[cairo] Strange pattern (gradient) behavior (cairo bug?)

[Jan Słupski]

Hi,

I'm trying to figure out why two nearly the same pictures draws differently.
I suspect that this can be a cairo bug, but maybe I'm just doing something wrong.

See attached example -

The code for pass=0 (upper rectangle) and pass=1 (lower rectangle) is almost
identical - just little difference on scaling matrix applied to the pattern.
But result of that change (image attached) is quite serious.
Moreover - exporting to SVG does not show that difference between two rectangles.

The code is little obscure, because it is (as much as I could) trimmed down
output of libcairowrap.

Note the second pattern that is supposed to be an ellipse radial pattern,
but all pattern stops are - for testing - made black and 100% transparent.
Disabling it (do_second_pattern=0) changes the output to correct one.

Any ideas?

Thanks!

Jan Slupski

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