This topic provides examples that demonstrate how to draw a polyline and how to draw and fill a self-crossing polygon.
The example code assumes the array of points used when drawing these shapes is defined as follows:
... // set up an array of points for drawing a polyline and a polygon etc. // will be used relative to top left of rectangle TPoint point1(20,20); TPoint point2(100,190); TPoint point3(110,90); TPoint point4(50,150); TPoint point5(200,150); CArrayFix<TPoint>* mypoints = new CArrayFixFlat<TPoint>(5); CleanupStack::PushL(mypoints); mypoints->AppendL(point1); mypoints->AppendL(point2); mypoints->AppendL(point3); mypoints->AppendL(point4); mypoints->AppendL(point5); ... // switch statement with example cases ... CleanupStack::PopAndDestroy(); // mypoints
You can draw a polyline using DrawPolyLine() from an array of points.
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:
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); gc.DrawPolygon(mypoints,CGraphicsContext::EWinding); ...
Drawing a polygon using the EAlternate fill rule
Use SetBrushStyle() to set a diamond cross-hatched brush style.
Use DrawPolygon() to draw the polygon with the EAlternate fill rule.
Copyright ©2010 Nokia Corporation and/or its subsidiary(-ies).
All rights reserved. Unless otherwise stated, these materials are provided under the terms of the Eclipse Public License v1.0.