tdf#101181 Implement glow effect on shapes

Glow effect is a color-blurred outline outside of the shape. In ooxml
document it is specified with the <a:glow> element.

The commit contains the following:
- Add support for importing and exporting <a:glow> from ooxml documents.
- Assign new properties to XShape which stores glow-related attributes.
- A new 2D primitive is introduced in module 'drawinglayer' which is
responsible for representing the glow primitive which is to be rendered.
+ A glow primitive is a clone of the original shape which has been
scaled up slightly and a new color has been assigned to it. The
radius of the glow effect and the color is defined in the <a:glow>
element being imported.
- A blur algorithm is introduced in module 'vcl', which is called during
rendering the primitive.
+ The blur algorithm works on a bitmap.
+ Since the algorithm is CPU-intensive, the result is cached in the
processor and it is recalculated only if needed.
- Add support for importing and exporting glow effect to ODF format. For
that, new attributes of element <style:graphic-properties> has been
added:
+ loext:glow, which can have the values "visible" or "hidden"
+ loext:glow-radius: which holds the radius of the glow effect in cm.
+ loext:glow-color: holds the color of the glow effect
- Tests have been added to assert properties after pptx import and
export.

Change-Id: I836aeb5e0f24e2c8d5725834c8c0f98083bc82e7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89125
Tested-by: Jenkins
Reviewed-by: Tamás Bunth <btomi96@gmail.com>

2 files changed, 72 insertions, 0 deletions

diff --git a/include/drawinglayer/primitive2d/drawinglayer_primitivetypes2d.hxx b/include/drawinglayer/primitive2d/drawinglayer_primitivetypes2d.hxx
index 1cc379d3e521..0c9aa3c0b4ba 100644
--- a/include/drawinglayer/primitive2d/drawinglayer_primitivetypes2d.hxx
+++ b/include/drawinglayer/primitive2d/drawinglayer_primitivetypes2d.hxx
@@ -102,6 +102,7 @@
 #define PRIMITIVE2D_ID_OBJECTINFOPRIMITIVE2D                (PRIMITIVE2D_ID_RANGE_DRAWINGLAYER| 68)
 #define PRIMITIVE2D_ID_POLYPOLYGONSELECTIONPRIMITIVE2D      (PRIMITIVE2D_ID_RANGE_DRAWINGLAYER| 69)
 #define PRIMITIVE2D_ID_PAGEHIERARCHYPRIMITIVE2D             (PRIMITIVE2D_ID_RANGE_DRAWINGLAYER| 70)
+#define PRIMITIVE2D_ID_GLOWPRIMITIVE2D                      (PRIMITIVE2D_ID_RANGE_DRAWINGLAYER| 71)
 // When you add a new primitive, please update the drawinglayer::primitive2d::idToString() function
 // in drawinglayer/source/primitive2d/baseprimitive2d.cxx.
 
diff --git a/include/drawinglayer/primitive2d/glowprimitive2d.hxx b/include/drawinglayer/primitive2d/glowprimitive2d.hxx
new file mode 100644
index 000000000000..0c77a9a94a6c
--- /dev/null
+++ b/include/drawinglayer/primitive2d/glowprimitive2d.hxx
@@ -0,0 +1,71 @@
+/* -*- 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 .
+ */
+
+#ifndef INCLUDED_DRAWINGLAYER_PRIMITIVE2D_GLOWPRIMITIVE2D_HXX
+#define INCLUDED_DRAWINGLAYER_PRIMITIVE2D_GLOWPRIMITIVE2D_HXX
+
+#include <drawinglayer/drawinglayerdllapi.h>
+
+#include <drawinglayer/primitive2d/groupprimitive2d.hxx>
+#include <basegfx/matrix/b2dhommatrix.hxx>
+#include <basegfx/color/bcolor.hxx>
+
+namespace drawinglayer
+{
+namespace primitive2d
+{
+class DRAWINGLAYER_DLLPUBLIC GlowPrimitive2D final : public GroupPrimitive2D
+{
+private:
+    /// the Glow transformation, normally just an offset
+    basegfx::B2DHomMatrix maGlowTransform;
+
+    /// the Glow color to which all geometry is to be forced
+    basegfx::BColor maGlowColor;
+
+public:
+    /// constructor
+    GlowPrimitive2D(const basegfx::B2DHomMatrix& rGlowTransform, const basegfx::BColor& rGlowColor,
+                    const Primitive2DContainer& rChildren);
+
+    /// data read access
+    const basegfx::B2DHomMatrix& getGlowTransform() const { return maGlowTransform; }
+    const basegfx::BColor& getGlowColor() const { return maGlowColor; }
+
+    /// 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 primitive2d
+} // end of namespace drawinglayer
+
+#endif //INCLUDED_DRAWINGLAYER_PRIMITIVE2D_GLOWPRIMITIVE2D_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */