python script does not start

I am porting my game from blender game engine to UE4.
python (3.3) 2d filter script doesn’t work.
it starts like this

uniform sampler2D bgl_DepthTexture;
uniform sampler2D bgl_RenderedTexture;
uniform sampler2D bgl_LuminanceTexture;
uniform float bgl_RenderedTextureWidth;
uniform float bgl_RenderedTextureHeight;

what do I need for the script to work correctly?