Rework of ShadowPrimitive2D

This is pretty much the same for ShadowPrimitive2D as the
change for GlowPrimitive2D and SoftEdgePrimitive2D, so for
more comments please refer to those commits:

c2d1458723c66c2fd717a112f89f773226adc841
707b0c328a282d993fa33b618083d20b6c521de6

There are some needed differences due to ShadowPrimitive2D
having existed longer and is used for non-blurred shadow
for a long time and is used as unchanged as possible.
Only for active glow of shadow is a buffering and local
decompose used.

Change-Id: I55e6516f59390079356ac16f24743b474e53fb05
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/139858
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <Armin.Le.Grand@me.com>

3 files changed, 56 insertions, 85 deletions

diff --git a/include/drawinglayer/primitive2d/GlowSoftEgdeShadowTools.hxx b/include/drawinglayer/primitive2d/GlowSoftEgdeShadowTools.hxx
deleted file mode 100644
index 61079728d841..000000000000
--- a/include/drawinglayer/primitive2d/GlowSoftEgdeShadowTools.hxx
+++ /dev/null
@@ -1,42 +0,0 @@
-/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/*
- * This file is part of the LibreOffice project.
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- *
- * This file incorporates work covered by the following license notice:
- *
- *   Licensed to the Apache Software Foundation (ASF) under one or more
- *   contributor license agreements. See the NOTICE file distributed
- *   with this work for additional information regarding copyright
- *   ownership. The ASF licenses this file to you under the Apache
- *   License, Version 2.0 (the "License"); you may not use this file
- *   except in compliance with the License. You may obtain a copy of
- *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
- */
-
-#pragma once
-
-#include <vcl/alpha.hxx>
-#include <drawinglayer/geometry/viewinformation2d.hxx>
-
-namespace drawinglayer::primitive2d
-{
-/* Returns 8-bit alpha mask created from passed mask.
-
-   Negative fErodeDilateRadius values mean erode, positive - dilate.
-   nTransparency defines minimal transparency level.
-*/
-AlphaMask ProcessAndBlurAlphaMask(const Bitmap& rMask, double fErodeDilateRadius,
-                                  double fBlurRadius, sal_uInt8 nTransparency,
-                                  bool bConvertTo1Bit = true);
-
-drawinglayer::geometry::ViewInformation2D
-expandB2DRangeAtViewInformation2D(const drawinglayer::geometry::ViewInformation2D& rViewInfo,
-                                  double nAmount);
-
-} // end of namespace drawinglayer::primitive2d
-
-/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/include/drawinglayer/primitive2d/glowprimitive2d.hxx b/include/drawinglayer/primitive2d/glowprimitive2d.hxx
index 6a60c85ad6ae..985137e23215 100644
--- a/include/drawinglayer/primitive2d/glowprimitive2d.hxx
+++ b/include/drawinglayer/primitive2d/glowprimitive2d.hxx
@@ -21,7 +21,6 @@
 
 #include <drawinglayer/drawinglayerdllapi.h>
 
-#include <drawinglayer/primitive2d/groupprimitive2d.hxx>
 #include <drawinglayer/primitive2d/BufferedDecompositionGroupPrimitive2D.hxx>
 #include <tools/color.hxx>
 
diff --git a/include/drawinglayer/primitive2d/shadowprimitive2d.hxx b/include/drawinglayer/primitive2d/shadowprimitive2d.hxx
index 45a97a96d476..79f2f30f700a 100644
--- a/include/drawinglayer/primitive2d/shadowprimitive2d.hxx
+++ b/include/drawinglayer/primitive2d/shadowprimitive2d.hxx
@@ -21,14 +21,12 @@
 
 #include <drawinglayer/drawinglayerdllapi.h>
 
-#include <drawinglayer/primitive2d/groupprimitive2d.hxx>
-#include <basegfx/matrix/b2dhommatrix.hxx>
+#include <drawinglayer/primitive2d/BufferedDecompositionGroupPrimitive2D.hxx>
 #include <basegfx/color/bcolor.hxx>
 
-
 namespace drawinglayer::primitive2d
 {
-        /** ShadowPrimitive2D class
+/** ShadowPrimitive2D class
 
