Mac OSX 
 addtogroup renderer_interfaces Rendering Engine Interfaces
 @{


 One of a number of interfaces (all starting with nsISVGRenderer*)
 to be implemented by an SVG rendering engine. See nsISVGRenderer
 for more details.

 This interface abstracts a rendering engine-native region object.
[scriptable, uuid(9356e1c6-66e6-49a0-8c67-7e910270ed1e)]
interface nsISVGRendererRegion : nsISupports

Methods

 Return union of this region with another region.

 @param other Region to combine with.
 @return Union region.
nsISVGRendererRegion combine(in nsISVGRendererRegion other) 
 Write a sequence of rectangles approximating this region to the
 sink object. The approximation can be crude but should fully
 contain the actual region area.

 @param sink Rectangle sink to write to.
void getRectangleScans(in nsISVGRectangleSink sink)