ref: 75d6267a5f788162d92e7a5ae126cd8b0770aa8a
dir: /sys/src/games/snes/dsp.c/
#include <u.h> #include <libc.h> #include <thread.h> #include "../eui.h" #include "dat.h" #include "fns.h" u8int dsp[256], dspstate; u16int dspcounter, noise = 0x8000; static s16int samp[2], echoin[2], echobuf[2*2*8]; static u16int echoaddr; static int echobp, echopos; enum { VOLL = 0, VOLR = 1, PITCHL = 2, PITCHH = 3, SRCN = 4, ADSR1 = 5, ADSR2 = 6, GAIN = 7, ENVX = 8, OUTX = 9, MVOLL = 0x0c, EFB = 0x0d, MVOLR = 0x1c, EVOLL = 0x2c, PMON = 0x2d, EVOLR = 0x3c, NON = 0x3d, EON = 0x4d, KON = 0x4c, KOFF = 0x5c, DIR = 0x5d, FLG = 0x6c, ESA = 0x6d, ENDX = 0x7c, EDL = 0x7d, NEWKON = 0x8e, INT = 0x80, }; enum { READY = 6, }; enum { RELEASE, ATTACK, DECAY, SUSTAIN }; enum { Freq = 44100 }; static s16int sbuf[2*2000], *sbufp; static int fd; void audioinit(void) { fd = open("/dev/audio", OWRITE); if(fd < 0) sysfatal("open: %r"); sbufp = sbuf; } static int hermite(int *x, int t) { int y; y = (x[0] - x[6]) / 2 + (x[4] - x[2]) * 3 / 2; y = y * t >> 15; y += x[6] - x[4] * 5 / 2 + x[2] * 2 - x[0] / 2; y = y * t >> 15; y += (x[2] - x[6]) / 2; y = y * t >> 15; y += x[4]; return y; } static void audiosample(s16int *s) { static int x[8], t; x[0] = s[0]; x[1] = s[1]; do { sbufp[0] = hermite(x, t); sbufp[1] = hermite(x + 1, t); sbufp += 2; t += (32000<<15)/Freq; } while(t < 1<<15); t -= 1<<15; memmove(x + 2, x, sizeof(x) - 2 * sizeof(x[0])); } int audioout(void) { int rc; if(sbufp == nil) return -1; if(sbufp == sbuf) return 0; rc = warp10 ? (sbufp - sbuf) * 2 : write(fd, sbuf, (sbufp - sbuf) * 2); if(rc > 0) sbufp -= (rc+1)/2; if(sbufp < sbuf) sbufp = sbuf; return 0; } static u16int spc16(u16int p) { u16int v; v = spcmem[p++]; v |= spcmem[p] << 8; return v; } static void spcput16(u16int p, u16int v) { spcmem[p++] = v; spcmem[p] = v >> 8; } u8int dspread(u8int p) { p &= 0x7f; return dsp[p]; } void dspwrite(u8int p, u8int v) { if(p >= 0x80) return; switch(p){ case KON: dsp[NEWKON] = v; break; case ENDX: v = 0; break; } dsp[p] = v; } int envyes(int r) { static u16int modulus[] = { 0, 2048, 1536, 1280, 1024, 768, 640, 512, 384, 320, 256, 192, 160, 128, 96, 80, 64, 48, 40, 32, 24, 20, 16, 12, 10, 8, 6, 5, 4, 3, }; u16int c; if(r == 0) return 0; if(r >= 30){ if(r == 31) return 1; return (dspcounter & 1) == 0; } c = dspcounter; switch(r % 3){ case 0: c += 536; break; case 2: c += 1040; break; } return c % modulus[r] == 0; } static s16int clamp16(int v) { if(v < -32768) return -32768; if(v > 32767) return 32767; return v; } typedef struct { int n; u8int *r; u16int hdrp, dp, sp; u8int hdr, bp; u16int brr; u8int envst; u16int env, envbent; u8int init; u16int interp; s16int buf[24]; u16int pitch; s16int sample, modin; } vctxt; vctxt vctxts[8]; static void env(vctxt *p) { u8int *r, a, g; r = p->r; a = r[INT|ADSR1]; if((a & 0x80) != 0) g = r[ADSR2]; else g = r[GAIN]; if(p->envst == RELEASE) p->env -= 8; else if((a & 0x80) != 0){ switch(p->envst){ case ATTACK: if(envyes((a & 0xf) << 1 | 1)) p->env += (a & 0xf) == 0xf ? 1024 : 32; break; case DECAY: if(envyes(a >> 3 & 0xe | 0x10)) p->env -= ((p->env - 1) >> 8) + 1; break; case SUSTAIN: if(envyes(g & 0x1f)) p->env -= ((p->env - 1) >> 8) + 1; break; } }else{ if((g & 0x80) != 0){ if(envyes(g & 0x1f)) switch((g >> 5) & 3){ case 0: p->env -= 32; break; case 1: p->env -= ((p->env - 1) >> 8) + 1; break; case 2: p->env += 32; break; case 3: if(p->envbent < 0x600) p->env += 32; else p->env += 8; break; } }else p->env = g << 4; } p->envbent = p->env & 0x7ff; if((p->env & 0x8000) != 0) p->env = 0; else if(p->env > 0x7ff){ p->env = 0x7ff; if(p->envst == ATTACK){ p->envst = DECAY; return; } } if(p->envst == DECAY && (p->env >> 8) == (g >> 5)) p->envst = SUSTAIN; } static void decode(vctxt *p) { int i, d, s1, s2; u8int f, s; s16int brr; f = (p->hdr >> 2) & 3; s = p->hdr >> 4; brr = p->brr; s1 = p->buf[p->bp + 11]; s2 = p->buf[p->bp + 10]; for(i = 0; i < 4; i++){ d = brr >> 12; if(s >= 13) d = d & ~0x7ff; else{ d <<= s; d >>= 1; } s2 >>= 1; switch(f){ case 1: d += s1 >> 1; d += (-s1) >> 5; break; case 2: d += s1; d -= s2; d += s2 >> 4; d += (s1 * -3) >> 6; break; case 3: d += s1; d -= s2; d += (s1 * -13) >> 7; d += (s2 * 3) >> 4; break; } d = (s16int)(clamp16(d) << 1); p->buf[p->bp] = d; p->buf[p->bp++ + 12] = d; s2 = s1; s1 = d; brr <<= 4; } if(p->bp == 12) p->bp = 0; } static s16int interp(u16int x, s16int *s) { extern u16int gauss[]; int v; u8int i, d; i = x >> 12; d = x >> 4; v = ((int)gauss[255 - d] * s[i]) >> 11; v += ((int)gauss[511 - d] * s[i+1]) >> 11; v += ((int)gauss[256 + d] * s[i+2]) >> 11; v = (s16int)v; v += ((int)gauss[d] * s[i+3]) >> 11; return clamp16(v) & ~1; } static void voice(int n, int s) { vctxt *p; u8int *r, m; u16int a; int v; p = vctxts + n; r = p->r; switch(s){ case 1: r[INT|SRCN] = r[SRCN]; break; case 2: a = (dsp[INT|DIR] << 8) + (r[INT|SRCN] << 2); if(p->init == READY) a += 2; p->sp = spc16(a); p->pitch = r[PITCHL]; r[INT|ADSR1] = r[ADSR1]; break; case 3: p->pitch |= r[PITCHH] << 8 & 0x3f00; if(n == 0) break; case 0x31: p->hdr = spcmem[p->hdrp]; p->brr = spcmem[p->dp] << 8; if(n == 0) break; case 0x32: if((dsp[INT|PMON] & 0xfe & 1<<n) != 0) p->pitch += ((p[-1].modin >> 5) * p->pitch) >> 10; if(p->init < READY){ p->pitch = 0; p->env = 0; } if((dsp[INT|NON] & 1<<n) != 0) p->sample = noise; else p->sample = interp(p->interp, p->buf + p->bp); p->sample = (((int)p->sample * p->env) >> 11) & ~1; p->modin = p->sample; r[INT|OUTX] = p->sample >> 8; r[INT|ENVX] = p->env >> 4; if((dsp[FLG] & 0x80) != 0 || (p->hdr & 3) == 1){ p->envst = RELEASE; p->env = 0; } if((dsp[INT|KOFF] & 1<<n) != 0) p->envst = RELEASE; if((dsp[INT|KON] & 1<<n) != 0){ p->envst = ATTACK; p->init = 0; } if(p->init >= READY - 1) env(p); break; case 4: v = (p->sample * ((s8int)r[VOLL])) >> 7; samp[0] = clamp16(samp[0] + v); if((dsp[INT|EON] & (1<<n)) != 0) echoin[0] = clamp16(echoin[0] + v); if(p->init == 1){ p->hdrp = p->sp; p->dp = p->hdrp + 1; p->bp = 0; } if(p->interp >= 0x4000 || p->init <= 4 && p->init >= 2){ p->brr |= spcmem[++p->dp]; decode(p); if(++p->dp == p->hdrp + 9){ if((p->hdr & 1) != 0){ dsp[INT|ENDX] |= 1<<n; p->hdrp = p->sp; }else p->hdrp += 9; p->dp = p->hdrp + 1; } } p->interp = (p->interp & 0x3fff) + p->pitch; if(p->interp >= 0x7fff) p->interp = 0x7fff; break; case 5: v = (p->sample * ((s8int)r[VOLR])) >> 7; samp[1] = clamp16(samp[1] + v); if((dsp[INT|EON] & (1<<n)) != 0) echoin[1] = clamp16(echoin[1] + v); break; case 7: m = 1<<n; if(p->init == 0) dsp[INT|ENDX] &= ~m; dsp[ENDX] = dsp[ENDX] & ~m | dsp[INT|ENDX] & m; break; case 8: r[OUTX] = r[INT|OUTX]; break; case 9: r[ENVX] = r[INT|ENVX]; if(p->init < READY) p->init++; break; } } static void echo(int s) { static s16int echoout[2]; s16int *x; s8int h; int a, b; x = echobuf + echobp; switch(s){ case 22: echoaddr = (dsp[INT|ESA] << 8) + echopos; x[0] = x[16] = spc16(echoaddr); h = dsp[0x0f]; echoout[0] = x[2] * h >> 7; echoout[1] = x[3] * h >> 7; break; case 23: h = dsp[0x1f]; echoout[0] += x[4] * h >> 7; echoout[1] += x[5] * h >> 7; h = dsp[0x2f]; echoout[0] += x[6] * h >> 7; echoout[1] += x[7] * h >> 7; x[1] = x[17] = spc16(echoaddr + 2); break; case 24: h = dsp[0x3f]; echoout[0] += x[8] * h >> 7; echoout[1] += x[9] * h >> 7; h = dsp[0x4f]; echoout[0] += x[10] * h >> 7; echoout[1] += x[11] * h >> 7; h = dsp[0x5f]; echoout[0] += x[12] * h >> 7; echoout[1] += x[13] * h >> 7; break; case 25: h = dsp[0x6f]; echoout[0] += x[14] * h >> 7; echoout[1] += x[15] * h >> 7; h = dsp[0x7f]; echoout[0] += x[16] * h >> 7; echoout[1] += x[17] * h >> 7; echoout[0] &= ~1; echoout[1] &= ~1; break; case 26: a = (samp[0] * (s8int)dsp[MVOLL]) >> 7; b = (echoout[0] * (s8int)dsp[EVOLL]) >> 7; samp[0] = clamp16(a + b); a = echoout[0] * (s8int)dsp[EFB] >> 7; echoin[0] = clamp16(echoin[0] + a) & ~1; a = echoout[1] * (s8int)dsp[EFB] >> 7; echoin[1] = clamp16(echoin[1] + a) & ~1; break; case 27: a = (samp[1] * (s8int)dsp[MVOLR]) >> 7; b = (echoout[1] * (s8int)dsp[EVOLR]) >> 7; samp[1] = clamp16(a + b); break; case 28: dsp[INT|FLG] = dsp[FLG]; break; case 29: dsp[INT|ESA] = dsp[ESA]; if(echopos == 0) dsp[INT|EDL] = dsp[EDL] & 0xf; echopos += 4; if(echopos >= dsp[INT|EDL] << 11) echopos = 0; if((dsp[INT|FLG] & 0x20) == 0) spcput16(echoaddr, echoin[0]); echoin[0] = 0; dsp[INT|FLG] = dsp[FLG]; break; case 30: if((dsp[INT|FLG] & 0x20) == 0) spcput16(echoaddr + 2, echoin[1]); echoin[1] = 0; echobp = echobp + 2 & 15; break; } } void dspstep(void) { if(sbufp == nil || sbufp >= sbuf+nelem(sbuf)-2) return; switch(dspstate++ & 31){ case 0: voice(0, 5); voice(1, 2); break; case 1: voice(0, 6); voice(1, 3); break; case 2: voice(0, 7); voice(1, 4); voice(3, 1); break; case 3: voice(0, 8); voice(1, 5); voice(2, 2); break; case 4: voice(0, 9); voice(1, 6); voice(2, 3); break; case 5: voice(1, 7); voice(2, 4); voice(4, 1); break; case 6: voice(1, 8); voice(2, 5); voice(3, 2); break; case 7: voice(1, 9); voice(2, 6); voice(3, 3); break; case 8: voice(2, 7); voice(3, 4); voice(5, 1); break; case 9: voice(2, 8); voice(3, 5); voice(4, 2); break; case 10: voice(2, 9); voice(3, 6); voice(4, 3); break; case 11: voice(3, 7); voice(4, 4); voice(6, 1); break; case 12: voice(3, 8); voice(4, 5); voice(5, 2); break; case 13: voice(3, 9); voice(4, 6); voice(5, 3); break; case 14: voice(4, 7); voice(5, 4); voice(7, 1); break; case 15: voice(4, 8); voice(5, 5); voice(6, 2); break; case 16: voice(4, 9); voice(5, 6); voice(6, 3); break; case 17: voice(5, 7); voice(6, 4); voice(0, 1); break; case 18: voice(5, 8); voice(6, 5); voice(7, 2); break; case 19: voice(5, 9); voice(6, 6); voice(7, 3); break; case 20: voice(6, 7); voice(7, 4); voice(1, 1); break; case 21: voice(6, 8); voice(7, 5); voice(0, 2); break; case 22: voice(6, 9); voice(7, 6); voice(0, 3); echo(22); break; case 23: voice(7, 7); echo(23); break; case 24: voice(7, 8); echo(24); break; case 25: voice(7, 