code: func CopyTexSubImage2D(target uint32, level int32, xoffset int32, yoffset int32, x int32, y int32, width int32, height int32) {
  	C.glowCopyTexSubImage2D(gpCopyTexSubImage2D, (C.GLenum)(target), (C.GLint)(level), (C.GLint)(xoffset), (C.GLint)(yoffset), (C.GLint)(x), (C.GLint)(y), (C.GLsizei)(width), (C.GLsizei)(height))
  }
docs: // copy a two-dimensional texture subimage