add oscilloscope view

8 files changed, 130 insertions, 26 deletions

diff --git a/libopna/opna.c b/libopna/opna.c
index 10155d0..1b0aa6c 100644
--- a/libopna/opna.c
+++ b/libopna/opna.c
@@ -1,4 +1,6 @@
 #include "opna.h"
+#include "oscillo/oscillo.h"
+#include <string.h>
 
 void opna_reset(struct opna *opna) {
   opna_fm_reset(&opna->fm);
@@ -23,8 +25,20 @@ unsigned opna_readreg(const struct opna *opna, unsigned reg) {
 }
 
 void opna_mix(struct opna *opna, int16_t *buf, unsigned samples) {
-  opna_fm_mix(&opna->fm, buf, samples);
-  opna_ssg_mix_55466(&opna->ssg, &opna->resampler, buf, samples);
+  opna_mix_oscillo(opna, buf, samples, 0);
+}
+
+void opna_mix_oscillo(struct opna *opna, int16_t *buf, unsigned samples, struct oscillodata *oscillo) {
+  if (oscillo) {
+    for (int i = 0; i < LIBOPNA_OSCILLO_TRACK_COUNT; i++) {
+      memmove(&oscillo[i].buf[0],
+              &oscillo[i].buf[samples],
+              (OSCILLO_SAMPLE_COUNT - samples)*sizeof(oscillo[i].buf[0]));
+    }
+  }
+  unsigned offset = OSCILLO_SAMPLE_COUNT - samples;
+  opna_fm_mix(&opna->fm, buf, samples, &oscillo[0], offset);
+  opna_ssg_mix_55466(&opna->ssg, &opna->resampler, buf, samples, &oscillo[6], offset);
   opna_drum_mix(&opna->drum, buf, samples);
   opna_adpcm_mix(&opna->adpcm, buf, samples);
 }
diff --git a/libopna/opna.h b/libopna/opna.h
index 7d7d722..2ebca0d 100644
--- a/libopna/opna.h
+++ b/libopna/opna.h
@@ -30,6 +30,10 @@ enum {
   LIBOPNA_CHAN_ADPCM = 0x8000,
 };
 
+enum {
+  LIBOPNA_OSCILLO_TRACK_COUNT = 11
+};
+
 struct opna {
   struct opna_fm fm;
   struct opna_ssg ssg;
@@ -43,6 +47,8 @@ void opna_reset(struct opna *opna);
 void opna_writereg(struct opna *opna, unsigned reg, unsigned val);
 unsigned opna_readreg(const struct opna *opna, unsigned reg);
 void opna_mix(struct opna *opna, int16_t *buf, unsigned samples);
+struct oscillodata;
+void opna_mix_oscillo(struct opna *opna, int16_t *buf, unsigned samples, struct oscillodata *oscillo);
 unsigned opna_get_mask(const struct opna *opna);
 void opna_set_mask(struct opna *opna, unsigned mask);
 
diff --git a/libopna/opnafm.c b/libopna/opnafm.c
index 3f5367f..abc36fa 100644
--- a/libopna/opnafm.c
+++ b/libopna/opnafm.c
@@ -1,4 +1,5 @@
 #include "opnafm.h"
+#include "oscillo/oscillo.h"
 
 #include "opnatables.h"
 
@@ -539,7 +540,46 @@ void opna_fm_chan_env(struct opna_fm_channel *chan) {
   }
 }
 
