cog/Frameworks/GME/gme/k051649.c

299 lines
7.8 KiB
C

/***************************************************************************
Konami 051649 - SCC1 sound as used in Haunted Castle, City Bomber
This file is pieced together by Bryan McPhail from a combination of
Namco Sound, Amuse by Cab, Haunted Castle schematics and whoever first
figured out SCC!
The 051649 is a 5 channel sound generator, each channel gets it's
waveform from RAM (32 bytes per waveform, 8 bit signed data).
This sound chip is the same as the sound chip in some Konami
megaROM cartridges for the MSX. It is actually well researched
and documented:
http://www.msxnet.org/tech/scc
Thanks to Sean Young (sean@mess.org) for some bugfixes.
K052539 is equivalent to this chip except channel 5 does not share
waveforms with channel 4.
***************************************************************************/
#include "mamedef.h"
#include <stdlib.h>
#include <memory.h>
//#include "emu.h"
//#include "streams.h"
#include "k051649.h"
#define FREQBASEBITS 16
/* this structure defines the parameters for a channel */
typedef struct
{
unsigned long counter;
int frequency;
int volume;
int key;
signed char waveform[32]; /* 19991207.CAB */
UINT8 Muted;
} k051649_sound_channel;
typedef struct _k051649_state k051649_state;
struct _k051649_state
{
k051649_sound_channel channel_list[5];
/* global sound parameters */
//sound_stream * stream;
int mclock,rate;
/* mixer tables and internal buffers */
INT16 *mixer_table;
INT16 *mixer_lookup;
short *mixer_buffer;
int f[10];
int cur_reg;
};
/*INLINE k051649_state *get_safe_token(running_device *device)
{
assert(device != NULL);
assert(device->type() == K051649);
return (k051649_state *)downcast<legacy_device_base *>(device)->token();
}*/
/* build a table to divide by the number of voices */
static void make_mixer_table(/*running_machine *machine,*/ k051649_state *info, int voices)
{
int count = voices * 256;
int i;
int gain = 8;
/* allocate memory */
//info->mixer_table = auto_alloc_array(machine, INT16, 512 * voices);
info->mixer_table = (INT16*)malloc(sizeof(INT16) * 512 * voices);
/* find the middle of the table */
info->mixer_lookup = info->mixer_table + (256 * voices);
/* fill in the table - 16 bit case */
for (i = 0; i < count; i++)
{
int val = i * gain * 16 / voices;
if (val > 32767) val = 32767;
info->mixer_lookup[ i] = val;
info->mixer_lookup[-i] = -val;
}
}
/* generate sound to the mix buffer */
//static STREAM_UPDATE( k051649_update )
void k051649_update(void *chip, stream_sample_t **outputs, int samples)
{
k051649_state *info = (k051649_state *) chip;
k051649_sound_channel *voice=info->channel_list;
stream_sample_t *buffer = outputs[0];
stream_sample_t *buffer2 = outputs[1];
short *mix;
int i,v,f,j,k;
/* zap the contents of the mixer buffer */
memset(info->mixer_buffer, 0, samples * sizeof(short));
for (j=0; j<5; j++) {
v=voice[j].volume;
f=voice[j].frequency;
k=voice[j].key;
/* SY 20040109: the SCC produces no sound for freq < 9 */
if (v && f > 8 && k && ! voice[j].Muted)
{
const signed char *w = voice[j].waveform; /* 19991207.CAB */
int c=voice[j].counter;
mix = info->mixer_buffer;
/* add our contribution */
for (i = 0; i < samples; i++)
{
int offs;
/* Amuse source: Cab suggests this method gives greater resolution */
/* Sean Young 20010417: the formula is really: f = clock/(16*(f+1))*/
c+=(long)((((float)info->mclock / (float)((f+1) * 16))*(float)(1<<FREQBASEBITS)) / (float)(info->rate / 32));
offs = (c >> 16) & 0x1f;
*mix++ += (w[offs] * v)>>3;
}
/* update the counter for this voice */
voice[j].counter = c;
}
}
/* mix it down */
mix = info->mixer_buffer;
for (i = 0; i < samples; i++)
*buffer++ = *buffer2++ = info->mixer_lookup[*mix++];
}
//static DEVICE_START( k051649 )
void * device_start_k051649(int clock)
{
//k051649_state *info = get_safe_token(device);
k051649_state *info;
