Method CalcEnvelope

Feedback360/Feedback360Effect.cpp:134–163

---------------------------------------------------------------------------------------------- CalcEnvelope ----------------------------------------------------------------------------------------------

// CalcEnvelope
//----------------------------------------------------------------------------------------------
void Feedback360Effect::CalcEnvelope(ULONG Duration, ULONG CurrentPos, LONG *NormalRate, LONG *AttackLevel, LONG *FadeLevel)
{
	if( ( DiEffect.dwFlags & FFEP_ENVELOPE ) && DiEffect.lpEnvelope != NULL )
	{
        // Calculate attack factor
		LONG	AttackRate	= 0;
		ULONG	AttackTime	= max( (DWORD)1, DiEnvelope.dwAttackTime / 1000 );
		if (CurrentPos < AttackTime)
        {
			AttackRate	= ( AttackTime - CurrentPos ) * 100 / AttackTime;
		}

        // Calculate fade factor
        LONG	FadeRate	= 0;
		ULONG	FadeTime	= max( (DWORD)1, DiEnvelope.dwFadeTime / 1000 );
		ULONG	FadePos		= Duration - FadeTime;
		if (FadePos < CurrentPos)
        {
			FadeRate	= ( CurrentPos - FadePos ) * 100 / FadeTime;
		}

		*NormalRate		= 100 - AttackRate - FadeRate;
		*AttackLevel	= DiEnvelope.dwAttackLevel * AttackRate;
		*FadeLevel		= DiEnvelope.dwFadeLevel * FadeRate;
	} else {
		*NormalRate		= 100;
		*AttackLevel	= 0;
		*FadeLevel		= 0;
	}
}

void Feedback360Effect::CalcForce(ULONG Duration, ULONG CurrentPos, LONG NormalRate, LONG AttackLevel, LONG FadeLevel, LONG * NormalLevel)
{