Del.» type TClipType = (ctIntersection, ctUnion, ctDifference, ctXor);

C++ » enum ClipType { ctIntersection, ctUnion, ctDifference, ctXor };

C#  » public enum ClipType { ctIntersection, ctUnion, ctDifference, ctXor };

There are four boolean operations - AND, OR, NOT & XOR.

Given that subject and clip polygon brush 'filling' is defined both by their vertices and their respective filling rules, the four boolean operations can be applied to polygons to define new filling regions:


All polygon clipping is performed with a Clipper object with the specific boolean operation indicated by the ClipType parameter passed in its Execute method.

With regard to open paths (polylines), clipping rules generally match those of closed paths (polygons).
However, when there are both polyline and polygon subjects, the following clipping rules apply:

Example of clipping behaviour when mixing polyline and polygon subjects:

See Also

Overview, Clipper, Clipper.Execute, PolyFillType