vcl: move Bitmap{Ex}::ReduceColors() to BitmapColorQuantizationFilter class

Change-Id: I32b58e8d451e7303e94788a546a5b5f9a5bb4590
Reviewed-on: https://gerrit.libreoffice.org/53037
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/include/vcl/BitmapColorQuantizationFilter.hxx b/include/vcl/BitmapColorQuantizationFilter.hxx
new file mode 100644
index 000000000000..e695567a7bc0
--- /dev/null
+++ b/include/vcl/BitmapColorQuantizationFilter.hxx
@@ -0,0 +1,45 @@
+/* -*- 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/.
+ *
+ */
+
+#ifndef INCLUDED_INCLUDE_VCL_BITMAPCOLORQUANTIZATIONFILTER_HXX
+#define INCLUDED_INCLUDE_VCL_BITMAPCOLORQUANTIZATIONFILTER_HXX
+
+#include <tools/color.hxx>
+
+#include <vcl/BitmapFilter.hxx>
+
+class VCL_DLLPUBLIC BitmapColorQuantizationFilter : public BitmapFilter
+{
+public:
+    /** Reduce number of colors for the bitmap using the POPULAR algorithm
+
+        @param nNewColorCount
+        Maximal number of bitmap colors after the reduce operation
+     */
+    BitmapColorQuantizationFilter(sal_uInt16 nNewColorCount)
+        : mnNewColorCount(nNewColorCount)
+    {
+    }
+
+    virtual BitmapEx execute(BitmapEx const& rBitmapEx) override;
+
+private:
+    sal_uInt16 mnNewColorCount;
+
+    struct PopularColorCount
+    {
+        sal_uInt32 mnIndex;
+        sal_uInt32 mnCount;
+    };
+};
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */