From a965433bbae9631aac807426e4f49bad272ba84b Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Fri, 7 Oct 2022 14:17:25 -0500
Subject: [PATCH] start working on LFO macro mode

---
 papers/format.md        | 12 ++++--------
 src/engine/macroInt.cpp | 28 +++++++++++++++++++++++++---
 src/engine/macroInt.h   |  5 +++--
 3 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/papers/format.md b/papers/format.md
index ee76ce70f..2649cd298 100644
--- a/papers/format.md
+++ b/papers/format.md
@@ -32,7 +32,8 @@ these fields are 0 in format versions prior to 100 (0.6pre1).
 
 the format versions are:
 
-- 119: Furnace dev119 (still not released)
+- 120: Furnace dev120
+- 119: Furnace dev119
 - 118: Furnace dev118
 - 117: Furnace dev117
 - 116: Furnace 0.6pre1.5
@@ -441,7 +442,6 @@ notes:
     - 0: sequence (normal)
     - 1: ADSR
     - 2: LFO
-    - 3: ADSR+LFO
   - see sub-section for information on how to interpret parameters.
 - FM operator order is:
   - 1/3/2/4 (internal order) for OPN, OPM, OPZ and OPL 4-op
@@ -1044,18 +1044,14 @@ size | description
   - `val[7]`: decay 2
   - `val[8]`: release
 - LFO:
-  - `val[9]`: bottom
-  - `val[10]`: top
   - `val[11]`: speed
   - `val[12]`: waveform
     - 0: triangle
-    - 1: sine
-    - 2: saw
-    - 3: pulse
+    - 1: saw
+    - 2: pulse
   - `val[13]`: phase
   - `val[14]`: loop
   - `val[15]`: global (not sure how will I implement this)
-- for ADSR+LFO just interpret both ADSR and LFO params.
 
 # wavetable
 
diff --git a/src/engine/macroInt.cpp b/src/engine/macroInt.cpp
index 90a4a6aa8..c463e7b24 100644
--- a/src/engine/macroInt.cpp
+++ b/src/engine/macroInt.cpp
@@ -31,11 +31,18 @@
 #define ADSR_SR source.val[7]
 #define ADSR_RR source.val[8]
 
+#define LFO_SPEED source.val[11]
+#define LFO_WAVE source.val[12]
+#define LFO_PHASE source.val[13]
+#define LFO_LOOP source.val[14]
+#define LFO_GLOBAL source.val[15]
+
 void DivMacroStruct::prepare(DivInstrumentMacro& source, DivEngine* e) {
   has=had=actualHad=will=true;
   mode=source.mode;
   type=(source.open>>1)&3;
   linger=(source.name=="vol" && e->song.volMacroLinger);
+  lfoPos=LFO_PHASE;
 }
 
 void DivMacroStruct::doMacro(DivInstrumentMacro& source, bool released, bool tick) {
@@ -86,7 +93,7 @@ void DivMacroStruct::doMacro(DivInstrumentMacro& source, bool released, bool tic
         }
       }
     }
-    if (type==1 || type==3) { // ADSR
+    if (type==1) { // ADSR
       if (released && lastPos<3) lastPos=3;
       switch (lastPos) {
         case 0: // attack
@@ -126,8 +133,23 @@ void DivMacroStruct::doMacro(DivInstrumentMacro& source, bool released, bool tic
       }
       val=ADSR_LOW+((pos+(ADSR_HIGH-ADSR_LOW)*pos)>>8);
     }
-    if (type==2 || type==3) { // LFO
-    
+    if (type==2) { // LFO
+      lfoPos+=LFO_SPEED;
+      lfoPos&=1023;
+
+      int lfoOut=0;
+      switch (LFO_WAVE&3) {
+        case 0: // triangle
+          lfoOut=((lfoPos&512)?(1023-lfoPos):(lfoPos))>>1;
+          break;
+        case 1: // saw
+          lfoOut=lfoPos>>2;
+          break;
+        case 2: // pulse
+          lfoOut=(lfoPos&512)?255:0;
+          break;
+      }
+      val=ADSR_LOW+((lfoOut+(ADSR_HIGH-ADSR_LOW)*lfoOut)>>8);
     }
   }
 }
diff --git a/src/engine/macroInt.h b/src/engine/macroInt.h
index 64d81e1bf..ac829a575 100644
--- a/src/engine/macroInt.h
+++ b/src/engine/macroInt.h
@@ -25,13 +25,13 @@
 class DivEngine;
 
 struct DivMacroStruct {
-  int pos, lastPos, delay;
+  int pos, lastPos, lfoPos, delay;
   int val;
   bool has, had, actualHad, finished, will, linger, began;
   unsigned int mode, type;
   void doMacro(DivInstrumentMacro& source, bool released, bool tick);
   void init() {
-    pos=lastPos=mode=type=delay=0;
+    pos=lastPos=lfoPos=mode=type=delay=0;
     has=had=actualHad=will=false;
     linger=false;
     began=true;
@@ -42,6 +42,7 @@ struct DivMacroStruct {
   DivMacroStruct():
     pos(0),
     lastPos(0),
+    lfoPos(0),
     delay(0),
     val(0),
     has(false),