glVertexAttribPointer Interface to glVertexAttribPointer
usage: glVertexAttribPointer( index, size, type, normalized, stride, pointer )
C function: void glVertexAttribPointer(GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid* pointer)
Psychtoolbox/PsychOpenGL/MOGL/wrap/glVertexAttribPointer.m