From 0bcd1b74ac1b9e37ff22729482ecd1857c76b5a3 Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Thu, 22 Jun 2023 04:55:12 -0500
Subject: [PATCH] VGM export: prepare for NES DPCM

---
 src/engine/platform/nes.cpp | 13 +++++++++++--
 src/engine/vgmOps.cpp       | 18 +++++++++++++-----
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/src/engine/platform/nes.cpp b/src/engine/platform/nes.cpp
index 99131ac30..8fac52356 100644
--- a/src/engine/platform/nes.cpp
+++ b/src/engine/platform/nes.cpp
@@ -346,7 +346,11 @@ void DivPlatformNES::tick(bool sysTick) {
           rWrite(0x4012,(dpcmAddr>>6)&0xff);
           rWrite(0x4013,dpcmLen&0xff);
           rWrite(0x4015,31);
-          dpcmBank=dpcmAddr>>14;
+          if (dpcmBank!=(dpcmAddr>>14)) {
+            dpcmBank=dpcmAddr>>14;
+            logV("switching bank to %d",dpcmBank);
+            if (dumpWrites) addWrite(0xffff0004,dpcmBank);
+          }
         }
       } else {
         if (nextDPCMFreq>=0) {
@@ -425,7 +429,11 @@ int DivPlatformNES::dispatch(DivCommand c) {
             rWrite(0x4012,(dpcmAddr>>6)&0xff);
             rWrite(0x4013,dpcmLen&0xff);
             rWrite(0x4015,31);
-            dpcmBank=dpcmAddr>>14;
+            if (dpcmBank!=(dpcmAddr>>14)) {
+              dpcmBank=dpcmAddr>>14;
+              logV("switching bank to %d",dpcmBank);
+              if (dumpWrites) addWrite(0xffff0004,dpcmBank);
+            }
           }
         }
         break;
@@ -854,6 +862,7 @@ int DivPlatformNES::init(DivEngine* p, int channels, int sugRate, const DivConfi
   dpcmMem=new unsigned char[262144];
   dpcmMemLen=0;
   dpcmBank=0;
+  if (dumpWrites) addWrite(0xffff0004,dpcmBank);
 
   init_nla_table(500,500);
   reset();
diff --git a/src/engine/vgmOps.cpp b/src/engine/vgmOps.cpp
index bc94415b9..7a6caa67a 100644
--- a/src/engine/vgmOps.cpp
+++ b/src/engine/vgmOps.cpp
@@ -1054,6 +1054,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
   bool willExport[DIV_MAX_CHIPS];
   bool isSecond[DIV_MAX_CHIPS];
   int streamIDs[DIV_MAX_CHIPS];
+  
   double loopTimer[DIV_MAX_CHANS];
   double loopFreq[DIV_MAX_CHANS];
   int loopSample[DIV_MAX_CHANS];
@@ -1096,6 +1097,9 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
   DivDispatch* writeGA20[2]={NULL,NULL};
   DivDispatch* writeNES[2]={NULL,NULL};
 
+  size_t bankOffsetNESCurrent=0;
+  size_t bankOffsetNES[2]={0,0};
+
   for (int i=0; i<song.systemLen; i++) {
     willExport[i]=false;
     isSecond[i]=false;
@@ -1837,6 +1841,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
     for (unsigned int j=0; j<sample->length8; j++) {
       w->writeC(((unsigned char)sample->data8[j]+0x80)>>1);
     }
+    bankOffsetNESCurrent+=sample->length8;
   }
 
   if (writePCESamples && !directStream) for (int i=0; i<song.sampleLen; i++) {
@@ -1973,13 +1978,14 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
     }
     // TODO
     if (writeNES[i]!=NULL && writeNES[i]->getSampleMemUsage()>0) {
+      size_t howMuchWillBeWritten=writeNES[i]->getSampleMemUsage();
       w->writeC(0x67);
       w->writeC(0x66);
-      w->writeC(0x07);
-      w->writeI((writeNES[i]->getSampleMemUsage()+8)|(i*0x80000000));
-      w->writeI(writeNES[i]->getSampleMemCapacity());
-      w->writeI(0);
-      w->write(writeNES[i]->getSampleMem(),writeNES[i]->getSampleMemUsage());
+      w->writeC(7);
+      w->writeI(howMuchWillBeWritten);
+      w->write(writeNES[i]->getSampleMem(),howMuchWillBeWritten);
+      bankOffsetNES[i]=bankOffsetNESCurrent;
+      bankOffsetNESCurrent+=howMuchWillBeWritten;
     }
   }
 
@@ -2231,6 +2237,8 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
           }
           // write write
           performVGMWrite(w,song.system[i.first],i.second.write,streamIDs[i.first],loopTimer,loopFreq,loopSample,sampleDir,isSecond[i.first],pendingFreq,playingSample,directStream);
+          // handle global Furnace commands
+
           writeCount++;
         }
         sortedWrites.clear();