change color if drawing shadow.
+      */
+      if ( drawBallHow == DRAW_BALL_SHADOW )
+         glColor3f( 0.35f, 0.35f, 0.35f );
+
+     /*
+      * Assign each Y.
+      */
+      vert_ne.y = vert_nw.y = (float) cos_deg(long_hi) * RADIUS;
+      vert_sw.y = vert_se.y = (float) cos_deg(long_lo) * RADIUS;
+
+     /*
+      * Assign each X,Z with sin,cos values scaled by latitude radius indexed by longitude.
+      * Eg, long=0 and long=180 are at the poles, so zero scale is sin(longitude),
+      * while long=90 (sin(90)=1) is at equator.
+      */
+      vert_ne.x = (float) cos_deg( lat_deg                 ) * (RADIUS * (float) sin_deg( long_lo + STEP_LONGITUDE ));
+      vert_se.x = (float) cos_deg( lat_deg                 ) * (RADIUS * (float) sin_deg( long_lo                  ));
+      vert_nw.x = (float) cos_deg( lat_deg + STEP_LATITUDE ) * (RADIUS * (float) sin_deg( long_lo + STEP_LONGITUDE ));
+      vert_sw.x = (float) cos_deg( lat_deg + STEP_LATITUDE ) * (RADIUS * (float) sin_deg( long_lo                  ));
+
+      vert_ne.z = (float) sin_deg( lat_deg                 ) * (RADIUS * (float) sin_deg( long_lo + STEP_LONGITUDE ));
+      vert_se.z = (float) sin_deg( lat_deg                 ) * (RADIUS * (float) sin_deg( long_lo                  ));
+      vert_nw.z = (float) sin_deg( lat_deg + STEP_LATITUDE ) * (RADIUS * (float) sin_deg( long_lo + STEP_LONGITUDE ));
+      vert_sw.z = (float) sin_deg( lat_deg + STEP_LATITUDE ) * (RADIUS * (float) sin_deg( long_lo                  ));
+
+     /*
+      * Draw the facet.
+      */
+      glBegin( GL_POLYGON );
+
+      CrossProduct( vert_ne, vert_nw, vert_sw, &vert_norm );
+      glNormal3f( vert_norm.x, vert_norm.y, vert_norm.z );
+
+      glVertex3f( vert_ne.x, vert_ne.y, vert_ne.z );
+      glVertex3f( vert_nw.x, vert_nw.y, vert_nw.z );
+      glVertex3f( vert_sw.x, vert_sw.y, vert_sw.z );
+      glVertex3f( vert_se.x, vert_se.y, vert_se.z );
+
+      glEnd();
+
+#if BOING_DEBUG
+      printf( "----------------------------------------------------------- \n" );
+      printf( "lat = %f  long_lo = %f  long_hi = %f \n", lat_deg, long_lo, long_hi );
+      printf( "vert_ne  x = %.8f  y = %.8f  z = %.8f \n", vert_ne.x, vert_ne.y, vert_ne.z );
+      printf( "vert_nw  x = %.8f  y = %.8f  z = %.8f \n", vert_nw.x, vert_nw.y, vert_nw.z );
+      printf( "vert_se  x = %.8f  y = %.8f  z = %.8f \n", vert_se.x, vert_se.y, vert_se.z );
+      printf( "vert_sw  x = %.8f  y = %.8f  z = %.8f \n", vert_sw.x, vert_sw.y, vert_sw.z );
+#endif
+
+   }
+
+  /*
+   * Toggle color so that next band will opposite red/white colors than this one.
+   */
+   colorToggle = ! colorToggle;
+
+  /*
+   * This circular band is done.
+   */
+   return;
+}
+
+
+/*****************************************************************************
+ * Draw the purple grid of lines, behind the Boing ball.
+ * When the Workbench is dropped to the bottom, Boing shows 12 rows.
+ *****************************************************************************/
+void DrawGrid( void )
+{
+   int              row, col;
+   const int        rowTotal    = 12;                   /* must be divisible by 2 */
+   const int        colTotal    = rowTotal;             /* must be same as rowTotal */
+   const GLfloat    widthLine   = 2.0;                  /* should be divisible by 2 */
+   const GLfloat    sizeCell    = GRID_SIZE / rowTotal;
+   const GLfloat    z_offset    = -40.0;
+   GLfloat          xl, xr;
+   GLfloat          yt, yb;
+
+   glPushMatrix();
+   glDisable( GL_CULL_FACE );
+
+  /*
+   * Another relative Z translation to separate objects.
+   */
+   glTranslatef( 0.0, 0.0, DIST_BALL );
+
+  /*
+   * Draw vertical lines (as skinny 3D rectangles).
+   */
+   for ( col = 0; col <= colTotal; col++ )
+   {
+     /*
+      * Compute co-ords of line.
+      */
+      xl = -GRID_SIZE / 2 + col * sizeCell;
+      xr = xl + widthLine;
+
+      yt =  GRID_SIZE / 2;
+      yb = -GRID_SIZE / 2 - widthLine;
+
+      glBegin( GL_POLYGON );
+
+      glColor3f( 0.6f, 0.1f, 0.6f );               /* purple */
+
+      glVertex3f( xr, yt, z_offset );       /* NE */
+      glVertex3f( xl, yt, z_offset );       /* NW */
+      glVertex3f( xl, yb, z_offset );       /* SW */
+      glVertex3f( xr, yb, z_offset );       /* SE */
+
+      glEnd();
+   }
+
+  /*
+   * Draw horizontal lines (as skinny 3D rectangles).
+   */
+   for ( row = 0; row <= rowTotal; row++ )
+   {
+     /*
+      * Compute co-ords of line.
+      */
+      yt = GRID_SIZE / 2 - row * sizeCell;
+      yb = yt - widthLine;
+
+      xl = -GRID_SIZE / 2;
+      xr =  GRID_SIZE / 2 + widthLine;
+
+      glBegin( GL_POLYGON );
+
+      glColor3f( 0.6f, 0.1f, 0.6f );               /* purple */
+
+      glVertex3f( xr, yt, z_offset );       /* NE */
+      glVertex3f( xl, yt, z_offset );       /* NW */
+      glVertex3f( xl, yb, z_offset );       /* SW */
+      glVertex3f( xr, yb, z_offset );       /* SE */
+
+      glEnd();
+   }
+
+   glPopMatrix();
+
+   return;
+}
+
+
+/*======================================================================*
+ * main()
+ *======================================================================*/
+
+int main( void )
+{
+   GLFWwindow* window;
+
+   /* Init GLFW */
+   if( !glfwInit() )
+      exit( EXIT_FAILURE );
+
+   window = glfwCreateWindow( 400, 400, "Boing (classic Amiga demo)", NULL, NULL );
+   if (!window)
+   {
+       glfwTerminate();
+       exit( EXIT_FAILURE );
+   }
+
+   glfwSetWindowAspectRatio(window, 1, 1);
+
+   glfwSetFramebufferSizeCallback(window, reshape);
+   glfwSetKeyCallback(window, key_callback);
+   glfwSetMouseButtonCallback(window, mouse_button_callback);
+   glfwSetCursorPosCallback(window, cursor_position_callback);
+
+   glfwMakeContextCurrent(window);
+   gladLoadGL(glfwGetProcAddress);
+   glfwSwapInterval( 1 );
+
+   glfwGetFramebufferSize(window, &width, &height);
+   reshape(window, width, height);
+
+   glfwSetTime( 0.0 );
+
+   init();
+
+   /* Main loop */
+   for (;;)
+   {
+       /* Timing */
+       t = glfwGetTime();
+       dt = t - t_old;
+       t_old = t;
+
+       /* Draw one frame */
+       display();
+
+       /* Swap buffers */
+       glfwSwapBuffers(window);
+       glfwPollEvents();
+
+       /* Check if we are still running */
+       if (glfwWindowShouldClose(window))
+           break;
+   }
+
+   glfwTerminate();
+   exit( EXIT_SUCCESS );
+}
+
diff --git a/libs/glfw-3.3.8/examples/gears.c b/libs/glfw-3.3.8/examples/gears.c
new file mode 100644
index 0000000..292f44b
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/gears.c
@@ -0,0 +1,360 @@
+/*
+ * 3-D gear wheels.  This program is in the public domain.
+ *
+ * Command line options:
+ *    -info      print GL implementation information
+ *    -exit      automatically exit after 30 seconds
+ *
+ *
+ * Brian Paul
+ *
+ *
+ * Marcus Geelnard:
+ *   - Conversion to GLFW
+ *   - Time based rendering (frame rate independent)
+ *   - Slightly modified camera that should work better for stereo viewing
+ *
+ *
+ * Camilla Löwy:
+ *   - Removed FPS counter (this is not a benchmark)
+ *   - Added a few comments
+ *   - Enabled vsync
+ */
+
+#if defined(_MSC_VER)
+ // Make MS math.h define M_PI
+ #define _USE_MATH_DEFINES
+#endif
+
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+/**
+
+  Draw a gear wheel.  You'll probably want to call this function when
+  building a display list since we do a lot of trig here.
+
+  Input:  inner_radius - radius of hole at center
+          outer_radius - radius at center of teeth
+          width - width of gear teeth - number of teeth
+          tooth_depth - depth of tooth
+
+ **/
+
+static void
+gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
+  GLint teeth, GLfloat tooth_depth)
+{
+  GLint i;
+  GLfloat r0, r1, r2;
+  GLfloat angle, da;
+  GLfloat u, v, len;
+
+  r0 = inner_radius;
+  r1 = outer_radius - tooth_depth / 2.f;
+  r2 = outer_radius + tooth_depth / 2.f;
+
+  da = 2.f * (float) M_PI / teeth / 4.f;
+
+  glShadeModel(GL_FLAT);
+
+  glNormal3f(0.f, 0.f, 1.f);
+
+  /* draw front face */
+  glBegin(GL_QUAD_STRIP);
+  for (i = 0; i <= teeth; i++) {
+    angle = i * 2.f * (float) M_PI / teeth;
+    glVertex3f(r0 * (float) cos(angle), r0 * (float) sin(angle), width * 0.5f);
+    glVertex3f(r1 * (float) cos(angle), r1 * (float) sin(angle), width * 0.5f);
+    if (i < teeth) {
+      glVertex3f(r0 * (float) cos(angle), r0 * (float) sin(angle), width * 0.5f);
+      glVertex3f(r1 * (float) cos(angle + 3 * da), r1 * (float) sin(angle + 3 * da), width * 0.5f);
+    }
+  }
+  glEnd();
+
+  /* draw front sides of teeth */
+  glBegin(GL_QUADS);
+  da = 2.f * (float) M_PI / teeth / 4.f;
+  for (i = 0; i < teeth; i++) {
+    angle = i * 2.f * (float) M_PI / teeth;
+
+    glVertex3f(r1 * (float) cos(angle), r1 * (float) sin(angle), width * 0.5f);
+    glVertex3f(r2 * (float) cos(angle + da), r2 * (float) sin(angle + da), width * 0.5f);
+    glVertex3f(r2 * (float) cos(angle + 2 * da), r2 * (float) sin(angle + 2 * da), width * 0.5f);
+    glVertex3f(r1 * (float) cos(angle + 3 * da), r1 * (float) sin(angle + 3 * da), width * 0.5f);
+  }
+  glEnd();
+
+  glNormal3f(0.0, 0.0, -1.0);
+
+  /* draw back face */
+  glBegin(GL_QUAD_STRIP);
+  for (i = 0; i <= teeth; i++) {
+    angle = i * 2.f * (float) M_PI / teeth;
+    glVertex3f(r1 * (float) cos(angle), r1 * (float) sin(angle), -width * 0.5f);
+    glVertex3f(r0 * (float) cos(angle), r0 * (float) sin(angle), -width * 0.5f);
+    if (i < teeth) {
+      glVertex3f(r1 * (float) cos(angle + 3 * da), r1 * (float) sin(angle + 3 * da), -width * 0.5f);
+      glVertex3f(r0 * (float) cos(angle), r0 * (float) sin(angle), -width * 0.5f);
+    }
+  }
+  glEnd();
+
+  /* draw back sides of teeth */
+  glBegin(GL_QUADS);
+  da = 2.f * (float) M_PI / teeth / 4.f;
+  for (i = 0; i < teeth; i++) {
+    angle = i * 2.f * (float) M_PI / teeth;
+
+    glVertex3f(r1 * (float) cos(angle + 3 * da), r1 * (float) sin(angle + 3 * da), -width * 0.5f);
+    glVertex3f(r2 * (float) cos(angle + 2 * da), r2 * (float) sin(angle + 2 * da), -width * 0.5f);
+    glVertex3f(r2 * (float) cos(angle + da), r2 * (float) sin(angle + da), -width * 0.5f);
+    glVertex3f(r1 * (float) cos(angle), r1 * (float) sin(angle), -width * 0.5f);
+  }
+  glEnd();
+
+  /* draw outward faces of teeth */
+  glBegin(GL_QUAD_STRIP);
+  for (i = 0; i < teeth; i++) {
+    angle = i * 2.f * (float) M_PI / teeth;
+
+    glVertex3f(r1 * (float) cos(angle), r1 * (float) sin(angle), width * 0.5f);
+    glVertex3f(r1 * (float) cos(angle), r1 * (float) sin(angle), -width * 0.5f);
+    u = r2 * (float) cos(angle + da) - r1 * (float) cos(angle);
+    v = r2 * (float) sin(angle + da) - r1 * (float) sin(angle);
+    len = (float) sqrt(u * u + v * v);
+    u /= len;
+    v /= len;
+    glNormal3f(v, -u, 0.0);
+    glVertex3f(r2 * (float) cos(angle + da), r2 * (float) sin(angle + da), width * 0.5f);
+    glVertex3f(r2 * (float) cos(angle + da), r2 * (float) sin(angle + da), -width * 0.5f);
+    glNormal3f((float) cos(angle), (float) sin(angle), 0.f);
+    glVertex3f(r2 * (float) cos(angle + 2 * da), r2 * (float) sin(angle + 2 * da), width * 0.5f);
+    glVertex3f(r2 * (float) cos(angle + 2 * da), r2 * (float) sin(angle + 2 * da), -width * 0.5f);
+    u = r1 * (float) cos(angle + 3 * da) - r2 * (float) cos(angle + 2 * da);
+    v = r1 * (float) sin(angle + 3 * da) - r2 * (float) sin(angle + 2 * da);
+    glNormal3f(v, -u, 0.f);
+    glVertex3f(r1 * (float) cos(angle + 3 * da), r1 * (float) sin(angle + 3 * da), width * 0.5f);
+    glVertex3f(r1 * (float) cos(angle + 3 * da), r1 * (float) sin(angle + 3 * da), -width * 0.5f);
+    glNormal3f((float) cos(angle), (float) sin(angle), 0.f);
+  }
+
+  glVertex3f(r1 * (float) cos(0), r1 * (float) sin(0), width * 0.5f);
+  glVertex3f(r1 * (float) cos(0), r1 * (float) sin(0), -width * 0.5f);
+
+  glEnd();
+
+  glShadeModel(GL_SMOOTH);
+
+  /* draw inside radius cylinder */
+  glBegin(GL_QUAD_STRIP);
+  for (i = 0; i <= teeth; i++) {
+    angle = i * 2.f * (float) M_PI / teeth;
+    glNormal3f(-(float) cos(angle), -(float) sin(angle), 0.f);
+    glVertex3f(r0 * (float) cos(angle), r0 * (float) sin(angle), -width * 0.5f);
+    glVertex3f(r0 * (float) cos(angle), r0 * (float) sin(angle), width * 0.5f);
+  }
+  glEnd();
+
+}
+
+
+static GLfloat view_rotx = 20.f, view_roty = 30.f, view_rotz = 0.f;
+static GLint gear1, gear2, gear3;
+static GLfloat angle = 0.f;
+
+/* OpenGL draw function & timing */
+static void draw(void)
+{
+  glClearColor(0.0, 0.0, 0.0, 0.0);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+  glPushMatrix();
+    glRotatef(view_rotx, 1.0, 0.0, 0.0);
+    glRotatef(view_roty, 0.0, 1.0, 0.0);
+    glRotatef(view_rotz, 0.0, 0.0, 1.0);
+
+    glPushMatrix();
+      glTranslatef(-3.0, -2.0, 0.0);
+      glRotatef(angle, 0.0, 0.0, 1.0);
+      glCallList(gear1);
+    glPopMatrix();
+
+    glPushMatrix();
+      glTranslatef(3.1f, -2.f, 0.f);
+      glRotatef(-2.f * angle - 9.f, 0.f, 0.f, 1.f);
+      glCallList(gear2);
+    glPopMatrix();
+
+    glPushMatrix();
+      glTranslatef(-3.1f, 4.2f, 0.f);
+      glRotatef(-2.f * angle - 25.f, 0.f, 0.f, 1.f);
+      glCallList(gear3);
+    glPopMatrix();
+
+  glPopMatrix();
+}
+
+
