text: /*
   * Copyright 2013 The Android Open Source Project
   *
   * 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.
   */
  
  #ifndef MATH_VEC3_H_
  #define MATH_VEC3_H_
  
  #include <math/vec2.h>
  #include <math/half.h>
  #include <stdint.h>
  #include <sys/types.h>
  
  
  namespace filament {
  namespace math {
  // -------------------------------------------------------------------------------------
  
  namespace details {
  
  template<typename T>
  class MATH_EMPTY_BASES TVec3 :
          public TVecProductOperators<TVec3, T>,
          public TVecAddOperators<TVec3, T>,
          public TVecUnaryOperators<TVec3, T>,
          public TVecComparisonOperators<TVec3, T>,
          public TVecFunctions<TVec3, T>,
          public TVecDebug<TVec3, T> {
  public:
      typedef T value_type;
      typedef T& reference;
      typedef T const& const_reference;
      typedef size_t size_type;
      static constexpr size_t SIZE = 3;
  
      union {
          T v[SIZE] MATH_CONSTEXPR_INIT;
          TVec2<T> xy;
          TVec2<T> st;
          TVec2<T> rg;
          struct {
              union {
                  T x;
                  T s;
                  T r;
              };
              union {
                  struct { T y, z; };
                  struct { T t, p; };
                  struct { T g, b; };
                  TVec2<T> yz;
                  TVec2<T> tp;
                  TVec2<T> gb;
              };
          };
      };
  
      inline constexpr size_type size() const { return SIZE; }
  
      // array access
      inline constexpr T const& operator[](size_t i) const noexcept {
          // only possible in C++0x14 with constexpr
          assert(i < SIZE);
          return v[i];
      }
  
      inline constexpr T& operator[](size_t i) noexcept {
          assert(i < SIZE);
          return v[i];
      }
  
      // constructors
  
      // default constructor
      MATH_DEFAULT_CTOR_CONSTEXPR TVec3() noexcept MATH_DEFAULT_CTOR
  
      // handles implicit conversion to a tvec3. must not be explicit.
      template<typename A, typename = enable_if_arithmetic_t<A>>
      constexpr TVec3(A v) noexcept : v{ T(v), T(v), T(v) } {}
  
      template<typename A, typename B, typename C,
              typename = enable_if_arithmetic_t<A, B, C>>
      constexpr TVec3(A x, B y, C z) noexcept : v{ T(x), T(y), T(z) } {}
  
      template<typename A, typename B, typename = enable_if_arithmetic_t<A, B>>
      constexpr TVec3(const TVec2<A>& v, B z) noexcept : v{ T(v[0]), T(v[1]), T(z) } {}
  
      template<typename A, typename = enable_if_arithmetic_t<A>>
      constexpr TVec3(const TVec3<A>& v) noexcept : v{ T(v[0]), T(v[1]), T(v[2]) } {}
  
      // cross product works only on vectors of size 3
      template<typename U>
      friend inline constexpr
      TVec3<arithmetic_result_t<T, U>> cross(const TVec3& u, const TVec3<U>& v) noexcept {
          return {
                  u[1] * v[2] - u[2] * v[1],
                  u[2] * v[0] - u[0] * v[2],
                  u[0] * v[1] - u[1] * v[0] };
      }
  };
  
  }  // namespace details
  
  // ----------------------------------------------------------------------------------------
  
  template<typename T, typename = details::enable_if_arithmetic_t<T>>
  using vec3 = details::TVec3<T>;
  
  using double3 = vec3<double>;
  using float3 = vec3<float>;
  using half3 = vec3<half>;
  using int3 = vec3<int32_t>;
  using uint3 = vec3<uint32_t>;
  using short3 = vec3<int16_t>;
  using ushort3 = vec3<uint16_t>;
  using byte3 = vec3<int8_t>;
  using ubyte3 = vec3<uint8_t>;
  using bool3 = vec3<bool>;
  
  // ----------------------------------------------------------------------------------------
  }  // namespace math
  }  // namespace filament
  
  #endif  // MATH_VEC3_H_
  