#i105937# Much improved gradient support for canvas/basegfx/drawinglayer.

See http://blog.thebehrens.net/2009/07/28/hackweek-iv-canvas-convwatch/ for more background information

5 files changed, 182 insertions, 4 deletions

diff --git a/basegfx/inc/basegfx/matrix/b2dhommatrixtools.hxx b/basegfx/inc/basegfx/matrix/b2dhommatrixtools.hxx
index 0b200b812bed..54d961d40ac2 100644
--- a/basegfx/inc/basegfx/matrix/b2dhommatrixtools.hxx
+++ b/basegfx/inc/basegfx/matrix/b2dhommatrixtools.hxx
@@ -36,6 +36,8 @@
 #include <basegfx/matrix/b2dhommatrix.hxx>
 #include <basegfx/vector/b2dvector.hxx>
 
+namespace rtl { class OUString; }
+
 ///////////////////////////////////////////////////////////////////////////////
 
 namespace basegfx
@@ -79,6 +81,10 @@ namespace basegfx
         double getRotate() const { const_cast< DecomposedB2DHomMatrixContainer* >(this)->impCheckDecompose(); return mfRotate; }
         double getShearX() const { const_cast< DecomposedB2DHomMatrixContainer* >(this)->impCheckDecompose(); return mfShearX; }
     };
+
+    /// Returns a string with svg's "matrix(m00,m10,m01,m11,m02,m12)" representation
+    ::rtl::OUString exportToSvg( const B2DHomMatrix& rMatrix );
+
 } // end of namespace basegfx
 
 ///////////////////////////////////////////////////////////////////////////////
diff --git a/basegfx/inc/basegfx/numeric/ftools.hxx b/basegfx/inc/basegfx/numeric/ftools.hxx
index 5003ede0c4cf..6cecbecc1f9f 100644
--- a/basegfx/inc/basegfx/numeric/ftools.hxx
+++ b/basegfx/inc/basegfx/numeric/ftools.hxx
@@ -112,7 +112,7 @@ namespace basegfx
 
     /** clamp given value against given minimum and maximum values
     */
-    template <class T> const T& clamp(const T& value, const T& minimum, const T& maximum)
+    template <class T> inline const T& clamp(const T& value, const T& minimum, const T& maximum)
     {
         if(value < minimum)
         {
diff --git a/basegfx/inc/basegfx/tools/gradienttools.hxx b/basegfx/inc/basegfx/tools/gradienttools.hxx
index 0c7f2ab2c060..dbcc5a3221f0 100644
--- a/basegfx/inc/basegfx/tools/gradienttools.hxx
+++ b/basegfx/inc/basegfx/tools/gradienttools.hxx
@@ -37,6 +37,9 @@
 #include <basegfx/matrix/b2dhommatrix.hxx>
 #include <basegfx/numeric/ftools.hxx>
 
+#include <vector>
+#include <algorithm>
+
 namespace basegfx
 {
     /** Gradient definition as used in ODF 1.2
@@ -78,6 +81,8 @@ namespace basegfx
     {
         /** Create matrix for ODF's linear gradient definition
 
+            Note that odf linear gradients are varying in y direction.
+
             @param o_rGradientInfo
             Receives the calculated texture transformation matrix (for
             use with standard [0,1]x[0,1] texture coordinates)
@@ -109,7 +114,7 @@ namespace basegfx
 
             @param rUV
             Current uv coordinate. Values outside [0,1] will be
-            clamped.
+            clamped. Assumes gradient color varies along the y axis.
 
             @param rGradInfo
             Gradient info, for transformation and number of steps
@@ -129,6 +134,14 @@ namespace basegfx
 
         /** Create matrix for ODF's axial gradient definition
 
+            Note that odf axial gradients are varying in y
+            direction. Note further that you can map the axial
+            gradient to a linear gradient (in case you want or need to
+            avoid an extra gradient renderer), by using
+            createLinearODFGradientInfo() instead, shifting the
+            resulting texture transformation by 0.5 to the top and
+            appending the same stop colors again, but mirrored.
+
             @param o_rGradientInfo
             Receives the calculated texture transformation matrix (for
             use with standard [0,1]x[0,1] texture coordinates)
@@ -160,7 +173,7 @@ namespace basegfx
 
             @param rUV
             Current uv coordinate. Values outside [0,1] will be
-            clamped.
+            clamped. Assumes gradient color varies along the y axis.
 