+/* update animation parameters */
+static void animate(void)
+{
+  angle = 100.f * (float) glfwGetTime();
+}
+
+
+/* change view angle, exit upon ESC */
+void key( GLFWwindow* window, int k, int s, int action, int mods )
+{
+  if( action != GLFW_PRESS ) return;
+
+  switch (k) {
+  case GLFW_KEY_Z:
+    if( mods & GLFW_MOD_SHIFT )
+      view_rotz -= 5.0;
+    else
+      view_rotz += 5.0;
+    break;
+  case GLFW_KEY_ESCAPE:
+    glfwSetWindowShouldClose(window, GLFW_TRUE);
+    break;
+  case GLFW_KEY_UP:
+    view_rotx += 5.0;
+    break;
+  case GLFW_KEY_DOWN:
+    view_rotx -= 5.0;
+    break;
+  case GLFW_KEY_LEFT:
+    view_roty += 5.0;
+    break;
+  case GLFW_KEY_RIGHT:
+    view_roty -= 5.0;
+    break;
+  default:
+    return;
+  }
+}
+
+
+/* new window size */
+void reshape( GLFWwindow* window, int width, int height )
+{
+  GLfloat h = (GLfloat) height / (GLfloat) width;
+  GLfloat xmax, znear, zfar;
+
+  znear = 5.0f;
+  zfar  = 30.0f;
+  xmax  = znear * 0.5f;
+
+  glViewport( 0, 0, (GLint) width, (GLint) height );
+  glMatrixMode( GL_PROJECTION );
+  glLoadIdentity();
+  glFrustum( -xmax, xmax, -xmax*h, xmax*h, znear, zfar );
+  glMatrixMode( GL_MODELVIEW );
+  glLoadIdentity();
+  glTranslatef( 0.0, 0.0, -20.0 );
+}
+
+
+/* program & OpenGL initialization */
+static void init(void)
+{
+  static GLfloat pos[4] = {5.f, 5.f, 10.f, 0.f};
+  static GLfloat red[4] = {0.8f, 0.1f, 0.f, 1.f};
+  static GLfloat green[4] = {0.f, 0.8f, 0.2f, 1.f};
+  static GLfloat blue[4] = {0.2f, 0.2f, 1.f, 1.f};
+
+  glLightfv(GL_LIGHT0, GL_POSITION, pos);
+  glEnable(GL_CULL_FACE);
+  glEnable(GL_LIGHTING);
+  glEnable(GL_LIGHT0);
+  glEnable(GL_DEPTH_TEST);
+
+  /* make the gears */
+  gear1 = glGenLists(1);
+  glNewList(gear1, GL_COMPILE);
+  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
+  gear(1.f, 4.f, 1.f, 20, 0.7f);
+  glEndList();
+
+  gear2 = glGenLists(1);
+  glNewList(gear2, GL_COMPILE);
+  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
+  gear(0.5f, 2.f, 2.f, 10, 0.7f);
+  glEndList();
+
+  gear3 = glGenLists(1);
+  glNewList(gear3, GL_COMPILE);
+  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
+  gear(1.3f, 2.f, 0.5f, 10, 0.7f);
+  glEndList();
+
+  glEnable(GL_NORMALIZE);
+}
+
+
+/* program entry */
+int main(int argc, char *argv[])
+{
+    GLFWwindow* window;
+    int width, height;
+
+    if( !glfwInit() )
+    {
+        fprintf( stderr, "Failed to initialize GLFW\n" );
+        exit( EXIT_FAILURE );
+    }
+
+    glfwWindowHint(GLFW_DEPTH_BITS, 16);
+    glfwWindowHint(GLFW_TRANSPARENT_FRAMEBUFFER, GLFW_TRUE);
+
+    window = glfwCreateWindow( 300, 300, "Gears", NULL, NULL );
+    if (!window)
+    {
+        fprintf( stderr, "Failed to open GLFW window\n" );
+        glfwTerminate();
+        exit( EXIT_FAILURE );
+    }
+
+    // Set callback functions
+    glfwSetFramebufferSizeCallback(window, reshape);
+    glfwSetKeyCallback(window, key);
+
+    glfwMakeContextCurrent(window);
+    gladLoadGL(glfwGetProcAddress);
+    glfwSwapInterval( 1 );
+
+    glfwGetFramebufferSize(window, &width, &height);
+    reshape(window, width, height);
+
+    // Parse command-line options
+    init();
+
+    // Main loop
+    while( !glfwWindowShouldClose(window) )
+    {
+        // Draw gears
+        draw();
+
+        // Update animation
+        animate();
+
+        // Swap buffers
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // Terminate GLFW
+    glfwTerminate();
+
+    // Exit program
+    exit( EXIT_SUCCESS );
+}
+
diff --git a/libs/glfw-3.3.8/examples/glfw.icns b/libs/glfw-3.3.8/examples/glfw.icns
new file mode 100644
index 0000000..ad98f39
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/glfw.icns
diff --git a/libs/glfw-3.3.8/examples/glfw.ico b/libs/glfw-3.3.8/examples/glfw.ico
new file mode 100644
index 0000000..882a660
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/glfw.ico
diff --git a/libs/glfw-3.3.8/examples/glfw.rc b/libs/glfw-3.3.8/examples/glfw.rc
new file mode 100644
index 0000000..f2b62f6
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/glfw.rc
@@ -0,0 +1,3 @@
+
+GLFW_ICON               ICON            "glfw.ico"
+
diff --git a/libs/glfw-3.3.8/examples/heightmap.c b/libs/glfw-3.3.8/examples/heightmap.c
new file mode 100644
index 0000000..988dd0b
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/heightmap.c
@@ -0,0 +1,512 @@
+//========================================================================
+// Heightmap example program using OpenGL 3 core profile
+// Copyright (c) 2010 Olivier Delannoy
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would
+//    be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not
+//    be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+//    distribution.
+//
+//========================================================================
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <assert.h>
+#include <stddef.h>
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+/* Map height updates */
+#define MAX_CIRCLE_SIZE (5.0f)
+#define MAX_DISPLACEMENT (1.0f)
+#define DISPLACEMENT_SIGN_LIMIT (0.3f)
+#define MAX_ITER (200)
+#define NUM_ITER_AT_A_TIME (1)
+
+/* Map general information */
+#define MAP_SIZE (10.0f)
+#define MAP_NUM_VERTICES (80)
+#define MAP_NUM_TOTAL_VERTICES (MAP_NUM_VERTICES*MAP_NUM_VERTICES)
+#define MAP_NUM_LINES (3* (MAP_NUM_VERTICES - 1) * (MAP_NUM_VERTICES - 1) + \
+               2 * (MAP_NUM_VERTICES - 1))
+
+
+/**********************************************************************
+ * Default shader programs
+ *********************************************************************/
+
+static const char* vertex_shader_text =
+"#version 150\n"
+"uniform mat4 project;\n"
+"uniform mat4 modelview;\n"
+"in float x;\n"
+"in float y;\n"
+"in float z;\n"
+"\n"
+"void main()\n"
+"{\n"
+"   gl_Position = project * modelview * vec4(x, y, z, 1.0);\n"
+"}\n";
+
+static const char* fragment_shader_text =
+"#version 150\n"
+"out vec4 color;\n"
+"void main()\n"
+"{\n"
+"    color = vec4(0.2, 1.0, 0.2, 1.0); \n"
+"}\n";
+
+/**********************************************************************
+ * Values for shader uniforms
+ *********************************************************************/
+
+/* Frustum configuration */
+static GLfloat view_angle = 45.0f;
+static GLfloat aspect_ratio = 4.0f/3.0f;
+static GLfloat z_near = 1.0f;
+static GLfloat z_far = 100.f;
+
+/* Projection matrix */
+static GLfloat projection_matrix[16] = {
+    1.0f, 0.0f, 0.0f, 0.0f,
+    0.0f, 1.0f, 0.0f, 0.0f,
+    0.0f, 0.0f, 1.0f, 0.0f,
+    0.0f, 0.0f, 0.0f, 1.0f
+};
+
+/* Model view matrix */
+static GLfloat modelview_matrix[16] = {
+    1.0f, 0.0f, 0.0f, 0.0f,
+    0.0f, 1.0f, 0.0f, 0.0f,
+    0.0f, 0.0f, 1.0f, 0.0f,
+    0.0f, 0.0f, 0.0f, 1.0f
+};
+
+/**********************************************************************
+ * Heightmap vertex and index data
+ *********************************************************************/
+
+static GLfloat map_vertices[3][MAP_NUM_TOTAL_VERTICES];
+static GLuint  map_line_indices[2*MAP_NUM_LINES];
+
+/* Store uniform location for the shaders
+ * Those values are setup as part of the process of creating
+ * the shader program. They should not be used before creating
+ * the program.
+ */
+static GLuint mesh;
+static GLuint mesh_vbo[4];
+
+/**********************************************************************
+ * OpenGL helper functions
+ *********************************************************************/
+
+/* Creates a shader object of the specified type using the specified text
+ */
+static GLuint make_shader(GLenum type, const char* text)
+{
+    GLuint shader;
+    GLint shader_ok;
+    GLsizei log_length;
+    char info_log[8192];
+
+    shader = glCreateShader(type);
+    if (shader != 0)
+    {
+        glShaderSource(shader, 1, (const GLchar**)&text, NULL);
+        glCompileShader(shader);
+        glGetShaderiv(shader, GL_COMPILE_STATUS, &shader_ok);
+        if (shader_ok != GL_TRUE)
+        {
+            fprintf(stderr, "ERROR: Failed to compile %s shader\n", (type == GL_FRAGMENT_SHADER) ? "fragment" : "vertex" );
+            glGetShaderInfoLog(shader, 8192, &log_length,info_log);
+            fprintf(stderr, "ERROR: \n%s\n\n", info_log);
+            glDeleteShader(shader);
+            shader = 0;
+        }
+    }
+    return shader;
+}
+
+/* Creates a program object using the specified vertex and fragment text
+ */
+static GLuint make_shader_program(const char* vs_text, const char* fs_text)
+{
+    GLuint program = 0u;
+    GLint program_ok;
+    GLuint vertex_shader = 0u;
+    GLuint fragment_shader = 0u;
+    GLsizei log_length;
+    char info_log[8192];
+
+    vertex_shader = make_shader(GL_VERTEX_SHADER, vs_text);
+    if (vertex_shader != 0u)
+    {
+        fragment_shader = make_shader(GL_FRAGMENT_SHADER, fs_text);
+        if (fragment_shader != 0u)
+        {
+            /* make the program that connect the two shader and link it */
+            program = glCreateProgram();
+            if (program != 0u)
+            {
+                /* attach both shader and link */
+                glAttachShader(program, vertex_shader);
+                glAttachShader(program, fragment_shader);
+                glLinkProgram(program);
+                glGetProgramiv(program, GL_LINK_STATUS, &program_ok);
+
+                if (program_ok != GL_TRUE)
+                {
+                    fprintf(stderr, "ERROR, failed to link shader program\n");
+                    glGetProgramInfoLog(program, 8192, &log_length, info_log);
+                    fprintf(stderr, "ERROR: \n%s\n\n", info_log);
+                    glDeleteProgram(program);
+                    glDeleteShader(fragment_shader);
+                    glDeleteShader(vertex_shader);
+                    program = 0u;
+                }
+            }
+        }
+        else
+        {
+            fprintf(stderr, "ERROR: Unable to load fragment shader\n");
+            glDeleteShader(vertex_shader);
+        }
+    }
+    else
+    {
+        fprintf(stderr, "ERROR: Unable to load vertex shader\n");
+    }
+    return program;
+}
+
+/**********************************************************************
+ * Geometry creation functions
+ *********************************************************************/
+
+/* Generate vertices and indices for the heightmap
+ */
+static void init_map(void)
+{
+    int i;
+    int j;
+    int k;
+    GLfloat step = MAP_SIZE / (MAP_NUM_VERTICES - 1);
+    GLfloat x = 0.0f;
+    GLfloat z = 0.0f;
+    /* Create a flat grid */
+    k = 0;
+    for (i = 0 ; i < MAP_NUM_VERTICES ; ++i)
+    {
+        for (j = 0 ; j < MAP_NUM_VERTICES ; ++j)
+        {
+            map_vertices[0][k] = x;
+            map_vertices[1][k] = 0.0f;
+            map_vertices[2][k] = z;
+            z += step;
+            ++k;
+        }
+        x += step;
+        z = 0.0f;
+    }
+#if DEBUG_ENABLED
+    for (i = 0 ; i < MAP_NUM_TOTAL_VERTICES ; ++i)
+    {
+        printf ("Vertice %d (%f, %f, %f)\n",
+                i, map_vertices[0][i], map_vertices[1][i], map_vertices[2][i]);
+
+    }
+#endif
+    /* create indices */
+    /* line fan based on i
+     * i+1
+     * |  / i + n + 1
+     * | /
+     * |/
+     * i --- i + n
+     */
+
+    /* close the top of the square */
+    k = 0;
+    for (i = 0 ; i < MAP_NUM_VERTICES  -1 ; ++i)
+    {
+        map_line_indices[k++] = (i + 1) * MAP_NUM_VERTICES -1;
+        map_line_indices[k++] = (i + 2) * MAP_NUM_VERTICES -1;
+    }
+    /* close the right of the square */
+    for (i = 0 ; i < MAP_NUM_VERTICES -1 ; ++i)
+    {
+        map_line_indices[k++] = (MAP_NUM_VERTICES - 1) * MAP_NUM_VERTICES + i;
+        map_line_indices[k++] = (MAP_NUM_VERTICES - 1) * MAP_NUM_VERTICES + i + 1;
+    }
+
+    for (i = 0 ; i < (MAP_NUM_VERTICES - 1) ; ++i)
+    {
+        for (j = 0 ; j < (MAP_NUM_VERTICES - 1) ; ++j)
+        {
+            int ref = i * (MAP_NUM_VERTICES) + j;
+            map_line_indices[k++] = ref;
+            map_line_indices[k++] = ref + 1;
+
+            map_line_indices[k++] = ref;
+            map_line_indices[k++] = ref + MAP_NUM_VERTICES;
+
+            map_line_indices[k++] = ref;
+            map_line_indices[k++] = ref + MAP_NUM_VERTICES + 1;
+        }
+    }
+
+#ifdef DEBUG_ENABLED
+    for (k = 0 ; k < 2 * MAP_NUM_LINES ; k += 2)
+    {
+        int beg, end;
+        beg = map_line_indices[k];
+        end = map_line_indices[k+1];
+        printf ("Line %d: %d -> %d (%f, %f, %f) -> (%f, %f, %f)\n",
+                k / 2, beg, end,
+                map_vertices[0][beg], map_vertices[1][beg], map_vertices[2][beg],
+                map_vertices[0][end], map_vertices[1][end], map_vertices[2][end]);
+    }
+#endif
+}
+
+static void generate_heightmap__circle(float* center_x, float* center_y,
+        float* size, float* displacement)
+{
+    float sign;
+    /* random value for element in between [0-1.0] */
+    *center_x = (MAP_SIZE * rand()) / (float) RAND_MAX;
+    *center_y = (MAP_SIZE * rand()) / (float) RAND_MAX;
+    *size = (MAX_CIRCLE_SIZE * rand()) / (float) RAND_MAX;
+    sign = (1.0f * rand()) / (float) RAND_MAX;
+    sign = (sign < DISPLACEMENT_SIGN_LIMIT) ? -1.0f : 1.0f;
