Skia
2DGraphicsLibrary

Static Public Member Functions  
static sk_sp< SkMaskFilter >  Make (const SkRRect &first, const SkRRect &second, SkScalar radius) 
Returns a mask filter that applies a Gaussian blur depending on distance to the edge of the intersection of two round rects. More...  

static 
Returns a mask filter that applies a Gaussian blur depending on distance to the edge of the intersection of two round rects.
Currently this is only useable with round rects that have the same radii at all the corners and for which the x & y radii are equal.
In order to minimize fill the coverage geometry that should be drawn should be no larger than the intersection of the bounding boxes of the two round rects. Ambitious users can omit the center area of the coverage geometry if it is known to be occluded.