#include "StdAfx.h"
#include "ColorTransitionHelper.h"

void CColorTransitionHelper::Clear(const float & c_rfRed,
								   const float & c_rfGreen,
								   const float & c_rfBlue,
								   const float & c_rfAlpha)
{

	m_fSrcRed	= c_rfRed;
	m_fSrcGreen	= c_rfGreen;
	m_fSrcBlue	= c_rfBlue;
	m_fSrcAlpha	= c_rfAlpha;

	m_fDstRed	= c_rfRed;
	m_fDstGreen	= c_rfGreen;
	m_fDstBlue	= c_rfBlue;
	m_fDstAlpha	= c_rfAlpha;

	m_dwCurColor = 0x00000000;

	m_dwStartTime = m_dwDuration = 0;
}

void CColorTransitionHelper::SetSrcColor(const float & c_rfRed,
										 const float & c_rfGreen,
										 const float & c_rfBlue,
										 const float & c_rfAlpha) 
{
	m_fSrcRed	= c_rfRed;
	m_fSrcGreen	= c_rfGreen;
	m_fSrcBlue	= c_rfBlue;
	m_fSrcAlpha	= c_rfAlpha;
}

void CColorTransitionHelper::SetTransition(const float & c_rfRed, 
										   const float & c_rfGreen, 
										   const float & c_rfBlue, 
										   const float & c_rfAlpha, 
										   const DWORD & dwDuration)
{
	m_fDstRed	= c_rfRed;
	m_fDstGreen	= c_rfGreen;
	m_fDstBlue	= c_rfBlue;
	m_fDstAlpha	= c_rfAlpha;

	m_dwDuration = dwDuration;
}

void CColorTransitionHelper::StartTransition()
{
	m_bTransitionStarted = true;
	m_dwStartTime = GetCurrentTime();
}

bool CColorTransitionHelper::Update()
{
//	if (!m_bTransitionStarted)
//		return false;

	DWORD dwCurTime = GetCurrentTime();
	DWORD dwElapsedTime = dwCurTime - m_dwStartTime;

	float fpercent = (float)(dwElapsedTime) / (float)(m_dwDuration);
	if (fpercent <= 0.0f)
		fpercent = 0.0f;
	if (fpercent >= 1.0f)
		fpercent = 1.0f;
	float fCurRed, fCurGreen, fCurBlue, fCurAlpha;
	fCurRed		= m_fSrcRed + (m_fDstRed - m_fSrcRed) * fpercent;
	fCurGreen	= m_fSrcGreen + (m_fDstGreen - m_fSrcGreen) * fpercent;
	fCurBlue	= m_fSrcBlue + (m_fDstBlue - m_fSrcBlue) * fpercent;
	fCurAlpha	= m_fSrcAlpha + (m_fDstAlpha - m_fSrcAlpha) * fpercent;

// 	Tracef("%f, %f, %f, %f\n", fCurRed, fCurGreen, fCurBlue, fCurAlpha);

	m_dwCurColor = (((DWORD)(fCurAlpha * 255.0f)&0xff)<< 24) |
		(((DWORD)(fCurRed * 255.0f)&0xff) << 16) |
		(((DWORD)(fCurGreen * 255.0f)&0xff) << 8) |
		((DWORD)(fCurBlue * 255.0f)&0xff);

	if ( (1.0f == fpercent) && (fCurAlpha == m_fDstAlpha) && (fCurRed == m_fDstRed) && (fCurGreen == m_fDstGreen) && (fCurBlue == m_fDstBlue) )
	{
		m_bTransitionStarted = false;
		return false;
	}

	return true;
}

const D3DCOLOR & CColorTransitionHelper::GetCurColor()
{
	return m_dwCurColor; 
}

CColorTransitionHelper::CColorTransitionHelper():m_bTransitionStarted(false)
{
	Clear(0.0f, 0.0f, 0.0f, 0.0f); 
}

CColorTransitionHelper::~CColorTransitionHelper()
{
	Clear(0.0f, 0.0f, 0.0f, 0.0f); 
}