/home/raskolnikov/dev/psynth/trunk/src/psynth/sound/planar_frame_iterator.hpp

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/*
 *  Copyright (C) 2010 Juan Pedro Bolivar Puente
 *
 *  This file is part of Psychosynth.
 *   
 *  Psychosynth is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Psychosynth 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 program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/*
 *  Copyright 2005-2007 Adobe Systems Incorporated
 * 
 *  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).
 */

#ifndef PSYNTH_SOUND_PLANAR_PTR_H
#define PSYNTH_SOUND_PLANAR_PTR_H

#include <cassert>
#include <iterator>
#include <boost/iterator/iterator_facade.hpp>

#include <psynth/base/compat.hpp>
#include <psynth/sound/frame.hpp>
#include <psynth/sound/step_iterator.hpp>

namespace psynth
{
namespace sound
{

/*
  forward declaration (as this file is included in
  planar_frame_reference.hpp)
*/
template <typename SampleReference, typename ChannelSpace> 
struct planar_frame_reference;

template <typename SamplePtr, typename ChannelSpace>
struct planar_frame_iterator
    : public boost::iterator_facade<
    planar_frame_iterator<SamplePtr,ChannelSpace>,
    frame<typename std::iterator_traits<
              SamplePtr>::value_type,
          layout<ChannelSpace> >,
    std::random_access_iterator_tag,
    const planar_frame_reference<
        typename std::iterator_traits<
            SamplePtr>::reference,
        ChannelSpace> >

    , public detail::homogeneous_channel_base<
    SamplePtr,
    layout<ChannelSpace>,
    boost::mpl::size<ChannelSpace>::value >
{
private:
    typedef
    boost::iterator_facade<
    planar_frame_iterator<SamplePtr,ChannelSpace>,
    frame<typename std::iterator_traits<SamplePtr>::value_type,
          layout<ChannelSpace> >,
              std::random_access_iterator_tag,
              const planar_frame_reference<
                  typename std::iterator_traits<SamplePtr>::reference,
                  ChannelSpace> >
    parent_type;

    typedef detail::homogeneous_channel_base<
        SamplePtr, layout<ChannelSpace>,
        boost::mpl::size<ChannelSpace>::value>
    channel_base_parent_type;

    typedef typename std::iterator_traits<SamplePtr>::value_type sample_type;

public:
    typedef typename parent_type::value_type         value_type;
    typedef typename parent_type::reference          reference;
    typedef typename parent_type::difference_type    difference_type;

    planar_frame_iterator () : channel_base_parent_type (0) {} 
    planar_frame_iterator (bool) {}
    // constructor that does not fill with zero (for performance)

    planar_frame_iterator (const SamplePtr& v0,
                           const SamplePtr& v1)
        : channel_base_parent_type (v0, v1) {}
    
    planar_frame_iterator (const SamplePtr& v0,
                           const SamplePtr& v1,
                           const SamplePtr& v2)
        : channel_base_parent_type (v0, v1, v2) {}

    planar_frame_iterator (const SamplePtr& v0,
                           const SamplePtr& v1,
                           const SamplePtr& v2,
                           const SamplePtr& v3)
        : channel_base_parent_type (v0, v1, v2, v3) {}
    
    planar_frame_iterator (const SamplePtr& v0,
                           const SamplePtr& v1,
                           const SamplePtr& v2,
                           const SamplePtr& v3,
                           const SamplePtr& v4)
        : channel_base_parent_type (v0, v1, v2, v3, v4) {}

    template <typename IC1, typename C1> 
    planar_frame_iterator (const planar_frame_iterator<IC1,C1>& ptr)
        : channel_base_parent_type (ptr) {}


    template <typename P> 
    planar_frame_iterator (P* pix)
        : channel_base_parent_type (pix, true)
    {
        boost::function_requires<FramesCompatibleConcept<P,value_type> >();
    }

    struct address_of
    {
        template <typename T>
        T* operator () (T& t) { return &t; }
    };
    
    template <typename P> 
    planar_frame_iterator& operator= (P* pix)
    {
        /*
          TODO:
          It seems that the following statements are optimized away by
          GCC in some strange cases...
         */
        boost::function_requires<FramesCompatibleConcept<P, value_type> >();    
        static_transform (*pix, *this, address_of ());
                
        /*
          TODO:
          Performance compare to this:
          this->template semantic_at_c<0>()=&pix->template
          semantic_at_c<0>();
          this->template semantic_at_c<1>()=&pix->template
          semantic_at_c<1>();
          this->template semantic_at_c<2>()=&pix->template
          semantic_at_c<2>();
        */
        return *this;
    }

    reference operator[] (difference_type d) const
    {
        return memunit_advanced_ref (*this, d * sizeof (sample_type));
    }

    reference operator-> () const
    {
        return **this;
    }

    // PERFORMANCE_CHECK: Remove?
    bool operator< (const planar_frame_iterator& ptr) const
    {
        return sound::at_c<0>(*this) < sound::at_c<0>(ptr);
    }
    
    bool operator!= (const planar_frame_iterator& ptr) const
    {
        return sound::at_c<0>(*this) != sound::at_c<0>(ptr);
    }
    