+    *displacement = (sign * (MAX_DISPLACEMENT * rand())) / (float) RAND_MAX;
+}
+
+/* Run the specified number of iterations of the generation process for the
+ * heightmap
+ */
+static void update_map(int num_iter)
+{
+    assert(num_iter > 0);
+    while(num_iter)
+    {
+        /* center of the circle */
+        float center_x;
+        float center_z;
+        float circle_size;
+        float disp;
+        size_t ii;
+        generate_heightmap__circle(&center_x, &center_z, &circle_size, &disp);
+        disp = disp / 2.0f;
+        for (ii = 0u ; ii < MAP_NUM_TOTAL_VERTICES ; ++ii)
+        {
+            GLfloat dx = center_x - map_vertices[0][ii];
+            GLfloat dz = center_z - map_vertices[2][ii];
+            GLfloat pd = (2.0f * (float) sqrt((dx * dx) + (dz * dz))) / circle_size;
+            if (fabs(pd) <= 1.0f)
+            {
+                /* tx,tz is within the circle */
+                GLfloat new_height = disp + (float) (cos(pd*3.14f)*disp);
+                map_vertices[1][ii] += new_height;
+            }
+        }
+        --num_iter;
+    }
+}
+
+/**********************************************************************
+ * OpenGL helper functions
+ *********************************************************************/
+
+/* Create VBO, IBO and VAO objects for the heightmap geometry and bind them to
+ * the specified program object
+ */
+static void make_mesh(GLuint program)
+{
+    GLuint attrloc;
+
+    glGenVertexArrays(1, &mesh);
+    glGenBuffers(4, mesh_vbo);
+    glBindVertexArray(mesh);
+    /* Prepare the data for drawing through a buffer inidices */
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh_vbo[3]);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLuint)* MAP_NUM_LINES * 2, map_line_indices, GL_STATIC_DRAW);
+
+    /* Prepare the attributes for rendering */
+    attrloc = glGetAttribLocation(program, "x");
+    glBindBuffer(GL_ARRAY_BUFFER, mesh_vbo[0]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * MAP_NUM_TOTAL_VERTICES, &map_vertices[0][0], GL_STATIC_DRAW);
+    glEnableVertexAttribArray(attrloc);
+    glVertexAttribPointer(attrloc, 1, GL_FLOAT, GL_FALSE, 0, 0);
+
+    attrloc = glGetAttribLocation(program, "z");
+    glBindBuffer(GL_ARRAY_BUFFER, mesh_vbo[2]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * MAP_NUM_TOTAL_VERTICES, &map_vertices[2][0], GL_STATIC_DRAW);
+    glEnableVertexAttribArray(attrloc);
+    glVertexAttribPointer(attrloc, 1, GL_FLOAT, GL_FALSE, 0, 0);
+
+    attrloc = glGetAttribLocation(program, "y");
+    glBindBuffer(GL_ARRAY_BUFFER, mesh_vbo[1]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * MAP_NUM_TOTAL_VERTICES, &map_vertices[1][0], GL_DYNAMIC_DRAW);
+    glEnableVertexAttribArray(attrloc);
+    glVertexAttribPointer(attrloc, 1, GL_FLOAT, GL_FALSE, 0, 0);
+}
+
+/* Update VBO vertices from source data
+ */
+static void update_mesh(void)
+{
+    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(GLfloat) * MAP_NUM_TOTAL_VERTICES, &map_vertices[1][0]);
+}
+
+/**********************************************************************
+ * GLFW callback functions
+ *********************************************************************/
+
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
+{
+    switch(key)
+    {
+        case GLFW_KEY_ESCAPE:
+            /* Exit program on Escape */
+            glfwSetWindowShouldClose(window, GLFW_TRUE);
+            break;
+    }
+}
+
+static void error_callback(int error, const char* description)
+{
+    fprintf(stderr, "Error: %s\n", description);
+}
+
+int main(int argc, char** argv)
+{
+    GLFWwindow* window;
+    int iter;
+    double dt;
+    double last_update_time;
+    int frame;
+    float f;
+    GLint uloc_modelview;
+    GLint uloc_project;
+    int width, height;
+
+    GLuint shader_program;
+
+    glfwSetErrorCallback(error_callback);
+
+    if (!glfwInit())
+        exit(EXIT_FAILURE);
+
+    glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
+    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
+
+    window = glfwCreateWindow(800, 600, "GLFW OpenGL3 Heightmap demo", NULL, NULL);
+    if (! window )
+    {
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    /* Register events callback */
+    glfwSetKeyCallback(window, key_callback);
+
+    glfwMakeContextCurrent(window);
+    gladLoadGL(glfwGetProcAddress);
+
+    /* Prepare opengl resources for rendering */
+    shader_program = make_shader_program(vertex_shader_text, fragment_shader_text);
+
+    if (shader_program == 0u)
+    {
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    glUseProgram(shader_program);
+    uloc_project   = glGetUniformLocation(shader_program, "project");
+    uloc_modelview = glGetUniformLocation(shader_program, "modelview");
+
+    /* Compute the projection matrix */
+    f = 1.0f / tanf(view_angle / 2.0f);
+    projection_matrix[0]  = f / aspect_ratio;
+    projection_matrix[5]  = f;
+    projection_matrix[10] = (z_far + z_near)/ (z_near - z_far);
+    projection_matrix[11] = -1.0f;
+    projection_matrix[14] = 2.0f * (z_far * z_near) / (z_near - z_far);
+    glUniformMatrix4fv(uloc_project, 1, GL_FALSE, projection_matrix);
+
+    /* Set the camera position */
+    modelview_matrix[12]  = -5.0f;
+    modelview_matrix[13]  = -5.0f;
+    modelview_matrix[14]  = -20.0f;
+    glUniformMatrix4fv(uloc_modelview, 1, GL_FALSE, modelview_matrix);
+
+    /* Create mesh data */
+    init_map();
+    make_mesh(shader_program);
+
+    /* Create vao + vbo to store the mesh */
+    /* Create the vbo to store all the information for the grid and the height */
+
+    /* setup the scene ready for rendering */
+    glfwGetFramebufferSize(window, &width, &height);
+    glViewport(0, 0, width, height);
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+
+    /* main loop */
+    frame = 0;
+    iter = 0;
+    last_update_time = glfwGetTime();
+
+    while (!glfwWindowShouldClose(window))
+    {
+        ++frame;
+        /* render the next frame */
+        glClear(GL_COLOR_BUFFER_BIT);
+        glDrawElements(GL_LINES, 2* MAP_NUM_LINES , GL_UNSIGNED_INT, 0);
+
+        /* display and process events through callbacks */
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+        /* Check the frame rate and update the heightmap if needed */
+        dt = glfwGetTime();
+        if ((dt - last_update_time) > 0.2)
+        {
+            /* generate the next iteration of the heightmap */
+            if (iter < MAX_ITER)
+            {
+                update_map(NUM_ITER_AT_A_TIME);
+                update_mesh();
+                iter += NUM_ITER_AT_A_TIME;
+            }
+            last_update_time = dt;
+            frame = 0;
+        }
+    }
+
+    glfwTerminate();
+    exit(EXIT_SUCCESS);
+}
+
diff --git a/libs/glfw-3.3.8/examples/offscreen.c b/libs/glfw-3.3.8/examples/offscreen.c
new file mode 100644
index 0000000..16b8f3c
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/offscreen.c
@@ -0,0 +1,177 @@
+//========================================================================
+// Offscreen rendering example
+// Copyright (c) Camilla Löwy <elmindreda@glfw.org>
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would
+//    be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not
+//    be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+//    distribution.
+//
+//========================================================================
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+#if USE_NATIVE_OSMESA
+ #define GLFW_EXPOSE_NATIVE_OSMESA
+ #include <GLFW/glfw3native.h>
+#endif
+
+#include "linmath.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include <stb_image_write.h>
+
+static const struct
+{
+    float x, y;
+    float r, g, b;
+} vertices[3] =
+{
+    { -0.6f, -0.4f, 1.f, 0.f, 0.f },
+    {  0.6f, -0.4f, 0.f, 1.f, 0.f },
+    {   0.f,  0.6f, 0.f, 0.f, 1.f }
+};
+
+static const char* vertex_shader_text =
+"#version 110\n"
+"uniform mat4 MVP;\n"
+"attribute vec3 vCol;\n"
+"attribute vec2 vPos;\n"
+"varying vec3 color;\n"
+"void main()\n"
+"{\n"
+"    gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n"
+"    color = vCol;\n"
+"}\n";
+
+static const char* fragment_shader_text =
+"#version 110\n"
+"varying vec3 color;\n"
+"void main()\n"
+"{\n"
+"    gl_FragColor = vec4(color, 1.0);\n"
+"}\n";
+
+static void error_callback(int error, const char* description)
+{
+    fprintf(stderr, "Error: %s\n", description);
+}
+
+int main(void)
+{
+    GLFWwindow* window;
+    GLuint vertex_buffer, vertex_shader, fragment_shader, program;
+    GLint mvp_location, vpos_location, vcol_location;
+    float ratio;
+    int width, height;
+    mat4x4 mvp;
+    char* buffer;
+
+    glfwSetErrorCallback(error_callback);
+
+    glfwInitHint(GLFW_COCOA_MENUBAR, GLFW_FALSE);
+
+    if (!glfwInit())
+        exit(EXIT_FAILURE);
+
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+    glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
+
+    window = glfwCreateWindow(640, 480, "Simple example", NULL, NULL);
+    if (!window)
+    {
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    glfwMakeContextCurrent(window);
+    gladLoadGL(glfwGetProcAddress);
+
+    // NOTE: OpenGL error checks have been omitted for brevity
+
+    glGenBuffers(1, &vertex_buffer);
+    glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    vertex_shader = glCreateShader(GL_VERTEX_SHADER);
+    glShaderSource(vertex_shader, 1, &vertex_shader_text, NULL);
+    glCompileShader(vertex_shader);
+
+    fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
+    glShaderSource(fragment_shader, 1, &fragment_shader_text, NULL);
+    glCompileShader(fragment_shader);
+
+    program = glCreateProgram();
+    glAttachShader(program, vertex_shader);
+    glAttachShader(program, fragment_shader);
+    glLinkProgram(program);
+
+    mvp_location = glGetUniformLocation(program, "MVP");
+    vpos_location = glGetAttribLocation(program, "vPos");
+    vcol_location = glGetAttribLocation(program, "vCol");
+
+    glEnableVertexAttribArray(vpos_location);
+    glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE,
+                          sizeof(vertices[0]), (void*) 0);
+    glEnableVertexAttribArray(vcol_location);
+    glVertexAttribPointer(vcol_location, 3, GL_FLOAT, GL_FALSE,
+                          sizeof(vertices[0]), (void*) (sizeof(float) * 2));
+
+    glfwGetFramebufferSize(window, &width, &height);
+    ratio = width / (float) height;
+
+    glViewport(0, 0, width, height);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    mat4x4_ortho(mvp, -ratio, ratio, -1.f, 1.f, 1.f, -1.f);
+
+    glUseProgram(program);
+    glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) mvp);
+    glDrawArrays(GL_TRIANGLES, 0, 3);
+    glFinish();
+
+#if USE_NATIVE_OSMESA
+    glfwGetOSMesaColorBuffer(window, &width, &height, NULL, (void**) &buffer);
+#else
+    buffer = calloc(4, width * height);
+    glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
+#endif
+
+    // Write image Y-flipped because OpenGL
+    stbi_write_png("offscreen.png",
+                   width, height, 4,
+                   buffer + (width * 4 * (height - 1)),
+                   -width * 4);
+
+#if USE_NATIVE_OSMESA
+    // Here is where there's nothing
+#else
+    free(buffer);
+#endif
+
+    glfwDestroyWindow(window);
+
+    glfwTerminate();
+    exit(EXIT_SUCCESS);
+}
+
diff --git a/libs/glfw-3.3.8/examples/particles.c b/libs/glfw-3.3.8/examples/particles.c
new file mode 100644
index 0000000..9556cca
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/particles.c
@@ -0,0 +1,1073 @@
+//========================================================================
+// A simple particle engine with threaded physics
+// Copyright (c) Marcus Geelnard
+// Copyright (c) Camilla Löwy <elmindreda@glfw.org>
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would
+//    be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not
+//    be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+//    distribution.
+//
+//========================================================================
+
+#if defined(_MSC_VER)
+ // Make MS math.h define M_PI
+ #define _USE_MATH_DEFINES
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include <time.h>
+
+#include <tinycthread.h>
+#include <getopt.h>
+#include <linmath.h>
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+// Define tokens for GL_EXT_separate_specular_color if not already defined
+#ifndef GL_EXT_separate_specular_color
+#define GL_LIGHT_MODEL_COLOR_CONTROL_EXT  0x81F8
+#define GL_SINGLE_COLOR_EXT               0x81F9
+#define GL_SEPARATE_SPECULAR_COLOR_EXT    0x81FA
+#endif // GL_EXT_separate_specular_color
+
+
+//========================================================================
+// Type definitions
+//========================================================================
+
+typedef struct
+{
+    float x, y, z;
+} Vec3;
+
+// This structure is used for interleaved vertex arrays (see the
+// draw_particles function)
+//
+// NOTE: This structure SHOULD be packed on most systems. It uses 32-bit fields
+// on 32-bit boundaries, and is a multiple of 64 bits in total (6x32=3x64). If
+// it does not work, try using pragmas or whatever to force the structure to be
+// packed.
