[Olena-patches] 2092: Add lazy_image type.

https://svn.lrde.epita.fr/svn/oln/trunk/milena Index: ChangeLog from Ugo Jardonnet &lt;ugo.jardonnet(a)lrde.epita.fr&gt; Add lazy_image type. * mln/core/lazy_image.hh: New Image type. Compute values on the fly. lazy_image.hh | 209 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 209 insertions(+) Index: mln/core/lazy_image.hh --- mln/core/lazy_image.hh (revision 0) +++ mln/core/lazy_image.hh (revision 0) @@ -0,0 +1,209 @@ +// Copyright (C) 2007 EPITA Research and Development Laboratory +// +// This file is part of the Olena Library. This library is free +// software; you can redistribute it and/or modify it under the terms +// of the GNU General Public License version 2 as published by the +// Free Software Foundation. +// +// This library 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 +// General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING. If not, write to +// the Free Software Foundation, 51 Franklin Street, Fifth Floor, +// Boston, MA 02111-1307, USA. +// +// As a special exception, you may use this file as part of a free +// software library without restriction. Specifically, if other files +// instantiate templates or use macros or inline functions from this +// file, or you compile this file and link it with other files to +// produce an executable, this file does not by itself cause the +// resulting executable to be covered by the GNU General Public +// License. This exception does not however invalidate any other +// reasons why the executable file might be covered by the GNU General +// Public License. + +#ifndef MLN_CORE_LAZY_IMAGE_HH +# define MLN_CORE_LAZY_IMAGE_HH + +/*! \file mln/core/lazy_image.hh + * + * \brief Definition of a lazy image. Values are computed on the fly + */ + +# include <cmath> + +# include <mln/core/internal/image_identity.hh> +# include <mln/core/box2d.hh> +# include <mln/core/line_piter.hh> + + +namespace mln +{ + + // Fwd decl. + template <typename I, typename F, typename B> struct lazy_image; + + namespace internal + { + + /// \internal Data structure for \c mln::lazy_image<I>. + template <typename I, typename F, typename B> + struct data_< lazy_image<I,F,B> > + { + data_(const F& fun_, const B& box); + + mutable mln_ch_value(I,mln_result(F)) ima_; + mutable mln_ch_value(I,bool) is_known; + const F& fun; + const B& bb_; + }; + + } // end of namespace mln::internal + + + + namespace trait + { + + template <typename I, typename F, typename B> + struct image_< lazy_image<I,F,B> > : default_image_morpher_< I, mln_value(I), + lazy_image<I,F,B> > + { + typedef trait::image::category::domain_morpher category; + + typedef mln_trait_image_access(I) access; + typedef mln_trait_image_space(I) space; + typedef mln_trait_image_size(I) size; + typedef mln_trait_image_support(I) support; + typedef mln_trait_image_border(I) border; + typedef mln_trait_image_io_from_(I) io; + typedef mln_trait_image_data_from_(I) data; + + }; + + } // end of namespace mln::trait + + + + /*! \brief Lazy image class. + * + * The parameter \c I is the type of image. + * The parameter \c F is the type of function. + * The parameter \c B is the type of box. + * + * This image class tage a functor \p fun and a box \p box. + * Access to ima(p) where \p p include \p box return fun(b) lazily. + * + */ + template <typename I, typename F, typename B> + struct lazy_image : public mln::internal::image_identity_< mln_ch_value(I, mln_result(F)), + mln_pset(I), lazy_image<I, F,B> > + { + typedef mln::internal::image_morpher_< mln_ch_value(I, mln_result(F)), + mln_pset(I), lazy_image<I,F,B> > super_; + typedef line_piter_<mln_psite(I)> line_piter; + + /// Return type of read access. + typedef mln_result(F) rvalue; + + /// Return type of read-write access. + typedef mln_result(F)& lvalue; + + /// Skeleton. + typedef lazy_image< tag::image_<I>, F, B > skeleton; + + /// Test if a pixel value is accessible at \p p. + using super_::has_data; + + /// Constructors. + lazy_image(const F& fun, const B& box); + + /// Return domain of lazyd_image. + const box2d& domain() const; + + /// Test if a pixel value is accessible at \p p. + bool owns_(const mln_psite(I)&) const; + + /// Read-only access of pixel value at point site \p p. + mln_result(F) operator()(const mln_psite(I)& p) const; + + /// Read and "write if possible" access of pixel value at point site \p p. + lvalue operator()(const mln_psite(I)& p); + }; + + + +# ifndef MLN_INCLUDE_ONLY + + namespace internal + { + + // internal::data_< lazy_image<I,S> > + + template <typename I, typename F, typename B> + inline + data_< lazy_image<I,F,B> >::data_(const F& fun, const B& box) + : ima_(box), is_known(box), fun(fun), bb_(box) + { + } + + } // end of namespace mln::internal + + template <typename I, typename F, typename B> + inline + lazy_image<I,F,B>::lazy_image(const F& fun, const B& box) + { + this->data_ = new internal::data_< lazy_image<I,F,B> >(fun, box); + } + + template <typename I, typename F, typename B> + inline + bool lazy_image<I,F,B>::owns_(const mln_psite(I)& p) const + { + return this->data_->ima_.owns_(p); + } + + template <typename I, typename F, typename B> + inline + mln_result(F) + lazy_image<I,F,B>::operator()(const mln_psite(I)& p) const + { + mln_assertion(this->owns_(p)); + if (this->data_->is_known(p)) + return this->data_->ima_(p); + this->data_->ima_(p) = this->data_->fun(p); + this->data_->is_known(p) = true; + return this->data_->ima_(p); + } + + + template <typename I, typename F, typename B> + inline + typename lazy_image<I,F,B>::lvalue + lazy_image<I,F,B>::operator()(const mln_psite(I)& p) + { + mln_assertion(this->owns_(p)); + if (this->data_->is_known(p)) + return this->data_->ima_(p); + this->data_->ima_(p) = this->data_->fun(p); + this->data_->is_known(p) = true; + return this->data_->ima_(p); + } + + template <typename I, typename F, typename B> + inline + const box2d& + lazy_image<I,F,B>::domain() const + { + return this->data_->bb_; + } + +# endif // ! MLN_INCLUDE_ONLY + +} // end of namespace mln + + +#endif // ! MLN_CORE_LAZY_IMAGE_HH