Retro/pcem
Watch
1
0
Fork
You've already forked pcem
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Refactored sound code - slight speedup.

Browse source
This commit is contained in:
TomW 2016-02-10 20:49:28 +00:00
commit 3a57341837
33 changed files with 706 additions and 535 deletions
Download patch file Download diff file Expand all files Collapse all files

73
src/sound_sn76489.c
View file

@ -17,48 +17,47 @@ static float volslog[16]=
#define PSGCONST ((3579545.0 / 64.0) / 48000.0)
void sn76489_poll(void *p)
void sn76489_update(sn76489_t *sn76489)
{
sn76489_t *sn76489 = (sn76489_t *)p;
int c;
int16_t result = 0;
if (sn76489->pos >= SOUNDBUFLEN)
return;
for (c = 1; c < 4; c++)
for (; sn76489->pos < sound_pos_global; sn76489->pos++)
{
if (sn76489->latch[c] > 256) result += (int16_t) (volslog[sn76489->vol[c]] * sn76489->stat[c]);
else result += (int16_t) (volslog[sn76489->vol[c]] * 127);
int c;
int16_t result = 0;
for (c = 1; c < 4; c++)
{
if (sn76489->latch[c] > 256) result += (int16_t) (volslog[sn76489->vol[c]] * sn76489->stat[c]);
else result += (int16_t) (volslog[sn76489->vol[c]] * 127);
sn76489->count[c] -= (256 * PSGCONST);
while ((int)sn76489->count[c] < 0)
{
sn76489->count[c] += sn76489->latch[c];
sn76489->stat[c] = -sn76489->stat[c];
sn76489->count[c] -= (256 * PSGCONST);
while ((int)sn76489->count[c] < 0)
{
sn76489->count[c] += sn76489->latch[c];
sn76489->stat[c] = -sn76489->stat[c];
}
}
}
result += (((sn76489->shift & 1) ^ 1) * 127 * volslog[sn76489->vol[0]] * 2);
result += (((sn76489->shift & 1) ^ 1) * 127 * volslog[sn76489->vol[0]] * 2);
sn76489->count[0] -= (512 * PSGCONST);
while ((int)sn76489->count[0] < 0 && sn76489->latch[0])
{
sn76489->count[0] += (sn76489->latch[0] * 4);
if (!(sn76489->noise & 4))
sn76489->count[0] -= (512 * PSGCONST);
while ((int)sn76489->count[0] < 0 && sn76489->latch[0])
{
if (sn76489->shift & 1)
sn76489->shift |= 0x8000;
sn76489->shift >>= 1;
sn76489->count[0] += (sn76489->latch[0] * 4);
if (!(sn76489->noise & 4))
{
if (sn76489->shift & 1)
sn76489->shift |= 0x8000;
sn76489->shift >>= 1;
}
else
{
if ((sn76489->shift & 1) ^ ((sn76489->shift >> 1) & 1))
sn76489->shift |= 0x8000;
sn76489->shift >>= 1;
}
}
else
{
if ((sn76489->shift & 1) ^ ((sn76489->shift >> 1) & 1))
sn76489->shift |= 0x8000;
sn76489->shift >>= 1;
}
}
sn76489->buffer[sn76489->pos++] = result;
sn76489->buffer[sn76489->pos] = result;
}
}
void sn76489_get_buffer(int16_t *buffer, int len, void *p)
@ -67,6 +66,8 @@ void sn76489_get_buffer(int16_t *buffer, int len, void *p)
int c;
sn76489_update(sn76489);
if (!sn76489_mute)
{
for (c = 0; c < len * 2; c++)
@ -81,6 +82,8 @@ void sn76489_write(uint16_t addr, uint8_t data, void *p)
sn76489_t *sn76489 = (sn76489_t *)p;
int freq;
sn76489_update(sn76489);
if (data & 0x80)
{
sn76489->firstdat = data;
@ -176,7 +179,7 @@ void sn74689_set_extra_divide(sn76489_t *sn76489, int enable)
void sn76489_init(sn76489_t *sn76489, uint16_t base, uint16_t size, int type)
{
sound_add_handler(sn76489_poll, sn76489_get_buffer, sn76489);
sound_add_handler(sn76489_get_buffer, sn76489);
sn76489->latch[0] = sn76489->latch[1] = sn76489->latch[2] = sn76489->latch[3] = 0x3FF << 6;
sn76489->vol[0] = 0;