code: func TexSubImage2D(target uint32, level int32, xoffset int32, yoffset int32, width int32, height int32, format uint32, xtype uint32, pixels unsafe.Pointer) {
  	syscall.Syscall9(gpTexSubImage2D, 9, uintptr(target), uintptr(level), uintptr(xoffset), uintptr(yoffset), uintptr(width), uintptr(height), uintptr(format), uintptr(xtype), uintptr(pixels))
  }
docs: // specify a two-dimensional texture subimage