glCopyTexSubImage3D Interface to
OpenGL function glCopyTexSubImage3D
usage: glCopyTexSubImage3D( target, level, xoffset, yoffset, zoffset, x, y, width, height )
C function: void glCopyTexSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLint x, GLint y, GLsizei width, GLsizei height)
Psychtoolbox/PsychOpenGL/MOGL/wrap/glCopyTexSubImage3D.m