             This primitive defines a generic shadow geometry construction
             for 2D objects. It decomposes to a TransformPrimitive2D embedded
@@ -42,44 +40,60 @@ namespace drawinglayer::primitive2d
             are needed for the shadow itself; all the local decompositions of the
             original geometry can be reused from the renderer for shadow visualisation.
         */
-        class DRAWINGLAYER_DLLPUBLIC ShadowPrimitive2D final : public GroupPrimitive2D
-        {
-        private:
-            /// the shadow transformation, normally just an offset
-            basegfx::B2DHomMatrix                   maShadowTransform;
-
-            /// the shadow color to which all geometry is to be forced
-            basegfx::BColor                         maShadowColor;
-
-            /// the blur radius of the shadow
-            double mfShadowBlur;
-
-
-    public:
-            /// constructor
-            ShadowPrimitive2D(
-                basegfx::B2DHomMatrix aShadowTransform,
-                const basegfx::BColor& rShadowColor,
-                double fShadowBlur,
-                Primitive2DContainer&& aChildren);
-
-            /// data read access
-            const basegfx::B2DHomMatrix& getShadowTransform() const { return maShadowTransform; }
-            const basegfx::BColor& getShadowColor() const { return maShadowColor; }
-            double getShadowBlur() const { return mfShadowBlur; }
-            /// compare operator
-            virtual bool operator==(const BasePrimitive2D& rPrimitive) const override;
-
-            /// get range
-            virtual basegfx::B2DRange getB2DRange(const geometry::ViewInformation2D& rViewInformation) const override;
-
-            ///  create decomposition
-            virtual void get2DDecomposition(Primitive2DDecompositionVisitor& rVisitor, const geometry::ViewInformation2D& rViewInformation) const override;
-
-            /// provide unique ID
-            virtual sal_uInt32 getPrimitive2DID() const override;
-        };
+class DRAWINGLAYER_DLLPUBLIC ShadowPrimitive2D final : public BufferedDecompositionGroupPrimitive2D
+{
+private:
+    /// the shadow transformation, normally just an offset
+    basegfx::B2DHomMatrix maShadowTransform;
+
+    /// the shadow color to which all geometry is to be forced
+    basegfx::BColor maShadowColor;
+
+    /// the blur radius of the shadow
+    double mfShadowBlur;
+
+    /// last used DiscreteBlurRadius and ClippedRange
+    double mfLastDiscreteBlurRadius;
+    basegfx::B2DRange maLastClippedRange;
+
+    /// helpers
+    void getFullyEmbeddedShadowPrimitives(Primitive2DContainer& rContainer) const;
+    bool prepareValuesAndcheckValidity(basegfx::B2DRange& rRange, basegfx::B2DRange& rClippedRange,
+                                       basegfx::B2DVector& rDiscreteSize,
+                                       double& rfDiscreteBlurRadius,
+                                       const geometry::ViewInformation2D& rViewInformation) const;
+
+protected:
+    /** method which is to be used to implement the local decomposition of a 2D primitive. */
+    virtual void
+    create2DDecomposition(Primitive2DContainer& rContainer,
+                          const geometry::ViewInformation2D& rViewInformation) const override;
+
+public:
+    /// constructor
+    ShadowPrimitive2D(basegfx::B2DHomMatrix aShadowTransform, const basegfx::BColor& rShadowColor,
+                      double fShadowBlur, Primitive2DContainer&& aChildren);
+
+    /// data read access
+    const basegfx::B2DHomMatrix& getShadowTransform() const { return maShadowTransform; }
+    const basegfx::BColor& getShadowColor() const { return maShadowColor; }
+    double getShadowBlur() const { return mfShadowBlur; }
+
+    /// compare operator
+    virtual bool operator==(const BasePrimitive2D& rPrimitive) const override;
+
+    /// get range
+    virtual basegfx::B2DRange
+    getB2DRange(const geometry::ViewInformation2D& rViewInformation) const override;
+
+    ///  create decomposition
+    virtual void
+    get2DDecomposition(Primitive2DDecompositionVisitor& rVisitor,
+                       const geometry::ViewInformation2D& rViewInformation) const override;
+
+    /// provide unique ID
+    virtual sal_uInt32 getPrimitive2DID() const override;
+};
 } // end of namespace drawinglayer::primitive2d
 
-
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */