Random.cpp

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// MIT License
//
// Copyright (c) 2019 Ian Parberry
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.

#pragma comment(lib,"Winmm.lib")

#include "Random.h"
#include "Includes.h"
#include "Helpers.h"

CRandom::CRandom(){ 
} //constructor


void CRandom::srand(){ 
  for(int i=0; i<4; i++)
    m_uState[i] = (::rand() << 16)|::rand(); //32-bit kluge (Knuth would cringe)
} //srand


UINT CRandom::randn(){ 
  UINT s = m_uState[3];

  s ^= s << 11;
  s ^= s >> 8;

  m_uState[3] = m_uState[2]; 
  m_uState[2] = m_uState[1]; 
  m_uState[1] = m_uState[0];

  s ^= m_uState[0];
  s ^= m_uState[0] >> 19; 

  m_uState[0] = s;

  return s;
} //randn


UINT CRandom::randn(UINT i, UINT j){  
  return randn()%(j - i + 1) + i;
} //randn


float CRandom::randf(){
  return float((double)randn()/(double)0xFFFFFFFF); 
} //randf


void CRandom::randclr(UINT rgb[3]){
  float RGB[3]; //RGB color in floating point format
  HSVtoRGB(randf(), 0.75f, 0.6f, RGB); //generate in HSV and convert to RGB

  for(int i=0; i<3; i++) //convert from floating point to [0..255]
    rgb[i] = (UINT)std::round(RGB[i]*255.0f);
} //randclr