Chris@16: /*
Chris@16:     Copyright 2005-2007 Adobe Systems Incorporated
Chris@16:    
Chris@16:     Use, modification and distribution are subject to the Boost Software License,
Chris@16:     Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:     http://www.boost.org/LICENSE_1_0.txt).
Chris@16: 
Chris@16:     See http://opensource.adobe.com/gil for most recent version including documentation.
Chris@16: */
Chris@16: 
Chris@16: /*************************************************************************************************/
Chris@16: 
Chris@16: #ifndef GIL_UTILITIES_H
Chris@16: #define GIL_UTILITIES_H
Chris@16: 
Chris@16: #include "gil_config.hpp"
Chris@16: #include <functional>
Chris@16: #include <boost/config/no_tr1/cmath.hpp>
Chris@16: #include <cstddef>
Chris@16: #include <algorithm>
Chris@16: #include <utility>
Chris@16: #include <iterator>
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <boost/type_traits.hpp>
Chris@16: #include <boost/mpl/size.hpp>
Chris@16: #include <boost/mpl/distance.hpp>
Chris@16: #include <boost/mpl/begin.hpp>
Chris@16: #include <boost/mpl/find.hpp>
Chris@16: #include <boost/mpl/range_c.hpp>
Chris@16: #include <boost/iterator/iterator_adaptor.hpp>
Chris@16: #include <boost/iterator/iterator_facade.hpp>
Chris@16: 
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: /// \file               
Chris@16: /// \brief  Various utilities not specific to the image library. Some are non-standard STL extensions or generic iterator adaptors
Chris@16: /// \author Lubomir Bourdev and Hailin Jin \n
Chris@16: ///         Adobe Systems Incorporated
Chris@16: /// \date   2005-2007 \n Last updated on September 18, 2007
Chris@16: ///
Chris@16: ///
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: namespace boost { namespace gil {
Chris@16: 
Chris@16: /**
Chris@16: \addtogroup PointModel
Chris@16: 
Chris@16: Example:
Chris@16: \code
Chris@16: point2<std::ptrdiff_t> p(3,2);
Chris@16: assert((p[0] == p.x) && (p[1] == p.y));
Chris@16: assert(axis_value<0>(p) == 3);
Chris@16: assert(axis_value<1>(p) == 2);
Chris@16: \endcode
Chris@16: */
Chris@16: 
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: //                           CLASS point2
Chris@16: ///
Chris@16: /// \brief 2D point both axes of which have the same dimension type
Chris@16: /// \ingroup PointModel
Chris@16: /// Models: Point2DConcept
Chris@16: ///
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: template <typename T>
Chris@16: class point2 {
Chris@16: public:
Chris@16:     typedef T value_type;
Chris@16:     template <std::size_t D> struct axis { typedef value_type coord_t; };
Chris@16:     static const std::size_t num_dimensions=2;
Chris@16: 
Chris@16:     point2()                : x(0),     y(0)    {}
Chris@16:     point2(T newX, T newY)  : x(newX),  y(newY) {}
Chris@16:     point2(const point2& p) : x(p.x), y(p.y) {}
Chris@16:     ~point2() {}
Chris@16: 
Chris@16:     point2& operator=(const point2& p)            { x=p.x; y=p.y; return *this; }
Chris@16: 
Chris@16:     point2        operator<<(std::ptrdiff_t shift)         const   { return point2(x<<shift,y<<shift); }
Chris@16:     point2        operator>>(std::ptrdiff_t shift)         const   { return point2(x>>shift,y>>shift); }
Chris@16:     point2& operator+=(const point2& p)           { x+=p.x; y+=p.y; return *this; }
Chris@16:     point2& operator-=(const point2& p)           { x-=p.x; y-=p.y; return *this; }
Chris@16:     point2& operator/=(double t)                  { x/=t; y/=t; return *this; }
Chris@16: 
Chris@16:     const T& operator[](std::size_t i)          const   { return this->*mem_array[i]; }
Chris@16:           T& operator[](std::size_t i)                  { return this->*mem_array[i]; }
Chris@16: 
Chris@16:     T x,y;
Chris@16: private:
Chris@16:     // this static array of pointers to member variables makes operator[] safe and doesn't seem to exhibit any performance penalty
Chris@16:     static T point2<T>::* const mem_array[num_dimensions];
Chris@16: };
Chris@16: 
Chris@16: template <typename T>
Chris@16: T point2<T>::* const point2<T>::mem_array[point2<T>::num_dimensions] = { &point2<T>::x, &point2<T>::y };
Chris@16: 
Chris@16: /// \ingroup PointModel
Chris@16: template <typename T> GIL_FORCEINLINE
Chris@16: bool operator==(const point2<T>& p1, const point2<T>& p2) { return (p1.x==p2.x && p1.y==p2.y); }
Chris@16: /// \ingroup PointModel
Chris@16: template <typename T> GIL_FORCEINLINE
Chris@16: bool operator!=(const point2<T>& p1, const point2<T>& p2) { return  p1.x!=p2.x || p1.y!=p2.y; }
Chris@16: /// \ingroup PointModel
Chris@16: template <typename T> GIL_FORCEINLINE
Chris@16: point2<T> operator+(const point2<T>& p1, const point2<T>& p2) { return point2<T>(p1.x+p2.x,p1.y+p2.y); }
Chris@16: /// \ingroup PointModel
Chris@16: template <typename T> GIL_FORCEINLINE
Chris@16: point2<T> operator-(const point2<T>& p) { return point2<T>(-p.x,-p.y); }
Chris@16: /// \ingroup PointModel
Chris@16: template <typename T> GIL_FORCEINLINE
Chris@16: point2<T> operator-(const point2<T>& p1, const point2<T>& p2) { return point2<T>(p1.x-p2.x,p1.y-p2.y); }
Chris@16: /// \ingroup PointModel
Chris@16: template <typename T> GIL_FORCEINLINE
Chris@16: point2<double> operator/(const point2<T>& p, double t)      { return t==0 ? point2<double>(0,0):point2<double>(p.x/t,p.y/t); }
Chris@16: /// \ingroup PointModel
Chris@16: template <typename T> GIL_FORCEINLINE
Chris@16: point2<T> operator*(const point2<T>& p, std::ptrdiff_t t)      { return point2<T>(p.x*t,p.y*t); }
Chris@16: /// \ingroup PointModel
Chris@16: template <typename T> GIL_FORCEINLINE
Chris@16: point2<T> operator*(std::ptrdiff_t t, const point2<T>& p)      { return point2<T>(p.x*t,p.y*t); }
Chris@16: 
Chris@16: /// \ingroup PointModel
Chris@16: template <std::size_t K, typename T> GIL_FORCEINLINE
Chris@16: const T& axis_value(const point2<T>& p) { return p[K]; }
Chris@16: 
Chris@16: /// \ingroup PointModel
Chris@16: template <std::size_t K, typename T> GIL_FORCEINLINE
Chris@16:       T& axis_value(      point2<T>& p) { return p[K]; }
Chris@16: 
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: ///  Rounding of real numbers / points to integers / integer points
Chris@16: ///
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: inline std::ptrdiff_t iround(float x ) { return static_cast<std::ptrdiff_t>(x + (x < 0.0f ? -0.5f : 0.5f)); }
Chris@16: inline std::ptrdiff_t iround(double x) { return static_cast<std::ptrdiff_t>(x + (x < 0.0 ? -0.5 : 0.5)); }
Chris@16: inline std::ptrdiff_t ifloor(float x ) { return static_cast<std::ptrdiff_t>(std::floor(x)); }
Chris@16: inline std::ptrdiff_t ifloor(double x) { return static_cast<std::ptrdiff_t>(std::floor(x)); }
Chris@16: inline std::ptrdiff_t iceil(float x )  { return static_cast<std::ptrdiff_t>(std::ceil(x)); }
Chris@16: inline std::ptrdiff_t iceil(double x)  { return static_cast<std::ptrdiff_t>(std::ceil(x)); }
Chris@16: 
Chris@16: /**
Chris@16: \addtogroup PointAlgorithm
Chris@16: 
Chris@16: Example:
Chris@16: \code
Chris@16: assert(iround(point2<double>(3.1, 3.9)) == point2<std::ptrdiff_t>(3,4));
Chris@16: \endcode
Chris@16: */
Chris@16: 
Chris@16: /// \ingroup PointAlgorithm
Chris@16: inline point2<std::ptrdiff_t> iround(const point2<float >& p)  { return point2<std::ptrdiff_t>(iround(p.x),iround(p.y)); }
Chris@16: /// \ingroup PointAlgorithm
Chris@16: inline point2<std::ptrdiff_t> iround(const point2<double>& p)  { return point2<std::ptrdiff_t>(iround(p.x),iround(p.y)); }
Chris@16: /// \ingroup PointAlgorithm
Chris@16: inline point2<std::ptrdiff_t> ifloor(const point2<float >& p)  { return point2<std::ptrdiff_t>(ifloor(p.x),ifloor(p.y)); }
Chris@16: /// \ingroup PointAlgorithm
Chris@16: inline point2<std::ptrdiff_t> ifloor(const point2<double>& p)  { return point2<std::ptrdiff_t>(ifloor(p.x),ifloor(p.y)); }
Chris@16: /// \ingroup PointAlgorithm
Chris@16: inline point2<std::ptrdiff_t> iceil (const point2<float >& p)  { return point2<std::ptrdiff_t>(iceil(p.x), iceil(p.y)); }
Chris@16: /// \ingroup PointAlgorithm
Chris@16: inline point2<std::ptrdiff_t> iceil (const point2<double>& p)  { return point2<std::ptrdiff_t>(iceil(p.x), iceil(p.y)); }
Chris@16: 
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: ///  computing size with alignment
Chris@16: ///
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: template <typename T> 
Chris@16: inline T align(T val, std::size_t alignment) { 
Chris@16:     return val+(alignment - val%alignment)%alignment; 
Chris@16: }
Chris@16: 
Chris@16: /// \brief Helper base class for pixel dereference adaptors. 
