glGetBufferSubData Interface to
OpenGL function glGetBufferSubData
usage: glGetBufferSubData( target, offset, dsize, data )
Caution: Caller needs to allocate 'data' as a matrix or vector of
suitable format and capacity for the data, otherwise bad things will
happen!
C function: void glGetBufferSubData(GLenum target, GLint offset, GLsizei dsize, GLvoid* data)
Psychtoolbox/PsychOpenGL/MOGL/wrap/glGetBufferSubData.m