From a99f1bd8a070045170352ad2cbec1f2898e9bd12 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Sat, 10 Sep 2022 02:34:47 -0500
Subject: [PATCH] fix walkSong

---
 src/engine/engine.cpp | 53 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 11 deletions(-)

diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index a184b5b5..f6fe659e 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -147,37 +147,68 @@ void DivEngine::walkSong(int& loopOrder, int& loopRow, int& loopEnd) {
   int nextOrder=-1;
   int nextRow=0;
   int effectVal=0;
+  int lastSuspectedLoopEnd=-1;
   DivPattern* pat[DIV_MAX_CHANS];
+  unsigned char wsWalked[8192];
+  memset(wsWalked,0,8192);
   for (int i=0; i<curSubSong->ordersLen; i++) {
     for (int j=0; j<chans; j++) {
       pat[j]=curPat[j].getPattern(curOrders->ord[j][i],false);
     }
+    if (i>lastSuspectedLoopEnd) {
+      lastSuspectedLoopEnd=i;
+    }
     for (int j=nextRow; j<curSubSong->patLen; j++) {
       nextRow=0;
+      bool changingOrder=false;
+      bool jumpingOrder=false;
+      if (wsWalked[((i<<5)+(j>>3))&8191]&(1<<(j&7))) {
+        loopOrder=i;
+        loopRow=j;
+        loopEnd=lastSuspectedLoopEnd;
+        return;
+      }
       for (int k=0; k<chans; k++) {
         for (int l=0; l<curPat[k].effectCols; l++) {
           effectVal=pat[k]->data[j][5+(l<<1)];
           if (effectVal<0) effectVal=0;
           if (pat[k]->data[j][4+(l<<1)]==0x0d) {
-            if (nextOrder==-1 && (i<curSubSong->ordersLen-1 || !song.ignoreJumpAtEnd)) {
-              nextOrder=i+1;
-              nextRow=effectVal;
+            if (song.jumpTreatment==2) {
+              if ((i<curSubSong->ordersLen-1 || !song.ignoreJumpAtEnd)) {
+                nextOrder=i+1;
+                nextRow=effectVal;
+                jumpingOrder=true;
+              }
+            } else if (song.jumpTreatment==1) {
+              if (nextOrder==-1 && (i<curSubSong->ordersLen-1 || !song.ignoreJumpAtEnd)) {
+                nextOrder=i+1;
+                nextRow=effectVal;
+                jumpingOrder=true;
+              }
+            } else {
+              if ((i<curSubSong->ordersLen-1 || !song.ignoreJumpAtEnd)) {
+                if (!changingOrder) {
+                  nextOrder=i+1;
+                }
+                jumpingOrder=true;
+                nextRow=effectVal;
+              }
             }
           } else if (pat[k]->data[j][4+(l<<1)]==0x0b) {
-            if (nextOrder==-1) {
+            if (nextOrder==-1 || song.jumpTreatment==0) {
               nextOrder=effectVal;
-              nextRow=0;
+              if (song.jumpTreatment==1 || song.jumpTreatment==2 || !jumpingOrder) {
+                nextRow=0;
+              }
+              changingOrder=true;
             }
           }
         }
       }
+
+      wsWalked[((i<<5)+(j>>3))&8191]|=1<<(j&7);
+      
       if (nextOrder!=-1) {
-        if (nextOrder<=i) {
-          loopOrder=nextOrder;
-          loopRow=nextRow;
-          loopEnd=i;
-          return;
-        }
         i=nextOrder-1;
         nextOrder=-1;
         break;