/* -----------------------------------------------------------------------------
	GSFramework
	Copyright 2001-2013 Emmanuel Julien. All Rights Reserved.
----------------------------------------------------------------------------- */


		#include "rand/rand.h"

		using namespace GS;


#define		__USE_CUSTOM_RAND	1

static	uint high = 0xDEADBEEF, low = high ^ 0x49616E42;
static	uint _rg_pn = 0;

//------------------------------------------------------------------------------
void				Random::Seed(uint s)
{
#if	__USE_CUSTOM_RAND
	high = 0xDEADBEEF;
	low = high ^ 0x49616E42;
	for (uint n = 0; n < (s & 0x1fff); ++n)
		Rand(1);
#else
	srand(s);
#endif
}
uint				Random::Rand(uint r)
{
	if	(!r)
		return 0;
#if	__USE_CUSTOM_RAND
    high = (high << 16) + (high >> 16);
    high += low;
    low += high;
	return high % r;
#else
	return rand() % r;
#endif
} 
float				Random::FRand(float r)
{
	return (float)Rand(65536) * r / 65536.0f;;
}
float				Random::FRRand(float lo, float hi)
{
	const float	v = (float)(Rand(65536)) / 65536.0f;
	return v * (hi - lo) + lo;
}
uint				Random::CRand(uint r)
{
	uint it;
	uint _rg_cn = 0;

	if	(!r)
		return 0;

	it = 4;
	while (it--)
	{
		_rg_cn = Rand(r);
		if	(_rg_cn != _rg_pn)
			break;
	}
	_rg_pn = _rg_cn;
	return _rg_cn;
}
//------------------------------------------------------------------------------