diff options
Diffstat (limited to 'boost/gil/premultiply.hpp')
| -rw-r--r-- | boost/gil/premultiply.hpp | 117 |
1 files changed, 63 insertions, 54 deletions
diff --git a/boost/gil/premultiply.hpp b/boost/gil/premultiply.hpp index eb865d3af1..e7fb315c65 100644 --- a/boost/gil/premultiply.hpp +++ b/boost/gil/premultiply.hpp @@ -1,69 +1,76 @@ -/* - Copyright 2014 - Use, modification and distribution are subject to the Boost Software License, - Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at - http://www.boost.org/LICENSE_1_0.txt). -*/ - -/*************************************************************************************************/ - +// +// Copyright 2014 Bill Gallafent +// +// Distributed under the Boost Software License, Version 1.0 +// See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt +// #ifndef BOOST_GIL_PREMULTIPLY_HPP #define BOOST_GIL_PREMULTIPLY_HPP -#include <iostream> - #include <boost/gil/rgba.hpp> + +#include <boost/core/ignore_unused.hpp> +#include <boost/mpl/for_each.hpp> #include <boost/mpl/remove.hpp> namespace boost { namespace gil { template <typename SrcP, typename DstP> -struct channel_premultiply { - channel_premultiply (SrcP const & src, DstP & dst) - : src_ (src), dst_ (dst) - {} - - template <typename Channel> - void operator () (Channel c) const { - // @todo: need to do a “channel_convert” too, in case the channel types aren't the same? - get_color (dst_, Channel()) = channel_multiply(get_color(src_,Channel()), alpha_or_max(src_)); - } - SrcP const & src_; - DstP & dst_; -}; +struct channel_premultiply +{ + channel_premultiply(SrcP const & src, DstP & dst) + : src_(src), dst_(dst) + {} + + template <typename Channel> + void operator()(Channel c) const + { + // FIXME: Is c input paramater not used intentionally? Add comment on relation between src_ vs c. + // @todo: need to do a “channel_convert” too, in case the channel types aren't the same? + get_color(dst_, Channel()) = channel_multiply(get_color(src_,Channel()), alpha_or_max(src_)); + } + SrcP const & src_; + DstP & dst_; +}; namespace detail { - template <typename SrcP, typename DstP> - void assign_alpha_if(mpl::true_, SrcP const &src, DstP &dst) - { - get_color (dst,alpha_t()) = alpha_or_max (src); - }; - - template <typename SrcP, typename DstP> - void assign_alpha_if(mpl::false_, SrcP const &src, DstP &dst) - { - // nothing to do - }; + template <typename SrcP, typename DstP> + void assign_alpha_if(mpl::true_, SrcP const &src, DstP &dst) + { + get_color(dst,alpha_t()) = alpha_or_max(src); + } + + template <typename SrcP, typename DstP> + void assign_alpha_if(mpl::false_, SrcP const& src, DstP& dst) + { + // nothing to do + boost::ignore_unused(src); + boost::ignore_unused(dst); + } } -struct premultiply { - template <typename SrcP, typename DstP> - void operator()(const SrcP& src, DstP& dst) const { - typedef typename color_space_type<SrcP>::type src_colour_space_t; - typedef typename color_space_type<DstP>::type dst_colour_space_t; - typedef typename mpl:: remove <src_colour_space_t, alpha_t>:: type src_colour_channels; - - typedef mpl::bool_<mpl::contains<dst_colour_space_t, alpha_t>::value> has_alpha_t; - mpl:: for_each <src_colour_channels> ( channel_premultiply <SrcP, DstP> (src, dst) ); - detail::assign_alpha_if(has_alpha_t(), src, dst); - } +struct premultiply +{ + template <typename SrcP, typename DstP> + void operator()(const SrcP& src, DstP& dst) const + { + typedef typename color_space_type<SrcP>::type src_colour_space_t; + typedef typename color_space_type<DstP>::type dst_colour_space_t; + typedef typename mpl::remove <src_colour_space_t, alpha_t>::type src_colour_channels; + + typedef mpl::bool_<mpl::contains<dst_colour_space_t, alpha_t>::value> has_alpha_t; + mpl::for_each<src_colour_channels>(channel_premultiply<SrcP, DstP>(src, dst)); + detail::assign_alpha_if(has_alpha_t(), src, dst); + } }; template <typename SrcConstRefP, // const reference to the source pixel typename DstP> // Destination pixel value (models PixelValueConcept) -class premultiply_deref_fn { +class premultiply_deref_fn +{ public: typedef premultiply_deref_fn const_t; typedef DstP value_type; @@ -73,15 +80,17 @@ public: typedef reference result_type; BOOST_STATIC_CONSTANT(bool, is_mutable=false); - result_type operator()(argument_type srcP) const { + result_type operator()(argument_type srcP) const + { result_type dstP; - premultiply () (srcP,dstP); + premultiply()(srcP,dstP); return dstP; } }; template <typename SrcView, typename DstP> -struct premultiplied_view_type { +struct premultiplied_view_type +{ private: typedef typename SrcView::const_t::reference src_pix_ref; // const reference to pixel in SrcView typedef premultiply_deref_fn<src_pix_ref, DstP> deref_t; // the dereference adaptor that performs color conversion @@ -92,11 +101,11 @@ public: }; template <typename DstP, typename View> inline -typename premultiplied_view_type<View,DstP>::type premultiply_view(const View& src) { +typename premultiplied_view_type<View,DstP>::type premultiply_view(const View& src) +{ return premultiplied_view_type<View,DstP>::make(src); } - } -} +}} // namespace boost::gil -#endif // BOOST_GIL_PREMULTIPLY_HPP +#endif |