[cairo-bugs] [Bug 84396] cairo-tor-scan-converter is off by half of a subrow.

bugzilla-daemon at freedesktop.org bugzilla-daemon at freedesktop.org
Mon Sep 29 00:43:50 PDT 2014


https://bugs.freedesktop.org/show_bug.cgi?id=84396

--- Comment #6 from Chris Wilson <chris at chris-wilson.co.uk> ---
commit 5c03b20732b84370950f0c7e5648da86ef45a571
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Mon Sep 29 08:37:56 2014 +0100

    test/coverage: Exercise invariance under mirror symmetry

    Massimo noticed that the record/record-flip were not being rasterised as
    identical mirror images due to a half-subpixel offset in the tor scan
    converter. This test attempts to reproduce this error by rendering a
    rhombus around the origin of each cell (that is it generates 4 mirror
    images of a triangle in the 4 different orientations0. The expectation
    is that each pixel in the group is lit identically as the coverage is
    identical.

    References: https://bugs.freedesktop.org/show_bug.cgi?id=84396
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

should be a good explicit test of this property. It is marked as a slow test,
so needs to be run as

./cairo-test-suite -s coverage-rhombus

(Not that it is that slow and cairo-test-suite should just run tests that are
named explicitly.)

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.cairographics.org/archives/cairo-bugs/attachments/20140929/9d0a26e7/attachment.html>


More information about the cairo-bugs mailing list