:wMerge branch 'gl-window' into main

1 files changed, 679 insertions, 0 deletions

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 );
+}
+