mirror of https://github.com/axmolengine/axmol.git
89 lines
2.8 KiB
C++
89 lines
2.8 KiB
C++
#ifndef RNGSEED_H_
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#define RNGSEED_H_
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/** A more effective seeded random number generator struct, made by kiss rng.
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* @since adxe-1.0.0b8
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*/
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struct RngSeed
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{
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const unsigned long RNG_RAND_MAX = 4294967295;
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const unsigned long RNG_RAND_MAX_SIGNED = 2147483647;
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unsigned long _x = 1;
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unsigned long _y = 2;
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unsigned long _z = 4;
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unsigned long _w = 8;
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unsigned long _carry = 0;
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unsigned long _k = 0;
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unsigned long _m = 0;
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unsigned long _seed = 0;
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RngSeed() { seed_rand(time(NULL)); }
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// initialize this object with seed
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void seed_rand(unsigned long seed)
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{
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_seed = seed;
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_x = seed | 1;
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_y = seed | 2;
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_z = seed | 4;
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_w = seed | 8;
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_carry = 0;
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}
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// returns an unsigned long random value
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unsigned long rand()
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{
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_x = _x * 69069 + 1;
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_y ^= _y << 13;
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_y ^= _y >> 17;
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_y ^= _y << 5;
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_k = (_z >> 2) + (_w >> 3) + (_carry >> 2);
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_m = _w + _w + _z + _carry;
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_z = _w;
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_w = _m;
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_carry = _k >> 30;
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return _x + _y + _w;
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}
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// returns a random integer from min to max
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int range(int min, int max)
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{
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return floor(min + static_cast<float>(rand()) / (static_cast<float>(RNG_RAND_MAX / (max - min))));
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}
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// returns a random unsigned integer from min to max
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unsigned int rangeu(unsigned int min, unsigned int max)
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{
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return floor(min + static_cast<float>(rand()) / (static_cast<float>(RNG_RAND_MAX / (max - min))));
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}
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// returns a random float from min to max
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float rangef(float min = -1.0F, float max = 1.0F)
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{
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return min + static_cast<float>(rand()) / (static_cast<float>(RNG_RAND_MAX / (max - min)));
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}
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// returns a random integer from 0 to max
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int max(int max = INT_MAX)
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{
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return floor(0 + static_cast<float>(rand()) / (static_cast<float>(RNG_RAND_MAX / (max - 0))));
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}
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// returns a random unsigned integer from 0 to max
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unsigned int maxu(unsigned int max = UINT_MAX)
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{
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return floor(0 + static_cast<float>(rand()) / (static_cast<float>(RNG_RAND_MAX / (max - 0))));
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}
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// returns a random float from 0.0 to max
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float maxf(float max) { return 0 + static_cast<float>(rand()) / (static_cast<float>(RNG_RAND_MAX / (max - 0))); }
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// returns a random float from 0.0 to 1.0
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float float01() { return 0 + static_cast<float>(rand()) / (static_cast<float>(RNG_RAND_MAX / (1 - 0))); }
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// returns either false or true randomly
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bool bool01() { return (bool)floor(0 + static_cast<float>(rand()) / (static_cast<float>(RNG_RAND_MAX / (2 - 0)))); }
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};
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#endif
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