grafx - Extensible Java Graphics Package Code

Adding clipRectTests() to NaNTest.

Discarding polygons with Double.isNaN().

In RasterFloatGraphics, breaking the FloatPolyEdge.initialize() calls into
separate loop, for clarity and for debugging purposes. Of course there is a
very slight performance penalty to be paid with this change.

In NaNTest adding some additional test cases for fillPolygon().

In FloatPolyEdge, moving numNodes() to the bottom of file (it's a debugging
call), making incrementY() private (was protected, I don't know why), and
adding printNodes() for debugging purposes.

In FloatPolyEdge, making numNodes() package visible. It used to be private and
not used anywhere. So why even have it?

Adding NaN handling in line drawing, 2D rendering.

Adding to NaNTest. I have work to do.

Adding more to NaNTest.

Adding NaNTest. Will add more.