Hello! I am working on an animation that shows how an actual rotation is handled in openGL. So far, I have a shape that starts at a position and I have it animated moving back and forth from the original spot to the origin and back.. however, I need to show the translation to the origin, then it needs to stop, animate the required rotation, then get translated back to the starting position. I am having a hard time understanding how I can actually stop when I am at the origin...I thought I had handled it but for some reason, the shape is not stopping or rotating... any ideas?

Thanks!

Code :
#include <stdlib.h>
#include <stdio.h>
#include <GLUT/glut.h>
 
 
 
 
static float yPosition = 0;
static float zPosition = 0;
float topLeftX = 0.5;
float topLeftY = 0.75;
float topRightX = 0.75;
float topRightY = 0.75;
float bottomRightX = 0.75;
float bottomRightY = 0.5;
float bottomLeftX = 0.5;
float bottomLeftY = 0.5;
float xPos = 0.75;
float yPos = 0.75;
float zPos = 0;
float startXPos = 0.75;
float startYPos = 0.75;
int yDirection = 0; //1-up, 0-down
int xDirection = 0; //1-right, 0-left, 3- STOPPED
 
 
//the init function is used to initialize things that only need to be execute once
void init()
{
	glClearColor(1.0,1.0,1.0,0.0);
	glEnable(GL_DEPTH_TEST);
	//glShadeModel (GL_SMOOTH);
}
 
void setWindow(double left, double right, double bottom, double top)
{
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
}
 
void setViewport(int left, int right, int bottom, int top)
{
	glViewport(left, bottom, right-left, top-bottom);
}
 
//function for drawing, called whenever there needs to be a redraw
void display(void)
{
	//color buffer gets cleared everytime a new frame is drawn
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	
	//glClear(GL_COLOR_BUFFER_BIT);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	setWindow(-9.0, 9.0, -1.0, 1.0);			// set the window
 
	glColor3f(1,0,0);
 
	glTranslated(xPos, yPos, zPos);
	glRotatef(yPosition, 0, 1, 0);
	glRotatef(zPosition, 0, 0, 1);
 
	glutWireCube(.25);  
 
 
	glutSwapBuffers();	
 
	if (xDirection==0){ //if moving left
		xPos-=0.0005;	//move in a negative direction along the xaxis	
		yPos = (startYPos*xPos/startXPos);
	}
	else if (xDirection==1){
		xPos+=0.0005;	//otherwise move in the positive direction
		yPos = (startYPos*xPos/startXPos);
	}
	else if (xDirection==3){
 
		//ROTATE
		yPosition=yPosition+0.5;
		if (yPosition>180)
			xDirection==1;
 
		zPosition=zPosition+0.5;
		if (zPosition>180)
			xDirection==1;
 
	} 
 
 
	if (xDirection==0 && xPos > 0.0) {
		xDirection=0;
	}
 
	if (xDirection==0 && xPos < 0.0) {
		xDirection=1;
	}
 
	if (xDirection==1 && xPos < startXPos) {
		xDirection=1;
	}
 
	if (xDirection==1 && xPos > startYPos) {
		xDirection=0;
	}
 
	if (xDirection==0 && xPos==0.0 && yPos==0.0) {
		xDirection=3;
	}
 
	glutPostRedisplay();
 
 
}
//called when window is resized, w and h are the new width and height
void reshape (int w, int h)
{
	glViewport (0, 0, (GLsizei) w, (GLsizei) h);
	glMatrixMode (GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(60.0, (GLfloat) w/ (GLfloat) h, 1.0, 20.0);
	glMatrixMode (GL_MODELVIEW);
 
}
 
int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode (GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);  //double pixel buffer that holds RGB 
 
	glutInitWindowSize(800, 800);
	glutInitWindowPosition(0,0);
 
	glutCreateWindow(argv[0]);
 
	init();
 
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
	//glutKeyboardFunc(keyboard);
	//glutIdleFunc(animate);
	glutIdleFunc(display);
	glutMainLoop();
	return 0;
}