Re: RGB channels are set to zero if alpha is 0.
Uli Schlachter <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
Hi, On 27.08.2017 02:55, Bram Stolk wrote: > The left half of the image is set to 1,1,1,0. > The right half of the image is set to 1,1,1,1 Uhm, why do you think so? These numbers do not appear in your example program. > cr.rectangle(0, 0, 0.5, 1) > cr.set_source_rgba(1, 1, 1, 0/255.0) > cr.fill() This is a no-op. You draw with alpha=0, i.e. fully transparent. Thus, nothing happens here. The image stays the way it was before, fully transparent. > cr.set_source_rgba(1,1,1, 1/255.0) > cr.rectangle(0.5,0,1,1) > cr.fill() Why this low alpha? Uli -- cairo mailing list [email protected] https://lists.cairographics.org/mailman/listinfo/cairo