Line Drawing - Dashed Line

Much like curved lines, the way dashed line works is by having agg::conv_dash to generate a line path from the line path passed in.

agg::conv_dash<CmdVertexPath> dashPath (path);
// specify dash pattern
dashPath.add_dash(3 * strokeWidth, 3 * strokeWidth);
dashPath.add_dash(1 * strokeWidth, 3 * strokeWidth);

It can take some efforts to create the correct dash pattern since its calculation can be slightly off comparing to SVG's.

In general, to generate almost exact equivalent images to SVG, use agg::butt_cap instead of agg::square_cap.

Example

tutorial_linedrawing_3.cpp generates an image containing a caret and a dome with dash dot lines.

An equivalent SVG is the following. However, notice the dash locations for the curves are somewhat different.