9); voice(0, 0x31); echo(25); break; case 26: echo(26); break; case 27: dsp[INT|PMON] = dsp[PMON]; echo(27); if((dsp[FLG] & 0x40) != 0) samp[0] = samp[1] = 0; audiosample(samp); samp[0] = samp[1] = 0; break; case 28: dsp[INT|NON] = dsp[NON]; dsp[INT|EON] = dsp[EON]; dsp[INT|DIR] = dsp[DIR]; echo(28); break; case 29: echo(29); if((dspstate & 32) == 0) dsp[NEWKON] &= ~dsp[INT|KON]; break; case 30: voice(0, 0x32); echo(30); if((dspstate & 32) == 0){ dsp[INT|KOFF] = dsp[KOFF]; dsp[INT|KON] = dsp[NEWKON]; } if(dspcounter-- == 0) dspcounter = 0x77ff; if(envyes(dsp[FLG] & 0x1f)) noise = (noise << 13 ^ noise << 14) & 0x8000 | noise >> 1 & ~1; break; case 31: voice(0, 4); voice(2, 1); break; } } void dspreset(void) { vctxt *p; int i; for(i = 0; i < 8; i++){ p = vctxts + i; p->n = i; p->r = dsp + (i << 4); } dsp[FLG] = 0xe0; } void dspsave(void) { vctxt *p; for(p = vctxts; p < vctxts + nelem(vctxts); p++){ put16(p->hdrp); put16(p->dp); put16(p->sp); put8(p->hdr); put8(p->bp); put16(p->brr); put8(p->envst); put16(p->env); put16(p->envbent); put8(p->init); put16(p->interp); put16(p->pitch); put16(p->modin); } } void dspload(void) { vctxt *p; for(p = vctxts; p < vctxts + nelem(vctxts); p++){ p->hdrp = get16(); p->dp = get16(); p->sp = get16(); p->hdr = get8(); p->bp = get8(); p->brr = get16(); p->envst = get8(); p->env = get16(); p->envbent = get16(); p->init = get8(); p->interp = get16(); p->pitch = get16(); p->modin = get16(); } } u16int gauss[512] = { 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x002, 0x002, 0x002, 0x002, 0x002, 0x002, 0x002, 0x003, 0x003, 0x003, 0x003, 0x003, 0x004, 0x004, 0x004, 0x004, 0x004, 0x005, 0x005, 0x005, 0x005, 0x006, 0x006, 0x006, 0x006, 0x007, 0x007, 0x007, 0x008, 0x008, 0x008, 0x009, 0x009, 0x009, 0x00A, 0x00A, 0x00A, 0x00B, 0x00B, 0x00B, 0x00C, 0x00C, 0x00D, 0x00D, 0x00E, 0x00E, 0x00F, 0x00F, 0x00F, 0x010, 0x010, 0x011, 0x011, 0x012, 0x013, 0x013, 0x014, 0x014, 0x015, 0x015, 0x016, 0x017, 0x017, 0x018, 0x018, 0x019, 0x01A, 0x01B, 0x01B, 0x01C, 0x01D, 0x01D, 0x01E, 0x01F, 0x020, 0x020, 0x021, 0x022, 0x023, 0x024, 0x024, 0x025, 0x026, 0x027, 0x028, 0x029, 0x02A, 0x02B, 0x02C, 0x02D, 0x02E, 0x02F, 0x030, 0x031, 0x032, 0x033, 0x034, 0x035, 0x036, 0x037, 0x038, 0x03A, 0x03B, 0x03C, 0x03D, 0x03E, 0x040, 0x041, 0x042, 0x043, 0x045, 0x046, 0x047, 0x049, 0x04A, 0x04C, 0x04D, 0x04E, 0x050, 0x051, 0x053, 0x054, 0x056, 0x057, 0x059, 0x05A, 0x05C, 0x05E, 0x05F, 0x061, 0x063, 0x064, 0x066, 0x068, 