1 files changed, 234 insertions, 0 deletions
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);
+}
+