From 9e1b43f4015f4641daaf84295da99f107fe73e3f Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Thu, 16 May 2024 12:35:34 -0500
Subject: [PATCH] OPLL: add effect to change patch

10xx
---
 doc/7-systems/opll.md        | 1 +
 src/engine/platform/opll.cpp | 7 +++++++
 src/engine/sysDef.cpp        | 1 +
 3 files changed, 9 insertions(+)

diff --git a/doc/7-systems/opll.md b/doc/7-systems/opll.md
index 4de890b22..dbbea413b 100644
--- a/doc/7-systems/opll.md
+++ b/doc/7-systems/opll.md
@@ -27,6 +27,7 @@ the YM2413 is equipped with the following features:
 
 ## effects
 
+- `10xx`: **change patch.**
 - `11xx`: **set feedback of channel.**
 - `12xx`: **set operator 1 level.**
 - `13xx`: **set operator 2 level.**
diff --git a/src/engine/platform/opll.cpp b/src/engine/platform/opll.cpp
index a5b554c6d..c231b749b 100644
--- a/src/engine/platform/opll.cpp
+++ b/src/engine/platform/opll.cpp
@@ -692,6 +692,13 @@ int DivPlatformOPLL::dispatch(DivCommand c) {
       chan[c.chan].freqChanged=true;
       break;
     }
+    case DIV_CMD_WAVE: {
+      if (c.chan>=6 && (crapDrums || properDrums)) break;
+      if (c.chan>=9) break;
+      chan[c.chan].state.opllPreset=c.value&15;
+      rWrite(0x30+c.chan,((15-VOL_SCALE_LOG_BROKEN(chan[c.chan].outVol,15-chan[c.chan].state.op[1].tl,15))&15)|(chan[c.chan].state.opllPreset<<4));
+      break;
+    }
     case DIV_CMD_FM_FB: {
       if (c.chan>=9 && !properDrums) return 0;
       //DivInstrumentFM::Operator& mod=chan[c.chan].state.op[0];
diff --git a/src/engine/sysDef.cpp b/src/engine/sysDef.cpp
index 45e0bb52a..1e52ce837 100644
--- a/src/engine/sysDef.cpp
+++ b/src/engine/sysDef.cpp
@@ -550,6 +550,7 @@ void DivEngine::registerSystems() {
   });
 
   EffectHandlerMap fmOPLLPostEffectHandlerMap={
+    {0x10, {DIV_CMD_WAVE, "10xx: Set patch (0 to F)"}},
     {0x11, {DIV_CMD_FM_FB, "11xx: Set feedback (0 to 7)"}},
     {0x12, {DIV_CMD_FM_TL, "12xx: Set level of operator 1 (0 highest, 3F lowest)", constVal<0>, effectVal}},
     {0x13, {DIV_CMD_FM_TL, "13xx: Set level of operator 2 (0 highest, 3F lowest)", constVal<1>, effectVal}},