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89 lines
4.0 KiB
89 lines
4.0 KiB
#ifndef Magnum_Math_Swizzle_h |
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#define Magnum_Math_Swizzle_h |
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/* |
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This file is part of Magnum. |
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Copyright © 2010, 2011, 2012, 2013, 2014 |
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Vladimír Vondruš <mosra@centrum.cz> |
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Permission is hereby granted, free of charge, to any person obtaining a |
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copy of this software and associated documentation files (the "Software"), |
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to deal in the Software without restriction, including without limitation |
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the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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and/or sell copies of the Software, and to permit persons to whom the |
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Software is furnished to do so, subject to the following conditions: |
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The above copyright notice and this permission notice shall be included |
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in all copies or substantial portions of the Software. |
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
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FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
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DEALINGS IN THE SOFTWARE. |
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*/ |
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/** @file |
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* @brief Function @ref Magnum::Math::swizzle() |
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*/ |
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#include "Magnum/Math/Vector.h" |
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namespace Magnum { namespace Math { |
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namespace Implementation { |
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template<std::size_t size, std::size_t position> struct ComponentAtPosition { |
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static_assert(size > position, "Swizzle parameter out of range of base vector"); |
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template<class T> constexpr static T value(const Math::Vector<size, T>& vector) { return vector[position]; } |
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}; |
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template<std::size_t size, char component> struct Component {}; |
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template<std::size_t size> struct Component<size, 'x'>: public ComponentAtPosition<size, 0> {}; |
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template<std::size_t size> struct Component<size, 'y'>: public ComponentAtPosition<size, 1> {}; |
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template<std::size_t size> struct Component<size, 'z'>: public ComponentAtPosition<size, 2> {}; |
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template<std::size_t size> struct Component<size, 'w'>: public ComponentAtPosition<size, 3> {}; |
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template<std::size_t size> struct Component<size, 'r'>: public ComponentAtPosition<size, 0> {}; |
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template<std::size_t size> struct Component<size, 'g'>: public ComponentAtPosition<size, 1> {}; |
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template<std::size_t size> struct Component<size, 'b'>: public ComponentAtPosition<size, 2> {}; |
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template<std::size_t size> struct Component<size, 'a'>: public ComponentAtPosition<size, 3> {}; |
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template<std::size_t size> struct Component<size, '0'> { |
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template<class T> constexpr static T value(const Math::Vector<size, T>&) { return T(0); } |
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}; |
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template<std::size_t size> struct Component<size, '1'> { |
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template<class T> constexpr static T value(const Math::Vector<size, T>&) { return T(1); } |
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}; |
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template<std::size_t size, class T> struct TypeForSize { |
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typedef Math::Vector<size, typename T::Type> Type; |
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}; |
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} |
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/** |
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@brief Swizzle Vector components |
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Creates new vector from given components. Example: |
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@code |
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Vector4i original(-1, 2, 3, 4); |
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auto vec = swizzle<'w', '1', '0', 'x', 'y', 'z'>(original); |
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// vec == { 4, 1, 0, -1, 2, 3 } |
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@endcode |
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You can use letters `x`, `y`, `z`, `w` and `r`, `g`, `b`, `a` for addressing |
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components or letters `0` and `1` for zero and one. Count of elements is |
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unlimited, but must be at least one. If the resulting vector is two, three or |
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four-component, corresponding @ref Math::Vector2, @ref Math::Vector3, |
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@ref Math::Vector4, @ref Color3 or @ref Color4 specialization is returned. |
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@see @ref matrix-vector-component-access, @ref Vector4::xyz(), |
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@ref Vector4::xy(), @ref Vector3::xy(), @ref BasicColor4::rgb() |
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*/ |
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template<char ...components, class T> constexpr typename Implementation::TypeForSize<sizeof...(components), T>::Type swizzle(const T& vector) { |
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return {Implementation::Component<T::Size, components>::value(vector)...}; |
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} |
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}} |
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#endif
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