mirror of https://github.com/mosra/magnum.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
75 lines
2.7 KiB
75 lines
2.7 KiB
14 years ago
|
#ifndef Magnum_Math_Swizzle_h
|
||
|
|
#define Magnum_Math_Swizzle_h
|
||
|
|
/*
|
||
|
|
Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
|
||
|
|
|
||
|
|
This file is part of Magnum.
|
||
|
|
|
||
|
|
Magnum is free software: you can redistribute it and/or modify
|
||
|
|
it under the terms of the GNU Lesser General Public License version 3
|
||
|
|
only, as published by the Free Software Foundation.
|
||
|
|
|
||
|
|
Magnum 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 Lesser General Public License version 3 for more details.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/** @file
|
||
|
|
* @brief Function Magnum::Math::swizzle()
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "Vector.h"
|
||
|
|
|
||
|
|
namespace Magnum { namespace Math {
|
||
|
|
|
||
|
|
#ifndef DOXYGEN_GENERATING_OUTPUT
|
||
|
|
namespace Implementation {
|
||
|
|
template<std::size_t size, std::size_t position> struct ComponentAtPosition {
|
||
|
|
static_assert(size > position, "Swizzle parameter out of range of base vector");
|
||
|
|
|
||
|
|
template<class T> inline constexpr static T value(const Math::Vector<size, T>& vector) { return vector[position]; }
|
||
|
|
};
|
||
|
|
|
||
|
|
template<std::size_t size, char component> struct Component {};
|
||
|
|
template<std::size_t size> struct Component<size, 'x'>: public ComponentAtPosition<size, 0> {};
|
||
|
|
template<std::size_t size> struct Component<size, 'y'>: public ComponentAtPosition<size, 1> {};
|
||
|
|
template<std::size_t size> struct Component<size, 'z'>: public ComponentAtPosition<size, 2> {};
|
||
|
|
template<std::size_t size> struct Component<size, 'w'>: public ComponentAtPosition<size, 3> {};
|
||
|
|
template<std::size_t size> struct Component<size, '0'> {
|
||
|
|
template<class T> inline constexpr static T value(const Math::Vector<size, T>&) { return T(0); }
|
||
|
|
};
|
||
|
|
template<std::size_t size> struct Component<size, '1'> {
|
||
|
|
template<class T> inline constexpr static T value(const Math::Vector<size, T>&) { return T(1); }
|
||
|
|
};
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/**
|
||
|
|
@brief Swizzle Vector components
|
||
|
|
|
||
|
|
Creates new vector from given components. Example:
|
||
|
|
@code
|
||
|
|
Vector4<std::int32_t> original(-1, 2, 3, 4);
|
||
|
|
|
||
|
|
auto vec = swizzle<'w', '1', '0', 'x', 'y', 'z'>(original);
|
||
|
|
// vec == { 4, 1, 0, -1, 2, 3 }
|
||
|
|
@endcode
|
||
|
|
You can use letters `x`, `y`, `z`, `w` for addressing components or letters
|
||
|
|
`0` and `1` for zero and one. Count of elements is unlimited, but must be at
|
||
|
|
least one.
|
||
|
|
|
||
|
|
See also Magnum::swizzle() which has some added convenience features not
|
||
|
|
present in this lightweight implementation for Math namespace.
|
||
|
|
|
||
|
|
@see @ref matrix-vector-component-access, Vector4::xyz(),
|
||
|
|
Vector4::xy(), Vector3::xy()
|
||
|
|
*/
|
||
|
|
template<char ...components, std::size_t size, class T> inline constexpr Vector<sizeof...(components), T> swizzle(const Vector<size, T>& vector) {
|
||
|
|
return {Implementation::Component<size, components>::value(vector)...};
|
||
|
|
}
|
||
|
|
|
||
|
|
}}
|
||
|
|
|
||
|
|
#endif
|