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Diffstat (limited to 'basegfx/inc/basegfx/tools/keystoplerp.hxx')
-rw-r--r-- | basegfx/inc/basegfx/tools/keystoplerp.hxx | 100 |
1 files changed, 100 insertions, 0 deletions
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 |