| part of sprites; |
| |
| |
| math.Random _random = new math.Random(); |
| |
| // Random methods |
| |
| double randomDouble() { |
| return _random.nextDouble(); |
| } |
| |
| double randomSignedDouble() { |
| return _random.nextDouble() * 2.0 - 1.0; |
| } |
| |
| int randomInt(int max) { |
| return _random.nextInt(max); |
| } |
| |
| // atan2 |
| |
| class _Atan2Constants { |
| |
| _Atan2Constants() { |
| for (int i = 0; i <= size; i++) { |
| double f = i.toDouble() / size.toDouble(); |
| ppy[i] = math.atan(f) * stretch / math.PI; |
| ppx[i] = stretch * 0.5 - ppy[i]; |
| pny[i] = -ppy[i]; |
| pnx[i] = ppy[i] - stretch * 0.5; |
| npy[i] = stretch - ppy[i]; |
| npx[i] = ppy[i] + stretch * 0.5; |
| nny[i] = ppy[i] - stretch; |
| nnx[i] = -stretch * 0.5 - ppy[i]; |
| } |
| } |
| |
| static const int size = 1024; |
| static const double stretch = math.PI; |
| |
| static const int ezis = -size; |
| |
| final Float64List ppy = new Float64List(size + 1); |
| final Float64List ppx = new Float64List(size + 1); |
| final Float64List pny = new Float64List(size + 1); |
| final Float64List pnx = new Float64List(size + 1); |
| final Float64List npy = new Float64List(size + 1); |
| final Float64List npx = new Float64List(size + 1); |
| final Float64List nny = new Float64List(size + 1); |
| final Float64List nnx = new Float64List(size + 1); |
| } |
| |
| class GameMath { |
| static final _Atan2Constants _atan2 = new _Atan2Constants(); |
| |
| static double atan2(double y, double x) { |
| if (x >= 0) { |
| if (y >= 0) { |
| if (x >= y) |
| return _atan2.ppy[(_Atan2Constants.size * y / x + 0.5).toInt()]; |
| else |
| return _atan2.ppx[(_Atan2Constants.size * x / y + 0.5).toInt()]; |
| } else { |
| if (x >= -y) |
| return _atan2.pny[(_Atan2Constants.ezis * y / x + 0.5).toInt()]; |
| else |
| return _atan2.pnx[(_Atan2Constants.ezis * x / y + 0.5).toInt()]; |
| } |
| } else { |
| if (y >= 0) { |
| if (-x >= y) |
| return _atan2.npy[(_Atan2Constants.ezis * y / x + 0.5).toInt()]; |
| else |
| return _atan2.npx[(_Atan2Constants.ezis * x / y + 0.5).toInt()]; |
| } else { |
| if (x <= y) |
| return _atan2.nny[(_Atan2Constants.size * y / x + 0.5).toInt()]; |
| else |
| return _atan2.nnx[(_Atan2Constants.size * x / y + 0.5).toInt()]; |
| } |
| } |
| } |
| } |