add macOS implementation

macos/include/math/vec3.h

@@ -0,0 +1,133 @@
+/*
+ * 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 TNT_MATH_VEC3_H
+#define TNT_MATH_VEC3_H
+
+#include <math/half.h>
+#include <math/vec2.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:
+    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 {
+        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  // TNT_MATH_VEC3_H