clarify arp algo

This commit is contained in:
Joachim Fenkes 2012-08-11 13:33:43 +02:00
parent 663b4b2943
commit 0247ce816b

View file

@ -117,16 +117,23 @@ static unsigned char voice_lead(unsigned long i, int voice_nr)
static inline unsigned char voice_arp(unsigned long i)
{
static uint16_t arp_osc = 0;
uint8_t arpptr2 = arpseq1[arpseq2[i >> 16]][(i >> 14) & 3];
uint8_t arpptr = arpseq1[arpseq2[i >> 16]][(i >> 14) & 3];
if (!(i & (1 << 13)))
arpptr2 >>= 4;
uint8_t arpptr = arpeggio[arpptr2 & 0xF][(i >> 8) & 1];
arpptr >>= 4;
arpptr = arpeggio[arpptr & 0xF][(i >> 8) & 1];
if (!(i & 0x80))
arpptr >>= 4;
int note = arpnotes[arpptr & 0xF];
arp_osc += note;
return ((arptiming & (1 << (31 - (i >> 9)))) && (arp_osc & (1 << 12)) && ((i >> 13) > 15)) ? 0 : 140;
if ((i >> 13) <= 15)
return 0;
if (!(arptiming & (1 << (31 - (i >> 9)))))
return 0;
return (arp_osc & (1 << 12)) ? 0 : 35;
}
static inline unsigned char voice_bass(unsigned long i)
@ -147,7 +154,7 @@ static inline unsigned char voice_bass(unsigned long i)
static inline uint8_t next_sample()
{
static unsigned long i = 0;//x40000;
uint8_t ret = (voice_lead(i, 0) >> 1) + THREEQUARTERS(voice_lead(i, 1) >> 2) + (voice_lead(i, 2) >> 3) + (voice_bass(i) >> 2) + (voice_arp(i) >> 2);
uint8_t ret = (voice_lead(i, 0) >> 1) + THREEQUARTERS(voice_lead(i, 1) >> 2) + (voice_lead(i, 2) >> 3) + (voice_bass(i) >> 2) + voice_arp(i);
i++;
if ((i >> 13) == ARPSIZE)
i = 16 << 13;