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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 05:54:39 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 05:54:39 +0000 |
commit | 267c6f2ac71f92999e969232431ba04678e7437e (patch) | |
tree | 358c9467650e1d0a1d7227a21dac2e3d08b622b2 /include/basegfx/utils/keystoplerp.hxx | |
parent | Initial commit. (diff) | |
download | libreoffice-267c6f2ac71f92999e969232431ba04678e7437e.tar.xz libreoffice-267c6f2ac71f92999e969232431ba04678e7437e.zip |
Adding upstream version 4:24.2.0.upstream/4%24.2.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/basegfx/utils/keystoplerp.hxx')
-rw-r--r-- | include/basegfx/utils/keystoplerp.hxx | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/include/basegfx/utils/keystoplerp.hxx b/include/basegfx/utils/keystoplerp.hxx new file mode 100644 index 0000000000..f8a821e7a5 --- /dev/null +++ b/include/basegfx/utils/keystoplerp.hxx @@ -0,0 +1,85 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#pragma once + +#include <vector> +#include <basegfx/basegfxdllapi.h> + +namespace com::sun::star::uno { + template<typename T> class Sequence; +} + +namespace basegfx::utils +{ + /** 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 BASEGFX_DLLPUBLIC 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 preferably more, otherwise you probably don't + need key stop lerping in the first place). All + elements must be of monotonically increasing value. + */ + explicit KeyStopLerp( std::vector<double>&& rKeyStops ); + + /** Create lerper with given sequence of stops + + @param rKeyStops + + Sequence of stops, must contain at least two elements + (though preferably 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 css::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; + }; +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |