1 files changed, 107 insertions, 0 deletions
diff --git a/basegfx/source/tools/keystoplerp.cxx b/basegfx/source/tools/keystoplerp.cxx
new file mode 100644
index 000000000000..883bfec6bc96
--- /dev/null
+++ b/basegfx/source/tools/keystoplerp.cxx
@@ -0,0 +1,107 @@
+/*************************************************************************
+ *
+ * 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.
+ *
+ ************************************************************************/
+
+// MARKER(update_precomp.py): autogen include statement, do not remove
+#include "precompiled_basegfx.hxx"
+
+#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));
+        }
+    }
+}