1067073 - Text shadow with mix-blend-mode: color-burn paints wrong

Status: RESOLVED WORKSFORME

(Core :: Graphics: Text, defect)

Description

[yoksel]

Attachment: 2014-09-14 10-47-46 Playing with mix-blend-mode - CodePen.png

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:35.0) Gecko/20100101 Firefox/35.0
Build ID: 20140913030206

Steps to reproduce:

I create this pen: http://codepen.io/yoksel/pen/nveJl

Text in it has text shadow defined with rgba and text has mix-blend-mode: color-burn;

Simple Code Example:

H1 {
  color: steelblue;
  mix-blend-mode: color-burn;
  text-shadow: 0 5px 10px rgba(0, 0, 0, .8);
}


Actual results:

I see black borders instead of semi transparent shadows.


Expected results:

I would see semi transparent shadows around the text.

Comment 1

[Markus Stange [:mstange]]

This is caused by a CoreGraphics bug when color-burn is used with a semi-transparent input.
If blending happens in the Compositor (which it now does since bug 1235995), or if we're using Skia for content rendering (bug 1207332), this bug does not occur.

Resolving WFM because bug 1235995 fixed it for this testcase, but until we've switched to Skia it can still appear in other contexts.