From 839dc3cd91169f3155120311633469c8717c31ad Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Thu, 5 Oct 2023 04:47:14 -0500
Subject: [PATCH] prepare to add channel pair and mode hints

---
 src/engine/dispatch.h            | 49 ++++++++++++++++++++++++++++++++
 src/engine/platform/abstract.cpp |  8 ++++++
 src/engine/platform/opl.cpp      |  9 ++++++
 src/engine/platform/opl.h        |  1 +
 src/gui/gui.cpp                  |  4 ++-
 5 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/src/engine/dispatch.h b/src/engine/dispatch.h
index ecb2ebc6e..1a8ec347d 100644
--- a/src/engine/dispatch.h
+++ b/src/engine/dispatch.h
@@ -339,6 +339,40 @@ struct DivDispatchOscBuffer {
   }
 };
 
+struct DivChannelPair {
+  const char* label;
+  // -1: none
+  signed char pairs[8];
+
+  DivChannelPair(const char* l, signed char p0, signed char p1, signed char p2, signed char p3, signed char p4, signed char p5, signed char p6, signed char p7):
+    label(l),
+    pairs{p0,p1,p2,p3,p4,p5,p6,p7} {}
+  DivChannelPair(const char* l, signed char p):
+    label(l),
+    pairs{p,-1,-1,-1,-1,-1,-1,-1} {}
+  DivChannelPair():
+    label(NULL),
+    pairs{-1,-1,-1,-1,-1,-1,-1,-1} {}
+};
+
+struct DivChannelModeHints {
+  const char* hint[4];
+  // valid types:
+  // - 0: disabled
+  // - 1: volume
+  // - 2: pitch
+  // - 3: panning
+  // - 4: ???
+  unsigned char type[4];
+  // up to 4
+  unsigned char count;
+
+  DivChannelModeHints():
+    hint{NULL,NULL,NULL,NULL},
+    type{0,0,0,0},
+    count(0) {}
+};
+
 class DivEngine;
 class DivMacroInt;
 
@@ -418,6 +452,21 @@ class DivDispatch {
      */
     virtual unsigned short getPan(int chan);
 
+    /**
+     * get "paired" channels.
+     * @param chan the channel to query.
+     * @return a DivChannelPair.
+     */
+    virtual DivChannelPair getPaired(int chan);
+
+    /**
+     * get channel mode hints.
+     * @param chan the channel to query.
+     * @return a DivChannelModeHints.
+     */
+    virtual DivChannelModeHints getModeHints(int chan);
+    
+
     /**
      * get currently playing sample (and its position).
      * @param chan the channel.
diff --git a/src/engine/platform/abstract.cpp b/src/engine/platform/abstract.cpp
index a06d9caf0..26221ebfd 100644
--- a/src/engine/platform/abstract.cpp
+++ b/src/engine/platform/abstract.cpp
@@ -37,6 +37,14 @@ unsigned short DivDispatch::getPan(int chan) {
   return 0;
 }
 
+DivChannelPair DivDispatch::getPaired(int chan) {
+  return DivChannelPair();
+}
+
+DivChannelModeHints DivDispatch::getModeHints(int chan) {
+  return DivChannelModeHints();
+}
+
 DivMacroInt* DivDispatch::getChanMacroInt(int chan) {
   return NULL;
 }
diff --git a/src/engine/platform/opl.cpp b/src/engine/platform/opl.cpp
index 5a7580a78..52968a1a5 100644
--- a/src/engine/platform/opl.cpp
+++ b/src/engine/platform/opl.cpp
@@ -1582,6 +1582,15 @@ unsigned short DivPlatformOPL::getPan(int ch) {
   return ((chan[ch].pan&1)<<8)|((chan[ch].pan&2)>>1);
 }
 
+DivChannelPair DivPlatformOPL::getPaired(int ch) {
+  if (oplType==3 && ch<12 && !(ch&1)) {
+    if (chan[ch].fourOp) {
+      return DivChannelPair("4OP",ch+1);
+    }
+  }
+  return DivChannelPair();
+}
+
 DivDispatchOscBuffer* DivPlatformOPL::getOscBuffer(int ch) {
   if (oplType==759 || chipType==8950) {
     if (ch>=totalChans+1) return NULL;
diff --git a/src/engine/platform/opl.h b/src/engine/platform/opl.h
index bcc147da1..54cf0c24d 100644
--- a/src/engine/platform/opl.h
+++ b/src/engine/platform/opl.h
@@ -115,6 +115,7 @@ class DivPlatformOPL: public DivDispatch {
     void* getChanState(int chan);
     DivMacroInt* getChanMacroInt(int ch);
     unsigned short getPan(int chan);
+    DivChannelPair getPaired(int chan);
     DivDispatchOscBuffer* getOscBuffer(int chan);
     unsigned char* getRegisterPool();
     int getRegisterPoolSize();
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 4fa69a16a..67d631521 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -6353,6 +6353,7 @@ bool FurnaceGUI::init() {
   } else {
     patChannelNames=e->getConfBool("patChannelNames",false);
   }
+  patChannelPairs=e->getConfBool("patChannelPairs",true);
   patChannelHints=e->getConfInt("patChannelHints",0);
   lockLayout=e->getConfBool("lockLayout",false);
 #ifdef IS_MOBILE
@@ -6893,6 +6894,7 @@ void FurnaceGUI::commitState() {
   e->setConf("waveEditStyle",waveEditStyle);
   e->setConf("patExtraButtons",patExtraButtons);
   e->setConf("patChannelNames",patChannelNames);
+  e->setConf("patChannelPairs",patChannelPairs);
   e->setConf("patChannelHints",(int)patChannelHints);
   e->setConf("lockLayout",lockLayout);
   e->setConf("fullScreen",fullScreen);
@@ -7145,7 +7147,7 @@ FurnaceGUI::FurnaceGUI():
   exportFadeOut(5.0),
   patExtraButtons(false),
   patChannelNames(false),
-  patChannelPairs(false),
+  patChannelPairs(true),
   patChannelHints(0),
   newSongFirstFrame(false),
   oldRowChanged(false),