Chapter 4 Programs:

• cube: displays a rotating cube with vertex colors interpolated across faces
• cubev: same as cube but with element arrays
• cubeq: same as cube but uses quaternions to do the rotation in the vertex shader
• trackball: creates a virtual trackball to control rotation of cube. Increments rotation matrix in application and send it to vertex shader
• trackballQuaternion: similar to trackball but uses quaternions. Rotation quaternion is incremented in application and sent to vertex shader