Proposal: Add FillPreserve/StrokePreserve, kill BeginPath.

[memononen]

Proposal: Add FillPreserve/StrokePreserve, kill BeginPath.

[Ziflin]

We had some similar issues and came up with the following changes as we're drawing more 'full' shapes than arbitrary paths:

• BeginPath, EndPath set a "buildingPath" flag
• .Rectangle, .RoundedRectangle, .Circle, .Ellipse auto-reset the current path if outside of a Begin/EndPath pair, otherwise they behave as the do now.
• .MoveTo/.LineTo/etc all assert if not inside Begin/EndPath

So normally now, we just have to call:
Rectangle( ... );
Fill( ... ); or Stroke( ... );

to further reduce the number of calls required to draw, we moved the paint-related items into a "Pen" and "Brush" (similar to WPF Graphics class) struct. So we should really only need to do:
SetTransform( ... );
Rectangle( .. );
Fill( myBrush );
Stroke( myPen );

So far the only issues that I've seen are that the paint's transform must be transformed per Fill/Stroke call instead of per SetFillPaint/SetStrokePaint, but is seems rare that we would be drawing the same transformed shape with the same paint more than once. (?)

This was all just something to make life easier for us. The code's great though!