GLUT [almost-]skeletal code

glut.c

#include <GL/glut.h>
#include <time.h>

void reshape(int width, int height)
{
	double aspect;
	if (height == 0) height = 1;

	aspect = width / height;

	glViewport(0, 0, width, height);

	glMatrixMode(GL_PROJECTION);
		glLoadIdentity();
		gluPerspective(45, aspect, 1.0, 1000.0); //fov, aspect, near, far
	glMatrixMode(GL_MODELVIEW);
}

void update_display(void)
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glLoadIdentity();
	gluLookAt(
		2.0, 2.0, 10.0, //eye
		0.0, 0.0,  0.0, //target
		0.0, 1.0,  0.0  //eyeUp
	);

	glPushMatrix();
		glTranslatef(+1.0f, +1.0f, -0.5f); //let's move up, right and back a bit
		
		glBegin(GL_TRIANGLES);
			glColor3f(1.0f, 0.0f, 0.0f);
			glVertex3f( 0.0f, +0.6f, 0.0f);
			glVertex3f(-0.4f,  0.0f, 0.0f);
			glVertex3f(+0.4f,  0.0f, 0.0f);
		glEnd();
	glPopMatrix();

	glBegin(GL_LINES); //axes
		//X
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(-100000.0f, 0.0f, 0.0f);
		glVertex3f(+100000.0f, 0.0f, 0.0f);
	
		//Y
		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(0.0f, -100000.0f, 0.0f);
		glVertex3f(0.0f, +100000.0f, 0.0f);
	
		//Z
		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(0.0f, 0.0f, -100000.0f);
		glVertex3f(0.0f, 0.0f, +100000.0f);
	glEnd();

	glutSwapBuffers();
}

void doUpdate(double elapsedSeconds)
{
}

void update_idle(void)
{
	static clock_t lastUpdate = 0;
	clock_t now;
	double elapsed;

	if (lastUpdate == 0) lastUpdate = clock();

	now = clock();
	elapsed = (now - lastUpdate) / (double) CLOCKS_PER_SEC;
	lastUpdate = now;

	doUpdate(elapsed);
	update_display();
}

void process_keys(unsigned char key, int x, int y)
{
	switch (key) {
	case '\033': //ESC
		exit(EXIT_SUCCESS); //crude
		break;
	}
}

int main(int argc, char* argv[])
{
	glutInit(&argc, argv);

	glutInitWindowSize(640, 480);
	glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
	glutCreateWindow("aibglutTest");

	glutReshapeFunc(reshape);
	glutDisplayFunc(update_display);
	glutIdleFunc(update_idle);
	glutKeyboardFunc(process_keys);

	glEnable(GL_DEPTH_TEST);

	glutMainLoop();

	return EXIT_SUCCESS;
}