I am writing a 3d engine in pascal, and I have a problem. When a texture-mapped polygon goes out of the screen borders and needs to be clipped, it's texture get's distorted like it's sucked outside. I have 3d clipping with parametric equations, and I am changing the U,V coordinates just like the x,y,z coordinates, and it works fine for x,y,z coordinates, but not for u,v. How should I clip the U and V coordinates?
Please help me.