trainer_see through CheckPathBetweenTrainerAndPlayer

12 files changed, 226 insertions, 506 deletions

diff --git a/asm/event_object_movement.s b/asm/event_object_movement.s
index f585a60bc..49724f61d 100644
--- a/asm/event_object_movement.s
+++ b/asm/event_object_movement.s
@@ -10521,7 +10521,7 @@ sub_80629B8: @ 80629B8
 	ldrsh r2, [r5, r0]
 	adds r0, r4, 0
 	adds r3, r6, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	cmp r0, 0
 	bne _08062A3E
@@ -10610,7 +10610,7 @@ sub_8062A70: @ 8062A70
 	ldrsh r2, [r5, r0]
 	adds r0, r4, 0
 	adds r3, r6, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	cmp r0, 0
 	bne _08062AF6
@@ -10699,7 +10699,7 @@ sub_8062B28: @ 8062B28
 	ldrsh r2, [r5, r0]
 	adds r0, r4, 0
 	adds r3, r6, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	cmp r0, 0
 	bne _08062BAE
@@ -10788,7 +10788,7 @@ sub_8062BE0: @ 8062BE0
 	ldrsh r2, [r5, r0]
 	adds r0, r4, 0
 	adds r3, r6, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	cmp r0, 0
 	bne _08062C66
@@ -10913,7 +10913,7 @@ sub_8062CE0: @ 8062CE0
 	ldrsh r2, [r5, r0]
 	adds r0, r4, 0
 	adds r3, r6, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	cmp r0, 0
 	bne _08062D66
@@ -11009,7 +11009,7 @@ oac_hopping: @ 8062D98
 	ldrsh r2, [r5, r0]
 	adds r0, r4, 0
 	adds r3, r6, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	cmp r0, 0
 	bne _08062E2C
@@ -12292,7 +12292,7 @@ npc_block_way__next_tile: @ 806366C
 	ldrsh r2, [r4, r0]
 	adds r0, r6, 0
 	adds r3, r5, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	lsrs r0, 24
 	add sp, 0x4
@@ -12301,8 +12301,8 @@ npc_block_way__next_tile: @ 806366C
 	bx r1
 	thumb_func_end npc_block_way__next_tile
 
-	thumb_func_start npc_block_way
-npc_block_way: @ 80636AC
+	thumb_func_start GetCollisionAtCoords
+GetCollisionAtCoords: @ 80636AC
 	push {r4-r7,lr}
 	mov r7, r10
 	mov r6, r9
@@ -12400,10 +12400,10 @@ _08063762:
 	pop {r4-r7}
 	pop {r1}
 	bx r1
-	thumb_func_end npc_block_way
+	thumb_func_end GetCollisionAtCoords
 
-	thumb_func_start sub_8063770
-sub_8063770: @ 8063770
+	thumb_func_start GetCollisionFlagsAtCoords
+GetCollisionFlagsAtCoords: @ 8063770
 	push {r4-r7,lr}
 	mov r7, r10
 	mov r6, r9
@@ -12503,7 +12503,7 @@ _0806382C:
 	pop {r4-r7}
 	pop {r1}
 	bx r1
-	thumb_func_end sub_8063770
+	thumb_func_end GetCollisionFlagsAtCoords
 
 	thumb_func_start IsCoordOutsideObjectEventMovementRect
 IsCoordOutsideObjectEventMovementRect: @ 806383C
diff --git a/asm/field_player_avatar.s b/asm/field_player_avatar.s
index a605f1439..7a2c5cbc5 100644
--- a/asm/field_player_avatar.s
+++ b/asm/field_player_avatar.s
@@ -1120,7 +1120,7 @@ sub_805BBA8: @ 805BBA8
 	adds r1, r5, 0
 	adds r2, r4, 0
 	adds r3, r6, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	lsrs r0, 24
 	mov r1, sp
@@ -1323,7 +1323,7 @@ sub_805BCEC: @ 805BCEC
 	ldrsh r2, [r5, r0]
 	adds r0, r4, 0
 	adds r3, r7, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	cmp r0, 0
 	bne _0805BDA0
@@ -2906,7 +2906,7 @@ IsPlayerFacingSurfableFishableWater: @ 805C8B0
 	lsls r3, 28
 	lsrs r3, 28
 	adds r0, r4, 0
-	bl npc_block_way
+	bl GetCollisionAtCoords
 	lsls r0, 24
 	lsrs r0, 24
 	cmp r0, 0x3
diff --git a/asm/trainer_see.s b/asm/trainer_see.s
index c12bcaeeb..11c4fcbcb 100644
--- a/asm/trainer_see.s
+++ b/asm/trainer_see.s
@@ -5,457 +5,6 @@
 
