https://bugs.webkit.org/show_bug.cgi?id=100039

Patch by Hans Muller <hmuller@adobe.com> on 2012-10-30
Reviewed by Dirk Schulze.

Source/WebCore:

Corrected the algorithm for computing included polygon intervals for rectilinear polygons,
and polygons with horizontal edges in general.

Tests: fast/exclusions/shape-inside/shape-inside-rectilinear-polygon-001.html
       fast/exclusions/shape-inside/shape-inside-rectilinear-polygon-002.html

* rendering/ExclusionPolygon.cpp: Removed some internal dead code related to the no-longer-used sortedEdgesMinY Vector.
(WebCore::ExclusionPolygon::ExclusionPolygon): Initialize new ExclusionPolygonEdge edgeIndex field.
(WebCore::getVertexIntersectionVertices): Return the previous, next, and target vertex indices for a vertex intersection.
(WebCore::ExclusionPolygon::computeXIntersections): Refactored the core of this method to improve handling of horizontal edges.
(WebCore::ExclusionPolygon::computeEdgeIntersections): Ignore zero-width edges.
* rendering/ExclusionPolygon.h: Removed the rightVertexY() method, since it's no longer used.
(WebCore::ExclusionPolygon::edgeAt): New method.
(WebCore::ExclusionPolygon::numberOfEdges): New method.
(ExclusionPolygon): Added support for retrieving edges.
(WebCore::ExclusionPolygonEdge::vertex1): Use vertex1Index.
(WebCore::ExclusionPolygonEdge::vertex2): Use vertex2Index.
(ExclusionPolygonEdge): Renamed index1, index2 fields to vertex1Index, vertex2Index.
(WebCore::ExclusionPolygonEdge::previousEdge): New method.
(WebCore::ExclusionPolygonEdge::nextEdge): New method.

LayoutTests:

Added tests for CSS Exclusion shape-inside polygons with horizontal edges.
Corrected the simple-polygon.js code for computing a polygon's included intervals.

* fast/exclusions/resources/simple-polygon.js:
* fast/exclusions/shape-inside/shape-inside-rectilinear-polygon-001-expected.html: Added.
* fast/exclusions/shape-inside/shape-inside-rectilinear-polygon-001.html: Added.
* fast/exclusions/shape-inside/shape-inside-rectilinear-polygon-002-expected.html: Added.
* fast/exclusions/shape-inside/shape-inside-rectilinear-polygon-002.html: Added.
* fast/exclusions/shape-inside/shape-inside-simple-polygon-004-expected.html:
* fast/exclusions/shape-inside/shape-inside-simple-polygon-004.html:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@132971 268f45cc-cd09-0410-ab3c-d52691b4dbfc