[cairo] CAIRO_OPERATOR_ADD question

[Bill Spitzak]

The results are clamped to the range the destination surface can 
represent. So if your image is 8-bit where 255 represents 1.0, then 2.0 
will be stored as the largest value it can, which is 1.0.

S Boucher wrote:
> I'm looking at http://cairographics.org/operators/ for CAIRO_OPERATOR_ADD.
> 
> I wonder whether the formulas are written correctly.
> 
> My reading of it is:
> 
> src: rgba(1, 0, 0, 1)
> OPERATOR_ADD
> dst: rgba(1, 0, 0, 1)
> RESULT: rgba(2,0,0,1).
> 
> i.e. the red is 200%.
> 
> But that can't fit in a CAIRO_FORMAT_ARGB32
> 
> What am I missing?
> 
> Thanks
> 
> 
> ------------------------------------------------------------------------
> 
> --
> cairo mailing list
> cairo at cairographics.org
> http://lists.cairographics.org/mailman/listinfo/cairo