+typedef struct
+{
+    GLfloat s, t;         // Texture coordinates
+    GLuint  rgba;         // Color (four ubytes packed into an uint)
+    GLfloat x, y, z;      // Vertex coordinates
+} Vertex;
+
+
+//========================================================================
+// Program control global variables
+//========================================================================
+
+// Window dimensions
+float aspect_ratio;
+
+// "wireframe" flag (true if we use wireframe view)
+int wireframe;
+
+// Thread synchronization
+struct {
+    double    t;         // Time (s)
+    float     dt;        // Time since last frame (s)
+    int       p_frame;   // Particle physics frame number
+    int       d_frame;   // Particle draw frame number
+    cnd_t     p_done;    // Condition: particle physics done
+    cnd_t     d_done;    // Condition: particle draw done
+    mtx_t     particles_lock; // Particles data sharing mutex
+} thread_sync;
+
+
+//========================================================================
+// Texture declarations (we hard-code them into the source code, since
+// they are so simple)
+//========================================================================
+
+#define P_TEX_WIDTH  8    // Particle texture dimensions
+#define P_TEX_HEIGHT 8
+#define F_TEX_WIDTH  16   // Floor texture dimensions
+#define F_TEX_HEIGHT 16
+
+// Texture object IDs
+GLuint particle_tex_id, floor_tex_id;
+
+// Particle texture (a simple spot)
+const unsigned char particle_texture[ P_TEX_WIDTH * P_TEX_HEIGHT ] = {
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x11, 0x22, 0x22, 0x11, 0x00, 0x00,
+    0x00, 0x11, 0x33, 0x88, 0x77, 0x33, 0x11, 0x00,
+    0x00, 0x22, 0x88, 0xff, 0xee, 0x77, 0x22, 0x00,
+    0x00, 0x22, 0x77, 0xee, 0xff, 0x88, 0x22, 0x00,
+    0x00, 0x11, 0x33, 0x77, 0x88, 0x33, 0x11, 0x00,
+    0x00, 0x00, 0x11, 0x33, 0x22, 0x11, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+// Floor texture (your basic checkered floor)
+const unsigned char floor_texture[ F_TEX_WIDTH * F_TEX_HEIGHT ] = {
+    0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+    0xff, 0xf0, 0xcc, 0xf0, 0xf0, 0xf0, 0xff, 0xf0, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+    0xf0, 0xcc, 0xee, 0xff, 0xf0, 0xf0, 0xf0, 0xf0, 0x30, 0x66, 0x30, 0x30, 0x30, 0x20, 0x30, 0x30,
+    0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xee, 0xf0, 0xf0, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+    0xf0, 0xf0, 0xf0, 0xf0, 0xcc, 0xf0, 0xf0, 0xf0, 0x30, 0x30, 0x55, 0x30, 0x30, 0x44, 0x30, 0x30,
+    0xf0, 0xdd, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0x33, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+    0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xff, 0xf0, 0xf0, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x60, 0x30,
+    0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0x33, 0x33, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
+    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x33, 0x30, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0,
+    0x30, 0x30, 0x30, 0x30, 0x30, 0x20, 0x30, 0x30, 0xf0, 0xff, 0xf0, 0xf0, 0xdd, 0xf0, 0xf0, 0xff,
+    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x55, 0x33, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xff, 0xf0, 0xf0,
+    0x30, 0x44, 0x66, 0x30, 0x30, 0x30, 0x30, 0x30, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0,
+    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0xf0, 0xf0, 0xf0, 0xaa, 0xf0, 0xf0, 0xcc, 0xf0,
+    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0xff, 0xf0, 0xf0, 0xf0, 0xff, 0xf0, 0xdd, 0xf0,
+    0x30, 0x30, 0x30, 0x77, 0x30, 0x30, 0x30, 0x30, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0,
+    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0, 0xf0,
+};
+
+
+//========================================================================
+// These are fixed constants that control the particle engine. In a
+// modular world, these values should be variables...
+//========================================================================
+
+// Maximum number of particles
+#define MAX_PARTICLES   3000
+
+// Life span of a particle (in seconds)
+#define LIFE_SPAN       8.f
+
+// A new particle is born every [BIRTH_INTERVAL] second
+#define BIRTH_INTERVAL (LIFE_SPAN/(float)MAX_PARTICLES)
+
+// Particle size (meters)
+#define PARTICLE_SIZE   0.7f
+
+// Gravitational constant (m/s^2)
+#define GRAVITY         9.8f
+
+// Base initial velocity (m/s)
+#define VELOCITY        8.f
+
+// Bounce friction (1.0 = no friction, 0.0 = maximum friction)
+#define FRICTION        0.75f
+
+// "Fountain" height (m)
+#define FOUNTAIN_HEIGHT 3.f
+
+// Fountain radius (m)
+#define FOUNTAIN_RADIUS 1.6f
+
+// Minimum delta-time for particle phisics (s)
+#define MIN_DELTA_T     (BIRTH_INTERVAL * 0.5f)
+
+
+//========================================================================
+// Particle system global variables
+//========================================================================
+
+// This structure holds all state for a single particle
+typedef struct {
+    float x,y,z;     // Position in space
+    float vx,vy,vz;  // Velocity vector
+    float r,g,b;     // Color of particle
+    float life;      // Life of particle (1.0 = newborn, < 0.0 = dead)
+    int   active;    // Tells if this particle is active
+} PARTICLE;
+
+// Global vectors holding all particles. We use two vectors for double
+// buffering.
+static PARTICLE particles[MAX_PARTICLES];
+
+// Global variable holding the age of the youngest particle
+static float min_age;
+
+// Color of latest born particle (used for fountain lighting)
+static float glow_color[4];
+
+// Position of latest born particle (used for fountain lighting)
+static float glow_pos[4];
+
+
+//========================================================================
+// Object material and fog configuration constants
+//========================================================================
+
+const GLfloat fountain_diffuse[4]  = { 0.7f, 1.f,  1.f,  1.f };
+const GLfloat fountain_specular[4] = {  1.f, 1.f,  1.f,  1.f };
+const GLfloat fountain_shininess   = 12.f;
+const GLfloat floor_diffuse[4]     = { 1.f,  0.6f, 0.6f, 1.f };
+const GLfloat floor_specular[4]    = { 0.6f, 0.6f, 0.6f, 1.f };
+const GLfloat floor_shininess      = 18.f;
+const GLfloat fog_color[4]         = { 0.1f, 0.1f, 0.1f, 1.f };
+
+
+//========================================================================
+// Print usage information
+//========================================================================
+
+static void usage(void)
+{
+    printf("Usage: particles [-bfhs]\n");
+    printf("Options:\n");
+    printf(" -f   Run in full screen\n");
+    printf(" -h   Display this help\n");
+    printf(" -s   Run program as single thread (default is to use two threads)\n");
+    printf("\n");
+    printf("Program runtime controls:\n");
+    printf(" W    Toggle wireframe mode\n");
+    printf(" Esc  Exit program\n");
+}
+
+
+//========================================================================
+// Initialize a new particle
+//========================================================================
+
+static void init_particle(PARTICLE *p, double t)
+{
+    float xy_angle, velocity;
+
+    // Start position of particle is at the fountain blow-out
+    p->x = 0.f;
+    p->y = 0.f;
+    p->z = FOUNTAIN_HEIGHT;
+
+    // Start velocity is up (Z)...
+    p->vz = 0.7f + (0.3f / 4096.f) * (float) (rand() & 4095);
+
+    // ...and a randomly chosen X/Y direction
+    xy_angle = (2.f * (float) M_PI / 4096.f) * (float) (rand() & 4095);
+    p->vx = 0.4f * (float) cos(xy_angle);
+    p->vy = 0.4f * (float) sin(xy_angle);
+
+    // Scale velocity vector according to a time-varying velocity
+    velocity = VELOCITY * (0.8f + 0.1f * (float) (sin(0.5 * t) + sin(1.31 * t)));
+    p->vx *= velocity;
+    p->vy *= velocity;
+    p->vz *= velocity;
+
+    // Color is time-varying
+    p->r = 0.7f + 0.3f * (float) sin(0.34 * t + 0.1);
+    p->g = 0.6f + 0.4f * (float) sin(0.63 * t + 1.1);
+    p->b = 0.6f + 0.4f * (float) sin(0.91 * t + 2.1);
+
+    // Store settings for fountain glow lighting
+    glow_pos[0] = 0.4f * (float) sin(1.34 * t);
+    glow_pos[1] = 0.4f * (float) sin(3.11 * t);
+    glow_pos[2] = FOUNTAIN_HEIGHT + 1.f;
+    glow_pos[3] = 1.f;
+    glow_color[0] = p->r;
+    glow_color[1] = p->g;
+    glow_color[2] = p->b;
+    glow_color[3] = 1.f;
+
+    // The particle is new-born and active
+    p->life = 1.f;
+    p->active = 1;
+}
+
+
+//========================================================================
+// Update a particle
+//========================================================================
+
+#define FOUNTAIN_R2 (FOUNTAIN_RADIUS+PARTICLE_SIZE/2)*(FOUNTAIN_RADIUS+PARTICLE_SIZE/2)
+
+static void update_particle(PARTICLE *p, float dt)
+{
+    // If the particle is not active, we need not do anything
+    if (!p->active)
+        return;
+
+    // The particle is getting older...
+    p->life -= dt * (1.f / LIFE_SPAN);
+
+    // Did the particle die?
+    if (p->life <= 0.f)
+    {
+        p->active = 0;
+        return;
+    }
+
+    // Apply gravity
+    p->vz = p->vz - GRAVITY * dt;
+
+    // Update particle position
+    p->x = p->x + p->vx * dt;
+    p->y = p->y + p->vy * dt;
+    p->z = p->z + p->vz * dt;
+
+    // Simple collision detection + response
+    if (p->vz < 0.f)
+    {
+        // Particles should bounce on the fountain (with friction)
+        if ((p->x * p->x + p->y * p->y) < FOUNTAIN_R2 &&
+            p->z < (FOUNTAIN_HEIGHT + PARTICLE_SIZE / 2))
+        {
+            p->vz = -FRICTION * p->vz;
+            p->z  = FOUNTAIN_HEIGHT + PARTICLE_SIZE / 2 +
+                    FRICTION * (FOUNTAIN_HEIGHT +
+                    PARTICLE_SIZE / 2 - p->z);
+        }
+
+        // Particles should bounce on the floor (with friction)
+        else if (p->z < PARTICLE_SIZE / 2)
+        {
+            p->vz = -FRICTION * p->vz;
+            p->z  = PARTICLE_SIZE / 2 +
+                    FRICTION * (PARTICLE_SIZE / 2 - p->z);
+        }
+    }
+}
+
+
+//========================================================================
+// The main frame for the particle engine. Called once per frame.
+//========================================================================
+
+static void particle_engine(double t, float dt)
+{
+    int i;
+    float dt2;
+
+    // Update particles (iterated several times per frame if dt is too large)
+    while (dt > 0.f)
+    {
+        // Calculate delta time for this iteration
+        dt2 = dt < MIN_DELTA_T ? dt : MIN_DELTA_T;
+
+        for (i = 0;  i < MAX_PARTICLES;  i++)
+            update_particle(&particles[i], dt2);
+
+        min_age += dt2;
+
+        // Should we create any new particle(s)?
+        while (min_age >= BIRTH_INTERVAL)
+        {
+            min_age -= BIRTH_INTERVAL;
+
+            // Find a dead particle to replace with a new one
+            for (i = 0;  i < MAX_PARTICLES;  i++)
+            {
+                if (!particles[i].active)
+                {
+                    init_particle(&particles[i], t + min_age);
+                    update_particle(&particles[i], min_age);
+                    break;
+                }
+            }
+        }
+
+        dt -= dt2;
+    }
+}
+
+
+//========================================================================
+// Draw all active particles. We use OpenGL 1.1 vertex
+// arrays for this in order to accelerate the drawing.
+//========================================================================
+
+#define BATCH_PARTICLES 70  // Number of particles to draw in each batch
+                            // (70 corresponds to 7.5 KB = will not blow
+                            // the L1 data cache on most CPUs)
+#define PARTICLE_VERTS  4   // Number of vertices per particle
+
+static void draw_particles(GLFWwindow* window, double t, float dt)
+{
+    int i, particle_count;
+    Vertex vertex_array[BATCH_PARTICLES * PARTICLE_VERTS];
+    Vertex* vptr;
+    float alpha;
+    GLuint rgba;
+    Vec3 quad_lower_left, quad_lower_right;
+    GLfloat mat[16];
+    PARTICLE* pptr;
+
+    // Here comes the real trick with flat single primitive objects (s.c.
+    // "billboards"): We must rotate the textured primitive so that it
+    // always faces the viewer (is coplanar with the view-plane).
+    // We:
+    //   1) Create the primitive around origo (0,0,0)
+    //   2) Rotate it so that it is coplanar with the view plane
+    //   3) Translate it according to the particle position
+    // Note that 1) and 2) is the same for all particles (done only once).
+
+    // Get modelview matrix. We will only use the upper left 3x3 part of
+    // the matrix, which represents the rotation.
+    glGetFloatv(GL_MODELVIEW_MATRIX, mat);
+
+    // 1) & 2) We do it in one swift step:
+    // Although not obvious, the following six lines represent two matrix/
+    // vector multiplications. The matrix is the inverse 3x3 rotation
+    // matrix (i.e. the transpose of the same matrix), and the two vectors
+    // represent the lower left corner of the quad, PARTICLE_SIZE/2 *
+    // (-1,-1,0), and the lower right corner, PARTICLE_SIZE/2 * (1,-1,0).
+    // The upper left/right corners of the quad is always the negative of
+    // the opposite corners (regardless of rotation).
+    quad_lower_left.x = (-PARTICLE_SIZE / 2) * (mat[0] + mat[1]);
+    quad_lower_left.y = (-PARTICLE_SIZE / 2) * (mat[4] + mat[5]);
+    quad_lower_left.z = (-PARTICLE_SIZE / 2) * (mat[8] + mat[9]);
+    quad_lower_right.x = (PARTICLE_SIZE / 2) * (mat[0] - mat[1]);
+    quad_lower_right.y = (PARTICLE_SIZE / 2) * (mat[4] - mat[5]);
+    quad_lower_right.z = (PARTICLE_SIZE / 2) * (mat[8] - mat[9]);
+
+    // Don't update z-buffer, since all particles are transparent!
+    glDepthMask(GL_FALSE);
+
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+
+    // Select particle texture
+    if (!wireframe)
+    {
+        glEnable(GL_TEXTURE_2D);
+        glBindTexture(GL_TEXTURE_2D, particle_tex_id);
+    }
+
+    // Set up vertex arrays. We use interleaved arrays, which is easier to
+    // handle (in most situations) and it gives a linear memory access
+    // access pattern (which may give better performance in some
+    // situations). GL_T2F_C4UB_V3F means: 2 floats for texture coords,
+    // 4 ubytes for color and 3 floats for vertex coord (in that order).
+    // Most OpenGL cards / drivers are optimized for this format.
+    glInterleavedArrays(GL_T2F_C4UB_V3F, 0, vertex_array);
+
+    // Wait for particle physics thread to be done
+    mtx_lock(&thread_sync.particles_lock);
+    while (!glfwWindowShouldClose(window) &&
+            thread_sync.p_frame <= thread_sync.d_frame)
+    {
+        struct timespec ts;
+        clock_gettime(CLOCK_REALTIME, &ts);
+        ts.tv_nsec += 100 * 1000 * 1000;
+        ts.tv_sec += ts.tv_nsec / (1000 * 1000 * 1000);
+        ts.tv_nsec %= 1000 * 1000 * 1000;
+        cnd_timedwait(&thread_sync.p_done, &thread_sync.particles_lock, &ts);
+    }
+
+    // Store the frame time and delta time for the physics thread
+    thread_sync.t = t;
+    thread_sync.dt = dt;
+
+    // Update frame counter
+    thread_sync.d_frame++;
+
+    // Loop through all particles and build vertex arrays.
