Files
glest-source/source/shared_lib/sources/util/randomgen.cpp
2019-02-20 02:37:59 +01:00

119 lines
3.3 KiB
C++

// This file is part of Glest <https://github.com/Glest>
//
// Copyright (C) 2018 The Glest team
//
// Glest is a fork of MegaGlest <https://megaglest.org/>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>
#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) {
int temp = min;
min = max;
max = temp;
}
int diff = max - min;
float numerator = static_cast<float>(diff + 1) * static_cast<float>(this->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 game_runtime_error(szBuf);
}
return res;
}
float RandomGen::randRange(float min, float max, string lastCaller) {
if (min > max) {
int temp = min;
min = max;
max = temp;
}
float rand01 = static_cast<float>(this->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 game_runtime_error(szBuf);
}
return res;
}
}
} //end namespace