
#include "cps3.h"

#define CPS3_VOICES		16

#define CPS3_SND_INT_RATE		60
#define CPS3_SND_RATE			(42954500 / 3 / 384)
#define CPS3_SND_BUFFER_SIZE	(CPS3_SND_RATE / CPS3_SND_INT_RATE)
#define CPS3_SND_LINEAR_SHIFT	12

typedef struct {
	unsigned short regs[16];
	unsigned int pos;
	unsigned short frac;
} cps3_voice;

typedef struct {
	cps3_voice voice[CPS3_VOICES];
	unsigned short key;

	unsigned char * rombase;
	unsigned int delta;

} cps3snd_chip;

static cps3snd_chip * chip;

unsigned char __fastcall cps3SndReadByte(unsigned int addr)
{
	addr &= 0x000003ff;
	bprintf(PRINT_NORMAL, _T("SND Attempt to read byte value of location %8x\n"), addr);
	return 0;
}

unsigned short __fastcall cps3SndReadWord(unsigned int addr)
{
	addr &= 0x000003ff;
	
	if (addr < 0x200)	{
		return chip->voice[addr >> 5].regs[(addr>>1) & 0xf];
	} else
	if (addr == 0x200)	{
		return chip->key;
	} else

	bprintf(PRINT_NORMAL, _T("SND Attempt to read word value of location %8x\n"), addr);
	return 0;
}

unsigned int __fastcall cps3SndReadLong(unsigned int addr)
{
	addr &= 0x000003ff;
	
	bprintf(PRINT_NORMAL, _T("SND Attempt to read long value of location %8x\n"), addr);
	return 0;
}

void __fastcall cps3SndWriteByte(unsigned int addr, unsigned char data)
{
	addr &= 0x000003ff;
	bprintf(PRINT_NORMAL, _T("SND Attempt to write byte value %2x to location %8x\n"), data, addr);
}

void __fastcall cps3SndWriteWord(unsigned int addr, unsigned short data)
{
	addr &= 0x000003ff;
	
	if (addr < 0x200) {
		chip->voice[addr >> 5].regs[(addr>>1) & 0xf] = data;
		//bprintf(PRINT_NORMAL, _T("SND Attempt to write word value %4x to Chip[%02d][%02d] %s\n"), data, addr >> 5, (addr>>2) & 7, (addr & 0x02) ? "lo" : "hi" );
	} else
	if (addr == 0x200) {
		unsigned short key = data;
		for (int i = 0; i < CPS3_VOICES; i++) {
			// Key off -> Key on
			if ((key & (1 << i)) && !(chip->key & (1 << i)))	{
				chip->voice[i].frac = 0;
				chip->voice[i].pos = 0;
			}
		}
		chip->key = key;
	} else
		bprintf(PRINT_NORMAL, _T("SND Attempt to write word value %4x to location %8x\n"), data, addr);
	
}

void __fastcall cps3SndWriteLong(unsigned int addr, unsigned int data)
{
	//addr &= 0x000003ff;
	bprintf(PRINT_NORMAL, _T("SND Attempt to write long value %8x to location %8x\n"), data, addr);
}

int cps3SndInit(unsigned char * sndrom)
{
	chip = (cps3snd_chip *) malloc( sizeof(cps3snd_chip) );
	if ( chip ) {
		memset( chip, 0, sizeof(cps3snd_chip) );
		chip->rombase = sndrom;
		
		/* 
		 * CPS-3 Sound chip clock: 42954500 / 3 / 384 = 37286.89
		 * Sound interupt 80Hz 
		 */
		
		if (nBurnSoundRate) {
			//chip->delta = 37286.9 / nBurnSoundRate;
			chip->delta = (CPS3_SND_BUFFER_SIZE << CPS3_SND_LINEAR_SHIFT) / nBurnSoundLen;
			//bprintf(0, _T("BurnSnd %08x, %d, %d\n"), chip->delta, chip->burnlen, nBurnSoundLen);
		}
		
		return 0;
	}
	return 1;
}

void cps3SndReset()
{
}

void cps3SndExit()
{
	free( chip );
}

void cps3SndUpdate()
{
	if (!pBurnSoundOut) {
		// TODO: ???
		// chip->key = 0;
		return;	
	}
	
	memset(pBurnSoundOut, 0, nBurnSoundLen * 2 * 2 );
	signed char * base = (signed char *)chip->rombase;
	cps3_voice *vptr = &chip->voice[0];

	for(int i=0; i<CPS3_VOICES; i++, vptr++) {
		if (chip->key & (1 << i)) {
			
			unsigned int start = ((vptr->regs[ 3] << 16) | vptr->regs[ 2]) - 0x400000;
			unsigned int end   = ((vptr->regs[11] << 16) | vptr->regs[10]) - 0x400000;
			unsigned int loop  = ((vptr->regs[ 9] << 16) | vptr->regs[ 7]) - 0x400000;
			unsigned int step  = ( vptr->regs[ 6] * chip->delta ) >> CPS3_SND_LINEAR_SHIFT;

			//int vol_l = ((signed short)vptr->regs[15] * 12) >> 4;
			//int vol_r = ((signed short)vptr->regs[14] * 12) >> 4;
			int vol_l = (signed short)vptr->regs[15];
			int vol_r = (signed short)vptr->regs[14];

			unsigned int pos = vptr->pos;
			unsigned int frac = vptr->frac;
			
			/* Go through the buffer and add voice contributions */
			signed short * buffer = (signed short *)pBurnSoundOut;

			for (int j=0; j<nBurnSoundLen; j++) {
				signed int sample;

				pos += (frac >> 12);
				frac &= 0xfff;

				if (start + pos >= end) {
					if (vptr->regs[5]) {
						pos = loop - start;
					} else {
						chip->key &= ~(1 << i);
						break;
					}
				}

				// 8bit sample store with 16bit bigend ???
				sample = base[(start + pos) ^ 1];
				frac += step;

#if 1
				int sample_l;

				sample_l = ((sample * vol_l) >> 8) + buffer[0];
				if (sample_l > 32767)		buffer[0] = 32767;
				else if (sample_l < -32768)	buffer[0] = -32768;
				else 						buffer[0] = sample_l;
				
				sample_l = ((sample * vol_r) >> 8) + buffer[1];
				if (sample_l > 32767)		buffer[1] = 32767;
				else if (sample_l < -32768)	buffer[1] = -32768;
				else 						buffer[1] = sample_l;
#else
				buffer[0] += (sample * (vol_l >> 8));
				buffer[1] += (sample * (vol_r >> 8));
#endif

				buffer += 2;
			}


			vptr->pos = pos;
			vptr->frac = frac;
		}
	}
	
}

int cps3SndScan(int nAction)
{
	if (nAction & ACB_DRIVER_DATA) {
		
		SCAN_VAR( chip->voice );
		SCAN_VAR( chip->key );
		
	}
	return 0;
}