+    particle_count = 0;
+    vptr = vertex_array;
+    pptr = particles;
+
+    for (i = 0;  i < MAX_PARTICLES;  i++)
+    {
+        if (pptr->active)
+        {
+            // Calculate particle intensity (we set it to max during 75%
+            // of its life, then it fades out)
+            alpha =  4.f * pptr->life;
+            if (alpha > 1.f)
+                alpha = 1.f;
+
+            // Convert color from float to 8-bit (store it in a 32-bit
+            // integer using endian independent type casting)
+            ((GLubyte*) &rgba)[0] = (GLubyte)(pptr->r * 255.f);
+            ((GLubyte*) &rgba)[1] = (GLubyte)(pptr->g * 255.f);
+            ((GLubyte*) &rgba)[2] = (GLubyte)(pptr->b * 255.f);
+            ((GLubyte*) &rgba)[3] = (GLubyte)(alpha * 255.f);
+
+            // 3) Translate the quad to the correct position in modelview
+            // space and store its parameters in vertex arrays (we also
+            // store texture coord and color information for each vertex).
+
+            // Lower left corner
+            vptr->s    = 0.f;
+            vptr->t    = 0.f;
+            vptr->rgba = rgba;
+            vptr->x    = pptr->x + quad_lower_left.x;
+            vptr->y    = pptr->y + quad_lower_left.y;
+            vptr->z    = pptr->z + quad_lower_left.z;
+            vptr ++;
+
+            // Lower right corner
+            vptr->s    = 1.f;
+            vptr->t    = 0.f;
+            vptr->rgba = rgba;
+            vptr->x    = pptr->x + quad_lower_right.x;
+            vptr->y    = pptr->y + quad_lower_right.y;
+            vptr->z    = pptr->z + quad_lower_right.z;
+            vptr ++;
+
+            // Upper right corner
+            vptr->s    = 1.f;
+            vptr->t    = 1.f;
+            vptr->rgba = rgba;
+            vptr->x    = pptr->x - quad_lower_left.x;
+            vptr->y    = pptr->y - quad_lower_left.y;
+            vptr->z    = pptr->z - quad_lower_left.z;
+            vptr ++;
+
+            // Upper left corner
+            vptr->s    = 0.f;
+            vptr->t    = 1.f;
+            vptr->rgba = rgba;
+            vptr->x    = pptr->x - quad_lower_right.x;
+            vptr->y    = pptr->y - quad_lower_right.y;
+            vptr->z    = pptr->z - quad_lower_right.z;
+            vptr ++;
+
+            // Increase count of drawable particles
+            particle_count ++;
+        }
+
+        // If we have filled up one batch of particles, draw it as a set
+        // of quads using glDrawArrays.
+        if (particle_count >= BATCH_PARTICLES)
+        {
+            // The first argument tells which primitive type we use (QUAD)
+            // The second argument tells the index of the first vertex (0)
+            // The last argument is the vertex count
+            glDrawArrays(GL_QUADS, 0, PARTICLE_VERTS * particle_count);
+            particle_count = 0;
+            vptr = vertex_array;
+        }
+
+        // Next particle
+        pptr++;
+    }
+
+    // We are done with the particle data
+    mtx_unlock(&thread_sync.particles_lock);
+    cnd_signal(&thread_sync.d_done);
+
+    // Draw final batch of particles (if any)
+    glDrawArrays(GL_QUADS, 0, PARTICLE_VERTS * particle_count);
+
+    // Disable vertex arrays (Note: glInterleavedArrays implicitly called
+    // glEnableClientState for vertex, texture coord and color arrays)
+    glDisableClientState(GL_VERTEX_ARRAY);
+    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+    glDisableClientState(GL_COLOR_ARRAY);
+
+    glDisable(GL_TEXTURE_2D);
+    glDisable(GL_BLEND);
+
+    glDepthMask(GL_TRUE);
+}
+
+
+//========================================================================
+// Fountain geometry specification
+//========================================================================
+
+#define FOUNTAIN_SIDE_POINTS 14
+#define FOUNTAIN_SWEEP_STEPS 32
+
+static const float fountain_side[FOUNTAIN_SIDE_POINTS * 2] =
+{
+    1.2f, 0.f,  1.f, 0.2f,  0.41f, 0.3f, 0.4f, 0.35f,
+    0.4f, 1.95f, 0.41f, 2.f, 0.8f, 2.2f,  1.2f, 2.4f,
+    1.5f, 2.7f,  1.55f,2.95f, 1.6f, 3.f,  1.f, 3.f,
+    0.5f, 3.f,  0.f, 3.f
+};
+
+static const float fountain_normal[FOUNTAIN_SIDE_POINTS * 2] =
+{
+    1.0000f, 0.0000f,  0.6428f, 0.7660f,  0.3420f, 0.9397f,  1.0000f, 0.0000f,
+    1.0000f, 0.0000f,  0.3420f,-0.9397f,  0.4226f,-0.9063f,  0.5000f,-0.8660f,
+    0.7660f,-0.6428f,  0.9063f,-0.4226f,  0.0000f,1.00000f,  0.0000f,1.00000f,
+    0.0000f,1.00000f,  0.0000f,1.00000f
+};
+
+
+//========================================================================
+// Draw a fountain
+//========================================================================
+
+static void draw_fountain(void)
+{
+    static GLuint fountain_list = 0;
+    double angle;
+    float  x, y;
+    int m, n;
+
+    // The first time, we build the fountain display list
+    if (!fountain_list)
+    {
+        fountain_list = glGenLists(1);
+        glNewList(fountain_list, GL_COMPILE_AND_EXECUTE);
+
+        glMaterialfv(GL_FRONT, GL_DIFFUSE, fountain_diffuse);
+        glMaterialfv(GL_FRONT, GL_SPECULAR, fountain_specular);
+        glMaterialf(GL_FRONT, GL_SHININESS, fountain_shininess);
+
+        // Build fountain using triangle strips
+        for (n = 0;  n < FOUNTAIN_SIDE_POINTS - 1;  n++)
+        {
+            glBegin(GL_TRIANGLE_STRIP);
+            for (m = 0;  m <= FOUNTAIN_SWEEP_STEPS;  m++)
+            {
+                angle = (double) m * (2.0 * M_PI / (double) FOUNTAIN_SWEEP_STEPS);
+                x = (float) cos(angle);
+                y = (float) sin(angle);
+
+                // Draw triangle strip
+                glNormal3f(x * fountain_normal[n * 2 + 2],
+                           y * fountain_normal[n * 2 + 2],
+                           fountain_normal[n * 2 + 3]);
+                glVertex3f(x * fountain_side[n * 2 + 2],
+                           y * fountain_side[n * 2 + 2],
+                           fountain_side[n * 2 +3 ]);
+                glNormal3f(x * fountain_normal[n * 2],
+                           y * fountain_normal[n * 2],
+                           fountain_normal[n * 2 + 1]);
+                glVertex3f(x * fountain_side[n * 2],
+                           y * fountain_side[n * 2],
+                           fountain_side[n * 2 + 1]);
+            }
+
+            glEnd();
+        }
+
+        glEndList();
+    }
+    else
+        glCallList(fountain_list);
+}
+
+
+//========================================================================
+// Recursive function for building variable tessellated floor
+//========================================================================
+
+static void tessellate_floor(float x1, float y1, float x2, float y2, int depth)
+{
+    float delta, x, y;
+
+    // Last recursion?
+    if (depth >= 5)
+        delta = 999999.f;
+    else
+    {
+        x = (float) (fabs(x1) < fabs(x2) ? fabs(x1) : fabs(x2));
+        y = (float) (fabs(y1) < fabs(y2) ? fabs(y1) : fabs(y2));
+        delta = x*x + y*y;
+    }
+
+    // Recurse further?
+    if (delta < 0.1f)
+    {
+        x = (x1 + x2) * 0.5f;
+        y = (y1 + y2) * 0.5f;
+        tessellate_floor(x1, y1,  x,  y, depth + 1);
+        tessellate_floor(x, y1, x2,  y, depth + 1);
+        tessellate_floor(x1,  y,  x, y2, depth + 1);
+        tessellate_floor(x,  y, x2, y2, depth + 1);
+    }
+    else
+    {
+        glTexCoord2f(x1 * 30.f, y1 * 30.f);
+        glVertex3f(  x1 * 80.f, y1 * 80.f, 0.f);
+        glTexCoord2f(x2 * 30.f, y1 * 30.f);
+        glVertex3f(  x2 * 80.f, y1 * 80.f, 0.f);
+        glTexCoord2f(x2 * 30.f, y2 * 30.f);
+        glVertex3f(  x2 * 80.f, y2 * 80.f, 0.f);
+        glTexCoord2f(x1 * 30.f, y2 * 30.f);
+        glVertex3f(  x1 * 80.f, y2 * 80.f, 0.f);
+    }
+}
+
+
+//========================================================================
+// Draw floor. We build the floor recursively and let the tessellation in the
+// center (near x,y=0,0) be high, while the tessellation around the edges be
+// low.
+//========================================================================
+
+static void draw_floor(void)
+{
+    static GLuint floor_list = 0;
+
+    if (!wireframe)
+    {
+        glEnable(GL_TEXTURE_2D);
+        glBindTexture(GL_TEXTURE_2D, floor_tex_id);
+    }
+
+    // The first time, we build the floor display list
+    if (!floor_list)
+    {
+        floor_list = glGenLists(1);
+        glNewList(floor_list, GL_COMPILE_AND_EXECUTE);
+
+        glMaterialfv(GL_FRONT, GL_DIFFUSE, floor_diffuse);
+        glMaterialfv(GL_FRONT, GL_SPECULAR, floor_specular);
+        glMaterialf(GL_FRONT, GL_SHININESS, floor_shininess);
+
+        // Draw floor as a bunch of triangle strips (high tessellation
+        // improves lighting)
+        glNormal3f(0.f, 0.f, 1.f);
+        glBegin(GL_QUADS);
+        tessellate_floor(-1.f, -1.f, 0.f, 0.f, 0);
+        tessellate_floor( 0.f, -1.f, 1.f, 0.f, 0);
+        tessellate_floor( 0.f,  0.f, 1.f, 1.f, 0);
+        tessellate_floor(-1.f,  0.f, 0.f, 1.f, 0);
+        glEnd();
+
+        glEndList();
+    }
+    else
+        glCallList(floor_list);
+
+    glDisable(GL_TEXTURE_2D);
+
+}
+
+
+//========================================================================
+// Position and configure light sources
+//========================================================================
+
+static void setup_lights(void)
+{
+    float l1pos[4], l1amb[4], l1dif[4], l1spec[4];
+    float l2pos[4], l2amb[4], l2dif[4], l2spec[4];
+
+    // Set light source 1 parameters
+    l1pos[0] =  0.f;  l1pos[1] = -9.f; l1pos[2] =   8.f;  l1pos[3] = 1.f;
+    l1amb[0] = 0.2f;  l1amb[1] = 0.2f;  l1amb[2] = 0.2f;  l1amb[3] = 1.f;
+    l1dif[0] = 0.8f;  l1dif[1] = 0.4f;  l1dif[2] = 0.2f;  l1dif[3] = 1.f;
+    l1spec[0] = 1.f; l1spec[1] = 0.6f; l1spec[2] = 0.2f; l1spec[3] = 0.f;
+
+    // Set light source 2 parameters
+    l2pos[0] =  -15.f; l2pos[1] =  12.f; l2pos[2] = 1.5f; l2pos[3] =  1.f;
+    l2amb[0] =    0.f; l2amb[1] =   0.f; l2amb[2] =  0.f; l2amb[3] =  1.f;
+    l2dif[0] =   0.2f; l2dif[1] =  0.4f; l2dif[2] = 0.8f; l2dif[3] =  1.f;
+    l2spec[0] =  0.2f; l2spec[1] = 0.6f; l2spec[2] = 1.f; l2spec[3] = 0.f;
+
+    glLightfv(GL_LIGHT1, GL_POSITION, l1pos);
+    glLightfv(GL_LIGHT1, GL_AMBIENT, l1amb);
+    glLightfv(GL_LIGHT1, GL_DIFFUSE, l1dif);
+    glLightfv(GL_LIGHT1, GL_SPECULAR, l1spec);
+    glLightfv(GL_LIGHT2, GL_POSITION, l2pos);
+    glLightfv(GL_LIGHT2, GL_AMBIENT, l2amb);
+    glLightfv(GL_LIGHT2, GL_DIFFUSE, l2dif);
+    glLightfv(GL_LIGHT2, GL_SPECULAR, l2spec);
+    glLightfv(GL_LIGHT3, GL_POSITION, glow_pos);
+    glLightfv(GL_LIGHT3, GL_DIFFUSE, glow_color);
+    glLightfv(GL_LIGHT3, GL_SPECULAR, glow_color);
+
+    glEnable(GL_LIGHT1);
+    glEnable(GL_LIGHT2);
+    glEnable(GL_LIGHT3);
+}
+
+
+//========================================================================
+// Main rendering function
+//========================================================================
+
+static void draw_scene(GLFWwindow* window, double t)
+{
+    double xpos, ypos, zpos, angle_x, angle_y, angle_z;
+    static double t_old = 0.0;
+    float dt;
+    mat4x4 projection;
+
+    // Calculate frame-to-frame delta time
+    dt = (float) (t - t_old);
+    t_old = t;
+
+    mat4x4_perspective(projection,
+                       65.f * (float) M_PI / 180.f,
+                       aspect_ratio,
+                       1.0, 60.0);
+
+    glClearColor(0.1f, 0.1f, 0.1f, 1.f);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadMatrixf((const GLfloat*) projection);
+
+    // Setup camera
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+
+    // Rotate camera
+    angle_x = 90.0 - 10.0;
+    angle_y = 10.0 * sin(0.3 * t);
+    angle_z = 10.0 * t;
+    glRotated(-angle_x, 1.0, 0.0, 0.0);
+    glRotated(-angle_y, 0.0, 1.0, 0.0);
+    glRotated(-angle_z, 0.0, 0.0, 1.0);
+
+    // Translate camera
+    xpos =  15.0 * sin((M_PI / 180.0) * angle_z) +
+             2.0 * sin((M_PI / 180.0) * 3.1 * t);
+    ypos = -15.0 * cos((M_PI / 180.0) * angle_z) +
+             2.0 * cos((M_PI / 180.0) * 2.9 * t);
+    zpos = 4.0 + 2.0 * cos((M_PI / 180.0) * 4.9 * t);
+    glTranslated(-xpos, -ypos, -zpos);
+
+    glFrontFace(GL_CCW);
+    glCullFace(GL_BACK);
+    glEnable(GL_CULL_FACE);
+
+    setup_lights();
+    glEnable(GL_LIGHTING);
+
+    glEnable(GL_FOG);
+    glFogi(GL_FOG_MODE, GL_EXP);
+    glFogf(GL_FOG_DENSITY, 0.05f);
+    glFogfv(GL_FOG_COLOR, fog_color);
+
+    draw_floor();
+
+    glEnable(GL_DEPTH_TEST);
+    glDepthFunc(GL_LEQUAL);
+    glDepthMask(GL_TRUE);
+
+    draw_fountain();
+
+    glDisable(GL_LIGHTING);
+    glDisable(GL_FOG);
+
+    // Particles must be drawn after all solid objects have been drawn
+    draw_particles(window, t, dt);
+
+    // Z-buffer not needed anymore
+    glDisable(GL_DEPTH_TEST);
+}
+
+
+//========================================================================
+// Window resize callback function
+//========================================================================
+
+static void resize_callback(GLFWwindow* window, int width, int height)
+{
+    glViewport(0, 0, width, height);
+    aspect_ratio = height ? width / (float) height : 1.f;
+}
+
+
+//========================================================================
+// Key callback functions
+//========================================================================
+
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
+{
+    if (action == GLFW_PRESS)
+    {
+        switch (key)
+        {
+            case GLFW_KEY_ESCAPE:
+                glfwSetWindowShouldClose(window, GLFW_TRUE);
+                break;
+            case GLFW_KEY_W:
+                wireframe = !wireframe;
+                glPolygonMode(GL_FRONT_AND_BACK,
+                              wireframe ? GL_LINE : GL_FILL);
+                break;
+            default:
+                break;
+        }
+    }
+}
+
+
+//========================================================================
+// Thread for updating particle physics
+//========================================================================
+
+static int physics_thread_main(void* arg)
+{
+    GLFWwindow* window = arg;
+
+    for (;;)
+    {
+        mtx_lock(&thread_sync.particles_lock);
+
+        // Wait for particle drawing to be done
+        while (!glfwWindowShouldClose(window) &&
+               thread_sync.p_frame > thread_sync.d_frame)
+        {
+            struct timespec ts;
+            clock_gettime(CLOCK_REALTIME, &ts);
+            ts.tv_nsec += 100 * 1000 * 1000;
+            ts.tv_sec += ts.tv_nsec / (1000 * 1000 * 1000);
+            ts.tv_nsec %= 1000 * 1000 * 1000;
+            cnd_timedwait(&thread_sync.d_done, &thread_sync.particles_lock, &ts);
+        }
+
+        if (glfwWindowShouldClose(window))
+            break;
+
+        // Update particles
+        particle_engine(thread_sync.t, thread_sync.dt);
+
+        // Update frame counter
+        thread_sync.p_frame++;
+
+        // Unlock mutex and signal drawing thread
+        mtx_unlock(&thread_sync.particles_lock);
