glTexSubImage2D Interface to
OpenGL function glTexSubImage2D
usage: glTexSubImage2D( target, level, xoffset, yoffset, width, height, format, type, pixels )
C function: void glTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, const GLvoid* pixels)
Psychtoolbox/PsychOpenGL/MOGL/wrap/glTexSubImage2D.m