MegaGlest/source/shared_lib/sources/util/randomgen.cpp

110 lines
3.1 KiB
C++

// ==============================================================
// This file is part of MegaGlest Shared Library (www.megaglest.org)
//
// Copyright (C) 2012 Mark Vejvoda, Titus Tscharntke
// 2001-2008 Martiño Figueroa
//
// You can redistribute this code and/or modify it under
// the terms of the GNU General Public License as published
// by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version
// ==============================================================
#include "randomgen.h"
#include <cassert>
#include "util.h"
#include <stdexcept>
#include "platform_util.h"
#include "math_util.h"
#include "leak_dumper.h"
using namespace std;
using namespace Shared::Graphics;
namespace Shared { namespace Util {
// =====================================================
// class RandomGen
// =====================================================
const int RandomGen::m= 714025;
const int RandomGen::a= 1366;
const int RandomGen::b= 150889;
RandomGen::RandomGen(){
lastNumber= 0;
disableLastCallerTracking = false;
}
void RandomGen::init(int seed){
lastNumber= seed % m;
}
int RandomGen::rand(string lastCaller) {
if(lastCaller != "") {
this->lastCaller.push_back(lastCaller);
}
this->lastNumber = (a*lastNumber + b) % m;
return lastNumber;
}
std::string RandomGen::getLastCaller() const {
std::string result = "";
if(lastCaller.empty() == false) {
for(unsigned int index = 0; index < lastCaller.size(); ++index) {
result += lastCaller[index] + "|";
}
}
return result;
}
void RandomGen::clearLastCaller() {
if(lastCaller.empty() == false) {
lastCaller.clear();
}
}
void RandomGen::addLastCaller(std::string text) {
if(disableLastCallerTracking == false) {
lastCaller.push_back(text);
}
}
int RandomGen::randRange(int min, int max,string lastCaller) {
if(min > max) {
char szBuf[8096]="";
snprintf(szBuf,8096,"In [%s::%s Line: %d] min > max, min = %d, max = %d",__FILE__,__FUNCTION__,__LINE__,min,max);
throw megaglest_runtime_error(szBuf);
}
int diff= max-min;
float numerator = static_cast<float>(diff + 1) * static_cast<float>(RandomGen::rand(lastCaller));
int res= min + static_cast<int>(truncateDecimal<float>(numerator / static_cast<float>(m),6));
if(res < min || res > max) {
char szBuf[8096]="";
snprintf(szBuf,8096,"In [%s::%s Line: %d] res < min || res > max, min = %d, max = %d, res = %d",__FILE__,__FUNCTION__,__LINE__,min,max,res);
throw megaglest_runtime_error(szBuf);
}
return res;
}
float RandomGen::randRange(float min, float max,string lastCaller) {
if(min > max) {
char szBuf[8096]="";
snprintf(szBuf,8096,"In [%s::%s Line: %d] min > max, min = %f, max = %f",__FILE__,__FUNCTION__,__LINE__,min,max);
throw megaglest_runtime_error(szBuf);
}
float rand01 = static_cast<float>(RandomGen::rand(lastCaller)) / (m-1);
float res= min + (max - min) * rand01;
res = truncateDecimal<float>(res,6);
if(res < min || res > max) {
char szBuf[8096]="";
snprintf(szBuf,8096,"In [%s::%s Line: %d] res < min || res > max, min = %f, max = %f, res = %f",__FILE__,__FUNCTION__,__LINE__,min,max,res);
throw megaglest_runtime_error(szBuf);
}
return res;
}
}}//end namespace