Chris@16: /// \ingroup PixelDereferenceAdaptorModel
Chris@16: ///
Chris@16: template <typename ConstT, typename Value, typename Reference, typename ConstReference,
Chris@16:           typename ArgType, typename ResultType, bool IsMutable>
Chris@16: struct deref_base : public std::unary_function<ArgType, ResultType> {
Chris@16:     typedef ConstT         const_t;
Chris@16:     typedef Value          value_type;
Chris@16:     typedef Reference      reference;
Chris@16:     typedef ConstReference const_reference;
Chris@16:     BOOST_STATIC_CONSTANT(bool, is_mutable = IsMutable);
Chris@16: };
Chris@16: 
Chris@16: /// \brief Composes two dereference function objects. Similar to std::unary_compose but needs to pull some typedefs from the component types.  Models: PixelDereferenceAdaptorConcept
Chris@16: /// \ingroup PixelDereferenceAdaptorModel
Chris@16: ///
Chris@16: template <typename D1, typename D2>
Chris@16: class deref_compose : public deref_base<
Chris@16:       deref_compose<typename D1::const_t, typename D2::const_t>,
Chris@16:       typename D1::value_type, typename D1::reference, typename D1::const_reference, 
Chris@16:       typename D2::argument_type, typename D1::result_type, D1::is_mutable && D2::is_mutable>
Chris@16: {
Chris@16: public:
Chris@16:     D1 _fn1;
Chris@16:     D2 _fn2;
Chris@16: 
Chris@16:     typedef typename D2::argument_type   argument_type;
Chris@16:     typedef typename D1::result_type     result_type;
Chris@16: 
Chris@16:     deref_compose() {}
Chris@16:     deref_compose(const D1& x, const D2& y) : _fn1(x), _fn2(y) {}
Chris@16:     deref_compose(const deref_compose& dc)  : _fn1(dc._fn1), _fn2(dc._fn2) {}
Chris@16:     template <typename _D1, typename _D2> deref_compose(const deref_compose<_D1,_D2>& dc) : _fn1(dc._fn1), _fn2(dc._fn2) {}
Chris@16: 
Chris@16:     result_type operator()(argument_type x) const { return _fn1(_fn2(x)); }
Chris@16:     result_type operator()(argument_type x)       { return _fn1(_fn2(x)); }
Chris@16: };
Chris@16: 
Chris@16: // reinterpret_cast is implementation-defined. Static cast is not.
Chris@16: template <typename OutPtr, typename In> GIL_FORCEINLINE
Chris@16:       OutPtr gil_reinterpret_cast(      In* p) { return static_cast<OutPtr>(static_cast<void*>(p)); }
Chris@16: 
Chris@16: template <typename OutPtr, typename In> GIL_FORCEINLINE
Chris@16: const OutPtr gil_reinterpret_cast_c(const In* p) { return static_cast<const OutPtr>(static_cast<const void*>(p)); }
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: ///
Chris@16: ///  \brief copy_n taken from SGI STL.
Chris@16: ///
Chris@16: ////////////////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: template <class InputIter, class Size, class OutputIter>
Chris@16: std::pair<InputIter, OutputIter> _copy_n(InputIter first, Size count,
Chris@16:                                          OutputIter result,
Chris@16:                                          std::input_iterator_tag) {
Chris@16:    for ( ; count > 0; --count) {
Chris@16:       *result = *first;
Chris@16:       ++first;
Chris@16:       ++result;
Chris@16:    }
Chris@16:    return std::pair<InputIter, OutputIter>(first, result);
Chris@16: }
Chris@16: 
Chris@16: template <class RAIter, class Size, class OutputIter>
Chris@16: inline std::pair<RAIter, OutputIter>
Chris@16: _copy_n(RAIter first, Size count, OutputIter result, std::random_access_iterator_tag) {
Chris@16:    RAIter last = first + count;
Chris@16:    return std::pair<RAIter, OutputIter>(last, std::copy(first, last, result));
Chris@16: }
Chris@16: 
Chris@16: template <class InputIter, class Size, class OutputIter>
Chris@16: inline std::pair<InputIter, OutputIter>
Chris@16: _copy_n(InputIter first, Size count, OutputIter result) {
Chris@16:    return _copy_n(first, count, result, typename std::iterator_traits<InputIter>::iterator_category());
Chris@16: }
Chris@16: 
Chris@16: template <class InputIter, class Size, class OutputIter>
Chris@16: inline std::pair<InputIter, OutputIter>
Chris@16: copy_n(InputIter first, Size count, OutputIter result) {
Chris@16:     return detail::_copy_n(first, count, result);
Chris@16: }
Chris@16: 
Chris@16: /// \brief identity taken from SGI STL.
Chris@16: template <typename T> 
Chris@16: struct identity : public std::unary_function<T,T> {
Chris@16:     const T& operator()(const T& val) const { return val; }
Chris@16: };
Chris@16: 
Chris@16: /*************************************************************************************************/
Chris@16: 
Chris@16: /// \brief plus function object whose arguments may be of different type.
Chris@16: template <typename T1, typename T2>
Chris@16: struct plus_asymmetric : public std::binary_function<T1,T2,T1> {
Chris@16:     T1 operator()(T1 f1, T2 f2) const {
Chris@16:         return f1+f2;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: /*************************************************************************************************/
Chris@16: 
Chris@16: /// \brief operator++ wrapped in a function object
Chris@16: template <typename T>
Chris@16: struct inc : public std::unary_function<T,T> {
Chris@16:     T operator()(T x) const { return ++x; }
Chris@16: };
Chris@16: 
Chris@16: /*************************************************************************************************/
Chris@16: 
Chris@16: /// \brief operator-- wrapped in a function object
Chris@16: template <typename T>
Chris@16: struct dec : public std::unary_function<T,T> {
Chris@16:     T operator()(T x) const { return --x; }
Chris@16: };
Chris@16: 
Chris@16: /// \brief Returns the index corresponding to the first occurrance of a given given type in 
Chris@16: //         a given MPL RandomAccessSequence (or size if the type is not present)
Chris@16: template <typename Types, typename T>
Chris@16: struct type_to_index 
Chris@16:     : public mpl::distance<typename mpl::begin<Types>::type, 
Chris@16:                                   typename mpl::find<Types,T>::type>::type {};
Chris@16: } // namespace detail
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: /// \ingroup ColorSpaceAndLayoutModel
Chris@16: /// \brief Represents a color space and ordering of channels in memory
Chris@16: template <typename ColorSpace, typename ChannelMapping = mpl::range_c<int,0,mpl::size<ColorSpace>::value> >
Chris@16: struct layout {
Chris@16:     typedef ColorSpace      color_space_t;
Chris@16:     typedef ChannelMapping  channel_mapping_t;
Chris@16: };
Chris@16: 
Chris@16: /// \brief A version of swap that also works with reference proxy objects
Chris@16: template <typename Value, typename T1, typename T2> // where value_type<T1>  == value_type<T2> == Value
Chris@16: void swap_proxy(T1& left, T2& right) {
Chris@16:     Value tmp = left;
Chris@16:     left = right;
Chris@16:     right = tmp;
Chris@16: }
Chris@16: 
Chris@16: /// \brief Run-time detection of whether the underlying architecture is little endian
Chris@16: inline bool little_endian() {
Chris@16:     short tester = 0x0001;
Chris@16:     return  *(char*)&tester!=0;
Chris@16: }
Chris@16: /// \brief Run-time detection of whether the underlying architecture is big endian
Chris@16: inline bool big_endian() {
Chris@16:     return !little_endian();
Chris@16: }
Chris@16: 
Chris@16: } }  // namespace boost::gil
Chris@16: 
Chris@16: #endif