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Diffstat (limited to 'basebmp/inc/basebmp/colortraits.hxx')
-rw-r--r-- | basebmp/inc/basebmp/colortraits.hxx | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/basebmp/inc/basebmp/colortraits.hxx b/basebmp/inc/basebmp/colortraits.hxx new file mode 100644 index 000000000000..9c30b8f082c0 --- /dev/null +++ b/basebmp/inc/basebmp/colortraits.hxx @@ -0,0 +1,150 @@ +/************************************************************************* + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * Copyright 2000, 2010 Oracle and/or its affiliates. + * + * OpenOffice.org - a multi-platform office productivity suite + * + * 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 INCLUDED_BASEBMP_COLORTRAITS_HXX +#define INCLUDED_BASEBMP_COLORTRAITS_HXX + +#include <basebmp/accessoradapters.hxx> +#include <basebmp/metafunctions.hxx> + +#include <vigra/mathutil.hxx> + +namespace basebmp +{ + +/** Functor template, to calculate alpha blending between two + values. Float case. + + @tpl polarity + When true, 0 means fully transparent, and 1 fully opaque. And vice + versa. + */ +template< typename ValueType, + typename AlphaType, + bool polarity > struct BlendFunctor; +template< typename ValueType, + typename AlphaType > struct BlendFunctor<ValueType,AlphaType,true> + : public TernaryFunctorBase<AlphaType,ValueType,ValueType,ValueType> +{ + ValueType operator()( AlphaType alpha, + ValueType v1, + ValueType v2 ) const + { + const typename vigra::NumericTraits<AlphaType>::RealPromote fAlpha( + vigra::NumericTraits<AlphaType>::toRealPromote(alpha)); + return (vigra::NumericTraits<AlphaType>::one()-fAlpha)*v1 + fAlpha*v2; + } +}; +template< typename ValueType, + typename AlphaType > struct BlendFunctor<ValueType,AlphaType,false> + : public TernaryFunctorBase<AlphaType,ValueType,ValueType,ValueType> +{ + ValueType operator()( AlphaType alpha, + ValueType v1, + ValueType v2 ) const + { + const typename vigra::NumericTraits<AlphaType>::RealPromote fAlpha( + vigra::NumericTraits<AlphaType>::toRealPromote(alpha)); + return fAlpha*v1 + (vigra::NumericTraits<AlphaType>::one()-fAlpha)*v2; + } +}; + +/** Functor template, to calculate alpha blending between two + values. Integer case. + + @tpl polarity + When true, 0 means fully transparent, and 1 fully opaque. And vice + versa. + */ +template< typename ValueType, + typename AlphaType, + bool polarity > struct IntegerBlendFunctor; +template< typename ValueType, + typename AlphaType > struct IntegerBlendFunctor<ValueType,AlphaType,true> + : public TernaryFunctorBase<AlphaType,ValueType,ValueType,ValueType> +{ + ValueType operator()( AlphaType alpha, + ValueType v1, + ValueType v2 ) const + { + return (vigra::NumericTraits<AlphaType>::toPromote( + vigra::NumericTraits<AlphaType>::max()-alpha)*v1 + alpha*v2) / + vigra::NumericTraits<AlphaType>::max(); + } +}; +template< typename ValueType, + typename AlphaType > struct IntegerBlendFunctor<ValueType,AlphaType,false> + : public TernaryFunctorBase<AlphaType,ValueType,ValueType,ValueType> +{ + ValueType operator()( AlphaType alpha, + ValueType v1, + ValueType v2 ) const + { + return (alpha*v1 + + vigra::NumericTraits<AlphaType>::toPromote( + vigra::NumericTraits<AlphaType>::max()-alpha)*v2) / + vigra::NumericTraits<AlphaType>::max(); + } +}; + +//----------------------------------------------------------------------------- + +template< typename ColorType > struct ColorTraits +{ + /// Metafunction to select blend functor from color and alpha type + template< typename AlphaType, bool polarity > struct blend_functor : public + ifScalarIntegral< AlphaType, + IntegerBlendFunctor< ColorType, AlphaType, polarity >, + BlendFunctor< ColorType, AlphaType, polarity > > {}; + + /// @return number of color channels + static int numChannels() { return 1; } + + /// Type of a color component (i.e. the type of an individual channel) + typedef ColorType component_type; + + /// Calculate normalized distance between color c1 and c2 + static inline vigra::NormTraits<ColorType> distance( ColorType c1, + ColorType c2 ) + { + return vigra::norm(c1 - c2); + } + + static inline component_type toGreyscale( ColorType c ) + { + return c; + } + + static inline ColorType fromGreyscale( component_type c ) + { + return c; + } +}; + +} // namespace basebmp + +#endif /* INCLUDED_BASEBMP_COLORTRAITS_HXX */ |