glfw_triangle_rotate.c

/*
From: http://www.glfw.org/docs/latest/quick.html

TODO:

- convert to delayed mode
- use time deltas and some user input
*/

#include "common.h"

static void error_callback(int error, const char* description) {
    fputs(description, stderr);
}

static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) {
    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
        glfwSetWindowShouldClose(window, GL_TRUE);
}

int main(void) {
    GLFWwindow* window;
    float ratio;
    int width, height;
    glfwSetErrorCallback(error_callback);
    if (!glfwInit())
        exit(EXIT_FAILURE);
    window = glfwCreateWindow(640, 480, __FILE__, NULL, NULL);
    if (!window) {
        glfwTerminate();
        exit(EXIT_FAILURE);
    }
    glfwMakeContextCurrent(window);
    glfwSwapInterval(1);
    glfwSetKeyCallback(window, key_callback);
    common_fps_init();
    while (!glfwWindowShouldClose(window)) {
        glfwGetFramebufferSize(window, &width, &height);
        ratio = width / (float) height;
        glViewport(0, 0, width, height);
        glClear(GL_COLOR_BUFFER_BIT);
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(-ratio, ratio, -1.f, 1.f, 1.f, -1.f);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        glRotatef((float) glfwGetTime() * 50.f, 0.f, 0.f, 1.f);
        glBegin(GL_TRIANGLES);
        glColor3f(1.f, 0.f, 0.f);
        glVertex3f(-0.6f, -0.4f, 0.f);
        glColor3f(0.f, 1.f, 0.f);
        glVertex3f(0.6f, -0.4f, 0.f);
        glColor3f(0.f, 0.f, 1.f);
        glVertex3f(0.f, 0.6f, 0.f);
        glEnd();
        glfwSwapBuffers(window);
        common_fps_print();
        glfwPollEvents();
    }
    glfwDestroyWindow(window);
    glfwTerminate();
    exit(EXIT_SUCCESS);
}