vcl: extract scale convolution from bitmap to its own class/file

Change-Id: Ibb10aa7450b78ca2709da38857f095ccbc679c54

vcl/Library_vcl.mk

@@ -314,6 +314,7 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/gdi/wall \
     vcl/source/bitmap/bitmapfilter \
     vcl/source/bitmap/bitmapscalesuper \
+    vcl/source/bitmap/BitmapScaleConvolution \
     vcl/source/bitmap/BitmapSymmetryCheck \
     vcl/source/bitmap/BitmapFilterStackBlur \
     vcl/source/bitmap/BitmapProcessor \

vcl/inc/BitmapScaleConvolution.hxx

+/* -*- 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_VCL_BITMAPSCALECONVOLUTION_HXX
+#define INCLUDED_VCL_BITMAPSCALECONVOLUTION_HXX
+
+#include <vcl/bitmapfilter.hxx>
+
+namespace vcl
+{
+
+enum class ConvolutionKernelType
+{
+    Box       = 0,
+    BiLinear  = 1,
+    BiCubic   = 2,
+    Lanczos3  = 3,
+};
+
+class VCL_DLLPUBLIC BitmapScaleConvolution : public BitmapFilter
+{
+public:
+
+    BitmapScaleConvolution(const double& rScaleX, const double& rScaleY, ConvolutionKernelType eKernelType)
+        : mrScaleX(rScaleX)
+        , mrScaleY(rScaleY)
+        , meKernelType(eKernelType)
+    {}
+
+    virtual ~BitmapScaleConvolution()
+    {}
+
+    virtual bool filter(Bitmap& rBitmap) override;
+
+private:
+    double mrScaleX;
+    double mrScaleY;
+
+    ConvolutionKernelType meKernelType;
+};
+
+}
+
+#endif // INCLUDED_VCL_BITMAPSCALECONVOLUTION_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */