#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

3 files changed, 144 insertions, 42 deletions

diff --git a/basegfx/source/tools/gradienttools.cxx b/basegfx/source/tools/gradienttools.cxx
index 9e78039cd590..337f9bd8e52b 100644
--- a/basegfx/source/tools/gradienttools.cxx
+++ b/basegfx/source/tools/gradienttools.cxx
@@ -52,6 +52,8 @@ namespace basegfx
         o_rGradientInfo.maBackTextureTransform.identity();
         o_rGradientInfo.mnSteps = nSteps;
 
+        fAngle = -fAngle;
+
         double fTargetSizeX(rTargetRange.getWidth());
         double fTargetSizeY(rTargetRange.getHeight());
         double fTargetOffsetX(rTargetRange.getMinX());
@@ -70,7 +72,23 @@ namespace basegfx
             fTargetSizeY = fNewY;
         }
 
-        // add object scale before rotate
+        double fSizeWithoutBorder=0;
+        double fTranslateY=0;
+        if( bAxial )
+        {
+            fSizeWithoutBorder = (1.0 - fBorder) * 0.5;
+            fTranslateY = 0.5;
+        }
+        else
+        {
+            fSizeWithoutBorder = 1.0 - fBorder;
+            fTranslateY = fBorder;
+        }
+
+        if(!fTools::equal(fSizeWithoutBorder, 0.0))
+            o_rGradientInfo.maTextureTransform.scale(1.0, fSizeWithoutBorder);
+
+        o_rGradientInfo.maTextureTransform.translate(0.0, fTranslateY);
         o_rGradientInfo.maTextureTransform.scale(fTargetSizeX, fTargetSizeY);
 
         // add texture rotate after scale to keep perpendicular angles
@@ -90,24 +108,9 @@ namespace basegfx
         // prepare aspect for texture
         o_rGradientInfo.mfAspectRatio = (0.0 != fTargetSizeY) ?  fTargetSizeX / fTargetSizeY : 1.0;
 
-        // build transform from u,v to [0.0 .. 1.0]. As base, use inverse texture transform
+        // build transform from u,v to [0.0 .. 1.0].
         o_rGradientInfo.maBackTextureTransform = o_rGradientInfo.maTextureTransform;
         o_rGradientInfo.maBackTextureTransform.invert();
-
-        double fSizeWithoutBorder=0;
-        if( bAxial )
-        {
-            fSizeWithoutBorder = (1.0 - fBorder) * 0.5;
-            o_rGradientInfo.maBackTextureTransform.translate(0.0, -0.5);
-        }
-        else
-        {
-            fSizeWithoutBorder = 1.0 - fBorder;
-            o_rGradientInfo.maBackTextureTransform.translate(0.0, -fBorder);
-        }
-
-        if(!fTools::equal(fSizeWithoutBorder, 0.0))
-            o_rGradientInfo.maBackTextureTransform.scale(1.0, 1.0 / fSizeWithoutBorder);
     }
 
     /** Most of the setup for radial & ellipsoidal gradient is the same,
@@ -125,6 +128,8 @@ namespace basegfx
         o_rGradientInfo.maBackTextureTransform.identity();
         o_rGradientInfo.mnSteps = nSteps;
 
+        fAngle = -fAngle;
+
         double fTargetSizeX(rTargetRange.getWidth());
         double fTargetSizeY(rTargetRange.getHeight());
         double fTargetOffsetX(rTargetRange.getMinX());
@@ -147,7 +152,11 @@ namespace basegfx
             fTargetSizeY = 1.4142 * fTargetSizeY;
         }
 
