CSCE 4230  Program #4


        Due date:  Thursday, March 26, 2009


	Write an interactive OpenGL program that displays a solid
	two-segment robot arm by modifying robot.c (OpenGL Programming
	Guide, p. 157) as follows.

	  1)  Use glutSolidCube in place of glutWireCube.  Remove hidden
	      surfaces by using a depth buffer:  add GLUT_DEPTH to the
	      call to glutInitDisplayMode and add GL_DEPTH_BUFFER_BIT to
	      the call to glClear.  Color the first segment (upper arm)
	      red and the second segment blue.	Refer to glColor3f.

	  2)  Change the scale factors (segment shapes) to (4,1,1) for
              the first segment and (3,1,1) for the second.  Note that
	      this requires changes to the translation distances.

	  3)  Allow the user to effectively change the eye position by
	      modifying rotation angles xrot and yrot for x- and y-axis
	      rotations (applied as part of the modelview transformation
	      as the last step before translating down the z-axis):

	      'x'  ==>	increase xrot
	      'X'  ==>	decrease xrot
	      'y'  ==>	increase yrot
	      'Y'  ==>	decrease yrot

	      Experiment to find reasonable increments for the angles.

	  The robot arm should be centered in the window and have aspect
	  ratio preserved.  The escape key (or a menu selection) should
	  terminate the program.  Attach the menu to the right menu button.


        Email the source code with file name prog4.c or prog4.cpp to
        Ismail Mohammed:  im0058@unt.edu.

        Also submit a source code listing at the beginning of class on
        the due date.