View difference between Paste ID: WA2t0dmE and seutCrU4

-Lbl Left
+Lbl Right
 .r₁=row scan offset
 .r₂=column scan index
 .r₃=column dest index
 .r₄=last value slid
- 0
+ 3
 .For each row
  For(4)
   →r₁
-  0→r₃→r₄
+  0→r₄
-  .For each column, starting from the left
+  12→r₃
   .For each column, starting from the right
   For(4)
    →r₂
    .If occupied by a tile
    If {+r₁+L₁}
     .Remove original tile
     Select(→r₅,0→{r₁+r₂+L₁})
     .If equal to the last slid tile
     !If -r₄
-     {r₁+r₃-1+L₁}++
+
      {r₁+r₃+4+L₁}++
     .If not equal to the last slid tile
-     .Store tile to destination and increment destination index
+
-     Select(r₅,→{r₃+++r₁-1+L₁})
+     .Store tile to destination and decrement destination index
      Select(r₅,→{r₃-4→r₃+r₁+4+L₁})
     End
     .Store value last slid (or garbage if a merge occured)
     →r₄
-   r₂+1
+
    r₂-4
-  r₁+4
+
   r₁-1
  End
 Return