ref: 9211d95a76975169ee7b71fc74582e5707e3fa04
dir: /tangled/osc.c/
#line 44 "osc.org" #include <stdint.h> #include <stdlib.h> #include <math.h> #define SK_OSC_PRIV #include "osc.h" #line 105 "osc.org" #define SK_OSC_MAXLEN 0x1000000L #define SK_OSC_PHASEMASK 0x0FFFFFFL #line 44 "osc.org" #line 92 "osc.org" void sk_osc_freq(sk_osc *osc, SKFLT freq) { osc->freq = freq; } void sk_osc_amp(sk_osc *osc, SKFLT amp) { osc->amp = amp; } #line 254 "osc.org" void sk_osc_init(sk_osc *osc, int sr, SKFLT *wt, int sz, SKFLT iphs) { #line 140 "osc.org" osc->freq = 440; osc->amp = 0.2; #line 149 "osc.org" osc->tab = wt; osc->sz = sz; #line 160 "osc.org" osc->inc = 0; #line 170 "osc.org" osc->lphs = ((int32_t)(iphs * SK_OSC_MAXLEN)) & SK_OSC_PHASEMASK; #line 205 "osc.org" { uint32_t tmp; tmp = SK_OSC_MAXLEN / sz; osc->nlb = 0; while (tmp >>= 1) osc->nlb++; } #line 228 "osc.org" osc->mask = (1<<osc->nlb) - 1; #line 205 "osc.org" #line 238 "osc.org" osc->inlb = 1.0 / (1<<osc->nlb); #line 205 "osc.org" #line 247 "osc.org" osc->maxlens = 1.0 * SK_OSC_MAXLEN / sr; #line 205 "osc.org" #line 257 "osc.org" } #line 266 "osc.org" SKFLT sk_osc_tick(sk_osc *osc) { SKFLT out; SKFLT fract; SKFLT x1, x2; int32_t phs; int pos; out = 0; #line 331 "osc.org" osc->inc = floor(lrintf(osc->freq * osc->maxlens)); #line 266 "osc.org" #line 342 "osc.org" phs = osc->lphs; pos = phs >> osc->nlb; x1 = osc->tab[pos]; x2 = osc->tab[(pos + 1) % osc->sz]; #line 266 "osc.org" #line 372 "osc.org" fract = (phs & osc->mask) * osc->inlb; #line 266 "osc.org" #line 397 "osc.org" out = (x1 + (x2 - x1) * fract) * osc->amp; #line 266 "osc.org" #line 406 "osc.org" phs += osc->inc; phs &= SK_OSC_PHASEMASK; osc->lphs = phs; #line 280 "osc.org" return out; } #line 44 "osc.org"