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/*
* Copyright 2010 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrRandom_DEFINED
#define GrRandom_DEFINED
class GrRandom {
public:
GrRandom() : fSeed(0) {}
GrRandom(uint32_t seed) : fSeed(seed) {}
uint32_t seed() const { return fSeed; }
uint32_t nextU() {
fSeed = fSeed * kMUL + kADD;
return fSeed;
}
int32_t nextS() { return (int32_t)this->nextU(); }
/**
* Returns value [0...1) as a float
*/
float nextF() {
// const is 1 / (2^32 - 1)
return (float)(this->nextU() * 2.32830644e-10);
}
/**
* Returns value [min...max) as a float
*/
float nextF(float min, float max) {
return min + this->nextF() * (max - min);
}
private:
/*
* These constants taken from "Numerical Recipes in C", reprinted 1999
*/
enum {
kMUL = 1664525,
kADD = 1013904223
};
uint32_t fSeed;
};
#endif
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