drawinglayer/source/processor2d/cairopixelprocessor2d.cxx | 31 +++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
New commits:
commit b3c7c30ca1e9102be7246d97792147997b5696a2
Author: Armin Le Grand (Collabora) <armin.le.gr...@me.com>
AuthorDate: Tue Aug 20 14:23:53 2024 +0200
Commit: Armin Le Grand <armin.le.gr...@me.com>
CommitDate: Tue Aug 20 20:58:11 2024 +0200
CairoSDPR: Finetuning some Cairo-Values
Experimented with painting 'problematic' bitmaps
e.g. RGBA 1xN or Nx1 pixels -> Cairo paints out of
bounds (?), so had to clip that. For more info,
see added code comments.
Change-Id: I4dcd488e5e0c692e236136a216ad7b460d681233
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/172112
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <armin.le.gr...@me.com>
diff --git a/drawinglayer/source/processor2d/cairopixelprocessor2d.cxx
b/drawinglayer/source/processor2d/cairopixelprocessor2d.cxx
index 5fbc9dfc2749..b5f56007cb77 100644
--- a/drawinglayer/source/processor2d/cairopixelprocessor2d.cxx
+++ b/drawinglayer/source/processor2d/cairopixelprocessor2d.cxx
@@ -825,6 +825,7 @@ CairoPixelProcessor2D::CairoPixelProcessor2D(const
geometry::ViewInformation2D&
cairo_set_antialias(pRT, rViewInformation.getUseAntiAliasing() ?
CAIRO_ANTIALIAS_DEFAULT
:
CAIRO_ANTIALIAS_NONE);
cairo_set_fill_rule(pRT, CAIRO_FILL_RULE_EVEN_ODD);
+ cairo_set_operator(pRT, CAIRO_OPERATOR_OVER);
setRenderTarget(pRT);
}
}
@@ -955,10 +956,18 @@ void CairoPixelProcessor2D::paintBitmapAlpha(const
BitmapEx& rBitmapEx,
// insert a ARGB image, zoom to the borders. Seems to be half
// a pixel. Very good to demonstrate: 8x1 pixel, some
// transparent.
+ // Also errors with images 1 pixel wide/high, e.g. insert
+ // RGBA 8x1, 1x8 to see (and deactivate fix below). It also
+ // depends on the used filter, see commnet below at
+ // cairo_pattern_set_filter. Found also errors with more
+ // than one pixel, so cannot use as criteria.
// This effect is also visible in the left/right/bottom/top
// page shadows, these DO use 8x1/1x8 images which led me to
- // that problem. I see two solutions:
+ // that problem. I double-checked that these *are* correctly
+ // defined, that is not the problem.
+ // I see two solutions:
static bool bRenderMasked(true);
+
if (bRenderMasked)
{
// Consequence is that these need clipping. That again is
@@ -989,6 +998,22 @@ void CairoPixelProcessor2D::paintBitmapAlpha(const
BitmapEx& rBitmapEx,
}
}
+ // The error/effect described above also is connected to the
+ // filter used, so I checked the filter modes available
+ // in Cairo:
+ //
+ // CAIRO_FILTER_FAST: okay, small errors, sometimes stretching some pixels
+ // CAIRO_FILTER_GOOD: stretching error
+ // CAIRO_FILTER_BEST: okay, small errors
+ // CAIRO_FILTER_NEAREST: similar to CAIRO_FILTER_FAST
+ // CAIRO_FILTER_BILINEAR: similar to CAIRO_FILTER_GOOD
+ // CAIRO_FILTER_GAUSSIAN: same as CAIRO_FILTER_GOOD/CAIRO_FILTER_BILINEAR,
should
+ // not be used anyways (see docs)
+ //
+ // CAIRO_FILTER_GOOD seems to be the default anyways, but set it
+ // to be on the safe side
+ cairo_pattern_set_filter(sourcepattern, CAIRO_FILTER_GOOD);
+
cairo_pattern_set_matrix(sourcepattern, &aMatrix);
// paint bitmap data, evtl. with additional alpha channel
@@ -1970,6 +1995,10 @@ void
CairoPixelProcessor2D::processFillGraphicPrimitive2D(
cairo_pattern_set_matrix(sourcepattern, &aMatrix);
cairo_pattern_set_extend(sourcepattern, CAIRO_EXTEND_REPEAT);
+ // CAIRO_FILTER_GOOD seems to be the default anyways, but set it
+ // to be on the safe side
+ cairo_pattern_set_filter(sourcepattern, CAIRO_FILTER_GOOD);
+
// paint
if (rFillGraphicPrimitive2D.hasTransparency())
cairo_paint_with_alpha(mpRT, 1.0 -
rFillGraphicPrimitive2D.getTransparency());
