[fpc-devel] TFPCustomCanvas Expanded Clipping

[michael.vancanneyt at wisa.be]

On Wed, 7 Dec 2011, Hans-Peter Diettrich wrote:

> 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.

Vectorial drawing - e.g. Postscript or PDF - does not work like that.

Michael.