Bug 101417 - alpha constant on tiling pattern
Summary: alpha constant on tiling pattern
Status: RESOLVED MOVED
Alias: None
Product: poppler
Classification: Unclassified
Component: glib frontend (show other bugs)
Version: unspecified
Hardware: Other All
: medium normal
Assignee: poppler-bugs
QA Contact:
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-06-14 03:17 UTC by novalazy+freedesktop
Modified: 2018-08-21 10:58 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
test case (1.41 KB, application/pdf)
2017-06-14 03:17 UTC, novalazy+freedesktop
Details

Description novalazy+freedesktop 2017-06-14 03:17:19 UTC
Created attachment 131943 [details]
test case

In the attached test case, the main content stream
1. sets the nonstroking colour to a tiling pattern
2. sets the nonstroking alpha constant to 0.5
3. fills a rectangle.

The tiling pattern itself sets the nonstroking alpha constant to 0.75, then paints a blue pattern cell.

I thought that the pattern cell should be rendered with alpha 0.75, then when it is used to fill the rectangle, the alpha constant 0.5 also has an effect. So the final image would be a blue rectangle with alpha 0.75 * 0.5. This is the behaviour exhibited by Acrobat, xpdf, poppler/test/gtk-test, and poppler/qt4/demos/poppler_qt4viewer

However, the output with evince and poppler-glib-demo is a blue rectangle with alpha 0.75, where the alpha constant set in the main content stream has no effect on the filling of the rectangle.

Sorry if this is not a bug, or if it is filed in the wrong place.
Comment 1 GitLab Migration User 2018-08-21 10:58:48 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/poppler/poppler/issues/456.


Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.