Decomped GetChebyshevDistance

Decomped by @SethBarberee

Author: AnonymousRandomPerson

asm/include/overlay_29_022E908C.inc

@@ -3,6 +3,13 @@
 
 #include "dungeon_mode.h"
 
+// Checks if a given target position is in sight from a given origin position.
+// If the origin position is on a hallway or r2 is true, checks if both positions are within <dungeon::display_data::visibility_range> tiles of each other.
+// If the origin position is on a room, checks that the target position is within the boundaries of said room.
+// origin: Origin position
+// target: Target position
+// user_has_dropeye: True to assume the entity standing on the origin position has the dropeye status
+// return: True if the target position is in sight from the origin position
 bool8 IsPositionActuallyInSight(struct position *origin, struct position *target, bool8 user_has_dropeye);
 
 #endif //PMDSKY_DUNGEON_RANGE_H

asm/overlay_29_022E908C.s

@@ -5,5 +5,7 @@
 
 // Gets the direction in which a monster should move to go from the origin position to the target position
 s32 GetDirectionTowardsPosition(struct position *origin, struct position *target);
+// Returns the Chebyshev distance between two positions. Calculated as max(abs(x0-x1), abs(y0-y1)).
+s32 GetChebyshevDistance(struct position *position_a, struct position *position_b);
 
 #endif //PMDSKY_POSITION_UTIL_H

include/dungeon_range.h

@@ -374,7 +374,6 @@ Overlay OVY_29
 	Object asm/overlay_29_022E37DC.o
 	Object src/position_util.o
 	Object asm/overlay_29_rodata_02351628.o
-	Object asm/overlay_29_022E908C.o
 	Object src/dungeon_range.o
 	Object asm/overlay_29_022E91A4.o
 	Object src/dg_uty.o

include/position_util.h

@@ -47,7 +47,6 @@ const s32 FACING_DIRECTION_INCREMENTS[] = {0, 1, -1, 2, -2, 3, -3, 4};
 
 extern bool8 CanTargetEntity(struct entity *user, struct entity *target);
 extern bool8 CanTargetPosition(struct entity *monster, struct position *position);
-extern s32 GetChebyshevDistance(struct position *position_a, struct position *position_b);
 extern bool8 IsBagFull();
 extern bool8 ShouldMonsterFollowLeader(struct entity *monster);
 extern bool8 IsPositionWithinTwoTiles(struct position *origin, struct position *target);

main.lsf

@@ -5,8 +5,7 @@
 #include "overlay_29_022F7364.h"
 #include "overlay_29_023018AC.h"
 #include "overlay_29_02336428.h"
-
-extern s32 GetChebyshevDistance(struct position *position_a, struct position *position_b);
+#include "position_util.h"
 
 bool8 ShouldMonsterHeadToStairs(struct entity *entity)
 {

src/dungeon_ai_movement.c

@@ -1,4 +1,5 @@
 #include "position_util.h"
+#include "main_0208655C.h"
 
 const s32 POSITION_DISPLACEMENT_TO_DIRECTION[3][3] =
 {
@@ -28,3 +29,10 @@ s32 GetDirectionTowardsPosition(struct position *origin, struct position *target
 
     return POSITION_DISPLACEMENT_TO_DIRECTION[++y_diff][++x_diff];
 }
+
+s32 GetChebyshevDistance(struct position *position_a, struct position *position_b)
+{
+    s32 var1 = abs(position_a->x - position_b->x);
+    s32 var0 = abs(position_a->y - position_b->y);
+    return MAX(var1, var0);
+}