libcruft-util/colour.hpp

121 lines
3.2 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2010-2017 Danny Robson <danny@nerdcruft.net>
*/
#ifndef __UTIL_COLOUR_HPP
#define __UTIL_COLOUR_HPP
#include "coord.hpp"
#include "introspection.hpp"
#include <ostream>
#include <type_traits>
namespace util {
/// An abstract colour POD type componsed of S components of type T.
///
/// Not to be used directly, instead the use of derived types is required.
/// This exists purely to simplify generic colour code.
template <
size_t S,
typename T,
typename SelfT
>
struct colour : coord::base<S,T,SelfT> {
using coord::base<S,T,SelfT>::base;
template <typename U>
auto
cast (void) const
{
::util::revalue_t<SelfT,U> ret;
std::transform (std::begin (*this),
std::end (*this),
std::begin (ret),
renormalise<T,U>);
return ret;
}
};
template <typename T>
struct util::coord::store<1,T,srgba<1,T>> {
union { struct { T r; }; T data[1]; };
};
template <typename T>
struct util::coord::store<2,T,srgba<2,T>> {
union { struct { T r, g; }; T data[2]; };
};
template <typename T>
struct util::coord::store<3,T,srgba<3,T>> {
union { struct { T r, g, b; }; T data[3]; };
};
template <typename T>
struct util::coord::store<4,T,srgba<4,T>> {
union { struct { T r, g, b, a; }; T data[4]; };
};
template <size_t S, typename T> struct srgba : colour<S,T,srgba<S,T>> {
using colour<S,T,srgba<S,T>>::colour;
};
using srgba3f = srgba<3,float>;
using srgba4f = srgba<4,float>;
using srgba3u = srgba<3,uint8_t>;
using srgba4u = srgba<4,uint8_t>;
template <size_t S, typename T> struct hsva : colour<S,T,hsva<S,T>> {};
template <size_t S, typename T>
struct redim_type<
srgba<S,T>
> { template <size_t _S> using type = srgba<_S,T>; };
template <size_t S, typename T>
struct revalue_type<srgba<S,T>> {
template <typename _T>
using type = srgba<S,_T>;
};
template <typename> struct is_colour : public std::false_type {};
template <
size_t S,
typename T,
template <
size_t,
typename
> typename ColourT
> struct is_colour<ColourT<S,T>>
:std::conditional_t<
std::is_base_of_v<
colour<S,T,ColourT<S,T>>,
ColourT<S,T>
>,
std::true_type,
std::false_type
> {};
template <typename T>
constexpr auto is_colour_v = is_colour<T>::value;
}
#include "colour.ipp"
#endif