[Libreoffice-commits] core.git: Branch 'distro/collabora/cp-6.0' - basegfx/source drawinglayer/source include/basegfx

[Miklos Vajna (via logerrit)]

 basegfx/source/polygon/b2dpolypolygontools.cxx          |   18 ++++++++++++++++
 drawinglayer/source/processor2d/vclpixelprocessor2d.cxx |   10 ++++++++
 drawinglayer/source/processor2d/vclprocessor2d.cxx      |   10 ++++++++
 include/basegfx/polygon/b2dpolygontools.hxx             |    3 ++
 4 files changed, 41 insertions(+)

New commits:
commit c42b28be2cbeac75c9ea53a2d74ea044fddad468
Author:     Miklos Vajna <vmiklos at collabora.com>
AuthorDate: Thu May 9 09:18:00 2019 +0200
Commit:     Miklos Vajna <vmiklos at collabora.com>
CommitDate: Fri May 10 08:49:28 2019 +0200

    drawinglayer: avoid AA for hairline polygons built from hori/vert lines only
    
    For one, it seems this was the intention already since commit
    85c70f37b56299f6fa02312c0fb73cc55af084ef (CWS-TOOLING: integrate CWS
    aw063, 2009-03-04): "suppress AntiAliasing for pure horizontal or
    vertical lines".
    
    For another, this fixes the TileCacheTests::testTileWireIDHandling()
    testcase in online.git, which assumes that the indicators at the corners
    of the Writer body frame (paragraph marks hidden / default case) can be
    painted multiple times, producing pixel-by-pixel matching results. But
    in reality AA breaks that assumption, and we know these indicators are
    never diagonal lines.
    
    (cherry picked from commit f8b4d371eddd27594d549fb00294c01229a9bd24)
    
    Conflicts:
            basegfx/test/B2DPolygonTest.cxx
    
    Change-Id: Ib74f823165799991296b64cee58ec106dbdcedcf
    Reviewed-on: https://gerrit.libreoffice.org/72032
    Reviewed-by: Ashod Nakashian <ashnakash at gmail.com>
    Tested-by: Miklos Vajna <vmiklos at collabora.com>

diff --git a/basegfx/source/polygon/b2dpolypolygontools.cxx b/basegfx/source/polygon/b2dpolypolygontools.cxx
index 644e08bb6358..046463e8f141 100644
--- a/basegfx/source/polygon/b2dpolypolygontools.cxx
+++ b/basegfx/source/polygon/b2dpolypolygontools.cxx
@@ -456,6 +456,24 @@ namespace basegfx
             return aRetval;
         }
 
+        bool containsOnlyHorizontalOrVerticalLines(const basegfx::B2DPolygon& rPolygon)
+        {
+            if (rPolygon.count() <= 1)
+                return false;
+
+            for (size_t i = 1; i < rPolygon.count(); ++i)
+            {
+                const basegfx::B2DPoint& rPrevPoint = rPolygon.getB2DPoint(i - 1);
+                const basegfx::B2DPoint& rPoint = rPolygon.getB2DPoint(i);
+                if (rPrevPoint.getX() == rPoint.getX() || rPrevPoint.getY() == rPoint.getY())
+                    continue;
+
+                return false;
+            }
+
+            return true;
+        }
+
         B2DPolyPolygon createSevenSegmentPolyPolygon(sal_Char nNumber, bool bLitSegments)
         {
             // config here
diff --git a/drawinglayer/source/processor2d/vclpixelprocessor2d.cxx b/drawinglayer/source/processor2d/vclpixelprocessor2d.cxx
index 9c21c83ee8f8..162f0e27e00f 100644
--- a/drawinglayer/source/processor2d/vclpixelprocessor2d.cxx
+++ b/drawinglayer/source/processor2d/vclpixelprocessor2d.cxx
@@ -165,6 +165,16 @@ namespace drawinglayer
             mpOutputDevice->SetLineColor(Color(aLineColor));
             aLocalPolygon.transform(maCurrentTransformation);
 