-        // add object scale before rotate
+        const double fHalfBorder((1.0 - fBorder) * 0.5);
+        if(!fTools::equal(fHalfBorder, 0.0))
+            o_rGradientInfo.maTextureTransform.scale(fHalfBorder, fHalfBorder);
+
+        o_rGradientInfo.maTextureTransform.translate(0.5, 0.5);
         o_rGradientInfo.maTextureTransform.scale(fTargetSizeX, fTargetSizeY);
 
         if( !bCircular )
@@ -155,9 +164,8 @@ namespace basegfx
             // add texture rotate after scale to keep perpendicular angles
             if(0.0 != fAngle)
             {
-                B2DPoint aCenter(0.5, 0.5);
-                aCenter *= o_rGradientInfo.maTextureTransform;
-
+                const B2DPoint aCenter(0.5*fTargetSizeX,
+                                       0.5*fTargetSizeY);
                 o_rGradientInfo.maTextureTransform.translate(-aCenter.getX(), -aCenter.getY());
                 o_rGradientInfo.maTextureTransform.rotate(fAngle);
                 o_rGradientInfo.maTextureTransform.translate(aCenter.getX(), aCenter.getY());
@@ -178,17 +186,9 @@ namespace basegfx
         // prepare aspect for texture
         o_rGradientInfo.mfAspectRatio = (0.0 != fTargetSizeY) ?  fTargetSizeX / fTargetSizeY : 1.0;
 
-        // build transform from u,v to [0.0 .. 1.0]. As base, use inverse texture transform
+        // build transform from u,v to [0.0 .. 1.0].
         o_rGradientInfo.maBackTextureTransform = o_rGradientInfo.maTextureTransform;
         o_rGradientInfo.maBackTextureTransform.invert();
-        o_rGradientInfo.maBackTextureTransform.translate(-0.5, -0.5);
-        const double fHalfBorder((1.0 - fBorder) * 0.5);
-
-        if(!fTools::equal(fHalfBorder, 0.0))
-        {
-            const double fFactor(1.0 / fHalfBorder);
-            o_rGradientInfo.maBackTextureTransform.scale(fFactor, fFactor);
-        }
     }
 
     /** Setup for rect & square gradient is exactly the same. Factored out
@@ -205,6 +205,8 @@ namespace basegfx
         o_rGradientInfo.maBackTextureTransform.identity();
         o_rGradientInfo.mnSteps = nSteps;
 
+        fAngle = -fAngle;
+
         double fTargetSizeX(rTargetRange.getWidth());
         double fTargetSizeY(rTargetRange.getHeight());
         double fTargetOffsetX(rTargetRange.getMinX());
@@ -223,15 +225,18 @@ namespace basegfx
             fTargetSizeY = fNewY;
         }
 
-        // add object scale before rotate
+        const double fHalfBorder((1.0 - fBorder) * 0.5);
+        if(!fTools::equal(fHalfBorder, 0.0))
+            o_rGradientInfo.maTextureTransform.scale(fHalfBorder, fHalfBorder);
+
+        o_rGradientInfo.maTextureTransform.translate(0.5, 0.5);
         o_rGradientInfo.maTextureTransform.scale(fTargetSizeX, fTargetSizeY);
 
         // add texture rotate after scale to keep perpendicular angles
         if(0.0 != fAngle)
         {
-            B2DPoint aCenter(0.5, 0.5);
-            aCenter *= o_rGradientInfo.maTextureTransform;
-
+            const B2DPoint aCenter(0.5*fTargetSizeX,
+                                   0.5*fTargetSizeY);
             o_rGradientInfo.maTextureTransform.translate(-aCenter.getX(), -aCenter.getY());
             o_rGradientInfo.maTextureTransform.rotate(fAngle);
             o_rGradientInfo.maTextureTransform.translate(aCenter.getX(), aCenter.getY());
@@ -254,14 +259,6 @@ namespace basegfx
         // build transform from u,v to [0.0 .. 1.0]. As base, use inverse texture transform
         o_rGradientInfo.maBackTextureTransform = o_rGradientInfo.maTextureTransform;
         o_rGradientInfo.maBackTextureTransform.invert();
-        o_rGradientInfo.maBackTextureTransform.translate(-0.5, -0.5);
-        const double fHalfBorder((1.0 - fBorder) * 0.5);
-
-        if(!fTools::equal(fHalfBorder, 0.0))
-        {
-            const double fFactor(1.0 / fHalfBorder);
-            o_rGradientInfo.maBackTextureTransform.scale(fFactor, fFactor);
-        }
     }
 
