Convert reopen test to GL2

tests/reopen.c

@@ -40,14 +40,33 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-static void error_callback(int error, const char* description)
+#include "linmath.h"
+
+static const char* vertex_shader_text =
+"uniform mat4 MVP;\n"
+"attribute vec2 vPos;\n"
+"void main()\n"
+"{\n"
+"    gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n"
+"}\n";
+
+static const char* fragment_shader_text =
+"void main()\n"
+"{\n"
+"    gl_FragColor = vec4(1.0);\n"
+"}\n";
+
+static const vec2 vertices[4] =
 {
-    fprintf(stderr, "Error: %s\n", description);
-}
+    { -0.5f, -0.5f },
+    {  0.5f, -0.5f },
+    {  0.5f,  0.5f },
+    { -0.5f,  0.5f }
+};
 
-static void framebuffer_size_callback(GLFWwindow* window, int width, int height)
+static void error_callback(int error, const char* description)
 {
-    glViewport(0, 0, width, height);
+    fprintf(stderr, "Error: %s\n", description);
 }
 
 static void window_close_callback(GLFWwindow* window)
@@ -69,40 +88,6 @@ static void key_callback(GLFWwindow* window, int key, int scancode, int action,
     }
 }
 
-static GLFWwindow* open_window(int width, int height, GLFWmonitor* monitor)
-{
-    double base;
-    GLFWwindow* window;
-
-    base = glfwGetTime();
-
-    window = glfwCreateWindow(width, height, "Window Re-opener", monitor, NULL);
-    if (!window)
-        return NULL;
-
-    glfwMakeContextCurrent(window);
-    gladLoadGLLoader((GLADloadproc) glfwGetProcAddress);
-    glfwSwapInterval(1);
-
-    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
-    glfwSetWindowCloseCallback(window, window_close_callback);
-    glfwSetKeyCallback(window, key_callback);
-
-    if (monitor)
-    {
-        printf("Opening full screen window on monitor %s took %0.3f seconds\n",
-               glfwGetMonitorName(monitor),
-               glfwGetTime() - base);
-    }
-    else
-    {
-        printf("Opening regular window took %0.3f seconds\n",
-               glfwGetTime() - base);
-    }
-
-    return window;
-}
-
 static void close_window(GLFWwindow* window)
 {
     double base = glfwGetTime();
@@ -113,6 +98,7 @@ static void close_window(GLFWwindow* window)
 int main(int argc, char** argv)
 {
     int count = 0;
+    double base;
     GLFWwindow* window;
 
     srand((unsigned int) time(NULL));
@@ -122,12 +108,17 @@ int main(int argc, char** argv)
     if (!glfwInit())
         exit(EXIT_FAILURE);
 
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+
     for (;;)
     {
         int width, height;
         GLFWmonitor* monitor = NULL;
+        GLuint vertex_shader, fragment_shader, program, vertex_buffer;
+        GLint mvp_location, vpos_location;
 
-        if (count % 2 == 0)
+        if (count & 1)
         {
             int monitorCount;
             GLFWmonitor** monitors = glfwGetMonitors(&monitorCount);
@@ -146,27 +137,81 @@ int main(int argc, char** argv)
             height = 480;
         }
 
-        window = open_window(width, height, monitor);
+        base = glfwGetTime();
+
+        window = glfwCreateWindow(width, height, "Window Re-opener", monitor, NULL);
         if (!window)
         {
             glfwTerminate();
             exit(EXIT_FAILURE);
         }
 
-        glMatrixMode(GL_PROJECTION);
-        glOrtho(-1.f, 1.f, -1.f, 1.f, 1.f, -1.f);
-        glMatrixMode(GL_MODELVIEW);
+        if (monitor)
+        {
+            printf("Opening full screen window on monitor %s took %0.3f seconds\n",
+                   glfwGetMonitorName(monitor),
+                   glfwGetTime() - base);
+        }
+        else
+        {
+            printf("Opening regular window took %0.3f seconds\n",
+                   glfwGetTime() - base);
+        }
+
+        glfwSetWindowCloseCallback(window, window_close_callback);
+        glfwSetKeyCallback(window, key_callback);
+
+        glfwMakeContextCurrent(window);
+        gladLoadGLLoader((GLADloadproc) glfwGetProcAddress);
+        glfwSwapInterval(1);
+
+        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");
+
+        glGenBuffers(1, &vertex_buffer);
+        glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+        glEnableVertexAttribArray(vpos_location);
+        glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE,
+                              sizeof(vertices[0]), (void*) 0);
 
         glfwSetTime(0.0);
 
         while (glfwGetTime() < 5.0)
         {
+            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);
 
-            glPushMatrix();
-            glRotatef((GLfloat) glfwGetTime() * 100.f, 0.f, 0.f, 1.f);
-            glRectf(-0.5f, -0.5f, 1.f, 1.f);
-            glPopMatrix();
+            mat4x4_ortho(p, -ratio, ratio, -1.f, 1.f, 0.f, 1.f);
+
+            mat4x4_identity(m);
+            mat4x4_rotate_Z(m, m, (float) glfwGetTime());
+            mat4x4_mul(mvp, p, m);
+
+            glUseProgram(program);
+            glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) mvp);
+            glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
 
             glfwSwapBuffers(window);
             glfwPollEvents();