[fpc-devel] TFPCustomCanvas Expanded Clipping

[Hans-Peter Diettrich]

Felipe Monteiro de Carvalho schrieb:
> On Wed, Dec 7, 2011 at 9:28 AM, zeljko <zeljko at holobit.net> wrote:
>> Note that xxx_boundingRect() functions of qt are marked as slow (I guess
>> it's case when you deal with eg 1000 rects in region and you must calculate
>> lower TopLeft and high BottomRight) in their docs, I hope that we'll have
>> faster ones :)
> 
> Regions with thousands of rectangles look something extremely exotic
> to me, unless qt regions work internally by reducing all regions to a
> series of rectangles.

IMO the fastest implementation paints everything to a bitmap, then masks 
the painting with the region. This should be faster than clipping every 
single drawing primitve.

DoDi