Bug 106026 – [CSS Exclusions] The ExclusionPolygon classes should allow more than one type of "Edge" class

• Component: CSS
• Status: RESOLVED FIXED

[Hans Muller]

The "first fit" algorithm for polygons, http://hansmuller-webkit.blogspot.com/2012/08/revised-algorithm-for-finding-first.html, depends on temporary "offset" edges.  Offset edges can be defined simply, as a pair of vertices.  

The existing ExclusionPolygonEdge struct similarly manages a pair of vertices however its implemention, and some of its operations, are specific to the ExclusionPolygon class.   ExclusionPolygonEdge manages a pair of indices into an ExclusionPolygon's array of vertices and provides operations for moving forwards and backwards in the polygon's vertex chain.

Both edge types will have some operations in common.  For example: 

    bool overlapsRect(const FloatRect&) const;
    bool intersection(const VertexPair&, FloatPoint&) const;

An absract VertexPair class would enable this.  The ExclusionPolygonEdge struct should become a class and inherit from VertexPair.

[Hans Muller]

Created attachment 181224 [details]
Patch

[Dirk Schulze]

Comment on attachment 181224 [details]
Patch

LGTM. r=me

[WebKit Review Bot]

Comment on attachment 181224 [details]
Patch

Clearing flags on attachment: 181224

Committed r138802: <http://trac.webkit.org/changeset/138802>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.