vcl: ImplSeparableBlurFilter() -> BitmapGaussianSeparableBlurFilter

Change-Id: I996c9fcb0524e14e0093142be0749f0e5836426b
Reviewed-on: https://gerrit.libreoffice.org/53071
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/include/vcl/BitmapGaussianSeparableBlurFilter.hxx b/include/vcl/BitmapGaussianSeparableBlurFilter.hxx
new file mode 100644
index 000000000000..6e6a3a09e6f0
--- /dev/null
+++ b/include/vcl/BitmapGaussianSeparableBlurFilter.hxx
@@ -0,0 +1,50 @@
+/* -*- 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_VCL_BITMAPGAUSSIANSEPARABLEBLURFILTER_HXX
+#define INCLUDED_VCL_BITMAPGAUSSIANSEPARABLEBLURFILTER_HXX
+
+#include <vcl/BitmapFilter.hxx>
+
+class BitmapEx;
+
+class VCL_DLLPUBLIC BitmapGaussianSeparableBlurFilter : public BitmapFilter
+{
+public:
+    BitmapGaussianSeparableBlurFilter(double fRadius)
+        : mfRadius(fRadius)
+    {
+    }
+
+    /** Separable Gaussian Blur filter and accepts a blur radius
+        as a parameter so the user can change the strength of the blur.
+        Radius of 1.0 is 3 * standard deviation of gauss function.
+
+        Separable Blur implementation uses 2x separable 1D convolution
+        to process the image.
+    */
+    virtual BitmapEx execute(BitmapEx const& rBitmapEx) override;
+
+private:
+    double mfRadius;
+
+    bool convolutionPass(Bitmap& rBitmap, Bitmap& aNewBitmap, BitmapReadAccess const* pReadAcc,
+                         int aNumberOfContributions, const double* pWeights, int const* pPixels,
+                         const int* pCount);
+
+    static double* makeBlurKernel(const double radius, int& rows);
+    static void blurContributions(const int aSize, const int aNumberOfContributions,
+                                  const double* pBlurVector, double*& pWeights, int*& pPixels,
+                                  int*& pCount);
+};
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */