Generic Image Library : utilities.hpp Source File

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# utilities.hpp

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    00001 /*
    00002     Copyright 2005-2007 Adobe Systems Incorporated
    00003
    00004     Use, modification and distribution are subject to the Boost Software License,
    00005     Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
    00006     http://www.boost.org/LICENSE_1_0.txt).
    00007
    00008     See http://opensource.adobe.com/gil for most recent version including documentation.
    00009 */
    00010
    00011 /*************************************************************************************************/
    00012
    00013 #ifndef GIL_UTILITIES_H
    00014 #define GIL_UTILITIES_H
    00015
    00016 #include "gil_config.hpp"
    00017 #include <functional>
    00018 #include <cmath>
    00019 #include <cstddef>
    00020 #include <boost/static_assert.hpp>
    00021 #include <boost/type_traits.hpp>
    00022 #include <boost/mpl/size.hpp>
    00023 #include <boost/mpl/distance.hpp>
    00024 #include <boost/mpl/begin.hpp>
    00025 #include <boost/mpl/find.hpp>
    00026 #include <boost/mpl/range_c.hpp>
    00027 #include <boost/iterator/iterator_adaptor.hpp>
    00028 #include <boost/iterator/iterator_facade.hpp>
    00029
    00039
    00040 namespace boost { namespace gil {
    00041
    00054
    00055 //                           CLASS point2
    00062
    00063 template <typename T>
    00064 class point2 {
    00065 public:
    00066     typedef T value_type;
    00067     template <std::size_t D> struct axis { typedef value_type coord_t; };
    00068     static const std::size_t num_dimensions=2;
    00069
    00070     point2()                : x(0),     y(0)    {}
    00071     point2(T newX, T newY)  : x(newX),  y(newY) {}
    00072     point2(const point2& p) : x(p.x), y(p.y) {}
    00073     ~point2() {}
    00074
    00075     point2& operator=(const point2& p)            { x=p.x; y=p.y; return *this; }
    00076
    00077     point2        operator<<(int shift)         const   { return point2(x<<shift,y<<shift); }
    00078     point2        operator>>(int shift)         const   { return point2(x>>shift,y>>shift); }
    00079     point2& operator+=(const point2& p)           { x+=p.x; y+=p.y; return *this; }
    00080     point2& operator-=(const point2& p)           { x-=p.x; y-=p.y; return *this; }
    00081     point2& operator/=(double t)                  { x/=t; y/=t; return *this; }
    00082
    00083     const T& operator[](std::size_t i)          const   { return this->*mem_array[i]; }
    00084           T& operator[](std::size_t i)                  { return this->*mem_array[i]; }
    00085
    00086     T x,y;
    00087 private:
    00088     // this static array of pointers to member variables makes operator[] safe and doesn't seem to exhibit any performance penalty
    00089     static T point2<T>::* const mem_array[num_dimensions];
    00090 };
    00091
    00092 template <typename T>
    00093 T point2<T>::* const point2<T>::mem_array[point2<T>::num_dimensions] = { &point2<T>::x, &point2<T>::y };
    00094
    00096 template <typename T> GIL_FORCEINLINE
    00097 bool operator==(const point2<T>& p1, const point2<T>& p2) { return (p1.x==p2.x && p1.y==p2.y); }
    00099 template <typename T> GIL_FORCEINLINE
    00100 bool operator!=(const point2<T>& p1, const point2<T>& p2) { return  p1.x!=p2.x || p1.y!=p2.y; }
    00102 template <typename T> GIL_FORCEINLINE
    00103 point2<T> operator+(const point2<T>& p1, const point2<T>& p2) { return point2<T>(p1.x+p2.x,p1.y+p2.y); }
    00105 template <typename T> GIL_FORCEINLINE
    00106 point2<T> operator-(const point2<T>& p) { return point2<T>(-p.x,-p.y); }
    00108 template <typename T> GIL_FORCEINLINE
    00109 point2<T> operator-(const point2<T>& p1, const point2<T>& p2) { return point2<T>(p1.x-p2.x,p1.y-p2.y); }
    00111 template <typename T> GIL_FORCEINLINE
    00112 point2<double> operator/(const point2<T>& p, double t)      { return t==0 ? point2<double>(0,0):point2<double>(p.x/t,p.y/t); }
    00114 template <typename T> GIL_FORCEINLINE
    00115 point2<T> operator*(const point2<T>& p, int t)      { return point2<T>(p.x*t,p.y*t); }
    00117 template <typename T> GIL_FORCEINLINE
    00118 point2<T> operator*(int t, const point2<T>& p)      { return point2<T>(p.x*t,p.y*t); }
    00119
    00121 template <std::size_t K, typename T> GIL_FORCEINLINE
    00122 const T& axis_value(const point2<T>& p) { return p[K]; }
    00123
    00125 template <std::size_t K, typename T> GIL_FORCEINLINE
    00126       T& axis_value(      point2<T>& p) { return p[K]; }
    00127
    00133
    00134 inline int iround(float x ) { return static_cast<int>(x + (x < 0.0f ? -0.5f : 0.5f)); }
    00135 inline int iround(double x) { return static_cast<int>(x + (x < 0.0 ? -0.5 : 0.5)); }
    00136 inline int ifloor(float x ) { return static_cast<int>(std::floor(x)); }
    00137 inline int ifloor(double x) { return static_cast<int>(std::floor(x)); }
    00138 inline int iceil(float x )  { return static_cast<int>(std::ceil(x)); }
    00139 inline int iceil(double x)  { return static_cast<int>(std::ceil(x)); }
    00140
    00150
    00151 inline point2<int> iround(const point2<float >& p)  { return point2<int>(iround(p.x),iround(p.y)); }
    00153 inline point2<int> iround(const point2<double>& p)  { return point2<int>(iround(p.x),iround(p.y)); }
    00155 inline point2<int> ifloor(const point2<float >& p)  { return point2<int>(ifloor(p.x),ifloor(p.y)); }
    00157 inline point2<int> ifloor(const point2<double>& p)  { return point2<int>(ifloor(p.x),ifloor(p.y)); }
    00159 inline point2<int> iceil (const point2<float >& p)  { return point2<int>(iceil(p.x), iceil(p.y)); }
    00161 inline point2<int> iceil (const point2<double>& p)  { return point2<int>(iceil(p.x), iceil(p.y)); }
    00162
    00168
    00169 template <typename T>
    00170 inline T align(T val, std::size_t alignment) {
    00171     return val+(alignment - val%alignment)%alignment;
    00172 }
    00173
    00177 template <typename ConstT, typename Value, typename Reference, typename ConstReference,
    00178                   typename ArgType, typename ResultType, bool IsMutable>
    00179 struct deref_base : public std::unary_function<ArgType, ResultType> {
    00180     typedef ConstT         const_t;
    00181         typedef Value          value_type;
    00182         typedef Reference      reference;
    00183         typedef ConstReference const_reference;
    00184         BOOST_STATIC_CONSTANT(bool, is_mutable = IsMutable);
    00185 };
    00186
    00190 template <typename D1, typename D2>
    00191 class deref_compose : public deref_base<
    00192       deref_compose<typename D1::const_t, typename D2::const_t>,
    00193           typename D1::value_type, typename D1::reference, typename D1::const_reference,
    00194           typename D2::argument_type, typename D1::result_type, D1::is_mutable && D2::is_mutable>
    00195 {
    00196 public:
    00197     D1 _fn1;
    00198     D2 _fn2;
    00199
    00200     typedef typename D2::argument_type   argument_type;
    00201     typedef typename D1::result_type     result_type;
    00202
    00203     deref_compose() {}
    00204     deref_compose(const D1& x, const D2& y) : _fn1(x), _fn2(y) {}
    00205     deref_compose(const deref_compose& dc)  : _fn1(dc._fn1), _fn2(dc._fn2) {}
    00206     template <typename _D1, typename _D2> deref_compose(const deref_compose<_D1,_D2>& dc) : _fn1(dc._fn1), _fn2(dc._fn2) {}
    00207
    00208     result_type operator()(argument_type x) const { return _fn1(_fn2(x)); }
    00209     result_type operator()(argument_type x)       { return _fn1(_fn2(x)); }
    00210 };
    00211
    00212 // reinterpret_cast is implementation-defined. Static cast is not.
    00213 template <typename OutPtr, typename In> GIL_FORCEINLINE
    00214       OutPtr gil_reinterpret_cast(      In* p) { return static_cast<OutPtr>(static_cast<void*>(p)); }
    00215
    00216 template <typename OutPtr, typename In> GIL_FORCEINLINE
    00217 const OutPtr gil_reinterpret_cast_c(const In* p) { return static_cast<const OutPtr>(static_cast<const void*>(p)); }
    00218
    00219 namespace detail {
    00220
    00226
    00227 template <class InputIter, class Size, class OutputIter>
    00228 std::pair<InputIter, OutputIter> _copy_n(InputIter first, Size count,
    00229                                          OutputIter result,
    00230                                          std::input_iterator_tag) {
    00231    for ( ; count > 0; --count) {
    00232       *result = *first;
    00233       ++first;
    00234       ++result;
    00235    }
    00236    return std::pair<InputIter, OutputIter>(first, result);
    00237 }
    00238
    00239 template <class RAIter, class Size, class OutputIter>
    00240 inline std::pair<RAIter, OutputIter>
    00241 _copy_n(RAIter first, Size count, OutputIter result, std::random_access_iterator_tag) {
    00242    RAIter last = first + count;
    00243    return std::pair<RAIter, OutputIter>(last, std::copy(first, last, result));
    00244 }
    00245
    00246 template <class InputIter, class Size, class OutputIter>
    00247 inline std::pair<InputIter, OutputIter>
    00248 _copy_n(InputIter first, Size count, OutputIter result) {
    00249    return _copy_n(first, count, result, typename std::iterator_traits<InputIter>::iterator_category());
    00250 }
    00251
    00252 template <class InputIter, class Size, class OutputIter>
    00253 inline std::pair<InputIter, OutputIter>
    00254 copy_n(InputIter first, Size count, OutputIter result) {
    00255     return detail::_copy_n(first, count, result);
    00256 }
    00257
    00259 template <typename T>
    00260 struct identity : public std::unary_function<T,T> {
    00261     const T& operator()(const T& val) const { return val; }
    00262 };
    00263
    00264 /*************************************************************************************************/
    00265
    00267 template <typename T1, typename T2>
    00268 struct plus_asymmetric : public std::binary_function<T1,T2,T1> {
    00269     T1 operator()(T1 f1, T2 f2) const {
    00270         return f1+f2;
    00271     }
    00272 };
    00273
    00274 /*************************************************************************************************/
    00275
    00277 template <typename T>
    00278 struct inc : public std::unary_function<T,T> {
    00279     T operator()(T x) const { return ++x; }
    00280 };
    00281
    00282 /*************************************************************************************************/
    00283
    00285 template <typename T>
    00286 struct dec : public std::unary_function<T,T> {
    00287     T operator()(T x) const { return --x; }
    00288 };
    00289
    00291 //         a given MPL RandomAccessSequence (or size if the type is not present)
    00292 template <typename Types, typename T>
    00293 struct type_to_index
    00294     : public mpl::distance<typename mpl::begin<Types>::type,
    00295                                   typename mpl::find<Types,T>::type>::type {};
    00296 } // namespace detail
    00297
    00298
    00299
    00302 template <typename ColorSpace, typename ChannelMapping = mpl::range_c<int,0,mpl::size<ColorSpace>::value> >
    00303 struct layout {
    00304     typedef ColorSpace      color_space_t;
    00305     typedef ChannelMapping  channel_mapping_t;
    00306 };
    00307
    00309 template <typename Value, typename T1, typename T2> // where value_type<T1>  == value_type<T2> == Value
    00310 void swap_proxy(T1& left, T2& right) {
    00311     Value tmp = left;
    00312     left = right;
    00313     right = tmp;
    00314 }
    00315
    00317 inline bool little_endian() {
    00318     short tester = 0x0001;
    00319     return  *(char*)&tester!=0;
    00320 }
    00322 inline bool big_endian() {
    00323     return !little_endian();
    00324 }
    00325
    00326 } }  // namespace boost::gil
    00327
    00328 #endif