cog/Frameworks/GME/vgmplay/chips/emu2149.c

525 lines
10 KiB
C

/****************************************************************************
emu2149.c -- YM2149/AY-3-8910 emulator by Mitsutaka Okazaki 2001
2001 04-28 : Version 1.00beta -- 1st Beta Release.
2001 08-14 : Version 1.10
2001 10-03 : Version 1.11 -- Added PSG_set_quality().
2002 03-02 : Version 1.12 -- Removed PSG_init & PSG_close.
2002 10-13 : Version 1.14 -- Fixed the envelope unit.
2003 09-19 : Version 1.15 -- Added PSG_setMask and PSG_toggleMask
2004 01-11 : Version 1.16 -- Fixed an envelope problem where the envelope
frequency register is written before key-on.
References:
psg.vhd -- 2000 written by Kazuhiro Tsujikawa.
s_fme7.c -- 1999,2000 written by Mamiya (NEZplug).
ay8910.c -- 1998-2001 Author unknown (MAME).
MSX-Datapack -- 1991 ASCII Corp.
AY-3-8910 data sheet
*****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "emu2149.h"
static e_uint32 voltbl[2][32] = {
{0x00, 0x01, 0x01, 0x02, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07, 0x09,
0x0B, 0x0D, 0x0F, 0x12,
0x16, 0x1A, 0x1F, 0x25, 0x2D, 0x35, 0x3F, 0x4C, 0x5A, 0x6A, 0x7F, 0x97,
0xB4, 0xD6, 0xEB, 0xFF},
{0x00, 0x00, 0x01, 0x01, 0x02, 0x02, 0x03, 0x03, 0x05, 0x05, 0x07, 0x07,
0x0B, 0x0B, 0x0F, 0x0F,
0x16, 0x16, 0x1F, 0x1F, 0x2D, 0x2D, 0x3F, 0x3F, 0x5A, 0x5A, 0x7F, 0x7F,
0xB4, 0xB4, 0xFF, 0xFF}
};
#define GETA_BITS 24
static void
internal_refresh (PSG * psg)
{
if (psg->quality)
{
psg->base_incr = 1 << GETA_BITS;
psg->realstep = (e_uint32) ((1 << 31) / psg->rate);
psg->psgstep = (e_uint32) ((1 << 31) / (psg->clk / 8));
psg->psgtime = 0;
}
else
{
psg->base_incr =
(e_uint32) ((double) psg->clk * (1 << GETA_BITS) / (8.0 * psg->rate));
}
}
EMU2149_API void
PSG_set_clock(PSG * psg, e_uint32 c)
{
psg->clk = c;
internal_refresh(psg);
}
EMU2149_API void
PSG_set_rate (PSG * psg, e_uint32 r)
{
psg->rate = r ? r : 44100;
internal_refresh (psg);
}
EMU2149_API void
PSG_set_quality (PSG * psg, e_uint32 q)
{
psg->quality = q;
internal_refresh (psg);
}
EMU2149_API PSG *
PSG_new (e_uint32 c, e_uint32 r)
{
PSG *psg;
psg = (PSG *) malloc (sizeof (PSG));
if (psg == NULL)
return NULL;
memset(psg, 0x00, sizeof(PSG));
PSG_setVolumeMode (psg, EMU2149_VOL_DEFAULT);
psg->clk = c;
psg->rate = r ? r : 44100;
PSG_set_quality (psg, 0);
psg->stereo_mask[0] = 0x03;
psg->stereo_mask[1] = 0x03;
psg->stereo_mask[2] = 0x03;
return psg;
}
EMU2149_API void
PSG_setFlags (PSG * psg, e_uint8 flags)
{
if (flags & EMU2149_ZX_STEREO)
{
// ABC Stereo
psg->stereo_mask[0] = 0x01;
psg->stereo_mask[1] = 0x03;
psg->stereo_mask[2] = 0x02;
}
else
{
psg->stereo_mask[0] = 0x03;
psg->stereo_mask[1] = 0x03;
psg->stereo_mask[2] = 0x03;
}
return;
}
EMU2149_API void
PSG_setVolumeMode (PSG * psg, int type)
{
switch (type)
{
case 1:
psg->voltbl = voltbl[EMU2149_VOL_YM2149];
break;
case 2:
psg->voltbl = voltbl[EMU2149_VOL_AY_3_8910];
break;
default:
psg->voltbl = voltbl[EMU2149_VOL_DEFAULT];
break;
}
}
EMU2149_API e_uint32
PSG_setMask (PSG *psg, e_uint32 mask)
{
e_uint32 ret = 0;
if(psg)
{
ret = psg->mask;
psg->mask = mask;
}
return ret;
}
EMU2149_API e_uint32
PSG_toggleMask (PSG *psg, e_uint32 mask)
{
e_uint32 ret = 0;
if(psg)
{
ret = psg->mask;
psg->mask ^= mask;
}
return ret;
}
EMU2149_API void
PSG_reset (PSG * psg)
{
int i;
psg->base_count = 0;
for (i = 0; i < 3; i++)
{
psg->cout[i] = 0;
psg->count[i] = 0x1000;
psg->freq[i] = 0;
psg->edge[i] = 0;
psg->volume[i] = 0;
}
psg->mask = 0;
for (i = 0; i < 16; i++)
psg->reg[i] = 0;
psg->adr = 0;
psg->noise_seed = 0xffff;
psg->noise_count = 0x40;
psg->noise_freq = 0;
psg->env_volume = 0;
psg->env_ptr = 0;
psg->env_freq = 0;
psg->env_count = 0;
psg->env_pause = 1;
psg->out = 0;
}
EMU2149_API void
PSG_delete (PSG * psg)
{
free (psg);
}
EMU2149_API e_uint8
PSG_readIO (PSG * psg)
{
return (e_uint8) (psg->reg[psg->adr]);
}
EMU2149_API e_uint8
PSG_readReg (PSG * psg, e_uint32 reg)
{
return (e_uint8) (psg->reg[reg & 0x1f]);
}
EMU2149_API void
PSG_writeIO (PSG * psg, e_uint32 adr, e_uint32 val)
{
if (adr & 1)
PSG_writeReg (psg, psg->adr, val);
else
psg->adr = val & 0x1f;
}
INLINE static e_int16
calc (PSG * psg)
{
int i, noise;
e_uint32 incr;
e_int32 mix = 0;
psg->base_count += psg->base_incr;
incr = (psg->base_count >> GETA_BITS);
psg->base_count &= (1 << GETA_BITS) - 1;
/* Envelope */
psg->env_count += incr;
while (psg->env_count>=0x10000 && psg->env_freq!=0)
{
if (!psg->env_pause)
{
if(psg->env_face)
psg->env_ptr = (psg->env_ptr + 1) & 0x3f ;
else
psg->env_ptr = (psg->env_ptr + 0x3f) & 0x3f;
}
if (psg->env_ptr & 0x20) /* if carry or borrow */
{
if (psg->env_continue)
{
if (psg->env_alternate^psg->env_hold) psg->env_face ^= 1;
if (psg->env_hold) psg->env_pause = 1;
psg->env_ptr = psg->env_face?0:0x1f;
}
else
{
psg->env_pause = 1;
psg->env_ptr = 0;
}
}
psg->env_count -= psg->env_freq;
}
/* Noise */
psg->noise_count += incr;
if (psg->noise_count & 0x40)
{
if (psg->noise_seed & 1)
psg->noise_seed ^= 0x24000;
psg->noise_seed >>= 1;
psg->noise_count -= psg->noise_freq;
}
noise = psg->noise_seed & 1;
/* Tone */
for (i = 0; i < 3; i++)
{
psg->count[i] += incr;
if (psg->count[i] & 0x1000)
{
if (psg->freq[i] > 1)
{
psg->edge[i] = !psg->edge[i];
psg->count[i] -= psg->freq[i];
}
else
{
psg->edge[i] = 1;
}
}
psg->cout[i] = 0; // BS maintaining cout for stereo mix
if (psg->mask&PSG_MASK_CH(i))
continue;
if ((psg->tmask[i] || psg->edge[i]) && (psg->nmask[i] || noise))
{
if (!(psg->volume[i] & 32))
psg->cout[i] = psg->voltbl[psg->volume[i] & 31];
else
psg->cout[i] = psg->voltbl[psg->env_ptr];
mix += psg->cout[i];
}
}
return (e_int16) mix;
}
EMU2149_API e_int16
PSG_calc (PSG * psg)
{
if (!psg->quality)
return (e_int16) (calc (psg) << 4);
/* Simple rate converter */
while (psg->realstep > psg->psgtime)
{
psg->psgtime += psg->psgstep;
psg->out += calc (psg);
psg->out >>= 1;
}
psg->psgtime = psg->psgtime - psg->realstep;
return (e_int16) (psg->out << 4);
}
INLINE static void
calc_stereo (PSG * psg, e_int32 out[2])
{
int i, noise;
e_uint32 incr;
e_int32 l = 0, r = 0;
psg->base_count += psg->base_incr;
incr = (psg->base_count >> GETA_BITS);
psg->base_count &= (1 << GETA_BITS) - 1;
/* Envelope */
psg->env_count += incr;
while (psg->env_count>=0x10000 && psg->env_freq!=0)
