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C140 Part 2

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This commit is contained in:
cam900 2023-08-09 20:30:00 +09:00
parent 54cd69aabf
commit 14c5d94499
21 changed files with 210 additions and 56 deletions
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10
src/engine/platform/sound/c140.c
View file

@ -46,6 +46,8 @@ static int c140_bit(int val, int bit) { return (val >> bit) & 1; }
void c140_tick(struct c140_t *c140, const int cycle)
{
c140->lout = 0;
c140->rout = 0;
for (int i = 0; i < 24; i++)
{
c140_voice_tick(c140, i, cycle);
@ -53,8 +55,8 @@ void c140_tick(struct c140_t *c140, const int cycle)
c140->rout += c140->voice[i].rout;
}
// scale as 16bit
c140->lout >>= 5;
c140->rout >>= 5;
c140->lout >>= 8;
c140->rout >>= 8;
}
void c140_voice_tick(struct c140_t *c140, const unsigned char voice, const int cycle)
@ -82,8 +84,8 @@ void c140_voice_tick(struct c140_t *c140, const unsigned char voice, const int c
c140_voice->frac &= 0xffff;
}
// fetch 12 bit sample
signed short s1 = c140->read_sample(c140_voice->bank, c140_voice->addr) & ~0xf;
signed short s2 = c140->read_sample(c140_voice->bank, c140_voice->addr + 1) & ~0xf;
signed short s1 = c140->sample_mem[((unsigned int)(c140_voice->bank) << 16) | c140_voice->addr] & ~0xf;
signed short s2 = c140->sample_mem[((unsigned int)(c140_voice->bank) << 16) | ((c140_voice->addr + 1) & 0xffff)] & ~0xf;
if (c140_voice->compressed)
{
s1 = c140->mulaw[(s1 >> 8) & 0xff];

2
src/engine/platform/sound/c140.h
View file

@ -69,7 +69,7 @@ struct c140_t
struct c140_voice_t voice[24];
signed int lout, rout;
signed short mulaw[256];
unsigned short (*read_sample)(unsigned char bank, unsigned short addr);
signed short *sample_mem;
};
void c140_tick(struct c140_t *c140, const int cycle);