+            if (getOptionsDrawinglayer().IsAntiAliasing() && getOptionsDrawinglayer().IsSnapHorVerLinesToDiscrete())
+            {
+                if (basegfx::utils::containsOnlyHorizontalOrVerticalLines(aLocalPolygon))
+                {
+                    // DrawPolyLineDirect() only works in AA mode, but pure horizontal or vertical
+                    // lines are better with AA off.
+                    return false;
+                }
+            }
+
             // try drawing; if it did not work, use standard fallback
             return mpOutputDevice->DrawPolyLineDirect( aLocalPolygon, 0.0, fTransparency);
         }
diff --git a/drawinglayer/source/processor2d/vclprocessor2d.cxx b/drawinglayer/source/processor2d/vclprocessor2d.cxx
index e1cf42b0f42c..74c662f82a12 100644
--- a/drawinglayer/source/processor2d/vclprocessor2d.cxx
+++ b/drawinglayer/source/processor2d/vclprocessor2d.cxx
@@ -328,6 +328,7 @@ namespace drawinglayer
             basegfx::B2DPolygon aLocalPolygon(rPolygonCandidate.getB2DPolygon());
             aLocalPolygon.transform(maCurrentTransformation);
 
+            bool bDisableAA = false;
             if(bPixelBased && getOptionsDrawinglayer().IsAntiAliasing() && getOptionsDrawinglayer().IsSnapHorVerLinesToDiscrete())
             {
                 // #i98289#
@@ -336,9 +337,18 @@ namespace drawinglayer
                 // not-AntiAliased such lines look more pleasing to the eye (e.g. 2D chart content). This
                 // NEEDS to be done in discrete coordinates, so only useful for pixel based rendering.
                 aLocalPolygon = basegfx::utils::snapPointsOfHorizontalOrVerticalEdges(aLocalPolygon);
+
+                // Also disable AA, snap would leave the start/end of lines still anti-aliased when
+                // their coordinates are provided in logic units.
+                bDisableAA = basegfx::utils::containsOnlyHorizontalOrVerticalLines(aLocalPolygon);
             }
 
+            const AntialiasingFlags nOriginalAA(mpOutputDevice->GetAntialiasing());
+            if (bDisableAA && (nOriginalAA & AntialiasingFlags::EnableB2dDraw))
+                mpOutputDevice->SetAntialiasing(nOriginalAA & ~AntialiasingFlags::EnableB2dDraw);
             mpOutputDevice->DrawPolyLine(aLocalPolygon, 0.0);
+            if (bDisableAA && (nOriginalAA & AntialiasingFlags::EnableB2dDraw))
+                mpOutputDevice->SetAntialiasing(mpOutputDevice->GetAntialiasing() | AntialiasingFlags::EnableB2dDraw);
         }
 
         // direct draw of transformed BitmapEx primitive
diff --git a/include/basegfx/polygon/b2dpolygontools.hxx b/include/basegfx/polygon/b2dpolygontools.hxx
index c20668995d56..cac3dccfe5a6 100644
--- a/include/basegfx/polygon/b2dpolygontools.hxx
+++ b/include/basegfx/polygon/b2dpolygontools.hxx
@@ -438,6 +438,9 @@ namespace basegfx
         */
         BASEGFX_DLLPUBLIC B2DPolygon snapPointsOfHorizontalOrVerticalEdges(const B2DPolygon& rCandidate);
 
+        /// Determines if rPolygon lacks diagonal lines or not.
+        BASEGFX_DLLPUBLIC bool containsOnlyHorizontalOrVerticalLines(const basegfx::B2DPolygon& rPolygon);
+
         /// get the tangent with which the given point is entered seen from the previous
         /// polygon path data. Take into account all stuff like closed state, zero-length edges and others.
         BASEGFX_DLLPUBLIC B2DVector getTangentEnteringPoint(const B2DPolygon& rCandidate, sal_uInt32 nIndex);