cog/Frameworks/GME/vgmplay/chips/iremga20.c

370 lines
8.8 KiB
C

/*********************************************************
Irem GA20 PCM Sound Chip
It's not currently known whether this chip is stereo.
Revisions:
04-15-2002 Acho A. Tang
- rewrote channel mixing
- added prelimenary volume and sample rate emulation
05-30-2002 Acho A. Tang
- applied hyperbolic gain control to volume and used
a musical-note style progression in sample rate
calculation(still very inaccurate)
02-18-2004 R. Belmont
- sample rate calculation reverse-engineered.
Thanks to Fujix, Yasuhiro Ogawa, the Guru, and Tormod
for real PCB samples that made this possible.
02-03-2007 R. Belmont
- Cleaned up faux x86 assembly.
*********************************************************/
//#include "emu.h"
#include <stdlib.h>
#include <string.h>
#include <stddef.h> // for NULL
#include "mamedef.h"
#include "iremga20.h"
#define MAX_VOL 256
struct IremGA20_channel_def
{
UINT32 rate;
//UINT32 size;
UINT32 start;
UINT32 pos;
UINT32 frac;
UINT32 end;
UINT32 volume;
UINT32 pan;
//UINT32 effect;
UINT8 play;
UINT8 Muted;
};
typedef struct _ga20_state ga20_state;
struct _ga20_state
{
UINT8 *rom;
UINT32 rom_size;
//sound_stream * stream;
UINT16 regs[0x40];
struct IremGA20_channel_def channel[4];
};
/*INLINE ga20_state *get_safe_token(device_t *device)
{
assert(device != NULL);
assert(device->type() == IREMGA20);
return (ga20_state *)downcast<legacy_device_base *>(device)->token();
}*/
//static STREAM_UPDATE( IremGA20_update )
void IremGA20_update(void *param, stream_sample_t **outputs, int samples)
{
ga20_state *chip = (ga20_state *)param;
UINT32 rate[4], pos[4], frac[4], end[4], vol[4], play[4];
UINT8 *pSamples;
stream_sample_t *outL, *outR;
int i, sampleout;
/* precache some values */
for (i=0; i < 4; i++)
{
rate[i] = chip->channel[i].rate;
pos[i] = chip->channel[i].pos;
frac[i] = chip->channel[i].frac;
end[i] = chip->channel[i].end - 0x20;
vol[i] = chip->channel[i].volume;
play[i] = (! chip->channel[i].Muted) ? chip->channel[i].play : 0;
}
i = samples;
pSamples = chip->rom;
outL = outputs[0];
outR = outputs[1];
for (i = 0; i < samples; i++)
{
sampleout = 0;
// update the 4 channels inline
if (play[0])
{
sampleout += (pSamples[pos[0]] - 0x80) * vol[0];
frac[0] += rate[0];
pos[0] += frac[0] >> 24;
frac[0] &= 0xffffff;
play[0] = (pos[0] < end[0]);
}
if (play[1])
{
sampleout += (pSamples[pos[1]] - 0x80) * vol[1];
frac[1] += rate[1];
pos[1] += frac[1] >> 24;
frac[1] &= 0xffffff;
play[1] = (pos[1] < end[1]);
}
if (play[2])
{
sampleout += (pSamples[pos[2]] - 0x80) * vol[2];
frac[2] += rate[2];
pos[2] += frac[2] >> 24;
frac[2] &= 0xffffff;
play[2] = (pos[2] < end[2]);
}
if (play[3])
{
sampleout += (pSamples[pos[3]] - 0x80) * vol[3];
frac[3] += rate[3];
pos[3] += frac[3] >> 24;
frac[3] &= 0xffffff;
play[3] = (pos[3] < end[3]);
}
sampleout >>= 2;
outL[i] = sampleout;
outR[i] = sampleout;
}
/* update the regs now */
for (i=0; i < 4; i++)
{
chip->channel[i].pos = pos[i];
chip->channel[i].frac = frac[i];
if (! chip->channel[i].Muted)
chip->channel[i].play = play[i];
}
}
//WRITE8_DEVICE_HANDLER( irem_ga20_w )
void irem_ga20_w(void *_info, offs_t offset, UINT8 data)
{
//ga20_state *chip = get_safe_token(device);
ga20_state *chip = (ga20_state *)_info;
int channel;
//logerror("GA20: Offset %02x, data %04x\n",offset,data);
//chip->stream->update();
channel = offset >> 3;
chip->regs[offset] = data;
switch (offset & 0x7)
{
case 0: /* start address low */
chip->channel[channel].start = ((chip->channel[channel].start)&0xff000) | (data<<4);
break;
case 1: /* start address high */
chip->channel[channel].start = ((chip->channel[channel].start)&0x00ff0) | (data<<12);
break;
case 2: /* end address low */
chip->channel[channel].end = ((chip->channel[channel].end)&0xff000) | (data<<4);
break;
case 3: /* end address high */
chip->channel[channel].end = ((chip->channel[channel].end)&0x00ff0) | (data<<12);
break;
case 4:
chip->channel[channel].rate = 0x1000000 / (256 - data);
break;
case 5: //AT: gain control
chip->channel[channel].volume = (data * MAX_VOL) / (data + 10);
break;
case 6: //AT: this is always written 2(enabling both channels?)
chip->channel[channel].play = data;
chip->channel[channel].pos = chip->channel[channel].start;
chip->channel[channel].frac = 0;
break;
}
}
//READ8_DEVICE_HANDLER( irem_ga20_r )
UINT8 irem_ga20_r(void *_info, offs_t offset)
{
//ga20_state *chip = get_safe_token(device);
ga20_state *chip = (ga20_state *)_info;
int channel;
//chip->stream->update();
channel = offset >> 3;
switch (offset & 0x7)
{
case 7: // voice status. bit 0 is 1 if active. (routine around 0xccc in rtypeleo)
return chip->channel[channel].play ? 1 : 0;
default:
#ifdef _DEBUG
logerror("GA20: read unk. register %d, channel %d\n", offset & 0xf, channel);
#endif
break;
}
return 0;
}
static void iremga20_reset(ga20_state *chip)
{
int i;
for( i = 0; i < 4; i++ ) {
chip->channel[i].rate = 0;
//chip->channel[i].size = 0;
chip->channel[i].start = 0;
chip->channel[i].pos = 0;
chip->channel[i].frac = 0;
chip->channel[i].end = 0;
chip->channel[i].volume = 0;
chip->channel[i].pan = 0;
//chip->channel[i].effect = 0;
chip->channel[i].play = 0;
}
}
//static DEVICE_RESET( iremga20 )
void device_reset_iremga20(void *_info)
{
//iremga20_reset(get_safe_token(device));
ga20_state *chip = (ga20_state *)_info;
iremga20_reset(chip);
memset(chip->regs, 0x00, 0x40 * sizeof(UINT16));
}
//static DEVICE_START( iremga20 )
int device_start_iremga20(void **_info, int clock)
{
//ga20_state *chip = get_safe_token(device);
ga20_state *chip;
int i;
chip = (ga20_state *) calloc(1, sizeof(ga20_state));
*_info = (void *) chip;
/* Initialize our chip structure */
//chip->rom = *device->region();
//chip->rom_size = device->region()->bytes();
chip->rom = NULL;
chip->rom_size = 0x00;
iremga20_reset(chip);
for ( i = 0; i < 0x40; i++ )
chip->regs[i] = 0;
//chip->stream = device->machine().sound().stream_alloc( *device, 0, 2, device->clock()/4, chip, IremGA20_update );
/*device->save_item(NAME(chip->regs));
for (i = 0; i < 4; i++)
{
device->save_item(NAME(chip->channel[i].rate), i);
device->save_item(NAME(chip->channel[i].size), i);
device->save_item(NAME(chip->channel[i].start), i);
device->save_item(NAME(chip->channel[i].pos), i);
device->save_item(NAME(chip->channel[i].end), i);
device->save_item(NAME(chip->channel[i].volume), i);
device->save_item(NAME(chip->channel[i].pan), i);
device->save_item(NAME(chip->channel[i].effect), i);
device->save_item(NAME(chip->channel[i].play), i);
}*/
for (i = 0; i < 4; i ++)
chip->channel[i].Muted = 0x00;
return clock / 4;
}
void device_stop_iremga20(void *_info)
{
ga20_state *chip = (ga20_state *)_info;
free(chip->rom); chip->rom = NULL;
free(chip);
return;
}
void iremga20_write_rom(void *_info, offs_t ROMSize, offs_t DataStart, offs_t DataLength,
const UINT8* ROMData)
{
ga20_state *chip = (ga20_state *)_info;
if (chip->rom_size != ROMSize)
{
chip->rom = (UINT8*)realloc(chip->rom, ROMSize);
chip->rom_size = ROMSize;
memset(chip->rom, 0xFF, ROMSize);
}
if (DataStart > ROMSize)
return;
if (DataStart + DataLength > ROMSize)
DataLength = ROMSize - DataStart;
memcpy(chip->rom + DataStart, ROMData, DataLength);
return;
}
void iremga20_set_mute_mask(void *_info, UINT32 MuteMask)
{
ga20_state *chip = (ga20_state *)_info;
UINT8 CurChn;
for (CurChn = 0; CurChn < 4; CurChn ++)
chip->channel[CurChn].Muted = (MuteMask >> CurChn) & 0x01;
return;
}
/**************************************************************************
* Generic get_info
**************************************************************************/
/*DEVICE_GET_INFO( iremga20 )
{
switch (state)
{
// --- the following bits of info are returned as 64-bit signed integers ---
case DEVINFO_INT_TOKEN_BYTES: info->i = sizeof(ga20_state); break;
// --- the following bits of info are returned as pointers to data or functions ---
case DEVINFO_FCT_START: info->start = DEVICE_START_NAME( iremga20 ); break;
case DEVINFO_FCT_STOP: // nothing // break;
case DEVINFO_FCT_RESET: info->reset = DEVICE_RESET_NAME( iremga20 ); break;
// --- the following bits of info are returned as NULL-terminated strings ---
case DEVINFO_STR_NAME: strcpy(info->s, "Irem GA20"); break;
case DEVINFO_STR_FAMILY: strcpy(info->s, "Irem custom"); break;
case DEVINFO_STR_VERSION: strcpy(info->s, "1.0"); break;
case DEVINFO_STR_SOURCE_FILE: strcpy(info->s, __FILE__); break;
case DEVINFO_STR_CREDITS: strcpy(info->s, "Copyright Nicola Salmoria and the MAME Team"); break;
}
}
DEFINE_LEGACY_SOUND_DEVICE(IREMGA20, iremga20);*/