[cairo] cairo internal design ideas

[Bill Spitzak]

On Thursday 06 January 2005 11:07 pm, Carl Worth wrote:

> > 1. get rid of all operators that can modify a pixel outside the path (or
> > when the alpha is zero in a source pattern).
>
> Will the recent proposals to fix clipping obviate the need to drop all
> these operators in your view?

Yes.

Also because I forgot we want operators that don't use the path (text is the 
obvious one, but this "draw the alpha of a surface" is also the same, and 
"clear the entire clip region" is another) there is no savings by combining 
the path and clip, which was the intention of my proposal.

> > 2. Add a "invert path" operator that makes the "interior" of the path be
> > everything outside it, rather than inside it.
>
> Rather than "invert path" though, how about extending the fill rules
> to do the inversion? Maybe something like:
>
> 	typedef enum cairo_fill_rule {
> 	    CAIRO_FILL_RULE_WINDING,
> 	    CAIRO_FILL_RULE_EVEN_ODD,
> 	    CAIRO_FILL_RULE_INVERSE_WINDING,
> 	    CAIRO_FILL_RULE_INVERSE_EVEN_ODD
> 	} cairo_fill_rule_t;
>
> Both cairo_fill and cairo_clip are already defined to use this fill
> rule.

I agree this would do exactly what is needed. And it avoids any questions 
about what "invert path" does to the "stroke" operator.

-- 
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     /\_       _|_========___         Bill Spitzak
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