1 /*
2  * Copyright 2013 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <math/TVecHelpers.h>
20 #include <math/half.h>
21 #include <assert.h>
22 #include <stdint.h>
23 #include <sys/types.h>
24 #include <type_traits>
25 
26 #pragma clang diagnostic push
27 #pragma clang diagnostic ignored "-Wgnu-anonymous-struct"
28 #pragma clang diagnostic ignored "-Wnested-anon-types"
29 
30 namespace android {
31 // -------------------------------------------------------------------------------------
32 
33 namespace details {
34 
35 template <typename T>
36 class TVec2 :   public TVecProductOperators<TVec2, T>,
37                 public TVecAddOperators<TVec2, T>,
38                 public TVecUnaryOperators<TVec2, T>,
39                 public TVecComparisonOperators<TVec2, T>,
40                 public TVecFunctions<TVec2, T>,
41                 public TVecDebug<TVec2, T> {
42 public:
43     enum no_init { NO_INIT };
44     typedef T value_type;
45     typedef T& reference;
46     typedef T const& const_reference;
47     typedef size_t size_type;
48 
49     union {
50         struct { T x, y; };
51         struct { T s, t; };
52         struct { T r, g; };
53     };
54 
55     static constexpr size_t SIZE = 2;
size()56     inline constexpr size_type size() const { return SIZE; }
57 
58     // array access
59     inline constexpr T const& operator[](size_t i) const {
60 #if __cplusplus >= 201402L
61         // only possible in C++0x14 with constexpr
62         assert(i < SIZE);
63 #endif
64         return (&x)[i];
65     }
66 
67     inline T& operator[](size_t i) {
68         assert(i < SIZE);
69         return (&x)[i];
70     }
71 
72     // -----------------------------------------------------------------------
73     // we want the compiler generated versions for these...
74     TVec2(const TVec2&) = default;
75     ~TVec2() = default;
76     TVec2& operator = (const TVec2&) = default;
77 
78     // constructors
79 
80     // leaves object uninitialized. use with caution.
81     explicit
TVec2(no_init)82     constexpr TVec2(no_init) { }
83 
84     // default constructor
TVec2()85     constexpr TVec2() : x(0), y(0) { }
86 
87     // handles implicit conversion to a tvec4. must not be explicit.
88     template<typename A, typename = typename std::enable_if<std::is_arithmetic<A>::value >::type>
TVec2(A v)89     constexpr TVec2(A v) : x(v), y(v) { }
90 
91     template<typename A, typename B>
TVec2(A x,B y)92     constexpr TVec2(A x, B y) : x(static_cast<T>(x)), y(static_cast<T>(y)) { }
93 
94     template<typename A>
95     explicit
TVec2(const TVec2<A> & v)96     constexpr TVec2(const TVec2<A>& v) : x(v.x), y(v.y) { }
97 
98     // cross product works only on vectors of size 2 or 3
99     template<typename RT>
100     friend inline
cross(const TVec2 & u,const TVec2<RT> & v)101     constexpr value_type cross(const TVec2& u, const TVec2<RT>& v) {
102         return value_type(u.x*v.y - u.y*v.x);
103     }
104 };
105 
106 }  // namespace details
107 
108 // ----------------------------------------------------------------------------------------
109 
110 typedef details::TVec2<double> double2;
111 typedef details::TVec2<float> float2;
112 typedef details::TVec2<float> vec2;
113 typedef details::TVec2<half> half2;
114 typedef details::TVec2<int32_t> int2;
115 typedef details::TVec2<uint32_t> uint2;
116 typedef details::TVec2<int16_t> short2;
117 typedef details::TVec2<uint16_t> ushort2;
118 typedef details::TVec2<int8_t> byte2;
119 typedef details::TVec2<uint8_t> ubyte2;
120 typedef details::TVec2<bool> bool2;
121 
122 // ----------------------------------------------------------------------------------------
123 }  // namespace android
124 
125 #pragma clang diagnostic pop
126