vcl/skia/gdiimpl.cxx | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
New commits:
commit 05d3a99aa687ee4e1706f9403651379b7ebdad89
Author: Patrick Luby <guibmac...@gmail.com>
AuthorDate: Fri Apr 26 20:25:03 2024 -0400
Commit: Patrick Luby <guibomac...@gmail.com>
CommitDate: Sat Apr 27 16:35:56 2024 +0200
tdf#153306 prevent subpixel shifting of X coordinate
HACK: for some unknown reason, if the X coordinate of the
path's bounds is more than 1024, SkBlendMode::kExclusion will
shift by about a half a pixel to the right with Skia/Metal on
a Retina display. Weirdly, if the same polygon is repeatedly
drawn, the total shift is cumulative so if the drawn polygon
is more than a few pixels wide, the blinking cursor in Writer
will exhibit this bug but only for one thin vertical slice at
a time. Apparently, shifting drawing a very tiny amount to
the left seems to be enough to quell this runaway cumulative
X coordinate shift.
Change-Id: Ic1ac8a390df51c4aa1cc3183590dce72059af6b6
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/166766
Reviewed-by: Patrick Luby <guibomac...@gmail.com>
Tested-by: Jenkins
diff --git a/vcl/skia/gdiimpl.cxx b/vcl/skia/gdiimpl.cxx
index f90fbace9d69..4c34d9ab2870 100644
--- a/vcl/skia/gdiimpl.cxx
+++ b/vcl/skia/gdiimpl.cxx
@@ -1508,6 +1508,26 @@ void SkiaSalGraphicsImpl::invert(basegfx::B2DPolygon
const& rPoly, SalInvert eFl
aPaint.setShader(aBitmap.makeShader(SkTileMode::kRepeat,
SkTileMode::kRepeat,
SkSamplingOptions()));
}
+
+#ifdef SK_METAL
+ // tdf#153306 prevent subpixel shifting of X coordinate
+ // HACK: for some unknown reason, if the X coordinate of the
+ // path's bounds is more than 1024, SkBlendMode::kExclusion will
+ // shift by about a half a pixel to the right with Skia/Metal on
+ // a Retina display. Weirdly, if the same polygon is repeatedly
+ // drawn, the total shift is cumulative so if the drawn polygon
+ // is more than a few pixels wide, the blinking cursor in Writer
+ // will exhibit this bug but only for one thin vertical slice at
+ // a time. Apparently, shifting drawing a very tiny amount to
+ // the left seems to be enough to quell this runaway cumulative
+ // X coordinate shift.
+ if (isGPU())
+ {
+ SkMatrix aMatrix;
+ aMatrix.set(SkMatrix::kMTransX, -0.001);
+ getDrawCanvas()->concat(aMatrix);
+ }
+#endif
}
getDrawCanvas()->drawPath(aPath, aPaint);
}
