glfw/examples/triangle.c
2012-06-05 23:55:10 +02:00

95 lines
2.7 KiB
C

//========================================================================
// This is a small test application for GLFW.
// The program opens a window (640x480), and renders a spinning colored
// triangle (it is controlled with both the GLFW timer and the mouse).
//========================================================================
#include <stdio.h>
#include <stdlib.h>
#define GLFW_INCLUDE_GLU
#include <GL/glfw3.h>
int main(void)
{
int width, height, x;
GLFWwindow window;
// Initialise GLFW
if (!glfwInit())
{
fprintf(stderr, "Failed to initialize GLFW\n");
exit(EXIT_FAILURE);
}
// Open a window and create its OpenGL context
window = glfwOpenWindow(640, 480, GLFW_WINDOWED, "Spinning Triangle", NULL);
if (!window)
{
fprintf(stderr, "Failed to open GLFW window\n");
exit(EXIT_FAILURE);
}
// Ensure we can capture the escape key being pressed below
glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);
// Enable vertical sync (on cards that support it)
glfwSwapInterval(1);
do
{
double t = glfwGetTime();
glfwGetMousePos(window, &x, NULL);
// Get window size (may be different than the requested size)
glfwGetWindowSize(window, &width, &height);
// Special case: avoid division by zero below
height = height > 0 ? height : 1;
glViewport(0, 0, width, height);
// Clear color buffer to black
glClearColor(0.f, 0.f, 0.f, 0.f);
glClear(GL_COLOR_BUFFER_BIT);
// Select and setup the projection matrix
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(65.f, (GLfloat) width / (GLfloat) height, 1.f, 100.f);
// Select and setup the modelview matrix
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
gluLookAt(0.f, 1.f, 0.f, // Eye-position
0.f, 20.f, 0.f, // View-point
0.f, 0.f, 1.f); // Up-vector
// Draw a rotating colorful triangle
glTranslatef(0.f, 14.f, 0.f);
glRotatef(0.3f * (GLfloat) x + (GLfloat) t * 100.f, 0.f, 0.f, 1.f);
glBegin(GL_TRIANGLES);
glColor3f(1.f, 0.f, 0.f);
glVertex3f(-5.f, 0.f, -4.f);
glColor3f(0.f, 1.f, 0.f);
glVertex3f(5.f, 0.f, -4.f);
glColor3f(0.f, 0.f, 1.f);
glVertex3f(0.f, 0.f, 6.f);
glEnd();
// Swap buffers
glfwSwapBuffers();
glfwPollEvents();
} // Check if the ESC key was pressed or the window was closed
while (glfwIsWindow(window) &&
glfwGetKey(window, GLFW_KEY_ESCAPE) != GLFW_PRESS);
// Close OpenGL window and terminate GLFW
glfwTerminate();
exit(EXIT_SUCCESS);
}