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minor cleanup/precompute rates

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This commit is contained in:
Michaël Banaan Ananas 2011-08-30 16:14:08 +00:00
parent ff2de72d6a
commit 03ada8a386
1 changed files with 60 additions and 43 deletions
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103
src/emu/sound/ymf278b.c
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@ -52,8 +52,8 @@
instruments in hotdebut). instruments in hotdebut).
Thanks to Team Japump! for MP3s from a real PCB. Thanks to Team Japump! for MP3s from a real PCB.
fixed crash if MAME is run with no sound. fixed crash if MAME is run with no sound.
June 4, 2003 - Changed to dual-license with LGPL for use in OpenMSX. June 4, 2003 - Changed to dual-license with LGPL for use in openMSX.
OpenMSX contributed a bugfix where looped samples were openMSX contributed a bugfix where looped samples were
not being addressed properly, causing pitch fluctuation. not being addressed properly, causing pitch fluctuation.
With further improvements over the years by MAME team. With further improvements over the years by MAME team.
@ -108,14 +108,15 @@ typedef struct
UINT32 env_vol_step; UINT32 env_vol_step;
UINT32 env_vol_lim; UINT32 env_vol_lim;
INT8 env_preverb; INT8 env_preverb;
int num; /* slot number (for debug only) */
struct _YMF278BChip *chip; /* pointer back to parent chip */
} YMF278BSlot; } YMF278BSlot;
typedef struct typedef struct _YMF278BChip
{ {
UINT8 pcmregs[256]; UINT8 pcmregs[256];
YMF278BSlot slots[24]; YMF278BSlot slots[24];
INT8 lsitest0;
INT8 lsitest1;
INT8 wavetblhdr; INT8 wavetblhdr;
INT8 memmode; INT8 memmode;
INT32 memadr; INT32 memadr;
@ -142,6 +143,9 @@ typedef struct
UINT32 romsize; UINT32 romsize;
int clock; int clock;
// precomputed tables
UINT32 lut_ar[64]; // attack rate
UINT32 lut_dr[64]; // decay rate
INT32 volume[256*4]; // precalculated attenuation values with some margin for envelope and pan levels INT32 volume[256*4]; // precalculated attenuation values with some margin for envelope and pan levels
int pan_left[16],pan_right[16]; // pan volume offsets int pan_left[16],pan_right[16]; // pan volume offsets
INT32 mix_level[8]; INT32 mix_level[8];
@ -172,6 +176,8 @@ INLINE UINT8 ymf278b_read_memory(YMF278BChip *chip, UINT32 offset)
} }
/**************************************************************************/
static int ymf278b_compute_rate(YMF278BSlot *slot, int val) static int ymf278b_compute_rate(YMF278BSlot *slot, int val)
{ {
int res, oct; int res, oct;
@ -198,36 +204,6 @@ static int ymf278b_compute_rate(YMF278BSlot *slot, int val)
return res; return res;
} }
INLINE UINT32 ymf278_compute_attack_rate(int num)
{
// estimated (less accurate on high rates)
UINT32 samples;
if (num <= 3 || num == 63)
samples = 0;
else if (num >= 60)
samples = 17;
else
samples = (67 << (15 - num / 4)) / (4 + num % 4);
return samples;
}
static UINT32 ymf278_compute_decay_rate(int num)
{
// estimated
UINT32 samples;
if (num <= 3)
samples = 0;
else if (num >= 60)
samples = 15 << 4;
else
samples = (15 << (21 - num / 4)) / (4 + num % 4);
return samples;
}
static UINT32 ymf278_compute_decay_env_vol_step(YMF278BSlot *slot, int val) static UINT32 ymf278_compute_decay_env_vol_step(YMF278BSlot *slot, int val)
{ {
int rate; int rate;
@ -248,7 +224,7 @@ static UINT32 ymf278_compute_decay_env_vol_step(YMF278BSlot *slot, int val)
if (rate < 4) if (rate < 4)
res = 0; res = 0;
else else
