/* From http://www.lighthouse3d.com/tutorials/glut-tutorial/animation/ */
// I think this version doesn’t work

#include <GL/glut.h>

void changeSize(int w, int h) {

	// Prevent a divide by zero, when window is too short
	// (you cant make a window of zero width).
	if (h == 0)
		h = 1;

	float ratio =  w * 1.0 / h;

	// Use the Projection Matrix
	glMatrixMode(GL_PROJECTION);

	// Reset Matrix
	glLoadIdentity();

	// Set the viewport to be the entire window
	glViewport(0, 0, w, h);

	// Set the correct perspective.
	gluPerspective(45.0f, ratio, 0.1f, 100.0f);

	// Get Back to the Modelview
	glMatrixMode(GL_MODELVIEW);
}

float angle = 0.0f;

void renderScene(void) {

	// Clear Color and Depth Buffers
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	// Reset transformations
	glLoadIdentity();
	// Set the camera
	gluLookAt(	0.0f, 0.0f, 10.0f,
				0.0f, 0.0f,  0.0f,
				0.0f, 1.0f,  0.0f);

	glRotatef(angle, 0.0f, 1.0f, 0.0f);

	glBegin(GL_TRIANGLES);
		glVertex3f(-2.0f,-2.0f, 0.0f);
		glVertex3f( 2.0f, 0.0f, 0.0);
		glVertex3f( 0.0f, 2.0f, 0.0);
	glEnd();

	angle+=0.1f;

	glutSwapBuffers();
}

int main(int argc, char **argv) {

	// init GLUT and create window
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
	glutInitWindowPosition(100,100);
	glutInitWindowSize(320,320);
	glutCreateWindow("Lighthouse3D- GLUT Tutorial");

	// register callbacks
	glutDisplayFunc(renderScene);
	glutReshapeFunc(changeSize);
	glutIdleFunc(renderScene);

	// enter GLUT event processing cycle
	glutMainLoop();

	return 1;
}