/*
 *   external.c
 *
 *   This file is part of Emu48
 *
 *   Copyright (C) 1995 Sebastien Carlier
 *   Copyright (C) 2005 Christoph Gießelink
 *
 */
#include "pch.h"
#include "Emu48.h"
#include "ops.h"

#define MUSIC_FREQ 11025					// this can be adjusted for quality

//| 38G  | 39G  | 40G  | 48SX | 48GX | 49G  | Name
//#F0E4F #80F0F #80F0F #706D2 #80850 #80F0F =SFLAG53_56

// memory address for flags -53 to -56
#define SFLAG53_56	(  (cCurrentRomType=='6')								\
	                 ? 0xE0E4F												\
					 : (  (cCurrentRomType=='A')							\
					    ? 0xF0E4F											\
					    : (  (cCurrentRomType!='E' && cCurrentRomType!='X')	\
					       ? (  (cCurrentRomType=='S')						\
					          ? 0x706D2										\
						      : 0x80850										\
						     )												\
						   : 0x80F0F										\
					      )													\
					   )													\
					)

BOOL  bWaveBeep = FALSE;					// PC speaker
DWORD dwWaveVol = 64;						// wave sound volume

static __inline VOID BeepWave(DWORD dwFrequency,DWORD dwDuration)
{
	HWAVEOUT     hSoundDevice;
	WAVEFORMATEX wf;
	WAVEHDR      wh;
	HANDLE       hEventSound;
	DWORD        i;

	if (dwFrequency == 0)					// this is just a delay
	{
		Sleep(dwDuration);
		return;
	}

	hEventSound = CreateEvent(NULL,FALSE,FALSE,NULL);

	wf.wFormatTag      = WAVE_FORMAT_PCM;
	wf.nChannels       = 1;
	wf.nSamplesPerSec  = MUSIC_FREQ;
	wf.nAvgBytesPerSec = MUSIC_FREQ;
	wf.nBlockAlign     = 1;
	wf.wBitsPerSample  = 8;
	wf.cbSize          = 0;

	if (waveOutOpen(&hSoundDevice,WAVE_MAPPER,&wf,(DWORD_PTR)hEventSound,0,CALLBACK_EVENT) != 0)
	{
		CloseHandle(hEventSound);			// no sound available
		return;
	}

	// (samp/sec) * msecs * (secs/msec) = samps
	wh.dwBufferLength = (DWORD) ((QWORD) MUSIC_FREQ * dwDuration / 1000);
	VERIFY(wh.lpData = malloc(wh.dwBufferLength));
	wh.dwBytesRecorded = 0;
	wh.dwUser = 0;
	wh.dwFlags = 0;
	wh.dwLoops = 0;

	for (i = 0; i < wh.dwBufferLength; ++i)	// generate square wave
	{
		wh.lpData[i] = (BYTE) ((((QWORD) 2 * dwFrequency * i / MUSIC_FREQ) & 1) * dwWaveVol);
	}

	VERIFY(waveOutPrepareHeader(hSoundDevice,&wh,sizeof(wh)) == MMSYSERR_NOERROR);

	ResetEvent(hEventSound);				// prepare event for finishing
	VERIFY(waveOutWrite(hSoundDevice,&wh,sizeof(wh)) == MMSYSERR_NOERROR);
	WaitForSingleObject(hEventSound,INFINITE); // wait for finishing

	VERIFY(waveOutUnprepareHeader(hSoundDevice,&wh,sizeof(wh)) == MMSYSERR_NOERROR);
	VERIFY(waveOutClose(hSoundDevice) == MMSYSERR_NOERROR);

	free(wh.lpData);
	CloseHandle(hEventSound);
	return;
}

static __inline VOID BeepWin9x(DWORD dwFrequency,DWORD dwDuration)
{
#if !defined _WIN64
	#define PIT8254_CNT2	0x42
	#define PIT8254_MCR		0x43
	#define PPI8255_PBO		0x61

	BYTE bySpk = _inp(PPI8255_PBO);			// get current status

	if (dwFrequency != 0)
	{
		WORD wCount;

