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Diffstat (limited to 'basegfx/source/tools/keystoplerp.cxx')
-rw-r--r-- | basegfx/source/tools/keystoplerp.cxx | 107 |
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)); + } + } +} |