vcl: move resample kernel classes out of bitmap.hxx

Since commit f31e6debfa7e330f985a0846a6ca91130d3dab20 this drags in
ridiculous amounts of boost headers, for probably negigible improvemnts
of sin(x)/x for tiny x values.

The compile time impact was not negligible, moving this nonsense to its
own header removes 1.79 GB of preprocessor input from a full build.

Change-Id: Ic41b2210eac8b130726610f2dbdbb449379225d1

4 files changed, 148 insertions, 2 deletions

diff --git a/vcl/inc/ResampleKernel.hxx b/vcl/inc/ResampleKernel.hxx
new file mode 100644
index 000000000000..20f0dfa820d5
--- /dev/null
+++ b/vcl/inc/ResampleKernel.hxx
@@ -0,0 +1,131 @@
+/* -*- 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_RESAMPLEKERNEL_HXX
+#define INCLUDED_VCL_RESAMPLEKERNEL_HXX
+
+#include <boost/math/special_functions/sinc.hpp>
+
+namespace vcl {
+
+// Resample kernels
+
+class Kernel
+{
+public:
+             Kernel() {}
+    virtual ~Kernel() {}
+
+    virtual double  GetWidth() const = 0;
+    virtual double  Calculate( double x ) const = 0;
+};
+
+class Lanczos3Kernel : public Kernel
+{
+public:
+    Lanczos3Kernel() : Kernel () {}
+
+    virtual double  GetWidth() const SAL_OVERRIDE { return 3.0; }
+    virtual double  Calculate (double x) const SAL_OVERRIDE
+    {
+        return (-3.0 <= x && x < 3.0) ? SincFilter(x) * SincFilter( x / 3.0 ) : 0.0;
+    }
+
+    static inline double SincFilter(double x)
+    {
+        if (x == 0.0)
+        {
+            return 1.0;
+        }
+        x = x * M_PI;
+        return boost::math::sinc_pi(x, SincPolicy());
+    }
+
+private:
+    typedef boost::math::policies::policy<
+        boost::math::policies::promote_double<false> > SincPolicy;
+};
+
+class BicubicKernel : public Kernel
+{
+public:
+    BicubicKernel() : Kernel () {}
+
+private:
+    virtual double  GetWidth() const SAL_OVERRIDE { return 2.0; }
+    virtual double  Calculate (double x) const SAL_OVERRIDE
+    {
+        if (x < 0.0)
+        {
+            x = -x;
+        }
+
+        if (x <= 1.0)
+        {
+            return (1.5 * x - 2.5) * x * x + 1.0;
+        }
+        else if (x < 2.0)
+        {
+            return ((-0.5 * x + 2.5) * x - 4) * x + 2;
+        }
+        return 0.0;
+    }
+};
+
+class BilinearKernel : public Kernel
+{
+public:
+    BilinearKernel() : Kernel () {}
+
+private:
+    virtual double  GetWidth() const SAL_OVERRIDE { return 1.0; }
+    virtual double  Calculate (double x) const SAL_OVERRIDE
+    {
+        if (x < 0.0)
+        {
+            x = -x;
+        }
+        if (x < 1.0)
+        {
+            return 1.0-x;
+        }
+        return 0.0;
+    }
+};
+
+class BoxKernel : public Kernel
+{
+public:
+    BoxKernel() : Kernel () {}
+
+private:
+    virtual double  GetWidth() const SAL_OVERRIDE { return 0.5; }
+    virtual double  Calculate (double x) const SAL_OVERRIDE
+    {
+        if (-0.5 <= x && x < 0.5)
+            return 1.0;
+        return 0.0;
+    }
+};
+
+} // namespace vcl
+
+#endif // INCLUDED_VCL_RESAMPLEKERNEL_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/inc/opengl/salbmp.hxx b/vcl/inc/opengl/salbmp.hxx
index ba9ac3f4fe2f..daefbe26b8a2 100644
--- a/vcl/inc/opengl/salbmp.hxx
+++ b/vcl/inc/opengl/salbmp.hxx
@@ -98,8 +98,8 @@ private:
 private:
 
     bool ImplScaleFilter( const double& rScaleX, const double& rScaleY, GLenum nFilter );
-    static void ImplCreateKernel( const double& fScale, const Kernel& rKernel, GLfloat*& pWeights, sal_uInt32& aKernelSize );
-    bool ImplScaleConvolution( const double& rScaleX, const double& rScaleY, const Kernel& aKernel );
+    static void ImplCreateKernel( const double& fScale, const vcl::Kernel& rKernel, GLfloat*& pWeights, sal_uInt32& aKernelSize );
+    bool ImplScaleConvolution(const double& rScaleX, const double& rScaleY, const vcl::Kernel& rKernel);
     bool ImplScaleArea( double rScaleX, double rScaleY );
 
 public:
diff --git a/vcl/opengl/scale.cxx b/vcl/opengl/scale.cxx
index 7b8691226e81..22db644c0454 100644
--- a/vcl/opengl/scale.cxx
+++ b/vcl/opengl/scale.cxx
@@ -28,6 +28,14 @@
 #include "opengl/program.hxx"
 #include "opengl/texture.hxx"
 
+#include <ResampleKernel.hxx>
+
+using vcl::Kernel;
+using vcl::Lanczos3Kernel;
+using vcl::BicubicKernel;
+using vcl::BilinearKernel;
+using vcl::BoxKernel;
+
 class ScaleOp : public OpenGLSalBitmapOp
 {
 private:
diff --git a/vcl/source/gdi/bitmap3.cxx b/vcl/source/gdi/bitmap3.cxx
index 130f065b87e5..b2704e15c17a 100644
--- a/vcl/source/gdi/bitmap3.cxx
+++ b/vcl/source/gdi/bitmap3.cxx
@@ -33,6 +33,13 @@
 #include <impvect.hxx>
 
 #include "octree.hxx"
+#include <ResampleKernel.hxx>
+
+using vcl::Kernel;
+using vcl::Lanczos3Kernel;
+using vcl::BicubicKernel;
+using vcl::BilinearKernel;
+using vcl::BoxKernel;
 
 #define RGB15( _def_cR, _def_cG, _def_cB )  (((sal_uLong)(_def_cR)<<10UL)|((sal_uLong)(_def_cG)<<5UL)|(sal_uLong)(_def_cB))
 #define GAMMA( _def_cVal, _def_InvGamma )   ((sal_uInt8)MinMax(FRound(pow( _def_cVal/255.0,_def_InvGamma)*255.0),0L,255L))