-void opna_fm_mix(struct opna_fm *fm, int16_t *buf, unsigned samples) {
+static int gcd(int a, int b) {
+  if (a < b) {
+    int t = a;
+    a = b;
+    b = t;
+  }
+  for (;;) {
+    int r = a % b;
+    if (!r) break;
+    a = b;
+    b = r;
+  }
+  return b;
+}
+
+
+
+void opna_fm_mix(struct opna_fm *fm, int16_t *buf, unsigned samples,
+                 struct oscillodata *oscillo, unsigned offset) {
+  if (oscillo) {
+    for (unsigned c = 0; c < 6; c++) {
+      const struct opna_fm_channel *ch = &fm->channel[c];
+      unsigned freq = blkfnum2freq(ch->blk, ch->fnum);
+      int mul[4];
+      for (int i = 0; i < 4; i++) {
+        mul[i] = ch->slot[i].mul << 1;
+        if (!mul[i]) mul[i] = 1;
+      }
+      freq *= gcd(gcd(gcd(mul[0], mul[1]), mul[2]), mul[3]);
+      freq /= 2;
+      unsigned period = 0;
+      if (freq) period = (1u<<(20+OSCILLO_OFFSET_SHIFT)) / freq;
+      if (period) {
+        oscillo[c].offset += (samples << OSCILLO_OFFSET_SHIFT);
+        oscillo[c].offset %= period;
+      } else {
+        oscillo[c].offset = 0;
+      }
+    }
+  }
   for (unsigned i = 0; i < samples; i++) {
     if (!fm->env_div3) {
       for (int c = 0; c < 6; c++) {
@@ -554,6 +594,7 @@ void opna_fm_mix(struct opna_fm *fm, int16_t *buf, unsigned samples) {
 
     for (int c = 0; c < 6; c++) {
       int16_t o = opna_fm_chanout(&fm->channel[c]);
+      if (oscillo) oscillo[c].buf[offset+i] = o*2;
       // TODO: CSM
       if (c == 2 && fm->ch3.mode != CH3_MODE_NORMAL) {
         opna_fm_chan_phase_se(&fm->channel[c], fm);
diff --git a/libopna/opnafm.h b/libopna/opnafm.h
index 1a7f55a..b62556e 100644
--- a/libopna/opnafm.h
+++ b/libopna/opnafm.h
@@ -88,7 +88,8 @@ struct opna_fm {
 };
 
 void opna_fm_reset(struct opna_fm *fm);
-void opna_fm_mix(struct opna_fm *fm, int16_t *buf, unsigned samples);
+struct oscillodata;
+void opna_fm_mix(struct opna_fm *fm, int16_t *buf, unsigned samples, struct oscillodata *oscillo, unsigned offset);
 void opna_fm_writereg(struct opna_fm *fm, unsigned reg, unsigned val);
 
 //
diff --git a/libopna/opnassg.c b/libopna/opnassg.c
index 223758c..ec03437 100644
--- a/libopna/opnassg.c
+++ b/libopna/opnassg.c
@@ -1,4 +1,5 @@
 #include "opnassg.h"
+#include "oscillo/oscillo.h"
 /*
 static const float voltable[32] = {
   0.0f,           0.0f,           0x1.ae89f9p-8f, 0x1.000000p-7f,
@@ -126,10 +127,12 @@ static bool opna_ssg_tone_out(const struct opna_ssg *ssg, int chan) {
   return (ssg->ch[chan].out || (reg & 0x1)) && ((ssg->lfsr & 1) || (reg & 0x8));
 }
 
+#if 0
 static bool opna_ssg_tone_silent(const struct opna_ssg *ssg, int chan) {
   unsigned reg = ssg->regs[0x7] >> chan;
   return (reg & 0x1) && (reg & 0x8);
 }
+#endif
 
 static int opna_ssg_noise_period(const struct opna_ssg *ssg) {
   return ssg->regs[0x6] & 0x1f;
@@ -149,6 +152,10 @@ int opna_ssg_channel_level(const struct opna_ssg *ssg, int ch) {
        : (opna_ssg_tone_volume(ssg, ch) << 1) + 1;
 }
 
+#define COEFF 0x3fff
+#define COEFFSH 14
+
+// 3 samples per frame
 void opna_ssg_generate_raw(struct opna_ssg *ssg, int16_t *buf, int samples) {
   for (int i = 0; i < samples; i++) {
     if (((++ssg->noise_counter) >> 1) >= opna_ssg_noise_period(ssg)) {
@@ -173,31 +180,38 @@ void opna_ssg_generate_raw(struct opna_ssg *ssg, int16_t *buf, int samples) {
       }
     }
 