UINT8 CurChn;
info = (k051649_state *) calloc(1, sizeof(k051649_state));
/* get stream channels */
//info->rate = device->clock()/16;
info->rate = clock/16;
//info->stream = stream_create(device, 0, 1, info->rate, info, k051649_update);
//info->mclock = device->clock();
info->mclock = clock;
/* allocate a buffer to mix into - 1 second's worth should be more than enough */
//info->mixer_buffer = auto_alloc_array(device->machine, short, 2 * info->rate);
info->mixer_buffer = (short*)malloc(sizeof(short) * info->rate);
/* build the mixer table */
//make_mixer_table(device->machine, info, 5);
make_mixer_table(info, 5);
for (CurChn = 0; CurChn < 5; CurChn ++)
info->channel_list[CurChn].Muted = 0x00;
return info; //return info->rate;
}
void device_stop_k051649(void *chip)
{
k051649_state *info = (k051649_state *) chip;
free(info->mixer_buffer);
free(info->mixer_table);
free(info);
}
//static DEVICE_RESET( k051649 )
void device_reset_k051649(void *chip)
{
k051649_state *info = (k051649_state *) chip;
k051649_sound_channel *voice = info->channel_list;
int i;
/* reset all the voices */
for (i = 0; i < 5; i++) {
voice[i].frequency = 0;
voice[i].volume = 0;
voice[i].counter = 0;
}
}
/********************************************************************************/
//WRITE8_DEVICE_HANDLER( k051649_waveform_w )
void k051649_waveform_w(void *chip, offs_t offset, UINT8 data)
{
k051649_state *info = (k051649_state *) chip;
//stream_update(info->stream);
info->channel_list[offset>>5].waveform[offset&0x1f]=data;
/* SY 20001114: Channel 5 shares the waveform with channel 4 */
if (offset >= 0x60)
info->channel_list[4].waveform[offset&0x1f]=data;
}
//READ8_DEVICE_HANDLER ( k051649_waveform_r )
UINT8 k051649_waveform_r(void *chip, offs_t offset)
{
k051649_state *info = (k051649_state *) chip;
return info->channel_list[offset>>5].waveform[offset&0x1f];
}
/* SY 20001114: Channel 5 doesn't share the waveform with channel 4 on this chip */
//WRITE8_DEVICE_HANDLER( k052539_waveform_w )
void k052539_waveform_w(void *chip, offs_t offset, UINT8 data)
{
k051649_state *info = (k051649_state *) chip;
//stream_update(info->stream);
info->channel_list[offset>>5].waveform[offset&0x1f]=data;
}
//WRITE8_DEVICE_HANDLER( k051649_volume_w )
void k051649_volume_w(void *chip, offs_t offset, UINT8 data)
{
k051649_state *info = (k051649_state *) chip;
//stream_update(info->stream);
info->channel_list[offset&0x7].volume=data&0xf;
}
//WRITE8_DEVICE_HANDLER( k051649_frequency_w )
void k051649_frequency_w(void *chip, offs_t offset, UINT8 data)
{
k051649_state *info = (k051649_state *) chip;
info->f[offset]=data;
//stream_update(info->stream);
info->channel_list[offset>>1].frequency=(info->f[offset&0xe] + (info->f[offset|1]<<8))&0xfff;
}
//WRITE8_DEVICE_HANDLER( k051649_keyonoff_w )
void k051649_keyonoff_w(void *chip, offs_t offset, UINT8 data)
{
k051649_state *info = (k051649_state *) chip;
//stream_update(info->stream);
info->channel_list[0].key=data&1;
info->channel_list[1].key=data&2;
info->channel_list[2].key=data&4;
info->channel_list[3].key=data&8;
info->channel_list[4].key=data&16;
}
void k051649_w(void *chip, offs_t offset, UINT8 data)
{
k051649_state *info = (k051649_state *) chip;
switch(offset & 1)
{
case 0x00:
info->cur_reg = data;
break;
case 0x01:
switch(offset >> 1)
{
case 0x00:
k051649_waveform_w(info, info->cur_reg, data);
break;
case 0x01:
k051649_frequency_w(info, info->cur_reg, data);
break;
case 0x02:
k051649_volume_w(info, info->cur_reg, data);
break;
case 0x03:
k051649_keyonoff_w(info, info->cur_reg, data);
break;
case 0x04:
k052539_waveform_w(info, info->cur_reg, data);
break;
}
break;
}
return;
}
void k051649_set_mute_mask(void *chip, UINT32 MuteMask)
{
k051649_state *info = (k051649_state *) chip;
UINT8 CurChn;
for (CurChn = 0; CurChn < 5; CurChn ++)
info->channel_list[CurChn].Muted = (MuteMask >> CurChn) & 0x01;
}