diff --git a/asm/ground_map_1.s b/asm/ground_map_1.s
index 41ac1fc3e..49c4d3096 100644
--- a/asm/ground_map_1.s
+++ b/asm/ground_map_1.s
@@ -5,103 +5,6 @@
 
 	.text
 
-	thumb_func_start sub_80A579C
-sub_80A579C:
-	push {r4-r7,lr}
-	adds r6, r0, 0
-	adds r5, r1, 0
-	ldr r0, _080A5838
-	ldr r3, [r0]
-	cmp r3, 0
-	beq _080A5854
-	ldr r0, _080A583C
-	ldr r0, [r0]
-	adds r2, r0, 0
-	adds r2, 0xE4
-	movs r0, 0
-	ldrsh r1, [r2, r0]
-	movs r0, 0x1
-	negs r0, r0
-	cmp r1, r0
-	beq _080A5854
-	adds r0, r1, 0
-	lsls r4, r0, 1
-	adds r4, r0
-	lsls r4, 2
-	ldr r0, _080A5840
-	adds r4, r0
-	adds r0, r3, 0
-	adds r1, r6, 0
-	adds r2, r5, 0
-	bl GetDungeonBounds
-	ldr r2, [r6]
-	mov r12, r2
-	movs r0, 0xF0
-	lsls r0, 7
-	add r0, r12
-	str r0, [r6]
-	ldr r3, [r6, 0x4]
-	movs r7, 0xA0
-	lsls r7, 7
-	adds r0, r3, r7
-	str r0, [r6, 0x4]
-	ldr r2, [r5]
-	ldr r1, _080A5844
-	adds r0, r2, r1
-	str r0, [r5]
-	ldr r1, [r5, 0x4]
-	ldr r7, _080A5848
-	adds r0, r1, r7
-	str r0, [r5, 0x4]
-	movs r7, 0
-	ldrsh r0, [r4, r7]
-	cmp r0, 0xA
-	bne _080A581E
-	movs r0, 0x90
-	lsls r0, 8
-	add r0, r12
-	str r0, [r6]
-	movs r4, 0xD0
-	lsls r4, 7
-	adds r0, r3, r4
-	str r0, [r6, 0x4]
-	ldr r7, _080A584C
-	adds r0, r2, r7
-	str r0, [r5]
-	ldr r2, _080A5850
-	adds r0, r1, r2
-	str r0, [r5, 0x4]
-_080A581E:
-	ldr r1, [r6]
-	ldr r0, [r5]
-	cmp r1, r0
-	ble _080A5828
-	str r1, [r5]
-_080A5828:
-	ldr r1, [r6, 0x4]
-	ldr r0, [r5, 0x4]
-	cmp r1, r0
-	ble _080A5832
-	str r1, [r5, 0x4]
-_080A5832:
-	movs r0, 0x1
-	b _080A5856
-	.align 2, 0
-_080A5838: .4byte gGroundMapDungeon_3001B70
-_080A583C: .4byte gGroundMapAction
-_080A5840: .4byte gGroundMapConversionTable
-_080A5844: .4byte 0xffff8800
-_080A5848: .4byte 0xffffb000
-_080A584C: .4byte 0xffff7000
-_080A5850: .4byte 0xffff9800
-_080A5854:
-	movs r0, 0
-_080A5856:
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	thumb_func_end sub_80A579C
-
 	thumb_func_start CheckMapCollision_80A585C
 CheckMapCollision_80A585C:
 	push {r4-r7,lr}
diff --git a/src/ground_map.c b/src/ground_map.c
index 61bbb1302..73d9a7223 100644
--- a/src/ground_map.c
+++ b/src/ground_map.c
@@ -1113,3 +1113,38 @@ bool8 GetCurrentDungeonBounds(PixelPos *pos1, PixelPos *pos2)
     }
 }
 
+bool8 sub_80A579C(PixelPos *pos1, PixelPos *pos2)
+{
+    const GroundConversionStruct *convTable;
+
+    if(gGroundMapDungeon_3001B70 != NULL)
+    {
+        if(gGroundMapAction->groundMapId != -1)
+        {
+            convTable = &gGroundMapConversionTable[gGroundMapAction->groundMapId];
+            GetDungeonBounds(gGroundMapDungeon_3001B70, pos1, pos2);   
+
+            pos1->x += 0x7800;
+            pos1->y += 0x5000;
+            pos2->x -= 0x7800;
+            pos2->y -= 0x5000;
+
+            if(convTable->unk0 == 0xA)
+            {
+                pos1->x += 0x1800;
+                pos1->y += 0x1800;
+                pos2->x -= 0x1800;
+                pos2->y -= 0x1800;
+            }
+
+            if (pos1->x > pos2->x) {
+                pos2->x = pos1->x;
+            }
+            if (pos1->y > pos2->y) {
+                pos2->y = pos1->y;
+            }
+            return TRUE;
+        }
+    }
+    return FALSE;
+}