-    int16_t out = 0;
+    //int16_t out = 0;
     for (int ch = 0; ch < 3; ch++) {
+      buf[i*3+ch] = 0;
       if (++ssg->ch[ch].tone_counter >= opna_ssg_tone_period(ssg, ch)) {
         ssg->ch[ch].tone_counter = 0;
         ssg->ch[ch].out = !ssg->ch[ch].out;
       }
-      if (ssg->mask & (1<<ch)) continue;
 #if 1
-      // may output DC offset
       // YMF288 seems to disable output when 0 <= Tp < 8
+      int32_t previntmp = 0;
       if (opna_ssg_tone_out(ssg, ch)) {
         int level = opna_ssg_chan_env(ssg, ch)
           ? opna_ssg_env_level(ssg)
           : (opna_ssg_tone_volume(ssg, ch) << 1) + 1;
-        out += voltable[level];
+        //out += voltable[level];
+        previntmp = voltable[level]/2;
       }
+      previntmp *= COEFF;
+      ssg->prevout[ch] = previntmp - ssg->previn[ch] + ((((int64_t)COEFF)*ssg->prevout[ch]) >> COEFFSH);
+      ssg->previn[ch] = previntmp;
+      buf[i*3+ch] = ssg->prevout[ch] >> COEFFSH;
+      //buf[i*3+ch] = voltable[level]/2;
 #else
       if (!opna_ssg_tone_silent(ssg, ch)) {
         int level = opna_ssg_channel_level(ssg, ch);
-        out += (opna_ssg_tone_out(ssg, ch) ? voltable[level] : -voltable[level]) / 2;
+        //out += (opna_ssg_tone_out(ssg, ch) ? voltable[level] : -voltable[level]) / 2;
+        buf[i*3+ch] = (opna_ssg_tone_out(ssg, ch) ? voltable[level] : -voltable[level]) / 4;
       }
 #endif
       
     }
-    buf[i] = out / 2;
+    //buf[i] = out / 2;
   }
 }
 
@@ -205,27 +219,46 @@ void opna_ssg_generate_raw(struct opna_ssg *ssg, int16_t *buf, int samples) {
 
 void opna_ssg_mix_55466(
   struct opna_ssg *ssg, struct opna_ssg_resampler *resampler,
-  int16_t *buf, int samples) {
+  int16_t *buf, int samples,
+  struct oscillodata *oscillo, unsigned offset
+) {
+  if (oscillo) {
+    for (unsigned c = 0; c < 3; c++) {
+      unsigned period = (opna_ssg_tone_period(ssg, c) << OSCILLO_OFFSET_SHIFT) * 2 * 32 / 144;
+      if (period) {
+        oscillo[c].offset += (samples << OSCILLO_OFFSET_SHIFT);
+        oscillo[c].offset %= period;
+      } else {
+        oscillo[c].offset = 0;
+      }
+    }
+  }
   for (int i = 0; i < samples; i++) {
     {
       int ssg_samples = ((resampler->index + 9)>>1) - ((resampler->index)>>1);
-      int16_t ssgbuf[5];
+      int16_t ssgbuf[15];
       opna_ssg_generate_raw(ssg, ssgbuf, ssg_samples);
       for (int j = 0; j < ssg_samples; j++) {
-        resampler->buf[BUFINDEX(j)] = ssgbuf[j];
+        resampler->buf[BUFINDEX(j)*3+0] = ssgbuf[j*3+0];
+        resampler->buf[BUFINDEX(j)*3+1] = ssgbuf[j*3+1];
+        resampler->buf[BUFINDEX(j)*3+2] = ssgbuf[j*3+2];
       }
       resampler->index += 9;
     }
     int32_t sample = 0;
-    for (int j = 0; j < SINCTABLELEN; j++) {
-      unsigned sincindex = j*2;
-      if (!(resampler->index&1)) sincindex++;
-      bool sincsign = sincindex & (1<<(SINCTABLEBIT));
-      unsigned sincmask = ((1<<(SINCTABLEBIT))-1);
-      sincindex = (sincindex & sincmask) ^ (sincsign ? sincmask : 0);
-      sample += (resampler->buf[BUFINDEX(j)] * sinctable[sincindex])>>2;
+    for (int ch = 0; ch < 3; ch++) {
+      int32_t chsample = 0;
+      for (int j = 0; j < SINCTABLELEN; j++) {
+        unsigned sincindex = j*2;
+        if (!(resampler->index&1)) sincindex++;
+        bool sincsign = sincindex & (1<<(SINCTABLEBIT));
+        unsigned sincmask = ((1<<(SINCTABLEBIT))-1);
+        sincindex = (sincindex & sincmask) ^ (sincsign ? sincmask : 0);
+        chsample += (resampler->buf[BUFINDEX(j)*3+ch] * sinctable[sincindex])>>2;
+      }
+      if (oscillo) oscillo[ch].buf[offset+i] = chsample >> 13;
+      if (!(ssg->mask & (1<<ch))) sample += chsample;
     }
-
     sample >>= 16;
     sample *= 13000;
     sample >>= 14;
diff --git a/libopna/opnassg.h b/libopna/opnassg.h
index 8a59d91..0321163 100644
--- a/libopna/opnassg.h
+++ b/libopna/opnassg.h
@@ -25,10 +25,12 @@ struct opna_ssg {
   bool env_hld;
   bool env_holding;
   unsigned mask;
+  int32_t previn[3];
+  int32_t prevout[3];
 };
 
