From b79d04b666f7cf18fee57570e198c57cadd4c22d Mon Sep 17 00:00:00 2001
From: Bryan Head <bryan.head@gmail.com>
Date: Wed, 4 Sep 2024 09:07:16 -0700
Subject: [PATCH] Ebb&LFO: Make clocked mode work with reset and oneshot

---
 software/src/applets/EbbAndLfo.h         | 23 +++++++++++++++--------
 software/src/util/util_phase_extractor.h | 23 ++++++++++++++++++-----
 2 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/software/src/applets/EbbAndLfo.h b/software/src/applets/EbbAndLfo.h
index 9ec699fb..09b31193 100644
--- a/software/src/applets/EbbAndLfo.h
+++ b/software/src/applets/EbbAndLfo.h
@@ -28,7 +28,8 @@ class EbbAndLfo : public HemisphereApplet {
     if (knob_accel > (1 << 8))
       knob_accel--;
 
-    if (Clock(1)) { // reset/retrigger
+    bool reset = Clock(1);
+    if (reset) { // reset/retrigger
       phase = 0;
       oneshot_active = true;
     }
@@ -36,7 +37,11 @@ class EbbAndLfo : public HemisphereApplet {
     int freq_div_mul = ratio;
     pitch_mod = pitch;
     bool got_clock = Clock(0);
-    oneshot_active |= got_clock;
+
+    // In clocked mode, Clock(0) is just used to set rate. In unclocked, it will
+    // start a oneshot but not restart it.
+    if (!clocked)
+      oneshot_active |= got_clock;
 
     // handle CV inputs
     slope_mod = slope * (65535 / 127);
@@ -74,16 +79,17 @@ class EbbAndLfo : public HemisphereApplet {
 
     // TODO: Make oneshot and clocked mode more compatible so you can trigger a
     // shot with one trig and have it synced to clock on the other trig.
-    if (oneshot_mode && !oneshot_active)
-      return;
-
     uint32_t oldphase = phase;
     if (clocked) {
-      phase = phase_extractor.Advance(got_clock, freq_div_mul);
+      phase = phase_extractor.Advance(got_clock, reset, freq_div_mul);
     } else {
       uint32_t phase_increment = ComputePhaseIncrement(pitch_mod);
       phase += phase_increment;
     }
+    if (oneshot_mode && !oneshot_active) {
+      phase = 0;
+      return;
+    }
 
     // check for rollover and stop for one-shot mode
     if (phase < oldphase && oneshot_mode) {
@@ -150,10 +156,11 @@ class EbbAndLfo : public HemisphereApplet {
         if (i > 0)
           gfxLine(i - 1, last, i, next);
         last = next;
-        // gfxPixel(i, 50 - disp_sample.unipolar * 35 / 65536);
       }
     }
-    uint32_t p = phase / (0xffffffff / 64);
+
+    // position is first 6 bits of phase, which gives 0 through 63.
+    uint32_t p = phase >> 26;
     gfxLine(p, 15, p, 50);
 
     const int param_y = 55;
diff --git a/software/src/util/util_phase_extractor.h b/software/src/util/util_phase_extractor.h
index a32193de..24fb8515 100644
--- a/software/src/util/util_phase_extractor.h
+++ b/software/src/util/util_phase_extractor.h
@@ -20,12 +20,21 @@ class PhaseExtractor {
   }
 
   // -2 => /3, -1 => /2, 0 => 1, 1 => x2, 2 => x3, etc
-  uint32_t Advance(bool clock, int simple_ratio) {
-    return Advance(clock, {static_cast<int16_t>(max(simple_ratio + 1, 1)),
-                           static_cast<uint16_t>(max(-simple_ratio + 1, 1))});
+  uint32_t Advance(bool clock, bool reset, int simple_ratio) {
+    return Advance(clock, reset,
+                   {static_cast<int16_t>(max(simple_ratio + 1, 1)),
+                    static_cast<uint16_t>(max(-simple_ratio + 1, 1))});
   }
 
-  uint32_t Advance(bool clock, Ratio r) {
+  uint32_t Advance(bool clock, bool reset, Ratio r) {
+    if (reset) {
+      // TODO: should offset phase as well. This will support oneshot mode too.
+      clocks_received = ratio.den - 1;
+      // phase_offset = -phase;
+      phase = 0;
+      phase_offset = 0;
+      set_offset = true;
+    }
     if (clock) {
       next_clock_tick = predictor.Predict(ticks);
       ticks = 0;
@@ -35,6 +44,8 @@ class PhaseExtractor {
         // discontinuities in the phase
         clocks_received = 0;
         ratio = r;
+        if (set_offset) phase_offset = phase;
+        set_offset = false;
         phase = 0;
       }
       phase_inc = 0xffffffff / (ratio.den * next_clock_tick) * ratio.num;
@@ -51,7 +62,7 @@ class PhaseExtractor {
       else if (phase_inc < 0 && phase >= static_cast<uint32_t>(phase_inc))
         phase = 0;
     }
-    return phase;
+    return phase + phase_offset;
   }
 
 private:
@@ -62,4 +73,6 @@ class PhaseExtractor {
   uint32_t ticks;
   uint32_t phase;
   int32_t phase_inc;
+  uint32_t phase_offset;
+  bool set_offset = false;
 };