[cairo] API Shakeup: cairo_set_rgb_color

Carl Worth cworth at cworth.org
Tue Feb 15 22:07:46 PST 2005


On Tue, 15 Feb 2005 17:24:58 -0800, Bill Spitzak wrote:
> Carl Worth wrote:
> > Allowing pre-multiplied colors does allow
> > the user to supply super-luminescent colors, (where color components
> > have values greater than alpha), which can be interesting.
> 
> Actually, since cairo_set_source_rgba takes double as the type of 
> parameter, you can do this with the other interface as well by setting 
> r,g,or b to a value greater than 1.0.

Not quite, since that still would not allow any color information to
remain in the case of alpha == 0.0.

> Only concern I have is that GDI+ allows a source image to "fade out" by 
> multiplying by a constant at the moment it is composited.

We've been debating quite a bit over the past couple of days about how
to make that sort of operation easy. Stay tuned for more shakeup
messages as fast as I can manage to type.

-Carl
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