+        cnd_signal(&thread_sync.p_done);
+    }
+
+    return 0;
+}
+
+
+//========================================================================
+// main
+//========================================================================
+
+int main(int argc, char** argv)
+{
+    int ch, width, height;
+    thrd_t physics_thread = 0;
+    GLFWwindow* window;
+    GLFWmonitor* monitor = NULL;
+
+    if (!glfwInit())
+    {
+        fprintf(stderr, "Failed to initialize GLFW\n");
+        exit(EXIT_FAILURE);
+    }
+
+    while ((ch = getopt(argc, argv, "fh")) != -1)
+    {
+        switch (ch)
+        {
+            case 'f':
+                monitor = glfwGetPrimaryMonitor();
+                break;
+            case 'h':
+                usage();
+                exit(EXIT_SUCCESS);
+        }
+    }
+
+    if (monitor)
+    {
+        const GLFWvidmode* mode = glfwGetVideoMode(monitor);
+
+        glfwWindowHint(GLFW_RED_BITS, mode->redBits);
+        glfwWindowHint(GLFW_GREEN_BITS, mode->greenBits);
+        glfwWindowHint(GLFW_BLUE_BITS, mode->blueBits);
+        glfwWindowHint(GLFW_REFRESH_RATE, mode->refreshRate);
+
+        width  = mode->width;
+        height = mode->height;
+    }
+    else
+    {
+        width  = 640;
+        height = 480;
+    }
+
+    window = glfwCreateWindow(width, height, "Particle Engine", monitor, NULL);
+    if (!window)
+    {
+        fprintf(stderr, "Failed to create GLFW window\n");
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    if (monitor)
+        glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+    glfwMakeContextCurrent(window);
+    gladLoadGL(glfwGetProcAddress);
+    glfwSwapInterval(1);
+
+    glfwSetFramebufferSizeCallback(window, resize_callback);
+    glfwSetKeyCallback(window, key_callback);
+
+    // Set initial aspect ratio
+    glfwGetFramebufferSize(window, &width, &height);
+    resize_callback(window, width, height);
+
+    // Upload particle texture
+    glGenTextures(1, &particle_tex_id);
+    glBindTexture(GL_TEXTURE_2D, particle_tex_id);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, P_TEX_WIDTH, P_TEX_HEIGHT,
+                 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, particle_texture);
+
+    // Upload floor texture
+    glGenTextures(1, &floor_tex_id);
+    glBindTexture(GL_TEXTURE_2D, floor_tex_id);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, F_TEX_WIDTH, F_TEX_HEIGHT,
+                 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, floor_texture);
+
+    if (glfwExtensionSupported("GL_EXT_separate_specular_color"))
+    {
+        glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL_EXT,
+                      GL_SEPARATE_SPECULAR_COLOR_EXT);
+    }
+
+    // Set filled polygon mode as default (not wireframe)
+    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+    wireframe = 0;
+
+    // Set initial times
+    thread_sync.t  = 0.0;
+    thread_sync.dt = 0.001f;
+    thread_sync.p_frame = 0;
+    thread_sync.d_frame = 0;
+
+    mtx_init(&thread_sync.particles_lock, mtx_timed);
+    cnd_init(&thread_sync.p_done);
+    cnd_init(&thread_sync.d_done);
+
+    if (thrd_create(&physics_thread, physics_thread_main, window) != thrd_success)
+    {
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    glfwSetTime(0.0);
+
+    while (!glfwWindowShouldClose(window))
+    {
+        draw_scene(window, glfwGetTime());
+
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    thrd_join(physics_thread, NULL);
+
+    glfwDestroyWindow(window);
+    glfwTerminate();
+
+    exit(EXIT_SUCCESS);
+}
+
diff --git a/libs/glfw-3.3.8/examples/sharing.c b/libs/glfw-3.3.8/examples/sharing.c
new file mode 100644
index 0000000..4a1a232
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/sharing.c
@@ -0,0 +1,234 @@
+//========================================================================
+// Context sharing example
+// Copyright (c) Camilla Löwy <elmindreda@glfw.org>
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would
+//    be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not
+//    be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+//    distribution.
+//
+//========================================================================
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "getopt.h"
+#include "linmath.h"
+
+static const char* vertex_shader_text =
+"#version 110\n"
+"uniform mat4 MVP;\n"
+"attribute vec2 vPos;\n"
+"varying vec2 texcoord;\n"
+"void main()\n"
+"{\n"
+"    gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n"
+"    texcoord = vPos;\n"
+"}\n";
+
+static const char* fragment_shader_text =
+"#version 110\n"
+"uniform sampler2D texture;\n"
+"uniform vec3 color;\n"
+"varying vec2 texcoord;\n"
+"void main()\n"
+"{\n"
+"    gl_FragColor = vec4(color * texture2D(texture, texcoord).rgb, 1.0);\n"
+"}\n";
+
+static const vec2 vertices[4] =
+{
+    { 0.f, 0.f },
+    { 1.f, 0.f },
+    { 1.f, 1.f },
+    { 0.f, 1.f }
+};
+
+static void error_callback(int error, const char* description)
+{
+    fprintf(stderr, "Error: %s\n", description);
+}
+
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
+{
+    if (action == GLFW_PRESS && key == GLFW_KEY_ESCAPE)
+        glfwSetWindowShouldClose(window, GLFW_TRUE);
+}
+
+int main(int argc, char** argv)
+{
+    GLFWwindow* windows[2];
+    GLuint texture, program, vertex_buffer;
+    GLint mvp_location, vpos_location, color_location, texture_location;
+
+    glfwSetErrorCallback(error_callback);
+
+    if (!glfwInit())
+        exit(EXIT_FAILURE);
+
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+
+    windows[0] = glfwCreateWindow(400, 400, "First", NULL, NULL);
+    if (!windows[0])
+    {
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    glfwSetKeyCallback(windows[0], key_callback);
+
+    glfwMakeContextCurrent(windows[0]);
+
+    // Only enable vsync for the first of the windows to be swapped to
+    // avoid waiting out the interval for each window
+    glfwSwapInterval(1);
+
+    // The contexts are created with the same APIs so the function
+    // pointers should be re-usable between them
+    gladLoadGL(glfwGetProcAddress);
+
+    // Create the OpenGL objects inside the first context, created above
+    // All objects will be shared with the second context, created below
+    {
+        int x, y;
+        char pixels[16 * 16];
+        GLuint vertex_shader, fragment_shader;
+
+        glGenTextures(1, &texture);
+        glBindTexture(GL_TEXTURE_2D, texture);
+
+        srand((unsigned int) glfwGetTimerValue());
+
+        for (y = 0;  y < 16;  y++)
+        {
+            for (x = 0;  x < 16;  x++)
+                pixels[y * 16 + x] = rand() % 256;
+        }
+
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, 16, 16, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, pixels);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+        vertex_shader = glCreateShader(GL_VERTEX_SHADER);
+        glShaderSource(vertex_shader, 1, &vertex_shader_text, NULL);
+        glCompileShader(vertex_shader);
+
+        fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
+        glShaderSource(fragment_shader, 1, &fragment_shader_text, NULL);
+        glCompileShader(fragment_shader);
+
+        program = glCreateProgram();
+        glAttachShader(program, vertex_shader);
+        glAttachShader(program, fragment_shader);
+        glLinkProgram(program);
+
+        mvp_location = glGetUniformLocation(program, "MVP");
+        color_location = glGetUniformLocation(program, "color");
+        texture_location = glGetUniformLocation(program, "texture");
+        vpos_location = glGetAttribLocation(program, "vPos");
+
+        glGenBuffers(1, &vertex_buffer);
+        glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+    }
+
+    glUseProgram(program);
+    glUniform1i(texture_location, 0);
+
+    glEnable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, texture);
+
+    glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
+    glEnableVertexAttribArray(vpos_location);
+    glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE,
+                          sizeof(vertices[0]), (void*) 0);
+
+    windows[1] = glfwCreateWindow(400, 400, "Second", NULL, windows[0]);
+    if (!windows[1])
+    {
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    // Place the second window to the right of the first
+    {
+        int xpos, ypos, left, right, width;
+
+        glfwGetWindowSize(windows[0], &width, NULL);
+        glfwGetWindowFrameSize(windows[0], &left, NULL, &right, NULL);
+        glfwGetWindowPos(windows[0], &xpos, &ypos);
+
+        glfwSetWindowPos(windows[1], xpos + width + left + right, ypos);
+    }
+
+    glfwSetKeyCallback(windows[1], key_callback);
+
+    glfwMakeContextCurrent(windows[1]);
+
+    // While objects are shared, the global context state is not and will
+    // need to be set up for each context
+
+    glUseProgram(program);
+
+    glEnable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, texture);
+
+    glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
+    glEnableVertexAttribArray(vpos_location);
+    glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE,
+                          sizeof(vertices[0]), (void*) 0);
+
+    while (!glfwWindowShouldClose(windows[0]) &&
+           !glfwWindowShouldClose(windows[1]))
+    {
+        int i;
+        const vec3 colors[2] =
+        {
+            { 0.8f, 0.4f, 1.f },
+            { 0.3f, 0.4f, 1.f }
+        };
+
+        for (i = 0;  i < 2;  i++)
+        {
+            int width, height;
+            mat4x4 mvp;
+
+            glfwGetFramebufferSize(windows[i], &width, &height);
+            glfwMakeContextCurrent(windows[i]);
+
+            glViewport(0, 0, width, height);
+
+            mat4x4_ortho(mvp, 0.f, 1.f, 0.f, 1.f, 0.f, 1.f);
+            glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) mvp);
+            glUniform3fv(color_location, 1, colors[i]);
+            glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+
+            glfwSwapBuffers(windows[i]);
+        }
+
+        glfwWaitEvents();
+    }
+
+    glfwTerminate();
+    exit(EXIT_SUCCESS);
+}
+
diff --git a/libs/glfw-3.3.8/examples/simple.c b/libs/glfw-3.3.8/examples/simple.c
new file mode 100644
index 0000000..95d8fe6
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/simple.c
@@ -0,0 +1,166 @@
+//========================================================================
+// Simple GLFW example
+// Copyright (c) Camilla Löwy <elmindreda@glfw.org>
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would
+//    be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not
+//    be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+//    distribution.
+//
+//========================================================================
+//! [code]
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+#include "linmath.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+static const struct
+{
+    float x, y;
+    float r, g, b;
+} vertices[3] =
+{
+    { -0.6f, -0.4f, 1.f, 0.f, 0.f },
+    {  0.6f, -0.4f, 0.f, 1.f, 0.f },
+    {   0.f,  0.6f, 0.f, 0.f, 1.f }
+};
+
+static const char* vertex_shader_text =
+"#version 110\n"
+"uniform mat4 MVP;\n"
+"attribute vec3 vCol;\n"
+"attribute vec2 vPos;\n"
+"varying vec3 color;\n"
+"void main()\n"
+"{\n"
+"    gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n"
+"    color = vCol;\n"
+"}\n";
+
+static const char* fragment_shader_text =
+"#version 110\n"
+"varying vec3 color;\n"
+"void main()\n"
+"{\n"
+"    gl_FragColor = vec4(color, 1.0);\n"
+"}\n";
+
+static void error_callback(int error, const char* description)
+{
+    fprintf(stderr, "Error: %s\n", description);
+}
+
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
+{
+    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
+        glfwSetWindowShouldClose(window, GLFW_TRUE);
+}
+
+int main(void)
+{
+    GLFWwindow* window;
+    GLuint vertex_buffer, vertex_shader, fragment_shader, program;
+    GLint mvp_location, vpos_location, vcol_location;
+
+    glfwSetErrorCallback(error_callback);
+
+    if (!glfwInit())
+        exit(EXIT_FAILURE);
+
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+
+    window = glfwCreateWindow(640, 480, "Simple example", NULL, NULL);
+    if (!window)
+    {
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    glfwSetKeyCallback(window, key_callback);
+
+    glfwMakeContextCurrent(window);
+    gladLoadGL(glfwGetProcAddress);
+    glfwSwapInterval(1);
+
+    // NOTE: OpenGL error checks have been omitted for brevity
+
+    glGenBuffers(1, &vertex_buffer);
+    glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    vertex_shader = glCreateShader(GL_VERTEX_SHADER);
+    glShaderSource(vertex_shader, 1, &vertex_shader_text, NULL);
+    glCompileShader(vertex_shader);
+
+    fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
+    glShaderSource(fragment_shader, 1, &fragment_shader_text, NULL);
+    glCompileShader(fragment_shader);
+
+    program = glCreateProgram();
+    glAttachShader(program, vertex_shader);
+    glAttachShader(program, fragment_shader);
+    glLinkProgram(program);
+
+    mvp_location = glGetUniformLocation(program, "MVP");
+    vpos_location = glGetAttribLocation(program, "vPos");
+    vcol_location = glGetAttribLocation(program, "vCol");
+
+    glEnableVertexAttribArray(vpos_location);
+    glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE,
+                          sizeof(vertices[0]), (void*) 0);
+    glEnableVertexAttribArray(vcol_location);
+    glVertexAttribPointer(vcol_location, 3, GL_FLOAT, GL_FALSE,
+                          sizeof(vertices[0]), (void*) (sizeof(float) * 2));
+
+    while (!glfwWindowShouldClose(window))
+    {
+        float ratio;
+        int width, height;
+        mat4x4 m, p, mvp;
+
+        glfwGetFramebufferSize(window, &width, &height);
+        ratio = width / (float) height;
+
+        glViewport(0, 0, width, height);
+        glClear(GL_COLOR_BUFFER_BIT);
+
+        mat4x4_identity(m);
+        mat4x4_rotate_Z(m, m, (float) glfwGetTime());
+        mat4x4_ortho(p, -ratio, ratio, -1.f, 1.f, 1.f, -1.f);
+        mat4x4_mul(mvp, p, m);
+
+        glUseProgram(program);
+        glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) mvp);
+        glDrawArrays(GL_TRIANGLES, 0, 3);
+
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    glfwDestroyWindow(window);
+
+    glfwTerminate();
+    exit(EXIT_SUCCESS);
+}
+
+//! [code]
diff --git a/libs/glfw-3.3.8/examples/splitview.c b/libs/glfw-3.3.8/examples/splitview.c
new file mode 100644
index 0000000..079c2cb
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/splitview.c
@@ -0,0 +1,546 @@
+//========================================================================
+// This is an example program for the GLFW library
+//
+// The program uses a "split window" view, rendering four views of the
+// same scene in one window (e.g. useful for 3D modelling software). This
+// demo uses scissors to separate the four different rendering areas from
+// each other.
