[cairo] Proper invocation of cairo_clip()?
Owen Taylor
otaylor at redhat.com
Tue Mar 15 10:58:29 PST 2005
On Tue, 2005-03-15 at 12:39 -0600, Bob Jamison wrote:
> Hi, all.
>
> I have been wondering how to properly call cairo_clip().
> Maybe someone could tell me what dumb mistake I am making.
> Here is where I want to grab a rect from the drawing area,
> and move it to 0,0, coding it similarly to test/clip-twice.c.
> It -seems- simple enough:
>
>
> cairo_save(cairo);
> //clip and move to 0,0
> cairo_new_path(cairo);
> cairo_rectangle(cairo, x, y, width, height);
> cairo_clip(cairo);
> cairo_translate(cairo, -x, -y);
> //do my drawing
> cairo_restore(cairo);
>
> It is segfaulting
Well, it shouldn't segfault ... so file a bug in bugzilla.
But it probably doesn't what you want... (not exactly
sure what that is, but that call establishes a clip
of [x,y,width,height] in device space, so after that call
"do my drawing" is going to have to draw at 2*x, 2*y to
not be clipped.)
Regards,
Owen
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