press 1 2 or 3 to control where vertices go with your mouse. the triangle will get clipped at the black line. I am making a 3d engine and i will need 3d clipping. how it works: case 1: if all vertices are above the line, it will draw the triangle like normal. case 2: if one vertex is under the line it will draw a quadrilateral case 3: if 2 vertices are under the line then it will draw a smaller triangle. case 4: all vertices are under line, it doesnt do anything