+//
+// (If the code seems a little bit strange here and there, it may be
+//  because I am not a friend of orthogonal projections)
+//========================================================================
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+#if defined(_MSC_VER)
+ // Make MS math.h define M_PI
+ #define _USE_MATH_DEFINES
+#endif
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <linmath.h>
+
+
+//========================================================================
+// Global variables
+//========================================================================
+
+// Mouse position
+static double xpos = 0, ypos = 0;
+
+// Window size
+static int width, height;
+
+// Active view: 0 = none, 1 = upper left, 2 = upper right, 3 = lower left,
+// 4 = lower right
+static int active_view = 0;
+
+// Rotation around each axis
+static int rot_x = 0, rot_y = 0, rot_z = 0;
+
+// Do redraw?
+static int do_redraw = 1;
+
+
+//========================================================================
+// Draw a solid torus (use a display list for the model)
+//========================================================================
+
+#define TORUS_MAJOR     1.5
+#define TORUS_MINOR     0.5
+#define TORUS_MAJOR_RES 32
+#define TORUS_MINOR_RES 32
+
+static void drawTorus(void)
+{
+    static GLuint torus_list = 0;
+    int    i, j, k;
+    double s, t, x, y, z, nx, ny, nz, scale, twopi;
+
+    if (!torus_list)
+    {
+        // Start recording displaylist
+        torus_list = glGenLists(1);
+        glNewList(torus_list, GL_COMPILE_AND_EXECUTE);
+
+        // Draw torus
+        twopi = 2.0 * M_PI;
+        for (i = 0;  i < TORUS_MINOR_RES;  i++)
+        {
+            glBegin(GL_QUAD_STRIP);
+            for (j = 0;  j <= TORUS_MAJOR_RES;  j++)
+            {
+                for (k = 1;  k >= 0;  k--)
+                {
+                    s = (i + k) % TORUS_MINOR_RES + 0.5;
+                    t = j % TORUS_MAJOR_RES;
+
+                    // Calculate point on surface
+                    x = (TORUS_MAJOR + TORUS_MINOR * cos(s * twopi / TORUS_MINOR_RES)) * cos(t * twopi / TORUS_MAJOR_RES);
+                    y = TORUS_MINOR * sin(s * twopi / TORUS_MINOR_RES);
+                    z = (TORUS_MAJOR + TORUS_MINOR * cos(s * twopi / TORUS_MINOR_RES)) * sin(t * twopi / TORUS_MAJOR_RES);
+
+                    // Calculate surface normal
+                    nx = x - TORUS_MAJOR * cos(t * twopi / TORUS_MAJOR_RES);
+                    ny = y;
+                    nz = z - TORUS_MAJOR * sin(t * twopi / TORUS_MAJOR_RES);
+                    scale = 1.0 / sqrt(nx*nx + ny*ny + nz*nz);
+                    nx *= scale;
+                    ny *= scale;
+                    nz *= scale;
+
+                    glNormal3f((float) nx, (float) ny, (float) nz);
+                    glVertex3f((float) x, (float) y, (float) z);
+                }
+            }
+
+            glEnd();
+        }
+
+        // Stop recording displaylist
+        glEndList();
+    }
+    else
+    {
+        // Playback displaylist
+        glCallList(torus_list);
+    }
+}
+
+
+//========================================================================
+// Draw the scene (a rotating torus)
+//========================================================================
+
+static void drawScene(void)
+{
+    const GLfloat model_diffuse[4]  = {1.0f, 0.8f, 0.8f, 1.0f};
+    const GLfloat model_specular[4] = {0.6f, 0.6f, 0.6f, 1.0f};
+    const GLfloat model_shininess   = 20.0f;
+
+    glPushMatrix();
+
+    // Rotate the object
+    glRotatef((GLfloat) rot_x * 0.5f, 1.0f, 0.0f, 0.0f);
+    glRotatef((GLfloat) rot_y * 0.5f, 0.0f, 1.0f, 0.0f);
+    glRotatef((GLfloat) rot_z * 0.5f, 0.0f, 0.0f, 1.0f);
+
+    // Set model color (used for orthogonal views, lighting disabled)
+    glColor4fv(model_diffuse);
+
+    // Set model material (used for perspective view, lighting enabled)
+    glMaterialfv(GL_FRONT, GL_DIFFUSE, model_diffuse);
+    glMaterialfv(GL_FRONT, GL_SPECULAR, model_specular);
+    glMaterialf(GL_FRONT, GL_SHININESS, model_shininess);
+
+    // Draw torus
+    drawTorus();
+
+    glPopMatrix();
+}
+
+
+//========================================================================
+// Draw a 2D grid (used for orthogonal views)
+//========================================================================
+
+static void drawGrid(float scale, int steps)
+{
+    int i;
+    float x, y;
+    mat4x4 view;
+
+    glPushMatrix();
+
+    // Set background to some dark bluish grey
+    glClearColor(0.05f, 0.05f, 0.2f, 0.0f);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    // Setup modelview matrix (flat XY view)
+    {
+        vec3 eye = { 0.f, 0.f, 1.f };
+        vec3 center = { 0.f, 0.f, 0.f };
+        vec3 up = { 0.f, 1.f, 0.f };
+        mat4x4_look_at(view, eye, center, up);
+    }
+    glLoadMatrixf((const GLfloat*) view);
+
+    // We don't want to update the Z-buffer
+    glDepthMask(GL_FALSE);
+
+    // Set grid color
+    glColor3f(0.0f, 0.5f, 0.5f);
+
+    glBegin(GL_LINES);
+
+    // Horizontal lines
+    x = scale * 0.5f * (float) (steps - 1);
+    y = -scale * 0.5f * (float) (steps - 1);
+    for (i = 0;  i < steps;  i++)
+    {
+        glVertex3f(-x, y, 0.0f);
+        glVertex3f(x, y, 0.0f);
+        y += scale;
+    }
+
+    // Vertical lines
+    x = -scale * 0.5f * (float) (steps - 1);
+    y = scale * 0.5f * (float) (steps - 1);
+    for (i = 0;  i < steps;  i++)
+    {
+        glVertex3f(x, -y, 0.0f);
+        glVertex3f(x, y, 0.0f);
+        x += scale;
+    }
+
+    glEnd();
+
+    // Enable Z-buffer writing again
+    glDepthMask(GL_TRUE);
+
+    glPopMatrix();
+}
+
+
+//========================================================================
+// Draw all views
+//========================================================================
+
+static void drawAllViews(void)
+{
+    const GLfloat light_position[4] = {0.0f, 8.0f, 8.0f, 1.0f};
+    const GLfloat light_diffuse[4]  = {1.0f, 1.0f, 1.0f, 1.0f};
+    const GLfloat light_specular[4] = {1.0f, 1.0f, 1.0f, 1.0f};
+    const GLfloat light_ambient[4]  = {0.2f, 0.2f, 0.3f, 1.0f};
+    float aspect;
+    mat4x4 view, projection;
+
+    // Calculate aspect of window
+    if (height > 0)
+        aspect = (float) width / (float) height;
+    else
+        aspect = 1.f;
+
+    // Clear screen
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    // Enable scissor test
+    glEnable(GL_SCISSOR_TEST);
+
+    // Enable depth test
+    glEnable(GL_DEPTH_TEST);
+    glDepthFunc(GL_LEQUAL);
+
+    // ** ORTHOGONAL VIEWS **
+
+    // For orthogonal views, use wireframe rendering
+    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+
+    // Enable line anti-aliasing
+    glEnable(GL_LINE_SMOOTH);
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+    // Setup orthogonal projection matrix
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glOrtho(-3.0 * aspect, 3.0 * aspect, -3.0, 3.0, 1.0, 50.0);
+
+    // Upper left view (TOP VIEW)
+    glViewport(0, height / 2, width / 2, height / 2);
+    glScissor(0, height / 2, width / 2, height / 2);
+    glMatrixMode(GL_MODELVIEW);
+    {
+        vec3 eye = { 0.f, 10.f, 1e-3f };
+        vec3 center = { 0.f, 0.f, 0.f };
+        vec3 up = { 0.f, 1.f, 0.f };
+        mat4x4_look_at( view, eye, center, up );
+    }
+    glLoadMatrixf((const GLfloat*) view);
+    drawGrid(0.5, 12);
+    drawScene();
+
+    // Lower left view (FRONT VIEW)
+    glViewport(0, 0, width / 2, height / 2);
+    glScissor(0, 0, width / 2, height / 2);
+    glMatrixMode(GL_MODELVIEW);
+    {
+        vec3 eye = { 0.f, 0.f, 10.f };
+        vec3 center = { 0.f, 0.f, 0.f };
+        vec3 up = { 0.f, 1.f, 0.f };
+        mat4x4_look_at( view, eye, center, up );
+    }
+    glLoadMatrixf((const GLfloat*) view);
+    drawGrid(0.5, 12);
+    drawScene();
+
+    // Lower right view (SIDE VIEW)
+    glViewport(width / 2, 0, width / 2, height / 2);
+    glScissor(width / 2, 0, width / 2, height / 2);
+    glMatrixMode(GL_MODELVIEW);
+    {
+        vec3 eye = { 10.f, 0.f, 0.f };
+        vec3 center = { 0.f, 0.f, 0.f };
+        vec3 up = { 0.f, 1.f, 0.f };
+        mat4x4_look_at( view, eye, center, up );
+    }
+    glLoadMatrixf((const GLfloat*) view);
+    drawGrid(0.5, 12);
+    drawScene();
+
+    // Disable line anti-aliasing
+    glDisable(GL_LINE_SMOOTH);
+    glDisable(GL_BLEND);
+
+    // ** PERSPECTIVE VIEW **
+
+    // For perspective view, use solid rendering
+    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+
+    // Enable face culling (faster rendering)
+    glEnable(GL_CULL_FACE);
+    glCullFace(GL_BACK);
+    glFrontFace(GL_CW);
+
+    // Setup perspective projection matrix
+    glMatrixMode(GL_PROJECTION);
+    mat4x4_perspective(projection,
+                       65.f * (float) M_PI / 180.f,
+                       aspect,
+                       1.f, 50.f);
+    glLoadMatrixf((const GLfloat*) projection);
+
+    // Upper right view (PERSPECTIVE VIEW)
+    glViewport(width / 2, height / 2, width / 2, height / 2);
+    glScissor(width / 2, height / 2, width / 2, height / 2);
+    glMatrixMode(GL_MODELVIEW);
+    {
+        vec3 eye = { 3.f, 1.5f, 3.f };
+        vec3 center = { 0.f, 0.f, 0.f };
+        vec3 up = { 0.f, 1.f, 0.f };
+        mat4x4_look_at( view, eye, center, up );
+    }
+    glLoadMatrixf((const GLfloat*) view);
+
+    // Configure and enable light source 1
+    glLightfv(GL_LIGHT1, GL_POSITION, light_position);
+    glLightfv(GL_LIGHT1, GL_AMBIENT, light_ambient);
+    glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse);
+    glLightfv(GL_LIGHT1, GL_SPECULAR, light_specular);
+    glEnable(GL_LIGHT1);
+    glEnable(GL_LIGHTING);
+
+    // Draw scene
+    drawScene();
+
+    // Disable lighting
+    glDisable(GL_LIGHTING);
+
+    // Disable face culling
+    glDisable(GL_CULL_FACE);
+
+    // Disable depth test
+    glDisable(GL_DEPTH_TEST);
+
+    // Disable scissor test
+    glDisable(GL_SCISSOR_TEST);
+
+    // Draw a border around the active view
+    if (active_view > 0 && active_view != 2)
+    {
+        glViewport(0, 0, width, height);
+
+        glMatrixMode(GL_PROJECTION);
+        glLoadIdentity();
+        glOrtho(0.0, 2.0, 0.0, 2.0, 0.0, 1.0);
+
+        glMatrixMode(GL_MODELVIEW);
+        glLoadIdentity();
+        glTranslatef((GLfloat) ((active_view - 1) & 1), (GLfloat) (1 - (active_view - 1) / 2), 0.0f);
+
+        glColor3f(1.0f, 1.0f, 0.6f);
+
+        glBegin(GL_LINE_STRIP);
+        glVertex2i(0, 0);
+        glVertex2i(1, 0);
+        glVertex2i(1, 1);
+        glVertex2i(0, 1);
+        glVertex2i(0, 0);
+        glEnd();
+    }
+}
+
+
+//========================================================================
+// Framebuffer size callback function
+//========================================================================
+
+static void framebufferSizeFun(GLFWwindow* window, int w, int h)
+{
+    width  = w;
+    height = h > 0 ? h : 1;
+    do_redraw = 1;
+}
+
+
+//========================================================================
+// Window refresh callback function
+//========================================================================
+
+static void windowRefreshFun(GLFWwindow* window)
+{
+    drawAllViews();
+    glfwSwapBuffers(window);
+    do_redraw = 0;
+}
+
+
+//========================================================================
+// Mouse position callback function
+//========================================================================
+
+static void cursorPosFun(GLFWwindow* window, double x, double y)
+{
+    int wnd_width, wnd_height, fb_width, fb_height;
+    double scale;
+
+    glfwGetWindowSize(window, &wnd_width, &wnd_height);
+    glfwGetFramebufferSize(window, &fb_width, &fb_height);
+
+    scale = (double) fb_width / (double) wnd_width;
+
+    x *= scale;
+    y *= scale;
+
+    // Depending on which view was selected, rotate around different axes
+    switch (active_view)
+    {
+        case 1:
+            rot_x += (int) (y - ypos);
+            rot_z += (int) (x - xpos);
+            do_redraw = 1;
+            break;
+        case 3:
+            rot_x += (int) (y - ypos);
+            rot_y += (int) (x - xpos);
+            do_redraw = 1;
+            break;
+        case 4:
+            rot_y += (int) (x - xpos);
+            rot_z += (int) (y - ypos);
+            do_redraw = 1;
+            break;
+        default:
+            // Do nothing for perspective view, or if no view is selected
+            break;
+    }
+
+    // Remember cursor position
+    xpos = x;
+    ypos = y;
+}
+
+
+//========================================================================
+// Mouse button callback function
+//========================================================================
+
+static void mouseButtonFun(GLFWwindow* window, int button, int action, int mods)
+{
+    if ((button == GLFW_MOUSE_BUTTON_LEFT) && action == GLFW_PRESS)
+    {
+        // Detect which of the four views was clicked
+        active_view = 1;
+        if (xpos >= width / 2)
+            active_view += 1;
+        if (ypos >= height / 2)
+            active_view += 2;
+    }
+    else if (button == GLFW_MOUSE_BUTTON_LEFT)
+    {
+        // Deselect any previously selected view
+        active_view = 0;
+    }
+
+    do_redraw = 1;
+}
+
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
+{
+    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
+        glfwSetWindowShouldClose(window, GLFW_TRUE);
+}
+
+
+//========================================================================
+// main
+//========================================================================
+
+int main(void)
+{
+    GLFWwindow* window;
+
+    // Initialise GLFW
+    if (!glfwInit())
+    {
