commit 3e010f3138593cc6953039ee0e3db8ee31881296
author Chris Craik <ccraik@google.com> Mon Feb 25 19:12:47 2013 -0800
committer Chris Craik <ccraik@google.com> Wed Feb 27 11:13:03 2013 -0800
tree 3761f1081c57732f4126eb086836c74cb91de44c
parent 68a029edbbd162f2ca783733df37a44d5082ddee

Add createTJunctionFreeRegion

T-junction free regions are useful for rendering regions with various
geometric transformations, and the Region's span-ordered, sorted rect
list supports T-junction free storage without modification.

This approach creates a T-junction free region by splitting each
rectangle that is part of a vertical T-junction. This approach is two
pass (up and down) so that divisions can trickle up/down to other
adjacent spans.

Change-Id: Ifcf5e6fe0034c96b00ef09a4433b2b0fce8f4300