i125349 moved clip enhancements to base clipping functionality

2 files changed, 78 insertions, 54 deletions

diff --git a/basegfx/source/polygon/b2dpolygonclipper.cxx b/basegfx/source/polygon/b2dpolygonclipper.cxx
index 39d7e8c9e436..b8e9fdb35f98 100644
--- a/basegfx/source/polygon/b2dpolygonclipper.cxx
+++ b/basegfx/source/polygon/b2dpolygonclipper.cxx
@@ -417,6 +417,73 @@ namespace basegfx
 
             if(rCandidate.count() && rClip.count())
             {
+                // #125349# detect if both given PolyPolygons are indeed ranges
+                bool bBothRectangle(false);
+
+                if(basegfx::tools::isRectangle(rCandidate))
+                {
+                    if(basegfx::tools::isRectangle(rClip))
+                    {
+                        // both are ranges
+                        bBothRectangle = true;
+                    }
+                    else
+                    {
+                        // rCandidate is rectangle -> clip rClip on rRectangle, use the much
+                        // cheaper and numerically more stable clipping against a range
+                        // This simplification (exchanging content and clip) is valid
+                        // since we do a logical AND operation
+                        return clipPolyPolygonOnRange(rClip, rCandidate.getB2DRange(), bInside, bStroke);
+                    }
+                }
+                else if(basegfx::tools::isRectangle(rClip))
+                {
+                    if(basegfx::tools::isRectangle(rCandidate))
+                    {
+                        // both are ranges
+                        bBothRectangle = true;
+                    }
+                    else
+                    {
+                        // rClip is rectangle -> clip rCandidate on rRectangle, use the much
+                        // cheaper and numerically more stable clipping against a range
+                        return clipPolyPolygonOnRange(rCandidate, rClip.getB2DRange(), bInside, bStroke);
+                    }
+                }
+
+                if(bBothRectangle)
+                {
+                    // both are rectangle
+                    if(rCandidate.getB2DRange().equal(rClip.getB2DRange()))
+                    {
+                        // if both are equal -> no change
+                        return rCandidate;
+                    }
+                    else
+                    {
+                        // not equal -> create new intersection from both ranges,
+                        // but much cheaper based on the ranges
+                        basegfx::B2DRange aIntersectionRange(rCandidate.getB2DRange());
+
+                        aIntersectionRange.intersect(rClip.getB2DRange());
+
+                        if(aIntersectionRange.isEmpty())
+                        {
+                            // no common IntersectionRange -> the clip will be empty
+                            return B2DPolyPolygon();
+                        }
+                        else
+                        {
+                            // use common aIntersectionRange as result, convert
+                            // to expected PolyPolygon form
+                            return basegfx::B2DPolyPolygon(
+                                basegfx::tools::createPolygonFromRect(aIntersectionRange));
+                        }
+                    }
+                }
+
+                // one or both are no rectangle - go the hard way and clip PolyPolygon
+                // against PolyPolygon...
                 if(bStroke)
                 {
                     // line clipping, create line snippets by first adding all cut points and
diff --git a/drawinglayer/source/processor2d/vclmetafileprocessor2d.cxx b/drawinglayer/source/processor2d/vclmetafileprocessor2d.cxx
index 5186719ef54d..d53f7a31dd96 100644
--- a/drawinglayer/source/processor2d/vclmetafileprocessor2d.cxx
+++ b/drawinglayer/source/processor2d/vclmetafileprocessor2d.cxx
@@ -1744,52 +1744,17 @@ namespace drawinglayer
 
                             if(maClipPolyPolygon.count())
                             {
-                                // due to the cost of PolyPolygon clipping and numerical reasons try first if the current
-                                // and the new ClipRegion are ranges. If yes, processing can be simplified
-                                if(basegfx::tools::isRectangle(aMask)
-                                    && basegfx::tools::isRectangle(maClipPolyPolygon))
-                                {
-                                    // both ClipPolygons are rectangles
-                                    if(aMask.getB2DRange().equal(maClipPolyPolygon.getB2DRange()))
-                                    {
-                                        // equal -> no change in ClipRegion needed, leave
-                                        // maClipPolyPolygon unchanged
-                                    }
-                                    else
-                                    {
-                                        // not equal -> create new ClipRegion from the two ranges
-                                        basegfx::B2DRange aClipRange(aMask.getB2DRange());
-
-                                        aClipRange.intersect(maClipPolyPolygon.getB2DRange());
-
-                                        if(aClipRange.isEmpty())
-                                        {
-                                            // no common ClipRegion -> set empty ClipRegion, no content to show
-                                            maClipPolyPolygon.clear();
-                                        }
-                                        else
-                                        {
-                                            // use common ClipRegion as new ClipRegion
-                                            maClipPolyPolygon = basegfx::B2DPolyPolygon(
-                                                basegfx::tools::createPolygonFromRect(aClipRange));
-                                        }
-                                    }
-                                }
-                                else
-                                {
-                                    // The current ClipRegion or the new one is not a rectangle;
-                                    // there is already a clip polygon set; build clipped union of
-                                    // current mask polygon and new one
-                                    maClipPolyPolygon = basegfx::tools::clipPolyPolygonOnPolyPolygon(
-                                        aMask,
-                                        maClipPolyPolygon,
-                                        true, // #i106516# we want the inside of aMask, not the outside
-                                        false);
-                                }
+                                // there is already a clip polygon set; build clipped union of
+                                // current mask polygon and new one
+                                maClipPolyPolygon = basegfx::tools::clipPolyPolygonOnPolyPolygon(
+                                    aMask,
+                                    maClipPolyPolygon,
+                                    true, // #i106516# we want the inside of aMask, not the outside
+                                    false);
                             }
                             else
                             {
-                                // use new mask directly as ClipRegion
+                                // use mask directly
                                 maClipPolyPolygon = aMask;
                             }
 
@@ -1798,13 +1763,8 @@ namespace drawinglayer
                                 // set VCL clip region; subdivide before conversion to tools polygon. Subdivision necessary (!)
                                 // Removed subdivision and fixed in Region::ImplPolyPolyRegionToBandRegionFunc() in VCL where
                                 // the ClipRegion is built from the Polygon. A AdaptiveSubdivide on the source polygon was missing there
-                                const bool bNewClipRegion(maClipPolyPolygon != aLastClipPolyPolygon);
-
-                                if(bNewClipRegion)
-                                {
-                                    mpOutputDevice->Push(PUSH_CLIPREGION);
-                                    mpOutputDevice->SetClipRegion(Region(maClipPolyPolygon));
-                                }
+                                mpOutputDevice->Push(PUSH_CLIPREGION);
+                                mpOutputDevice->SetClipRegion(Region(maClipPolyPolygon));
 
                                 // recursively paint content
                                 // #121267# Only need to process sub-content when clip polygon is *not* empty.
@@ -1812,10 +1772,7 @@ namespace drawinglayer
                                 process(rMaskCandidate.getChildren());
 
                                 // restore VCL clip region
-                                if(bNewClipRegion)
-                                {
-                                    mpOutputDevice->Pop();
-                                }
+                                mpOutputDevice->Pop();
                             }
 
                             // restore to rescued clip polygon