res = (256U<<23) / ymf278_compute_decay_rate(rate); res = (256U<<23) / slot->chip->lut_dr[rate];
return res; return res;
} }
@ -293,8 +269,8 @@ static void ymf278b_compute_envelope(YMF278BSlot *slot)
else else
{ {
// NOTE: attack rate is linear here, but datasheet shows a smooth curve // NOTE: attack rate is linear here, but datasheet shows a smooth curve
LOG(("YMF278B: Attack, val = %d, rate = %d, delay = %g\n", slot->AR, rate, ymf278_compute_attack_rate(rate)*1000.0)); LOG(("YMF278B: Attack, val = %d, rate = %d, delay = %g\n", slot->AR, rate, slot->chip->lut_ar[rate]*1000.0));
slot->env_vol_step = ~((256U<<23) / ymf278_compute_attack_rate(rate)); slot->env_vol_step = ~((256U<<23) / slot->chip->lut_ar[rate]);
} }
break; break;
@ -304,7 +280,7 @@ static void ymf278b_compute_envelope(YMF278BSlot *slot)
case 1: case 1:
if(slot->DL) if(slot->DL)
{ {
LOG(("YMF278B: Decay step 1, dl=%d, val = %d rate = %d, delay = %g, PRVB = %d, DAMP = %d\n", slot->DL, slot->D1R, ymf278b_compute_rate(slot, slot->D1R), ymf278_compute_decay_rate(ymf278b_compute_rate(slot, slot->D1R))*1000.0, slot->preverb, slot->DAMP)); LOG(("YMF278B: Decay step 1, dl=%d, val = %d rate = %d, delay = %g, PRVB = %d, DAMP = %d\n", slot->DL, slot->D1R, ymf278b_compute_rate(slot, slot->D1R), slot->chip->lut_dr[ymf278b_compute_rate(slot, slot->D1R)]*1000.0, slot->preverb, slot->DAMP));
slot->env_vol_step = ymf278_compute_decay_env_vol_step(slot, slot->D1R); slot->env_vol_step = ymf278_compute_decay_env_vol_step(slot, slot->D1R);
slot->env_vol_lim = (slot->DL*8)<<23; slot->env_vol_lim = (slot->DL*8)<<23;
} }
@ -319,7 +295,7 @@ static void ymf278b_compute_envelope(YMF278BSlot *slot)
// Decay 2 // Decay 2
case 2: case 2:
LOG(("YMF278B: Decay step 2, val = %d, rate = %d, delay = %g, , PRVB = %d, DAMP = %d, current vol = %d\n", slot->D2R, ymf278b_compute_rate(slot, slot->D2R), ymf278_compute_decay_rate(ymf278b_compute_rate(slot, slot->D2R))*1000.0, slot->preverb, slot->DAMP, slot->env_vol >> 23)); LOG(("YMF278B: Decay step 2, val = %d, rate = %d, delay = %g, , PRVB = %d, DAMP = %d, current vol = %d\n", slot->D2R, ymf278b_compute_rate(slot, slot->D2R), slot->chip->lut_dr[ymf278b_compute_rate(slot, slot->D2R)]*1000.0, slot->preverb, slot->DAMP, slot->env_vol >> 23));
slot->env_vol_step = ymf278_compute_decay_env_vol_step(slot, slot->D2R); slot->env_vol_step = ymf278_compute_decay_env_vol_step(slot, slot->D2R);
slot->env_vol_lim = 256U<<23; slot->env_vol_lim = 256U<<23;
break; break;
@ -335,7 +311,7 @@ static void ymf278b_compute_envelope(YMF278BSlot *slot)
// Release // Release
case 4: case 4:
LOG(("YMF278B: Release, val = %d, rate = %d, delay = %g, PRVB = %d, DAMP = %d\n", slot->RR, ymf278b_compute_rate(slot, slot->RR), ymf278_compute_decay_rate(ymf278b_compute_rate(slot, slot->RR))*1000.0, slot->preverb, slot->DAMP)); LOG(("YMF278B: Release, val = %d, rate = %d, delay = %g, PRVB = %d, DAMP = %d\n", slot->RR, ymf278b_compute_rate(slot, slot->RR), slot->chip->lut_dr[ymf278b_compute_rate(slot, slot->RR)]*1000.0, slot->preverb, slot->DAMP));
slot->env_vol_step = ymf278_compute_decay_env_vol_step(slot, slot->RR); slot->env_vol_step = ymf278_compute_decay_env_vol_step(slot, slot->RR);
slot->env_vol_lim = 256U<<23; slot->env_vol_lim = 256U<<23;
break; break;
@ -468,6 +444,9 @@ static TIMER_CALLBACK( ymf278b_timer_b_tick )
} }
} }
/**************************************************************************/
static void ymf278b_A_w(running_machine &machine, YMF278BChip *chip, UINT8 reg, UINT8 data) static void ymf278b_A_w(running_machine &machine, YMF278BChip *chip, UINT8 reg, UINT8 data)
