54         Double2 res = new Double2();  in add()  local
55         res.x = a.x + b.x;  in add()
56         res.y = a.y + b.y;  in add()
58         return res;  in add()
89         Double2 res = new Double2();  in add()  local
90         res.x = a.x + b;  in add()
91         res.y = a.y + b;  in add()
93         return res;  in add()
114         Double2 res = new Double2();  in sub()  local
115         res.x = a.x - b.x;  in sub()
116         res.y = a.y - b.y;  in sub()
118         return res;  in sub()
139         Double2 res = new Double2();  in sub()  local
140         res.x = a.x - b;  in sub()
141         res.y = a.y - b;  in sub()
143         return res;  in sub()
164         Double2 res = new Double2();  in mul()  local
165         res.x = a.x * b.x;  in mul()
166         res.y = a.y * b.y;  in mul()
168         return res;  in mul()
189         Double2 res = new Double2();  in mul()  local
190         res.x = a.x * b;  in mul()
191         res.y = a.y * b;  in mul()
193         return res;  in mul()
214         Double2 res = new Double2();  in div()  local
215         res.x = a.x / b.x;  in div()
216         res.y = a.y / b.y;  in div()
218         return res;  in div()
239         Double2 res = new Double2();  in div()  local
240         res.x = a.x / b;  in div()
241         res.y = a.y / b;  in div()
243         return res;  in div()