0x06A, 0x06B, 0x06D, 0x06F, 0x071, 0x073, 0x075, 0x076, 0x078, 0x07A, 0x07C, 0x07E, 0x080, 0x082, 0x084, 0x086, 0x089, 0x08B, 0x08D, 0x08F, 0x091, 0x093, 0x096, 0x098, 0x09A, 0x09C, 0x09F, 0x0A1, 0x0A3, 0x0A6, 0x0A8, 0x0AB, 0x0AD, 0x0AF, 0x0B2, 0x0B4, 0x0B7, 0x0BA, 0x0BC, 0x0BF, 0x0C1, 0x0C4, 0x0C7, 0x0C9, 0x0CC, 0x0CF, 0x0D2, 0x0D4, 0x0D7, 0x0DA, 0x0DD, 0x0E0, 0x0E3, 0x0E6, 0x0E9, 0x0EC, 0x0EF, 0x0F2, 0x0F5, 0x0F8, 0x0FB, 0x0FE, 0x101, 0x104, 0x107, 0x10B, 0x10E, 0x111, 0x114, 0x118, 0x11B, 0x11E, 0x122, 0x125, 0x129, 0x12C, 0x130, 0x133, 0x137, 0x13A, 0x13E, 0x141, 0x145, 0x148, 0x14C, 0x150, 0x153, 0x157, 0x15B, 0x15F, 0x162, 0x166, 0x16A, 0x16E, 0x172, 0x176, 0x17A, 0x17D, 0x181, 0x185, 0x189, 0x18D, 0x191, 0x195, 0x19A, 0x19E, 0x1A2, 0x1A6, 0x1AA, 0x1AE, 0x1B2, 0x1B7, 0x1BB, 0x1BF, 0x1C3, 0x1C8, 0x1CC, 0x1D0, 0x1D5, 0x1D9, 0x1DD, 0x1E2, 0x1E6, 0x1EB, 0x1EF, 0x1F3, 0x1F8, 0x1FC, 0x201, 0x205, 0x20A, 0x20F, 0x213, 0x218, 0x21C, 0x221, 0x226, 0x22A, 0x22F, 0x233, 0x238, 0x23D, 0x241, 0x246, 0x24B, 0x250, 0x254, 0x259, 0x25E, 0x263, 0x267, 0x26C, 0x271, 0x276, 0x27B, 0x280, 0x284, 0x289, 0x28E, 0x293, 0x298, 0x29D, 0x2A2, 0x2A6, 0x2AB, 0x2B0, 0x2B5, 0x2BA, 0x2BF, 0x2C4, 0x2C9, 0x2CE, 0x2D3, 0x2D8, 0x2DC, 0x2E1, 0x2E6, 0x2EB, 0x2F0, 0x2F5, 0x2FA, 0x2FF, 0x304, 0x309, 0x30E, 0x313, 0x318, 0x31D, 0x322, 0x326, 0x32B, 0x330, 0x335, 0x33A, 0x33F, 0x344, 0x349, 0x34E, 0x353, 0x357, 0x35C, 0x361, 0x366, 0x36B, 0x370, 0x374, 0x379, 0x37E, 0x383, 0x388, 0x38C, 0x391, 0x396, 0x39B, 0x39F, 0x3A4, 0x3A9, 0x3AD, 0x3B2, 0x3B7, 0x3BB, 0x3C0, 0x3C5, 0x3C9, 0x3CE, 0x3D2, 0x3D7, 0x3DC, 0x3E0, 0x3E5, 0x3E9, 0x3ED, 0x3F2, 0x3F6, 0x3FB, 0x3FF, 0x403, 0x408, 0x40C, 0x410, 0x415, 0x419, 0x41D, 0x421, 0x425, 0x42A, 0x42E, 0x432, 0x436, 0x43A, 0x43E, 0x442, 0x446, 0x44A, 0x44E, 0x452, 0x455, 0x459, 0x45D, 0x461, 0x465, 0x468, 0x46C, 0x470, 0x473, 0x477, 0x47A, 0x47E, 0x481, 0x485, 0x488, 0x48C, 0x48F, 0x492, 0x496, 0x499, 0x49C, 0x49F, 0x4A2, 0x4A6, 0x4A9, 0x4AC, 0x4AF, 0x4B2, 0x4B5, 0x4B7, 0x4BA, 0x4BD, 0x4C0, 0x4C3, 0x4C5, 0x4C8, 0x4CB, 0x4CD, 0x4D0, 0x4D2, 0x4D5, 0x4D7, 0x4D9, 0x4DC, 0x4DE, 0x4E0, 0x4E3, 0x4E5, 0x4E7, 0x4E9, 0x4EB, 0x4ED, 0x4EF, 0x4F1, 0x4F3, 0x4F5, 0x4F6, 0x4F8, 0x4FA, 0x4FB, 0x4FD, 0x4FF, 0x500, 0x502, 0x503, 0x504, 0x506, 0x507, 0x508, 0x50A, 0x50B, 0x50C, 0x50D, 0x50E, 0x50F, 0x510, 0x511, 0x511, 0x512, 0x513, 0x514, 0x514, 0x515, 0x516, 0x516, 0x517, 0x517, 0x517, 0x518, 0x518, 0x518, 0x518, 0x518, 0x519, 0x519 };