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ios/include/math/vec2.h

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+/*
+ * 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_VEC2_H_
+#define MATH_VEC2_H_
+
+#include <math/TVecHelpers.h>
+#include <math/half.h>
+#include <assert.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <type_traits>
+
+
+namespace filament {
+namespace math {
+// -------------------------------------------------------------------------------------
+
+namespace details {
+
+template<typename T>
+class MATH_EMPTY_BASES TVec2 :
+        public TVecProductOperators<TVec2, T>,
+        public TVecAddOperators<TVec2, T>,
+        public TVecUnaryOperators<TVec2, T>,
+        public TVecComparisonOperators<TVec2, T>,
+        public TVecFunctions<TVec2, T> {
+public:
+    typedef T value_type;
+    typedef T& reference;
+    typedef T const& const_reference;
+    typedef size_t size_type;
+    static constexpr size_t SIZE = 2;
+
+    union {
+        T v[SIZE] MATH_CONSTEXPR_INIT;
+        struct { T x, y; };
+        struct { T s, t; };
+        struct { T r, g; };
+    };
+
+    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 TVec2() MATH_DEFAULT_CTOR
+
+    // handles implicit conversion to a tvec4. must not be explicit.
+    template<typename A, typename = enable_if_arithmetic_t<A>>
+    constexpr TVec2(A v) noexcept : v{ T(v), T(v) } {}
+
+    template<typename A, typename B, typename = enable_if_arithmetic_t<A, B>>
+    constexpr TVec2(A x, B y) noexcept : v{ T(x), T(y) } {}
+
+    template<typename A, typename = enable_if_arithmetic_t<A>>
+    constexpr TVec2(const TVec2<A>& v) noexcept : v{ T(v[0]), T(v[1]) } {}
+
+    // cross product works only on vectors of size 2 or 3
+    template<typename U>
+    friend inline constexpr
+    arithmetic_result_t<T, U> cross(const TVec2& u, const TVec2<U>& v) noexcept {
+        return u[0] * v[1] - u[1] * v[0];
+    }
+};
+
+}  // namespace details
+
+// ----------------------------------------------------------------------------------------
+
+template<typename T, typename = details::enable_if_arithmetic_t<T>>
+using vec2 = details::TVec2<T>;
+
+using double2 = vec2<double>;
+using float2 = vec2<float>;
+using half2 = vec2<half>;
+using int2 = vec2<int32_t>;
+using uint2 = vec2<uint32_t>;
+using short2 = vec2<int16_t>;
+using ushort2 = vec2<uint16_t>;
+using byte2 = vec2<int8_t>;
+using ubyte2 = vec2<uint8_t>;
+using bool2 = vec2<bool>;
+
+// ----------------------------------------------------------------------------------------
+}  // namespace math
+}  // namespace filament
+
+#endif  // MATH_VEC2_H_