{
if (!psg->env_pause)
{
if(psg->env_face)
psg->env_ptr = (psg->env_ptr + 1) & 0x3f ;
else
psg->env_ptr = (psg->env_ptr + 0x3f) & 0x3f;
}
if (psg->env_ptr & 0x20) /* if carry or borrow */
{
if (psg->env_continue)
{
if (psg->env_alternate^psg->env_hold) psg->env_face ^= 1;
if (psg->env_hold) psg->env_pause = 1;
psg->env_ptr = psg->env_face?0:0x1f;
}
else
{
psg->env_pause = 1;
psg->env_ptr = 0;
}
}
psg->env_count -= psg->env_freq;
}
/* Noise */
psg->noise_count += incr;
if (psg->noise_count & 0x40)
{
if (psg->noise_seed & 1)
psg->noise_seed ^= 0x24000;
psg->noise_seed >>= 1;
psg->noise_count -= psg->noise_freq;
}
noise = psg->noise_seed & 1;
/* Tone */
for (i = 0; i < 3; i++)
{
psg->count[i] += incr;
if (psg->count[i] & 0x1000)
{
if (psg->freq[i] > 1)
{
psg->edge[i] = !psg->edge[i];
psg->count[i] -= psg->freq[i];
}
else
{
psg->edge[i] = 1;
}
}
psg->cout[i] = 0; // BS maintaining cout for stereo mix
if (psg->mask&PSG_MASK_CH(i))
continue;
if ((psg->tmask[i] || psg->edge[i]) && (psg->nmask[i] || noise))
{
if (!(psg->volume[i] & 32))
psg->cout[i] = psg->voltbl[psg->volume[i] & 31];
else
psg->cout[i] = psg->voltbl[psg->env_ptr];
if (psg->stereo_mask[i] & 0x01)
l += psg->cout[i];
if (psg->stereo_mask[i] & 0x02)
r += psg->cout[i];
}
}
out[0] = l << 5;
out[1] = r << 5;
return;
}
EMU2149_API void
PSG_calc_stereo (PSG * psg, e_int32 **out, e_int32 samples)
{
e_int32 *bufMO = out[0];
e_int32 *bufRO = out[1];
e_int32 buffers[2];
int i;
for (i = 0; i < samples; i ++)
{
if (!psg->quality)
{
calc_stereo (psg, buffers);
bufMO[i] = buffers[0];
bufRO[i] = buffers[1];
}
else
{
while (psg->realstep > psg->psgtime)
{
psg->psgtime += psg->psgstep;
psg->sprev[0] = psg->snext[0];
psg->sprev[1] = psg->snext[1];
calc_stereo (psg, psg->snext);
}
psg->psgtime -= psg->realstep;
bufMO[i] = (e_int32) (((double) psg->snext[0] * (psg->psgstep - psg->psgtime)
+ (double) psg->sprev[0] * psg->psgtime) / psg->psgstep);
bufRO[i] = (e_int32) (((double) psg->snext[1] * (psg->psgstep - psg->psgtime)
+ (double) psg->sprev[1] * psg->psgtime) / psg->psgstep);
}
}
}
EMU2149_API void
PSG_writeReg (PSG * psg, e_uint32 reg, e_uint32 val)
{
int c;
if (reg > 15) return;
psg->reg[reg] = (e_uint8) (val & 0xff);
switch (reg)
{
case 0:
case 2:
case 4:
case 1:
case 3:
case 5:
c = reg >> 1;
psg->freq[c] = ((psg->reg[c * 2 + 1] & 15) << 8) + psg->reg[c * 2];
break;
case 6:
psg->noise_freq = (val == 0) ? 1 : ((val & 31) << 1);
break;
case 7:
psg->tmask[0] = (val & 1);
psg->tmask[1] = (val & 2);
psg->tmask[2] = (val & 4);
psg->nmask[0] = (val & 8);
psg->nmask[1] = (val & 16);
psg->nmask[2] = (val & 32);
break;
case 8:
case 9:
case 10:
psg->volume[reg - 8] = val << 1;
break;
case 11:
case 12:
psg->env_freq = (psg->reg[12] << 8) + psg->reg[11];
break;
case 13:
psg->env_continue = (val >> 3) & 1;
psg->env_attack = (val >> 2) & 1;
psg->env_alternate = (val >> 1) & 1;
psg->env_hold = val & 1;
psg->env_face = psg->env_attack;
psg->env_pause = 0;
psg->env_count = 0x10000 - psg->env_freq;
psg->env_ptr = psg->env_face?0:0x1f;
break;
case 14:
case 15:
default:
break;
}
return;
}