Files
86Box-fork/src/sound_cms.c

184 lines
6.6 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include "ibm.h"
#include "device.h"
#include "io.h"
#include "sound.h"
#include "sound_cms.h"
typedef struct cms_t
{
int addrs[2];
uint8_t regs[2][32];
uint16_t latch[2][6];
int freq[2][6];
float count[2][6];
int vol[2][6][2];
int stat[2][6];
uint16_t noise[2][2];
uint16_t noisefreq[2][2];
int noisecount[2][2];
int noisetype[2][2];
int16_t buffer[SOUNDBUFLEN * 2];
int pos;
} cms_t;
void cms_update(cms_t *cms)
{
for (; cms->pos < sound_pos_global; cms->pos++)
{
int c, d;
int16_t out_l = 0, out_r = 0;
for (c = 0; c < 4; c++)
{
switch (cms->noisetype[c >> 1][c & 1])
{
case 0: cms->noisefreq[c >> 1][c & 1] = 31250; break;
case 1: cms->noisefreq[c >> 1][c & 1] = 15625; break;
case 2: cms->noisefreq[c >> 1][c & 1] = 7812; break;
case 3: cms->noisefreq[c >> 1][c & 1] = cms->freq[c >> 1][(c & 1) * 3]; break;
}
}
for (c = 0; c < 2; c ++)
{
if (cms->regs[c][0x1C] & 1)
{
for (d = 0; d < 6; d++)
{
if (cms->regs[c][0x14] & (1 << d))
{
if (cms->stat[c][d]) out_l += (cms->vol[c][d][0] * 90);
if (cms->stat[c][d]) out_r += (cms->vol[c][d][1] * 90);
cms->count[c][d] += cms->freq[c][d];
if (cms->count[c][d] >= 24000)
{
cms->count[c][d] -= 24000;
cms->stat[c][d] ^= 1;
}
}
else if (cms->regs[c][0x15] & (1 << d))
{
if (cms->noise[c][d / 3] & 1) out_l += (cms->vol[c][d][0] * 90);
if (cms->noise[c][d / 3] & 1) out_r += (cms->vol[c][d][0] * 90);
}
}
for (d = 0; d < 2; d++)
{
cms->noisecount[c][d] += cms->noisefreq[c][d];
while (cms->noisecount[c][d] >= 24000)
{
cms->noisecount[c][d] -= 24000;
cms->noise[c][d] <<= 1;
if (!(((cms->noise[c][d] & 0x4000) >> 8) ^ (cms->noise[c][d] & 0x40)))
cms->noise[c][d] |= 1;
}
}
}
}
cms->buffer[(cms->pos << 1)] = out_l;
cms->buffer[(cms->pos << 1) + 1] = out_r;
}
}
void cms_get_buffer(int32_t *buffer, int len, void *p)
{
cms_t *cms = (cms_t *)p;
int c;
cms_update(cms);
for (c = 0; c < len * 2; c++)
buffer[c] += cms->buffer[c];
cms->pos = 0;
}
void cms_write(uint16_t addr, uint8_t val, void *p)
{
cms_t *cms = (cms_t *)p;
int voice;
int chip = (addr & 2) >> 1;
pclog("cms_write : addr %04X val %02X\n", addr, val);
if (addr & 1)
cms->addrs[chip] = val & 31;
else
{
cms_update(cms);
cms->regs[chip][cms->addrs[chip] & 31] = val;
switch (cms->addrs[chip] & 31)
{
case 0x00: case 0x01: case 0x02: /*Volume*/
case 0x03: case 0x04: case 0x05:
voice = cms->addrs[chip] & 7;
cms->vol[chip][voice][0] = val & 0xf;
cms->vol[chip][voice][1] = val >> 4;
break;
case 0x08: case 0x09: case 0x0A: /*Frequency*/
case 0x0B: case 0x0C: case 0x0D:
voice = cms->addrs[chip] & 7;
cms->latch[chip][voice] = (cms->latch[chip][voice] & 0x700) | val;
cms->freq[chip][voice] = (15625 << (cms->latch[chip][voice] >> 8)) / (511 - (cms->latch[chip][voice] & 255));
break;
case 0x10: case 0x11: case 0x12: /*Octave*/
voice = (cms->addrs[chip] & 3) << 1;
cms->latch[chip][voice] = (cms->latch[chip][voice] & 0xFF) | ((val & 7) << 8);
cms->latch[chip][voice + 1] = (cms->latch[chip][voice + 1] & 0xFF) | ((val & 0x70) << 4);
cms->freq[chip][voice] = (15625 << (cms->latch[chip][voice] >> 8)) / (511 - (cms->latch[chip][voice] & 255));
cms->freq[chip][voice + 1] = (15625 << (cms->latch[chip][voice + 1] >> 8)) / (511 - (cms->latch[chip][voice + 1] & 255));
break;
case 0x16: /*Noise*/
cms->noisetype[chip][0] = val & 3;
cms->noisetype[chip][1] = (val >> 4) & 3;
break;
}
}
}
uint8_t cms_read(uint16_t addr, void *p)
{
cms_t *cms = (cms_t *)p;
int chip = (addr & 2) >> 1;
if (addr & 1)
return cms->addrs[chip];
return cms->regs[chip][cms->addrs[chip] & 31];
}
void *cms_init()
{
cms_t *cms = malloc(sizeof(cms_t));
memset(cms, 0, sizeof(cms_t));
pclog("cms_init\n");
io_sethandler(0x0220, 0x0004, cms_read, NULL, NULL, cms_write, NULL, NULL, cms);
sound_add_handler(cms_get_buffer, cms);
return cms;
}
void cms_close(void *p)
{
cms_t *cms = (cms_t *)p;
free(cms);
}
device_t cms_device =
{
"Creative Music System / Game Blaster",
0,
cms_init,
cms_close,
NULL,
NULL,
NULL,
NULL
};