[cairo] Exclusive OR (XOR) fillRect drawing

[Benjamin Otte]

You cannot do XOR with Cairo. What you can get (and I suspect that's
what you want) is INVERT.

To get the effect of INVERT, you'd do:
cairo_set_operator (cr, CAIRO_OPERATOR_DIFFERENCE);
cairo_set_source_rgb (cr, 1, 1, 1);

Note that this requires Cairo 1.9 snapshots.

Benjamin


On Wed, 2010-08-25 at 17:02 +0530, Prasanta Sadhukhan wrote:
> Hi
> 
> I am a newbie to cairo. I saw in some of the discussion that cairo
> does not support bitwise XOR drawing (like drawing same shape on same
> area will make it disappear)
> Can anyone please suggest as to how can I perform XOR drawing of
> draw/fill shape ex fillrect with cairo APIs? 
> 
> I have some legacy programs that need to use XOR based drawing like
> blinking of cursor under a line
> Thx in advance
> 
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