+        fprintf(stderr, "Failed to initialize GLFW\n");
+        exit(EXIT_FAILURE);
+    }
+
+    glfwWindowHint(GLFW_SAMPLES, 4);
+
+    // Open OpenGL window
+    window = glfwCreateWindow(500, 500, "Split view demo", NULL, NULL);
+    if (!window)
+    {
+        fprintf(stderr, "Failed to open GLFW window\n");
+
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    // Set callback functions
+    glfwSetFramebufferSizeCallback(window, framebufferSizeFun);
+    glfwSetWindowRefreshCallback(window, windowRefreshFun);
+    glfwSetCursorPosCallback(window, cursorPosFun);
+    glfwSetMouseButtonCallback(window, mouseButtonFun);
+    glfwSetKeyCallback(window, key_callback);
+
+    // Enable vsync
+    glfwMakeContextCurrent(window);
+    gladLoadGL(glfwGetProcAddress);
+    glfwSwapInterval(1);
+
+    if (GLAD_GL_ARB_multisample || GLAD_GL_VERSION_1_3)
+        glEnable(GL_MULTISAMPLE_ARB);
+
+    glfwGetFramebufferSize(window, &width, &height);
+    framebufferSizeFun(window, width, height);
+
+    // Main loop
+    for (;;)
+    {
+        // Only redraw if we need to
+        if (do_redraw)
+            windowRefreshFun(window);
+
+        // Wait for new events
+        glfwWaitEvents();
+
+        // Check if the window should be closed
+        if (glfwWindowShouldClose(window))
+            break;
+    }
+
+    // Close OpenGL window and terminate GLFW
+    glfwTerminate();
+
+    exit(EXIT_SUCCESS);
+}
+
diff --git a/libs/glfw-3.3.8/examples/wave.c b/libs/glfw-3.3.8/examples/wave.c
new file mode 100644
index 0000000..7acb8b9
--- /dev/null
+++ b/libs/glfw-3.3.8/examples/wave.c
@@ -0,0 +1,462 @@
+/*****************************************************************************
+ * Wave Simulation in OpenGL
+ * (C) 2002 Jakob Thomsen
+ * http://home.in.tum.de/~thomsen
+ * Modified for GLFW by Sylvain Hellegouarch - sh@programmationworld.com
+ * Modified for variable frame rate by Marcus Geelnard
+ * 2003-Jan-31: Minor cleanups and speedups / MG
+ * 2010-10-24: Formatting and cleanup - Camilla Löwy
+ *****************************************************************************/
+
+#if defined(_MSC_VER)
+ // Make MS math.h define M_PI
+ #define _USE_MATH_DEFINES
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+#include <linmath.h>
+
+// Maximum delta T to allow for differential calculations
+#define MAX_DELTA_T 0.01
+
+// Animation speed (10.0 looks good)
+#define ANIMATION_SPEED 10.0
+
+GLfloat alpha = 210.f, beta = -70.f;
+GLfloat zoom = 2.f;
+
+double cursorX;
+double cursorY;
+
+struct Vertex
+{
+    GLfloat x, y, z;
+    GLfloat r, g, b;
+};
+
+#define GRIDW 50
+#define GRIDH 50
+#define VERTEXNUM (GRIDW*GRIDH)
+
+#define QUADW (GRIDW - 1)
+#define QUADH (GRIDH - 1)
+#define QUADNUM (QUADW*QUADH)
+
+GLuint quad[4 * QUADNUM];
+struct Vertex vertex[VERTEXNUM];
+
+/* The grid will look like this:
+ *
+ *      3   4   5
+ *      *---*---*
+ *      |   |   |
+ *      | 0 | 1 |
+ *      |   |   |
+ *      *---*---*
+ *      0   1   2
+ */
+
+//========================================================================
+// Initialize grid geometry
+//========================================================================
+
+void init_vertices(void)
+{
+    int x, y, p;
+
+    // Place the vertices in a grid
+    for (y = 0;  y < GRIDH;  y++)
+    {
+        for (x = 0;  x < GRIDW;  x++)
+        {
+            p = y * GRIDW + x;
+
+            vertex[p].x = (GLfloat) (x - GRIDW / 2) / (GLfloat) (GRIDW / 2);
+            vertex[p].y = (GLfloat) (y - GRIDH / 2) / (GLfloat) (GRIDH / 2);
+            vertex[p].z = 0;
+
+            if ((x % 4 < 2) ^ (y % 4 < 2))
+                vertex[p].r = 0.0;
+            else
+                vertex[p].r = 1.0;
+
+            vertex[p].g = (GLfloat) y / (GLfloat) GRIDH;
+            vertex[p].b = 1.f - ((GLfloat) x / (GLfloat) GRIDW + (GLfloat) y / (GLfloat) GRIDH) / 2.f;
+        }
+    }
+
+    for (y = 0;  y < QUADH;  y++)
+    {
+        for (x = 0;  x < QUADW;  x++)
+        {
+            p = 4 * (y * QUADW + x);
+
+            quad[p + 0] = y       * GRIDW + x;     // Some point
+            quad[p + 1] = y       * GRIDW + x + 1; // Neighbor at the right side
+            quad[p + 2] = (y + 1) * GRIDW + x + 1; // Upper right neighbor
+            quad[p + 3] = (y + 1) * GRIDW + x;     // Upper neighbor
+        }
+    }
+}
+
+double dt;
+double p[GRIDW][GRIDH];
+double vx[GRIDW][GRIDH], vy[GRIDW][GRIDH];
+double ax[GRIDW][GRIDH], ay[GRIDW][GRIDH];
+
+//========================================================================
+// Initialize grid
+//========================================================================
+
+void init_grid(void)
+{
+    int x, y;
+    double dx, dy, d;
+
+    for (y = 0; y < GRIDH;  y++)
+    {
+        for (x = 0; x < GRIDW;  x++)
+        {
+            dx = (double) (x - GRIDW / 2);
+            dy = (double) (y - GRIDH / 2);
+            d = sqrt(dx * dx + dy * dy);
+            if (d < 0.1 * (double) (GRIDW / 2))
+            {
+                d = d * 10.0;
+                p[x][y] = -cos(d * (M_PI / (double)(GRIDW * 4))) * 100.0;
+            }
+            else
+                p[x][y] = 0.0;
+
+            vx[x][y] = 0.0;
+            vy[x][y] = 0.0;
+        }
+    }
+}
+
+
+//========================================================================
+// Draw scene
+//========================================================================
+
+void draw_scene(GLFWwindow* window)
+{
+    // Clear the color and depth buffers
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    // We don't want to modify the projection matrix
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+
+    // Move back
+    glTranslatef(0.0, 0.0, -zoom);
+    // Rotate the view
+    glRotatef(beta, 1.0, 0.0, 0.0);
+    glRotatef(alpha, 0.0, 0.0, 1.0);
+
+    glDrawElements(GL_QUADS, 4 * QUADNUM, GL_UNSIGNED_INT, quad);
+
+    glfwSwapBuffers(window);
+}
+
+
+//========================================================================
+// Initialize Miscellaneous OpenGL state
+//========================================================================
+
+void init_opengl(void)
+{
+    // Use Gouraud (smooth) shading
+    glShadeModel(GL_SMOOTH);
+
+    // Switch on the z-buffer
+    glEnable(GL_DEPTH_TEST);
+
+    glEnableClientState(GL_VERTEX_ARRAY);
+    glEnableClientState(GL_COLOR_ARRAY);
+    glVertexPointer(3, GL_FLOAT, sizeof(struct Vertex), vertex);
+    glColorPointer(3, GL_FLOAT, sizeof(struct Vertex), &vertex[0].r); // Pointer to the first color
+
+    glPointSize(2.0);
+
+    // Background color is black
+    glClearColor(0, 0, 0, 0);
+}
+
+
+//========================================================================
+// Modify the height of each vertex according to the pressure
+//========================================================================
+
+void adjust_grid(void)
+{
+    int pos;
+    int x, y;
+
+    for (y = 0; y < GRIDH;  y++)
+    {
+        for (x = 0;  x < GRIDW;  x++)
+        {
+            pos = y * GRIDW + x;
+            vertex[pos].z = (float) (p[x][y] * (1.0 / 50.0));
+        }
+    }
+}
+
+
+//========================================================================
+// Calculate wave propagation
+//========================================================================
+
+void calc_grid(void)
+{
+    int x, y, x2, y2;
+    double time_step = dt * ANIMATION_SPEED;
+
+    // Compute accelerations
+    for (x = 0;  x < GRIDW;  x++)
+    {
+        x2 = (x + 1) % GRIDW;
+        for(y = 0; y < GRIDH; y++)
+            ax[x][y] = p[x][y] - p[x2][y];
+    }
+
+    for (y = 0;  y < GRIDH;  y++)
+    {
+        y2 = (y + 1) % GRIDH;
+        for(x = 0; x < GRIDW; x++)
+            ay[x][y] = p[x][y] - p[x][y2];
+    }
+
+    // Compute speeds
+    for (x = 0;  x < GRIDW;  x++)
+    {
+        for (y = 0;  y < GRIDH;  y++)
+        {
+            vx[x][y] = vx[x][y] + ax[x][y] * time_step;
+            vy[x][y] = vy[x][y] + ay[x][y] * time_step;
+        }
+    }
+
+    // Compute pressure
+    for (x = 1;  x < GRIDW;  x++)
+    {
+        x2 = x - 1;
+        for (y = 1;  y < GRIDH;  y++)
+        {
+            y2 = y - 1;
+            p[x][y] = p[x][y] + (vx[x2][y] - vx[x][y] + vy[x][y2] - vy[x][y]) * time_step;
+        }
+    }
+}
+
+
+//========================================================================
+// Print errors
+//========================================================================
+
+static void error_callback(int error, const char* description)
+{
+    fprintf(stderr, "Error: %s\n", description);
+}
+
+
+//========================================================================
+// Handle key strokes
+//========================================================================
+
+void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
+{
+    if (action != GLFW_PRESS)
+        return;
+
+    switch (key)
+    {
+        case GLFW_KEY_ESCAPE:
+            glfwSetWindowShouldClose(window, GLFW_TRUE);
+            break;
+        case GLFW_KEY_SPACE:
+            init_grid();
+            break;
+        case GLFW_KEY_LEFT:
+            alpha += 5;
+            break;
+        case GLFW_KEY_RIGHT:
+            alpha -= 5;
+            break;
+        case GLFW_KEY_UP:
+            beta -= 5;
+            break;
+        case GLFW_KEY_DOWN:
+            beta += 5;
+            break;
+        case GLFW_KEY_PAGE_UP:
+            zoom -= 0.25f;
+            if (zoom < 0.f)
+                zoom = 0.f;
+            break;
+        case GLFW_KEY_PAGE_DOWN:
+            zoom += 0.25f;
+            break;
+        default:
+            break;
+    }
+}
+
+
+//========================================================================
+// Callback function for mouse button events
+//========================================================================
+
+void mouse_button_callback(GLFWwindow* window, int button, int action, int mods)
+{
+    if (button != GLFW_MOUSE_BUTTON_LEFT)
+        return;
+
+    if (action == GLFW_PRESS)
+    {
+        glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+        glfwGetCursorPos(window, &cursorX, &cursorY);
+    }
+    else
+        glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_NORMAL);
+}
+
+
+//========================================================================
+// Callback function for cursor motion events
+//========================================================================
+
+void cursor_position_callback(GLFWwindow* window, double x, double y)
+{
+    if (glfwGetInputMode(window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
+    {
+        alpha += (GLfloat) (x - cursorX) / 10.f;
+        beta += (GLfloat) (y - cursorY) / 10.f;
+
+        cursorX = x;
+        cursorY = y;
+    }
+}
+
+
+//========================================================================
+// Callback function for scroll events
+//========================================================================
+
+void scroll_callback(GLFWwindow* window, double x, double y)
+{
+    zoom += (float) y / 4.f;
+    if (zoom < 0)
+        zoom = 0;
+}
+
+
+//========================================================================
+// Callback function for framebuffer resize events
+//========================================================================
+
+void framebuffer_size_callback(GLFWwindow* window, int width, int height)
+{
+    float ratio = 1.f;
+    mat4x4 projection;
+
+    if (height > 0)
+        ratio = (float) width / (float) height;
+
+    // Setup viewport
+    glViewport(0, 0, width, height);
+
+    // Change to the projection matrix and set our viewing volume
+    glMatrixMode(GL_PROJECTION);
+    mat4x4_perspective(projection,
+                       60.f * (float) M_PI / 180.f,
+                       ratio,
+                       1.f, 1024.f);
+    glLoadMatrixf((const GLfloat*) projection);
+}
+
+
+//========================================================================
+// main
+//========================================================================
+
+int main(int argc, char* argv[])
+{
+    GLFWwindow* window;
+    double t, dt_total, t_old;
+    int width, height;
+
+    glfwSetErrorCallback(error_callback);
+
+    if (!glfwInit())
+        exit(EXIT_FAILURE);
+
+    window = glfwCreateWindow(640, 480, "Wave Simulation", NULL, NULL);
+    if (!window)
+    {
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    glfwSetKeyCallback(window, key_callback);
+    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+    glfwSetMouseButtonCallback(window, mouse_button_callback);
+    glfwSetCursorPosCallback(window, cursor_position_callback);
+    glfwSetScrollCallback(window, scroll_callback);
+
+    glfwMakeContextCurrent(window);
+    gladLoadGL(glfwGetProcAddress);
+    glfwSwapInterval(1);
+
+    glfwGetFramebufferSize(window, &width, &height);
+    framebuffer_size_callback(window, width, height);
+
+    // Initialize OpenGL
+    init_opengl();
+
+    // Initialize simulation
+    init_vertices();
+    init_grid();
+    adjust_grid();
+
+    // Initialize timer
+    t_old = glfwGetTime() - 0.01;
+
+    while (!glfwWindowShouldClose(window))
+    {
+        t = glfwGetTime();
+        dt_total = t - t_old;
+        t_old = t;
+
+        // Safety - iterate if dt_total is too large
+        while (dt_total > 0.f)
+        {
+            // Select iteration time step
+            dt = dt_total > MAX_DELTA_T ? MAX_DELTA_T : dt_total;
+            dt_total -= dt;
+
+            // Calculate wave propagation
+            calc_grid();
+        }
+
+        // Compute height of each vertex
+        adjust_grid();
+
+        // Draw wave grid to OpenGL display
+        draw_scene(window);
+
+        glfwPollEvents();
+    }
+
+    glfwTerminate();
+    exit(EXIT_SUCCESS);
+}
+