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| -rw-r--r-- | slideshow/source/engine/activities/interpolation.hxx | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/slideshow/source/engine/activities/interpolation.hxx b/slideshow/source/engine/activities/interpolation.hxx new file mode 100644 index 000000000..155456ed5 --- /dev/null +++ b/slideshow/source/engine/activities/interpolation.hxx @@ -0,0 +1,190 @@ +/* -*- 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 . + */ + +#ifndef INCLUDED_SLIDESHOW_SOURCE_ENGINE_ACTIVITIES_INTERPOLATION_HXX +#define INCLUDED_SLIDESHOW_SOURCE_ENGINE_ACTIVITIES_INTERPOLATION_HXX + +#include <basegfx/utils/lerp.hxx> +#include <osl/diagnose.h> +#include <rtl/ustring.hxx> + +#include <rgbcolor.hxx> +#include <hslcolor.hxx> + +namespace basegfx +{ + namespace utils + { + // Interpolator specializations + // ============================ + + // NOTE: generic lerp is included from lerp.hxx. Following + // are some specializations for various + // not-straight-forward-interpolatable types + + /// Specialization for RGBColor, to employ color-specific interpolator + template<> ::slideshow::internal::RGBColor lerp< ::slideshow::internal::RGBColor >( + const ::slideshow::internal::RGBColor& rFrom, + const ::slideshow::internal::RGBColor& rTo, + double t ) + { + return interpolate( rFrom, rTo, t ); + } + + /// Specialization also for sal_Int16, although this code should not be called + template<> sal_Int16 lerp< sal_Int16 >( const sal_Int16&, + const sal_Int16& rTo, + double ) + { + OSL_FAIL( "lerp<sal_Int16> called" ); + return rTo; + } + + /// Specialization also for string, although this code should not be called + template<> OUString lerp< OUString >( const OUString&, + const OUString& rTo, + double ) + { + OSL_FAIL( "lerp<OUString> called" ); + return rTo; + } + + /// Specialization also for bool, although this code should not be called + template<> bool lerp< bool >( const bool&, + const bool& rTo, + double ) + { + OSL_FAIL( "lerp<bool> called" ); + return rTo; + } + } +} + +namespace slideshow +{ + namespace internal + { + template< typename ValueType > struct Interpolator + { + ValueType operator()( const ValueType& rFrom, + const ValueType& rTo, + double t ) const + { + return basegfx::utils::lerp( rFrom, rTo, t ); + } + }; + + /// Specialization for HSLColor, to employ color-specific interpolator + template<> struct Interpolator< HSLColor > + { + explicit Interpolator( bool bCCW ) : + mbCCW( bCCW ) + { + } + + HSLColor operator()( const HSLColor& rFrom, + const HSLColor& rTo, + double t ) const + { + return interpolate( rFrom, rTo, t, mbCCW ); + } + + private: + /// When true: interpolate counter-clockwise + const bool mbCCW; + }; + + + /** Generic linear interpolator + + @tpl ValueType + Must have operator+ and operator* defined, and should + have value semantics. + + @param rInterpolator + Interpolator to use for lerp + + @param nFrame + Must be in the [0,nTotalFrames) range + + @param nTotalFrames + Total number of frames. Should be greater than zero. + */ + template< typename ValueType > ValueType lerp( const Interpolator< ValueType >& rInterpolator, + const ValueType& rFrom, + const ValueType& rTo, + sal_uInt32 nFrame, + ::std::size_t nTotalFrames ) + { + // TODO(P1): There's a nice HAKMEM trick for that + // nTotalFrames > 1 condition below + + // for 1 and 0 frame animations, always take end value + const double nFraction( nTotalFrames > 1 ? double(nFrame)/(nTotalFrames-1) : 1.0 ); + + return rInterpolator( rFrom, rTo, nFraction ); + } + + /// Specialization for non-interpolatable constants/enums + template<> sal_Int16 lerp< sal_Int16 >( const Interpolator< sal_Int16 >& /*rInterpolator*/, + const sal_Int16& rFrom, + const sal_Int16& rTo, + sal_uInt32 nFrame, + ::std::size_t nTotalFrames ) + { + // until one half of the total frames are over, take from value. + // after that, take to value. + // For nFrames not divisible by 2, we prefer to over from, which + // also neatly yields to for 1 frame activities + return nFrame < nTotalFrames/2 ? rFrom : rTo; + } + + /// Specialization for non-interpolatable strings + template<> OUString lerp< OUString >( const Interpolator< OUString >& /*rInterpolator*/, + const OUString& rFrom, + const OUString& rTo, + sal_uInt32 nFrame, + ::std::size_t nTotalFrames ) + { + // until one half of the total frames are over, take from value. + // after that, take to value. + // For nFrames not divisible by 2, we prefer to over from, which + // also neatly yields to for 1 frame activities + return nFrame < nTotalFrames/2 ? rFrom : rTo; + } + + /// Specialization for non-interpolatable bools + template<> bool lerp< bool >( const Interpolator< bool >& /*rInterpolator*/, + const bool& bFrom, + const bool& bTo, + sal_uInt32 nFrame, + ::std::size_t nTotalFrames ) + { + // until one half of the total frames are over, take from value. + // after that, take to value. + // For nFrames not divisible by 2, we prefer to over from, which + // also neatly yields to for 1 frame activities + return nFrame < nTotalFrames/2 ? bFrom : bTo; + } + } +} + +#endif // INCLUDED_SLIDESHOW_SOURCE_ENGINE_ACTIVITIES_INTERPOLATION_HXX + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |