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

3 files changed, 19 insertions, 66 deletions

diff --git a/drawinglayer/source/primitive2d/shadowprimitive2d.cxx b/drawinglayer/source/primitive2d/shadowprimitive2d.cxx
index 3d4bbdfecb92..6ea066b35754 100644
--- a/drawinglayer/source/primitive2d/shadowprimitive2d.cxx
+++ b/drawinglayer/source/primitive2d/shadowprimitive2d.cxx
@@ -22,7 +22,6 @@
 #include <drawinglayer/primitive2d/modifiedcolorprimitive2d.hxx>
 #include <drawinglayer/primitive2d/transformprimitive2d.hxx>
 #include <drawinglayer/primitive2d/drawinglayer_primitivetypes2d.hxx>
-#include <drawinglayer/primitive2d/BufferedDecompositionPrimitive2D.hxx>
 
 #include <memory>
 
@@ -31,28 +30,6 @@ using namespace com::sun::star;
 
 namespace drawinglayer::primitive2d
 {
-namespace
-{
-void get2DDecompositionOfChildren(const ShadowPrimitive2D& rPrimitive,
-                                  Primitive2DDecompositionVisitor& rVisitor,
-                                  const Primitive2DContainer& rChildren)
-{
-    if (rChildren.empty())
-        return;
-
-    // create a modifiedColorPrimitive containing the shadow color and the content
-    const basegfx::BColorModifierSharedPtr aBColorModifier
-        = std::make_shared<basegfx::BColorModifier_replace>(rPrimitive.getShadowColor());
-    const Primitive2DReference xRefA(
-        new ModifiedColorPrimitive2D(Primitive2DContainer(rChildren), aBColorModifier));
-    Primitive2DContainer aSequenceB{ xRefA };
-
-    // build transformed primitiveVector with shadow offset and add to target
-    rVisitor.append(
-        new TransformPrimitive2D(rPrimitive.getShadowTransform(), std::move(aSequenceB)));
-}
-}
-
         ShadowPrimitive2D::ShadowPrimitive2D(
             const basegfx::B2DHomMatrix& rShadowTransform,
             const basegfx::BColor& rShadowColor,
@@ -89,41 +66,21 @@ void get2DDecompositionOfChildren(const ShadowPrimitive2D& rPrimitive,
 
         void ShadowPrimitive2D::get2DDecomposition(Primitive2DDecompositionVisitor& rVisitor, const geometry::ViewInformation2D& /*rViewInformation*/) const
         {
-            get2DDecompositionOfChildren(*this, rVisitor, getChildren());
-        }
-
-        void ShadowPrimitive2D::get2DDecompositionWithoutBlur(
-            Primitive2DDecompositionVisitor& rVisitor,
-            const geometry::ViewInformation2D& /*rViewInformation*/) const
-        {
-            Primitive2DContainer aChildren;
-            // Only decompose children which are not blurred (they opted in for this).
-            std::copy_if(getChildren().begin(), getChildren().end(), std::back_inserter(aChildren),
-                         [](const Primitive2DReference& xChild) {
-                             auto pChild
-                                 = dynamic_cast<primitive2d::BufferedDecompositionPrimitive2D*>(
-                                     xChild.get());
-                             return pChild && pChild->getExcludeFromBlur();
-                         });
-
-            get2DDecompositionOfChildren(*this, rVisitor, aChildren);
-        }
-
-        void ShadowPrimitive2D::get2DDecompositionWithBlur(
-            Primitive2DDecompositionVisitor& rVisitor,
-            const geometry::ViewInformation2D& /*rViewInformation*/) const
-        {
-            // Only decompose children which are blurred (which is the default).
-            Primitive2DContainer aChildren;
-            std::copy_if(getChildren().begin(), getChildren().end(), std::back_inserter(aChildren),
-                         [](const Primitive2DReference& xChild) {
-                             auto pChild
-                                 = dynamic_cast<primitive2d::BufferedDecompositionPrimitive2D*>(
-                                     xChild.get());
-                             return !pChild || !pChild->getExcludeFromBlur();
-                         });
-
-            get2DDecompositionOfChildren(*this, rVisitor, aChildren);
+            if(getChildren().empty())
+                return;
+
+            // create a modifiedColorPrimitive containing the shadow color and the content
+            const basegfx::BColorModifierSharedPtr aBColorModifier =
+                std::make_shared<basegfx::BColorModifier_replace>(
+                    getShadowColor());
+            const Primitive2DReference xRefA(
+                new ModifiedColorPrimitive2D(
+                    Primitive2DContainer(getChildren()),
+                    aBColorModifier));
+            Primitive2DContainer aSequenceB { xRefA };
+
+            // build transformed primitiveVector with shadow offset and add to target
+            rVisitor.append(new TransformPrimitive2D(getShadowTransform(), std::move(aSequenceB)));
         }
 
         // provide unique ID
diff --git a/drawinglayer/source/processor2d/vclpixelprocessor2d.cxx b/drawinglayer/source/processor2d/vclpixelprocessor2d.cxx
index be53d4712aa3..27dbd89f1d06 100644
--- a/drawinglayer/source/processor2d/vclpixelprocessor2d.cxx
+++ b/drawinglayer/source/processor2d/vclpixelprocessor2d.cxx
@@ -1164,16 +1164,12 @@ void VclPixelProcessor2D::processShadowPrimitive2D(const primitive2d::ShadowPrim
     const double fBlurRadius = aBlurRadiusVector.getLength();
 
     impBufferDevice aBufferDevice(*mpOutputDevice, aRange);
-    if (aBufferDevice.isVisible())
+    if (aBufferDevice.isVisible() && !aRange.isEmpty())
     {
-        // Process children which don't want blur.
-        rCandidate.get2DDecompositionWithoutBlur(*this, getViewInformation2D());
-
-        // Process children which want blur.
         OutputDevice* pLastOutputDevice = mpOutputDevice;
         mpOutputDevice = &aBufferDevice.getContent();
 
-        rCandidate.get2DDecompositionWithBlur(*this, getViewInformation2D());
+        process(rCandidate);
 
         const tools::Rectangle aRect(static_cast<tools::Long>(std::floor(aRange.getMinX())),
                                      static_cast<tools::Long>(std::floor(aRange.getMinY())),
diff --git a/drawinglayer/source/tools/primitive2dxmldump.cxx b/drawinglayer/source/tools/primitive2dxmldump.cxx
index d0496b482669..17bb707b666e 100644
--- a/drawinglayer/source/tools/primitive2dxmldump.cxx
+++ b/drawinglayer/source/tools/primitive2dxmldump.cxx
@@ -641,8 +641,8 @@ void Primitive2dXmlDump::decomposeAndWrite(
                 if (pBufferedDecomposition)
                 {
                     rWriter.attribute(
-                        "excludeFromBlur",
-                        OString::boolean(pBufferedDecomposition->getExcludeFromBlur()));
+                        "transparenceForShadow",
+                        OString::number(pBufferedDecomposition->getTransparenceForShadow()));
                 }
 
                 drawinglayer::primitive2d::Primitive2DContainer aPrimitiveContainer;