Drawing a polygon

The following example code illustrates how to draw a filled polygon from an array of points. The polygon is self-crossing. Self-crossing polygons can be filled according to one of two rules, TFillRule::EAlternate (the default), or TFillRule::EWinding. These rules work with the concept of a winding number, as shown in the following figure:

Winding numbers -

EWinding fills all areas, while EAlternate only fills areas with odd winding numbers.

Drawing a polygon using the EWinding fill rule

Use SetBrushStyle() to set a cross-hatched brush style.
Use DrawPolygon() to draw the polygon with the EWinding fill rule.

... +

EWinding fills all areas, while EAlternate only fills areas with odd winding numbers.

Drawing a polygon using the EWinding fill rule

Use SetBrushStyle() to set a cross-hatched brush style.
Use DrawPolygon() to draw the polygon with the EWinding fill rule.

... // draw self-crossing polygon using the winding fill rule gc.SetBrushStyle(CGraphicsContext::ESquareCrossHatchBrush); gc.SetBrushColor(black);