From b0788ff11481568b413ff6e4c3ea4871984af974 Mon Sep 17 00:00:00 2001
From: Luboš Luňák <l.lunak@collabora.com>
Date: Wed, 19 Aug 2020 11:10:12 +0200
Subject: don't split polypolygon in canvas if not needed (tdf#135395)
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Those polygons will be merged back in Skia because of
12147e0322e0fdd1b561c94e7ebd3fdd69ceaac0, which is costly with
tdf#135395. And if the only reason for the splitting is that
the polygon requires a winding rule but DrawPolyPolygon() uses
evenodd rule, then simply convert the polygon to the evenodd rule.

Change-Id: Iba5ec31d6d6407f734b20badc80c846071068d40
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/100976
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>
---
 canvas/source/vcl/canvashelper.cxx | 44 +++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 17 deletions(-)

(limited to 'canvas/source')

diff --git a/canvas/source/vcl/canvashelper.cxx b/canvas/source/vcl/canvashelper.cxx
index 78a0ae336b96..fcfabb8e033d 100644
--- a/canvas/source/vcl/canvashelper.cxx
+++ b/canvas/source/vcl/canvashelper.cxx
@@ -25,6 +25,7 @@
 #include <basegfx/polygon/b2dlinegeometry.hxx>
 #include <basegfx/polygon/b2dpolygon.hxx>
 #include <basegfx/polygon/b2dpolygontools.hxx>
+#include <basegfx/polygon/b2dpolypolygoncutter.hxx>
 #include <basegfx/polygon/b2dpolypolygontools.hxx>
 #include <basegfx/range/b2drectangle.hxx>
 #include <basegfx/utils/canvastools.hxx>
@@ -394,24 +395,33 @@ namespace vclcanvas
             // user coordinates.
             aStrokedPolyPoly.transform( aMatrix );
 
-            // TODO(F2): When using alpha here, must handle that via
-            // temporary surface or somesuch.
-
-            // Note: the generated stroke poly-polygon is NOT free of
-            // self-intersections. Therefore, if we would render it
-            // via OutDev::DrawPolyPolygon(), on/off fill would
-            // generate off areas on those self-intersections.
-            for( sal_uInt32 i=0; i<aStrokedPolyPoly.count(); ++i )
+            if(aStrokedPolyPoly.isClosed())
             {
-                const basegfx::B2DPolygon& polygon = aStrokedPolyPoly.getB2DPolygon( i );
-                if( polygon.isClosed()) {
-                    mpOutDevProvider->getOutDev().DrawPolygon( polygon );
-                    if( mp2ndOutDevProvider )
-                        mp2ndOutDevProvider->getOutDev().DrawPolygon( polygon );
-                } else {
-                    mpOutDevProvider->getOutDev().DrawPolyLine( polygon );
-                    if( mp2ndOutDevProvider )
-                        mp2ndOutDevProvider->getOutDev().DrawPolyLine( polygon );
+                // Note: the generated stroke poly-polygon is NOT free of
+                // self-intersections. Therefore, if we would render it
+                // directly via OutDev::DrawPolyPolygon(), on/off fill would
+                // generate off areas on those self-intersections.
+                aStrokedPolyPoly = basegfx::utils::createNonzeroConform( aStrokedPolyPoly );
+                mpOutDevProvider->getOutDev().DrawPolyPolygon( aStrokedPolyPoly );
+                if( mp2ndOutDevProvider )
+                    mp2ndOutDevProvider->getOutDev().DrawPolyPolygon( aStrokedPolyPoly );
+            }
+            else
+            {
+                // TODO(F2): When using alpha here, must handle that via
+                // temporary surface or somesuch.
+                for( sal_uInt32 i=0; i<aStrokedPolyPoly.count(); ++i )
+                {
+                    const basegfx::B2DPolygon& polygon = aStrokedPolyPoly.getB2DPolygon( i );
+                    if( polygon.isClosed()) {
+                        mpOutDevProvider->getOutDev().DrawPolygon( polygon );
+                        if( mp2ndOutDevProvider )
+                            mp2ndOutDevProvider->getOutDev().DrawPolygon( polygon );
+                    } else {
+                        mpOutDevProvider->getOutDev().DrawPolyLine( polygon );
+                        if( mp2ndOutDevProvider )
+                            mp2ndOutDevProvider->getOutDev().DrawPolyLine( polygon );
+                    }
                 }
             }
         }
-- 
cgit