| 9 | } surface, output; |
| 10 | |
| 11 | struct Point |
| 12 | { |
| 13 | double x, y, z; |
| 14 | Point(){}; |
| 15 | Point(double _x, double _y, double _z) |
| 16 | { |
| 17 | x = _x; |
| 18 | y = _y; |
| 19 | z = _z; |
| 20 | }; |
| 21 | Point operator-(const Point &v) const |
| 22 | { |
| 23 | return Point(x - v.x, y - v.y, z - v.z); |
| 24 | }; |
| 25 | |
| 26 | Point operator+(const Point &v) const |
| 27 | { |
| 28 | return Point(x + v.x, y + v.y, z + v.z); |
| 29 | }; |
| 30 | |
| 31 | Point operator*(const double t) const |
| 32 | { |
| 33 | return Point(x * t, y * t, z * t); |
| 34 | } |
| 35 | |
| 36 | double length() |
| 37 | { |
| 38 | return sqrt(x * x + y * y + z * z); |
| 39 | } |
| 40 | |
| 41 | void normalize() |
| 42 | { |
| 43 | double l = length(); |
| 44 | x /= l; |
| 45 | y /= l; |
| 46 | z /= l; |
| 47 | return; |
| 48 | } |
| 49 | |
| 50 | float dot(const Point &v) const |
| 51 | { |
| 52 | return x * v.x + y * v.y + z * v.z; |
| 53 | }; |
| 54 | |
| 55 | Point cross(const Point &v) const |
| 56 | { |
| 57 | return Point( |
| 58 | y * v.z - z * v.y, |
| 59 | z * v.x - x * v.z, |
| 60 | x * v.y - y * v.x); |
| 61 | }; |
| 62 | |
| 63 | void print() |
| 64 | { |
| 65 | printf("%lf %lf %lf\n", x, y, z); |
| 66 | } |
| 67 | }; |
| 68 | |