private:
    friend class boost::iterator_core_access;

    void increment()
    {
        static_transform (*this, *this, detail::inc<SamplePtr>());
    }
    
    void decrement ()
    {
        static_transform (*this, *this, detail::dec<SamplePtr>());
    }
    
    void advance (ptrdiff_t d)
    {
        static_transform (
            *this, *this,
            std::bind2nd (detail::plus_asymmetric<SamplePtr, ptrdiff_t>(), d));
    }
    
    reference dereference () const
    {
        return this->template deref<reference> ();
    }

    ptrdiff_t distance_to (const planar_frame_iterator& it) const
    {
        return sound::at_c<0>(it) - sound::at_c<0>(*this);
    }
    
    bool equal (const planar_frame_iterator& it) const
    {
        return sound::at_c<0>(*this) == sound::at_c<0>(it);
    }
};

namespace detail
{

template <typename IC>
struct sample_iterator_is_mutable : public boost::mpl::true_ {};
template <typename T>
struct sample_iterator_is_mutable<const T*> : public boost::mpl::false_ {};

} /* namespace detail */

template <typename IC, typename C> 
struct const_iterator_type<planar_frame_iterator<IC,C> >
{ 
private:
    typedef typename std::iterator_traits<IC>::value_type sample_type;

public:
    typedef
    planar_frame_iterator<typename sample_traits<sample_type>::const_pointer,
                          C> type; 
};

template <typename IC, typename C> 
struct iterator_is_mutable<planar_frame_iterator<IC,C> > :
        public detail::sample_iterator_is_mutable<IC> {};

/*
 *
 *    ChannelBasedConcept
 *
 */

template <typename IC, typename C, int K>  
struct kth_element_type<planar_frame_iterator<IC, C>, K>
{
    typedef IC type;
};

template <typename IC, typename C, int K>  
struct kth_element_reference_type<planar_frame_iterator<IC,C>, K> :
    public boost::add_reference<IC> {};

template <typename IC, typename C, int K>  
struct kth_element_const_reference_type<planar_frame_iterator<IC, C>, K> :
    public boost::add_reference<typename boost::add_const<IC>::type> {};


/*
 *
 *    HomogeneousFrameBasedConcept
 *
 */

template <typename IC, typename C>
struct channel_space_type<planar_frame_iterator<IC,C> >
{
    typedef C type;
};

template <typename IC, typename C>
struct sample_mapping_type<planar_frame_iterator<IC,C> > :
    public sample_mapping_type<
    typename planar_frame_iterator<IC,C>::value_type> {};

template <typename IC, typename C>
struct is_planar<planar_frame_iterator<IC,C> > : public boost::mpl::true_ {};

template <typename IC, typename C>
struct sample_type<planar_frame_iterator<IC,C> >
{
    typedef typename std::iterator_traits<IC>::value_type type;
};


/*
 *
 *    MemoryBasedIteratorConcept
 *
 */

template <typename IC, typename C>
inline std::ptrdiff_t memunit_step (const planar_frame_iterator<IC,C>&)
{
    return sizeof (typename std::iterator_traits<IC>::value_type);
}

template <typename IC, typename C>
inline std::ptrdiff_t memunit_distance (const planar_frame_iterator<IC,C>& p1,
                                        const planar_frame_iterator<IC,C>& p2)
{ 
    return memunit_distance (sound::at_c<0>(p1), sound::at_c<0>(p2)); 
}

template <typename IC>
struct memunit_advance_fn
{
    memunit_advance_fn (std::ptrdiff_t diff)
        : _diff (diff) {}

    IC operator () (const IC& p) const { return memunit_advanced (p, _diff); }

    std::ptrdiff_t _diff;
};

template <typename IC, typename C>
inline void memunit_advance (planar_frame_iterator<IC, C>& p,
                             std::ptrdiff_t diff)
{ 
    static_transform (p, p, memunit_advance_fn<IC> (diff));
}

template <typename IC, typename C>
inline planar_frame_iterator<IC,C> memunit_advanced (
    const planar_frame_iterator<IC,C>& p, std::ptrdiff_t diff)
{
    planar_frame_iterator<IC,C> ret = p;
    memunit_advance (ret, diff);
    return ret;
}

template <typename SamplePtr, typename ChannelSpace> inline
planar_frame_reference<typename std::iterator_traits<SamplePtr>::reference,
                       ChannelSpace> 
memunit_advanced_ref (const planar_frame_iterator<SamplePtr, ChannelSpace>& ptr,
                      std::ptrdiff_t diff)
{
    return planar_frame_reference<
        typename std::iterator_traits<SamplePtr>::reference,
        ChannelSpace> (ptr, diff);
}


/*
 *
 *    HasDynamicStepTypeConcept
 *
 */

template <typename IC, typename C>
struct dynamic_step_type<planar_frame_iterator<IC,C> >
{
    typedef memory_based_step_iterator<planar_frame_iterator<IC,C> > type;
};

} /* namespace sound */
} /* namespace psynth */

#endif /* PSYNTH_SOUND_PLANAR_FRAME_ITERATOR */