/****************************************************************************
*                                                                           *
* Project 64 - A Nintendo 64 emulator.                                      *
* http://www.pj64-emu.com/                                                  *
* Copyright (C) 2012 Project64. All rights reserved.                        *
*                                                                           *
* License:                                                                  *
* GNU/GPLv2 http://www.gnu.org/licenses/gpl-2.0.html                        *
*                                                                           *
****************************************************************************/
#include "stdafx.h"

CAudio::CAudio()
{
	Reset();
}

CAudio::~CAudio()
{
	
}

void CAudio::Reset()
{
	m_SecondBuff = 0;
	m_Status = 0;
	m_BytesPerSecond = 0;
	m_CountsPerByte = g_System->AiCountPerBytes(); // should be calculated ... see below, instead allow from user settings
	if (m_CountsPerByte == 0) m_CountsPerByte = 500; // If the user has no defined value, grant a default and we will calculate
	m_FramesPerSecond = 60;
}

DWORD CAudio::GetLength()
{
	WriteTraceF(TraceAudio,__FUNCTION__ ": Start (m_SecondBuff = %d)",m_SecondBuff);
	DWORD TimeLeft = g_SystemTimer->GetTimer(CSystemTimer::AiTimerInterrupt), Res = 0;
	if (TimeLeft > 0)
	{
		Res = (TimeLeft / m_CountsPerByte);
	}
	WriteTraceF(TraceAudio,__FUNCTION__ ": Done (res = %d, TimeLeft = %d)",Res, TimeLeft);
	return (Res+3)&~3;
}

DWORD CAudio::GetStatus()
{
	WriteTraceF(TraceAudio,__FUNCTION__ ": m_Status = %X",m_Status);
	return m_Status;
}

void CAudio::LenChanged()
{
	WriteTraceF(TraceAudio,__FUNCTION__ ": Start (g_Reg->AI_LEN_REG = %d)",g_Reg->AI_LEN_REG);
	if (g_Reg->AI_LEN_REG != 0)
	{
		if (g_Reg->AI_LEN_REG >= 0x40000)
		{
			WriteTraceF(TraceAudio,__FUNCTION__ ": *** Ignoring Write, To Large (%X)",g_Reg->AI_LEN_REG);
		} else {
			m_Status |= ai_busy;
			DWORD AudioLeft = g_SystemTimer->GetTimer(CSystemTimer::AiTimerInterrupt);
			if (m_SecondBuff == 0)
			{
				if (AudioLeft == 0)
				{
					WriteTraceF(TraceAudio, __FUNCTION__ ": Set Timer  AI_LEN_REG: %d m_CountsPerByte: %d", g_Reg->AI_LEN_REG, m_CountsPerByte);
					g_SystemTimer->SetTimer(CSystemTimer::AiTimerInterrupt, g_Reg->AI_LEN_REG * m_CountsPerByte, false);
				}
				else
				{
					WriteTraceF(TraceAudio, __FUNCTION__ ": Increasing Second Buffer (m_SecondBuff %d Increase: %d)", m_SecondBuff, g_Reg->AI_LEN_REG);
					m_SecondBuff += g_Reg->AI_LEN_REG;
					m_Status |= ai_full;
				}
			}
			else
			{
				g_Notify->BreakPoint(__FILEW__, __LINE__);
			}
		}
	}
	else
	{
		WriteTraceF(TraceAudio,__FUNCTION__ ": *** Reset Timer to 0");
		g_SystemTimer->StopTimer(CSystemTimer::AiTimerBusy);
		g_SystemTimer->StopTimer(CSystemTimer::AiTimerInterrupt);
		m_SecondBuff = 0;
		m_Status = 0;
	}

	if (g_Plugins->Audio()->AiLenChanged != NULL)
	{
		g_Plugins->Audio()->AiLenChanged();
	}
	WriteTraceF(TraceAudio,__FUNCTION__ ": Done");
}

void CAudio::InterruptTimerDone()
{
	WriteTraceF(TraceAudio,__FUNCTION__ ": Start (m_SecondBuff = %d)",m_SecondBuff);
	m_Status &= ~ai_full;
	g_Reg->MI_INTR_REG |= MI_INTR_AI;
	g_Reg->CheckInterrupts();
	if (m_SecondBuff != 0)
	{
		g_SystemTimer->SetTimer(CSystemTimer::AiTimerInterrupt,m_SecondBuff * m_CountsPerByte,false);
		m_SecondBuff = 0;
	}
	else
	{
		m_Status &= ~ai_busy;
	}
	if (g_Reg->m_AudioIntrReg == 0)
	{
		g_System->SyncToAudio();
	}
	WriteTrace(TraceAudio,__FUNCTION__ ": Done");
}

void CAudio::BusyTimerDone()
{
	WriteTraceF(TraceAudio,__FUNCTION__ ": Start (m_SecondBuff = %d)",m_SecondBuff);
	g_Notify->BreakPoint(__FILEW__,__LINE__);
	m_Status &= ~ai_busy;
}

void CAudio::SetViIntr ( DWORD VI_INTR_TIME )
{
	double CountsPerSecond = (DWORD)((double)VI_INTR_TIME * m_FramesPerSecond);
	if (m_BytesPerSecond != 0 && (g_System->AiCountPerBytes() == 0))
	{
		m_CountsPerByte = (int)((double)CountsPerSecond / (double)m_BytesPerSecond);
	}
}


void CAudio::SetFrequency (DWORD Dacrate, DWORD System) 
{
	WriteTraceF(TraceAudio,__FUNCTION__ "(Dacrate: %X System: %d): AI_BITRATE_REG = %X",Dacrate,System,g_Reg->AI_BITRATE_REG);
	DWORD Frequency;

	switch (System)
	{
	case SYSTEM_PAL:  Frequency = 49656530 / (Dacrate + 1); break;
	case SYSTEM_MPAL: Frequency = 48628316 / (Dacrate + 1); break;
	default:          Frequency = 48681812 / (Dacrate + 1); break;
	}

	//nBlockAlign = 16 / 8 * 2;
	m_BytesPerSecond = Frequency * 4;
	//m_BytesPerSecond = 194532;
	//m_BytesPerSecond = 128024;

	m_FramesPerSecond = System == SYSTEM_PAL ? 50 : 60;
}