#include <GL\glut.h>

GLfloat xRotated, yRotated, zRotated;
GLdouble size = 1;


void display(void)
{

	glMatrixMode(GL_MODELVIEW);
	// clear the drawing buffer.
	glClear(GL_COLOR_BUFFER_BIT);
	// clear the identity matrix.
	glLoadIdentity();
	// traslate the draw by z = -4.0
	// Note this when you decrease z like -8.0 the drawing will looks far , or smaller.
	glTranslatef(0.0, 0.0, -4.5);
	// Red color used to draw.
	glColor3f(0.8, 0.2, 0.1);
	// changing in transformation matrix.
	// rotation about X axis
	glRotatef(xRotated, 1.0, 0.0, 0.0);
	// rotation about Y axis
	glRotatef(yRotated, 0.0, 1.0, 0.0);
	// rotation about Z axis
	glRotatef(zRotated, 0.0, 0.0, 1.0);
	// scaling transfomation
	glScalef(1.0, 1.0, 1.0);
	// built-in (glut library) function , draw you a Teapot.
	glutSolidTeapot(size);
	// Flush buffers to screen

	glFlush();
	// sawp buffers called because we are using double buffering
   // glutSwapBuffers();
}

void reshapeFunc(int x, int y)
{
	if (y == 0 || x == 0) return;  //Nothing is visible then, so return
	//Set a new projection matrix
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	//Angle of view:40 degrees
	//Near clipping plane distance: 0.5
	//Far clipping plane distance: 20.0

	gluPerspective(40.0, (GLdouble)x / (GLdouble)y, 0.5, 20.0);

	glViewport(0, 0, x, y);  //Use the whole window for rendering
}

void idleFunc(void)
{

	yRotated += 0.01;

	display();
}


int main(int argc, char **argv)
{
	//Initialize GLUT
	glutInit(&argc, argv);
	//double buffering used to avoid flickering problem in animation
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	// window size
	glutInitWindowSize(400, 350);
	// create the window
	glutCreateWindow("Teapot Rotating Animation");
	glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
	xRotated = yRotated = zRotated = 30.0;
	xRotated = 33;
	yRotated = 40;
	glClearColor(0.0, 0.0, 0.0, 0.0);
	//Assign  the function used in events
	glutDisplayFunc(display);
	glutReshapeFunc(reshapeFunc);
	glutIdleFunc(idleFunc);
	//Let start glut loop
	glutMainLoop();
	return 0;
}