{ {
// FM register array 0 (compatible with YMF262) // FM register array 0 (compatible with YMF262)
@ -902,6 +881,8 @@ READ8_DEVICE_HANDLER( ymf278b_r )
} }
/**************************************************************************/
static DEVICE_RESET( ymf278b ) static DEVICE_RESET( ymf278b )
{ {
YMF278BChip *chip = get_safe_token(device); YMF278BChip *chip = get_safe_token(device);
@ -954,6 +935,8 @@ static DEVICE_RESET( ymf278b )
static void ymf278b_init(device_t *device, YMF278BChip *chip, void (*cb)(device_t *, int)) static void ymf278b_init(device_t *device, YMF278BChip *chip, void (*cb)(device_t *, int))
{ {
int i;
chip->rom = *device->region(); chip->rom = *device->region();
chip->romsize = device->region()->bytes(); chip->romsize = device->region()->bytes();
chip->clock = device->clock(); chip->clock = device->clock();
@ -964,6 +947,39 @@ static void ymf278b_init(device_t *device, YMF278BChip *chip, void (*cb)(device_
chip->timer_b = device->machine().scheduler().timer_alloc(FUNC(ymf278b_timer_b_tick), chip); chip->timer_b = device->machine().scheduler().timer_alloc(FUNC(ymf278b_timer_b_tick), chip);
chip->timer_busy = device->machine().scheduler().timer_alloc(FUNC(ymf278b_timer_busy_clear), chip); chip->timer_busy = device->machine().scheduler().timer_alloc(FUNC(ymf278b_timer_busy_clear), chip);
chip->timer_ld = device->machine().scheduler().timer_alloc(FUNC(ymf278b_timer_ld_clear), chip); chip->timer_ld = device->machine().scheduler().timer_alloc(FUNC(ymf278b_timer_ld_clear), chip);
for (i = 0; i < 24; i++)
{
chip->slots[i].num = i;
chip->slots[i].chip = chip;
}
}
static void precompute_rate_tables(YMF278BChip *chip)
{
int i;
// decay rate
for (i = 0; i < 64; i++)
{
if (i <= 3)
chip->lut_dr[i] = 0;
else if (i >= 60)
chip->lut_dr[i] = 15 << 4;
else
chip->lut_dr[i] = (15 << (21 - i / 4)) / (4 + i % 4);
}
// attack rate (manual shows curve instead of linear though, so this is not entirely accurate)
for (i = 0; i < 64; i++)
{
if (i <= 3 || i == 63)
chip->lut_ar[i] = 0;
else if (i >= 60)
chip->lut_ar[i] = 17;
else
chip->lut_ar[i] = (67 << (15 - i / 4)) / (4 + i % 4);
}
} }
static void ymf278b_register_save_state(device_t *device, YMF278BChip *chip) static void ymf278b_register_save_state(device_t *device, YMF278BChip *chip)
@ -971,8 +987,6 @@ static void ymf278b_register_save_state(device_t *device, YMF278BChip *chip)
int i; int i;
device->save_item(NAME(chip->pcmregs)); device->save_item(NAME(chip->pcmregs));
device->save_item(NAME(chip->lsitest0));
device->save_item(NAME(chip->lsitest1));
device->save_item(NAME(chip->wavetblhdr)); device->save_item(NAME(chip->wavetblhdr));
device->save_item(NAME(chip->memmode)); device->save_item(NAME(chip->memmode));
device->save_item(NAME(chip->memadr)); device->save_item(NAME(chip->memadr));
@ -1045,6 +1059,9 @@ static DEVICE_START( ymf278b )
ymf278b_init(device, chip, intf->irq_callback); ymf278b_init(device, chip, intf->irq_callback);
chip->stream = device->machine().sound().stream_alloc(*device, 0, 2, device->clock()/768, chip, ymf278b_pcm_update); chip->stream = device->machine().sound().stream_alloc(*device, 0, 2, device->clock()/768, chip, ymf278b_pcm_update);
// rate tables
precompute_rate_tables(chip);
// Volume table, 1 = -0.375dB, 8 = -3dB, 256 = -96dB // Volume table, 1 = -0.375dB, 8 = -3dB, 256 = -96dB
for(i = 0; i < 256; i++) for(i = 0; i < 256; i++)
chip->volume[i] = 65536*pow(2.0, (-0.375/6)*i); chip->volume[i] = 65536*pow(2.0, (-0.375/6)*i);