		// limit low frequency
		if (lFreq.QuadPart / 65535 >= dwFrequency)
			dwFrequency = (DWORD) (lFreq.QuadPart / 65535) + 1;

		// determine the timer frequency
		wCount = (WORD) (lFreq.QuadPart / dwFrequency);

		_outp(PIT8254_MCR,0xB6);			// set up the timer

		_outp(PIT8254_CNT2,wCount&0xff);
		_outp(PIT8254_CNT2,wCount>>8);

		_outp(PPI8255_PBO,bySpk | 0x03);	// turn on the speaker
	}

	Sleep(dwDuration);

	_outp(PPI8255_PBO,bySpk & 0xFC);		// turn off the speaker
	return;
	#undef PIT8254_CNT2
	#undef PIT8254_MCR
	#undef PPI8255_PBO
#endif
}

static VOID Beeper(DWORD freq,DWORD dur)
{
	if (bWaveBeep)
	{
		BeepWave(freq,dur);					// wave output over sound card
	}
	else
	{
		OSVERSIONINFO version;
		version.dwOSVersionInfoSize = sizeof(version);
		GetVersionEx(&version);

		if (version.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS)
		{
			BeepWin9x(freq,dur);			// do it the hard way on '9x / Me
		}
		else								// VER_PLATFORM_WIN32_NT
		{
			if (freq < 37) freq = 37;		// low limit of freqency (NT)

			_ASSERT(freq >= 0x25 && freq <= 0x7FFF);
			Beep(freq,dur);					// NT: ok, Windows 95: default sound or standard system beep
		}
	}
	return;
}

VOID External(CHIPSET* w)					// Beep patch
{
	BYTE  fbeep;
	DWORD freq,dur;

	freq = Npack(w->D,5);					// frequency in Hz
	dur = Npack(w->C,5);					// duration in ms
	Nread(&fbeep,SFLAG53_56,1);				// fetch system flags -53 to -56

	w->carry = TRUE;						// setting of no beep
	if (!(fbeep & 0x8) && freq)				// bit -56 clear and frequency > 0 Hz
	{
		if (freq > 4400) freq = 4400;		// high limit of HP (SX)

		Beeper(freq,dur);					// beeping

		// estimate cpu cycles for beeping time (2MHz / 4MHz)
		w->cycles += dur * ((cCurrentRomType=='S') ? 2000 : 4000);           

		// original routine return with...
		w->P = 0;							// P=0
		w->intk = TRUE;						// INTON
		w->carry = FALSE;					// RTNCC
	}
	w->pc = rstkpop();
	return;
}

VOID RCKBp(CHIPSET* w)						// ROM Check Beep patch
{
	DWORD dw2F,dwCpuFreq;
	DWORD freq,dur;
	BYTE f,d;

	f = w->C[1];							// f = freq ctl
	d = w->C[0];							// d = duration ctl
	
	if (cCurrentRomType == 'S')				// Clarke chip with 48S ROM
	{	
		// CPU strobe frequency @ RATE 14 = 1.97MHz
		dwCpuFreq = ((14 + 1) * 524288) >> 2;

		dw2F = f * 126 + 262;				// F=f*63+131
	}
	else									// York chip with 48G and later ROM
	{
		// CPU strobe frequency @ RATE 27 = 3.67MHz
		// CPU strobe frequency @ RATE 29 = 3.93MHz
		dwCpuFreq = ((27 + 1) * 524288) >> 2;

		dw2F = f * 180 + 367;				// F=f*90+183.5
	}

	freq = dwCpuFreq / dw2F;
	dur = (dw2F * (256 - 16 * d)) * 1000 / 2 / dwCpuFreq;

	if (freq > 4400) freq = 4400;			// high limit of HP

	Beeper(freq,dur);						// beeping

	// estimate cpu cycles for beeping time (2MHz / 4MHz)
	w->cycles += dur * ((cCurrentRomType=='S') ? 2000 : 4000);           

	w->P = 0;								// P=0
	w->carry = FALSE;						// RTNCC
	w->pc = rstkpop();
	return;
}