diff options
| author | Allan Sandfeld Jensen <allan.jensen@digia.com> | 2014-01-23 16:09:20 +0100 |
|---|---|---|
| committer | The Qt Project <gerrit-noreply@qt-project.org> | 2014-01-29 08:54:55 +0100 |
| commit | 0226795cf33363a872c777034e0d8934ffaa3819 (patch) | |
| tree | e65b5dac925c965754ac03928e54ec566504ec2b /src/gui/image/qimage.cpp | |
| parent | fa83803119296c2224cf1c7fb7474057a77aa51b (diff) | |
Round evenly in INV_PREMUL
Currently INV_PREMUL rounds strictly down. While PREMUL rounds evenly.
This patch adds 0x8000 to the intermediate results in INV_PREMUL before
right shifting, thereby achieving even rounding.
The rounding also makes PREMUL(INV_PREMUL()) into an identify operation,
which means we can safely convert ARGB32PM to ARGB32 and back without
ever losing color details. A test is added to verify this.
Change-Id: I1267e109caddcff0c01d726cb5c1c1e9fa5f7996
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>
Diffstat (limited to 'src/gui/image/qimage.cpp')
0 files changed, 0 insertions, 0 deletions