     namespace tools
diff --git a/basegfx/source/tools/keystoplerp.cxx b/basegfx/source/tools/keystoplerp.cxx
new file mode 100644
index 000000000000..99c74a350a69
--- /dev/null
+++ b/basegfx/source/tools/keystoplerp.cxx
@@ -0,0 +1,104 @@
+/*************************************************************************
+ *
+ * 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.
+ *
+ ************************************************************************/
+
+#include "basegfx/tools/keystoplerp.hxx"
+#include <com/sun/star/uno/Sequence.hxx>
+
+#include <algorithm>
+
+static void validateInput(const std::vector<double>& rKeyStops)
+{
+    (void)rKeyStops;
+#ifdef DBG_UTIL
+    OSL_ENSURE( rKeyStops.size() > 1,
+                "KeyStopLerp::KeyStopLerp(): key stop vector must have two entries or more" );
+
+    // rKeyStops must be sorted in ascending order
+    for( ::std::size_t i=1, len=rKeyStops.size(); i<len; ++i )
+    {
+        if( rKeyStops[i-1] > rKeyStops[i] )
+            OSL_ENSURE( false,
+                        "KeyStopLerp::KeyStopLerp(): time vector is not sorted in ascending order!" );
+    }
+#endif
+}
+
+namespace basegfx
+{
+    namespace tools
+    {
+        KeyStopLerp::KeyStopLerp( const std::vector<double>& rKeyStops ) :
+            maKeyStops(rKeyStops),
+            mnLastIndex(0)
+        {
+            validateInput(maKeyStops);
+        }
+
+        KeyStopLerp::KeyStopLerp( const ::com::sun::star::uno::Sequence<double>& rKeyStops ) :
+            maKeyStops(rKeyStops.getLength()),
+            mnLastIndex(0)
+        {
+            std::copy( rKeyStops.getConstArray(),
+                       rKeyStops.getConstArray()+rKeyStops.getLength(),
+                       maKeyStops.begin() );
+            validateInput(maKeyStops);
+        }
+
+        KeyStopLerp::ResultType KeyStopLerp::lerp(double fAlpha) const
+        {
+            // cached value still okay?
+            if( maKeyStops.at(mnLastIndex) < fAlpha ||
+                maKeyStops.at(mnLastIndex+1) >= fAlpha )
+            {
+                // nope, find new index
+                mnLastIndex = std::min<std::ptrdiff_t>(
+                    maKeyStops.size()-2,
+                    // range is ensured by max below
+                    std::max<std::ptrdiff_t>(
+                        0,
+                        std::distance( maKeyStops.begin(),
+                                       std::lower_bound( maKeyStops.begin(),
+                                                         maKeyStops.end(),
+                                                         fAlpha )) - 1 ));
+            }
+
+            // lerp between stop and stop+1
+            const double fRawLerp=
+                (fAlpha-maKeyStops.at(mnLastIndex)) /
+                (maKeyStops.at(mnLastIndex+1) - maKeyStops.at(mnLastIndex));
+
+            // clamp to permissible range (input fAlpha might be
+            // everything)
+            return ResultType(
+                mnLastIndex,
+                clamp(fRawLerp,0.0,1.0));
+        }
+    }
+}
diff --git a/basegfx/source/tools/makefile.mk b/basegfx/source/tools/makefile.mk
index 1bede8b22d88..d55bbae12f8f 100755
--- a/basegfx/source/tools/makefile.mk
+++ b/basegfx/source/tools/makefile.mk
@@ -44,6 +44,7 @@ ENABLE_EXCEPTIONS=TRUE
 SLOFILES= $(SLO)$/canvastools.obj	\
           $(SLO)$/gradienttools.obj	\
           $(SLO)$/debugplotter.obj	\
+          $(SLO)$/keystoplerp.obj	\
           $(SLO)$/liangbarsky.obj	\
           $(SLO)$/tools.obj		    \
           $(SLO)$/unopolypolygon.obj