 struct opna_ssg_resampler {
-  int16_t buf[(1<<7)];
+  int16_t buf[(1<<7)*3];
   unsigned index;
 };
 
@@ -46,9 +48,10 @@ void opna_ssg_generate_raw(struct opna_ssg *ssg, int16_t *buf, int samples);
 // call to buffer written with OPNA output
 // samplerate: 7987200/144 Hz
 //            (55466.66..) Hz
+struct oscillodata;
 void opna_ssg_mix_55466(
   struct opna_ssg *ssg, struct opna_ssg_resampler *resampler,
-  int16_t *buf, int samples);
+  int16_t *buf, int samples, struct oscillodata *oscillo, unsigned offset);
 void opna_ssg_writereg(struct opna_ssg *ssg, unsigned reg, unsigned val);
 unsigned opna_ssg_readreg(const struct opna_ssg *ssg, unsigned reg);
 // channel level (0 - 31)
diff --git a/libopna/opnatimer.c b/libopna/opnatimer.c
index 789c28e..142176f 100644
--- a/libopna/opnatimer.c
+++ b/libopna/opnatimer.c
@@ -1,5 +1,6 @@
 #include "opnatimer.h"
 #include "opna.h"
+#include "oscillo/oscillo.h"
 
 enum {
   TIMERA_BITS = 10,
@@ -65,9 +66,12 @@ void opna_timer_writereg(struct opna_timer *timer, unsigned reg, unsigned val) {
     }
   }
 }
-#include <stdio.h>
-#include <stdlib.h>
+
 void opna_timer_mix(struct opna_timer *timer, int16_t *buf, unsigned samples) {
+  opna_timer_mix_oscillo(timer, buf, samples, 0);
+}
+
+void opna_timer_mix_oscillo(struct opna_timer *timer, int16_t *buf, unsigned samples, struct oscillodata *oscillo) {
   do {
     unsigned generate_samples = samples;
     if (timer->timerb_enable && timer->timerb_load) {
@@ -82,7 +86,7 @@ void opna_timer_mix(struct opna_timer *timer, int16_t *buf, unsigned samples) {
         generate_samples = timera_samples;
       }
     }
-    opna_mix(timer->opna, buf, generate_samples);
+    opna_mix_oscillo(timer->opna, buf, generate_samples, oscillo);
     if (timer->mix_cb) {
       timer->mix_cb(timer->mix_userptr, buf, generate_samples);
     }
diff --git a/libopna/opnatimer.h b/libopna/opnatimer.h
index ad0fe0b..c7b9511 100644
--- a/libopna/opnatimer.h
+++ b/libopna/opnatimer.h
@@ -37,6 +37,8 @@ void opna_timer_set_mix_callback(struct opna_timer *timer,
                                  opna_timer_mix_cb_t func, void *userptr);
 void opna_timer_writereg(struct opna_timer *timer, unsigned reg, unsigned val);
 void opna_timer_mix(struct opna_timer *timer, int16_t *buf, unsigned samples);
+struct oscillodata;
+void opna_timer_mix_oscillo(struct opna_timer *timer, int16_t *buf, unsigned samples, struct oscillodata *oscillo);
 
 #ifdef __cplusplus
 }