Related: tdf#144091 svx: fix interaction of transp cell fill and transp shadow

This is a follow-up to commit 37a52d30bbfcf1d073779b50139c4dafa507be4b
(tdf#144091 svx: fix unwanted blur of shadow from table cell fill,
2021-09-20), where it turned out that the original bugdoc was just a
special case of almost full transparency (80%), that's why avoiding the
blur fixed the problem.

A more general approach instead is to multiply the alpha or the cell
fill of table shapes and the alpha of the shadow itself. The end result
is the same (80% transparency) for the first bugdoc, but this gives back
the blur on the second bugdoc.

Change-Id: I63560e3a73473c70157ecee8365ec7154217f269
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/122532
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

2 files changed, 8 insertions, 12 deletions

diff --git a/include/drawinglayer/primitive2d/BufferedDecompositionPrimitive2D.hxx b/include/drawinglayer/primitive2d/BufferedDecompositionPrimitive2D.hxx
index c09635c6d60d..c67c3262ec1c 100644
--- a/include/drawinglayer/primitive2d/BufferedDecompositionPrimitive2D.hxx
+++ b/include/drawinglayer/primitive2d/BufferedDecompositionPrimitive2D.hxx
@@ -67,8 +67,9 @@ private:
     /// a sequence used for buffering the last create2DDecomposition() result
     Primitive2DContainer maBuffered2DDecomposition;
 
-    /// When blur is invoked on a list of primitives, exclude this primitive from the blur effect.
-    bool mbExcludeFromBlur = false;
+    /// When a shadow wraps a list of primitives, this primitive wants to influence the transparency
+    /// of the shadow.
+    sal_uInt16 mnTransparenceForShadow = 0;
 
 protected:
     /** access methods to maBuffered2DDecomposition. The usage of this methods may allow
@@ -103,9 +104,12 @@ public:
     get2DDecomposition(Primitive2DDecompositionVisitor& rVisitor,
                        const geometry::ViewInformation2D& rViewInformation) const override;
 
-    void setExcludeFromBlur(bool bExcludeFromBlur) { mbExcludeFromBlur = bExcludeFromBlur; }
+    void setTransparenceForShadow(sal_uInt16 nTransparenceForShadow)
+    {
+        mnTransparenceForShadow = nTransparenceForShadow;
+    }
 
-    bool getExcludeFromBlur() const { return mbExcludeFromBlur; }
+    sal_uInt16 getTransparenceForShadow() const { return mnTransparenceForShadow; }
 };
 
 } // end of namespace drawinglayer::primitive2d
diff --git a/include/drawinglayer/primitive2d/shadowprimitive2d.hxx b/include/drawinglayer/primitive2d/shadowprimitive2d.hxx
index d388eaf1b90d..7df83a395f19 100644
--- a/include/drawinglayer/primitive2d/shadowprimitive2d.hxx
+++ b/include/drawinglayer/primitive2d/shadowprimitive2d.hxx
@@ -76,14 +76,6 @@ namespace drawinglayer::primitive2d
             ///  create decomposition
             virtual void get2DDecomposition(Primitive2DDecompositionVisitor& rVisitor, const geometry::ViewInformation2D& rViewInformation) const override;
 
-            void get2DDecompositionWithoutBlur(
-                Primitive2DDecompositionVisitor& rVisitor,
-                const geometry::ViewInformation2D& rViewInformation) const;
-
-            void
-            get2DDecompositionWithBlur(Primitive2DDecompositionVisitor& rVisitor,
-                                       const geometry::ViewInformation2D& rViewInformation) const;
-
             /// provide unique ID
             virtual sal_uInt32 getPrimitive2DID() const override;
         };