             @param rGradInfo
             Gradient info, for transformation and number of steps
@@ -394,7 +407,6 @@ namespace basegfx
         {
             return getSquareGradientAlpha(rUV, rGradInfo); // only matrix setup differs
         }
-
     }
 }
 
diff --git a/basegfx/inc/basegfx/tools/keystoplerp.hxx b/basegfx/inc/basegfx/tools/keystoplerp.hxx
new file mode 100644
index 000000000000..a54b3485b1a1
--- /dev/null
+++ b/basegfx/inc/basegfx/tools/keystoplerp.hxx
@@ -0,0 +1,100 @@
+/*************************************************************************
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Copyright 2008 by Sun Microsystems, Inc.
+ *
+ * OpenOffice.org - a multi-platform office productivity suite
+ *
+ * $RCSfile: canvastools.hxx,v $
+ * $Revision: 1.10 $
+ *
+ * This file is part of OpenOffice.org.
+ *
+ * OpenOffice.org is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 3
+ * only, as published by the Free Software Foundation.
+ *
+ * OpenOffice.org is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License version 3 for more details
+ * (a copy is included in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * version 3 along with OpenOffice.org.  If not, see
+ * <http://www.openoffice.org/license.html>
+ * for a copy of the LGPLv3 License.
+ *
+ ************************************************************************/
+
+#ifndef _BGFX_TOOLS_KEYSTOPLERP_HXX
+#define _BGFX_TOOLS_KEYSTOPLERP_HXX
+
+#include <basegfx/numeric/ftools.hxx>
+#include <vector>
+
+namespace com{ namespace sun{ namespace star{ namespace uno {
+    template<typename T> class Sequence;
+}}}}
+
+namespace basegfx
+{
+    namespace tools
+    {
+        /** Lerp in a vector of key stops
+
+            This class holds a key stop vector and provides the
+            functionality to lerp inside it. Useful e.g. for
+            multi-stop gradients, or the SMIL key time activity.
+
+            For those, given a global [0,1] lerp alpha, one need to
+            find the suitable bucket index from key stop vector, and
+            then calculate the relative alpha between the two buckets
+            found.
+         */
+        class KeyStopLerp
+        {
+        public:
+            typedef std::pair<std::ptrdiff_t,double> ResultType;
+
+            /** Create lerper with given vector of stops
+
+                @param rKeyStops
+
+                Vector of stops, must contain at least two elements
+                (though preferrably more, otherwise you probably don't
+                need key stop lerping in the first place). All
+                elements must be of monotonically increasing value.
+             */
+            explicit KeyStopLerp( const std::vector<double>& rKeyStops );
+
+            /** Create lerper with given sequence of stops
+
+                @param rKeyStops
+
+                Sequence of stops, must contain at least two elements
+                (though preferrably more, otherwise you probably don't
+                need key stop lerping in the first place). All
+                elements must be of monotonically increasing value.
+             */
+            explicit KeyStopLerp( const ::com::sun::star::uno::Sequence<double>& rKeyStops );
+
+            /** Find two nearest bucket index & interpolate
+
+                @param fAlpha
+                Find bucket index i, with keyStops[i] < fAlpha <=
+                keyStops[i+1]. Return new alpha value in [0,1),
+                proportional to fAlpha's position between keyStops[i]
+                and keyStops[i+1]
+             */
+            ResultType lerp(double fAlpha) const;
+
+        private:
+            std::vector<double>    maKeyStops;
+            mutable std::ptrdiff_t mnLastIndex;
+        };
+    }
+}
+
+#endif
diff --git a/basegfx/inc/basegfx/tools/lerp.hxx b/basegfx/inc/basegfx/tools/lerp.hxx
new file mode 100644
index 000000000000..590ef34c2009
--- /dev/null
+++ b/basegfx/inc/basegfx/tools/lerp.hxx
@@ -0,0 +1,60 @@
+/*************************************************************************
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Copyright 2008 by Sun Microsystems, Inc.
+ *
+ * OpenOffice.org - a multi-platform office productivity suite
+ *
+ * $RCSfile: lerp.hxx,v $
+ * $Revision: 1.6 $
+ *
+ * This file is part of OpenOffice.org.
+ *
+ * OpenOffice.org is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 3
+ * only, as published by the Free Software Foundation.
+ *
+ * OpenOffice.org is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License version 3 for more details
+ * (a copy is included in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * version 3 along with OpenOffice.org.  If not, see
+ * <http://www.openoffice.org/license.html>
+ * for a copy of the LGPLv3 License.
+ *
+ ************************************************************************/
+
+#ifndef _BGFX_TOOLS_LERP_HXX
+#define _BGFX_TOOLS_LERP_HXX
+
+#include <sal/types.h>
+
+namespace basegfx
+{
+    namespace tools
+    {
+        /** Generic linear interpolator
+
+            @tpl ValueType
+            Must have operator+ and operator* defined, and should
+            have value semantics.
+
+            @param t
+            As usual, t must be in the [0,1] range
+        */
+        template< typename ValueType > ValueType lerp( const ValueType&     rFrom,
+                                                       const ValueType&     rTo,
+                                                       double               t )
+        {
+            // This is only to suppress a double->int warning. All other
+            // types should be okay here.
+            return static_cast<ValueType>( (1.0-t)*rFrom + t*rTo );
+        }
+    }
+}
+
+#endif /* _BGFX_TOOLS_LERP_HXX */