##HOW to configure in Xcode for OpenGLDemo
Check this post for detail: http://lnx.cx/docs/opengl-in-xcode/
##Tracking
- Compile issue under Mac: updated OpenGL/GLut.h files.
- Remove unnecessary files and components.
- add mouse listener, fix the issue of not responding. (must placed after display callback)
- add translation function to deal with location move/change.
- fix the issue of display, cannot refresh/re-display the ball.
- fix mouse listener's drawing, change the coordinates(ballX,ballY,ballZ), and only draw it in the display function with the glTranslatef()
- minor/major fix for keyboard control with respect to the shape and location of ball
- remove shadow, change move/scale(use larger changes/scales)
- make the sphere more round(use more slices/stacks)
- set GLUT initial window position and size
- add reshape function to avoid being ellipse instead of circle(avoid losing original shape)
- add color control, use
cto randomly change the color of sphere - add rolling effect, when moving upside/down/left/right
- adjust parameters for better rolling effect
- h - move the ball to the left
- l - move the ball to the right
- j - move down
- k - move up
- p - enlarge the ball, increase scale
- q - make the ball smaller, decrease scale
- c - change the color of the ball/sphere