 	.text
 
-	thumb_func_start CheckForTrainersWantingBattle
-CheckForTrainersWantingBattle: @ 8081B30
-	push {r4,r5,lr}
-	bl sub_8111C2C
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	bne _08081B44
-	b _08081B78
-_08081B40:
-	movs r0, 0x1
-	b _08081B7A
-_08081B44:
-	movs r4, 0
-	ldr r5, _08081B80 @ =gObjectEvents
-_08081B48:
-	lsls r0, r4, 3
-	adds r0, r4
-	lsls r0, 2
-	adds r1, r0, r5
-	ldrb r0, [r1]
-	lsls r0, 31
-	cmp r0, 0
-	beq _08081B6E
-	ldrb r0, [r1, 0x7]
-	cmp r0, 0x1
-	beq _08081B62
-	cmp r0, 0x3
-	bne _08081B6E
-_08081B62:
-	adds r0, r4, 0
-	bl sub_8081B84
-	lsls r0, 24
-	cmp r0, 0
-	bne _08081B40
-_08081B6E:
-	adds r0, r4, 0x1
-	lsls r0, 24
-	lsrs r4, r0, 24
-	cmp r4, 0xF
-	bls _08081B48
-_08081B78:
-	movs r0, 0
-_08081B7A:
-	pop {r4,r5}
-	pop {r1}
-	bx r1
-	.align 2, 0
-_08081B80: .4byte gObjectEvents
-	thumb_func_end CheckForTrainersWantingBattle
-
-	thumb_func_start sub_8081B84
-sub_8081B84: @ 8081B84
-	push {r4-r7,lr}
-	lsls r0, 24
-	lsrs r5, r0, 24
-	adds r0, r5, 0
-	bl GetObjectEventScriptPointerByObjectEventId
-	adds r6, r0, 0
-	bl GetTrainerFlagFromScriptPointer
-	cmp r0, 0
-	bne _08081BE4
-	lsls r4, r5, 3
-	adds r0, r4, r5
-	lsls r0, 2
-	ldr r1, _08081BE0 @ =gObjectEvents
-	adds r0, r1
-	bl sub_8081BEC
-	lsls r0, 24
-	lsrs r7, r0, 24
-	cmp r7, 0
-	beq _08081BE4
-	ldrb r0, [r6, 0x1]
-	cmp r0, 0x4
-	bne _08081BC0
-	bl GetMonsStateToDoubles
-	lsls r0, 24
-	cmp r0, 0
-	bne _08081BE4
-_08081BC0:
-	adds r0, r5, 0
-	adds r1, r6, 0
-	bl ConfigureAndSetUpOneTrainerBattle
-	adds r0, r4, r5
-	lsls r0, 2
-	ldr r1, _08081BE0 @ =gObjectEvents
-	adds r0, r1
-	subs r1, r7, 0x1
-	lsls r1, 24
-	lsrs r1, 24
-	bl sub_8081E68
-	movs r0, 0x1
-	b _08081BE6
-	.align 2, 0
-_08081BE0: .4byte gObjectEvents
-_08081BE4:
-	movs r0, 0
-_08081BE6:
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	thumb_func_end sub_8081B84
-
-	thumb_func_start sub_8081BEC
-sub_8081BEC: @ 8081BEC
-	push {r4-r7,lr}
-	mov r7, r8
-	push {r7}
-	sub sp, 0x4
-	adds r7, r0, 0
-	mov r4, sp
-	adds r4, 0x2
-	mov r0, sp
-	adds r1, r4, 0
-	bl PlayerGetDestCoords
-	ldrb r0, [r7, 0x7]
-	mov r8, r4
-	cmp r0, 0x1
-	bne _08081C4C
-	ldr r1, _08081C44 @ =gUnknown_83C7248
-	ldrb r0, [r7, 0x18]
-	lsls r0, 28
-	lsrs r0, 26
-	subs r0, 0x4
-	adds r0, r1
-	ldrb r1, [r7, 0x1D]
-	mov r2, sp
-	movs r3, 0
-	ldrsh r2, [r2, r3]
-	movs r5, 0
-	ldrsh r3, [r4, r5]
-	ldr r4, [r0]
-	adds r0, r7, 0
-	bl _call_via_r4
-	lsls r0, 24
-	lsrs r6, r0, 24
-	ldrb r2, [r7, 0x18]
-	lsls r2, 28
-	lsrs r2, 28
-	adds r0, r7, 0
-	adds r1, r6, 0
-	bl CheckPathBetweenTrainerAndPlayer
-	lsls r0, 24
-	lsrs r0, 24
-	b _08081C8C
-	.align 2, 0
-_08081C44: .4byte gUnknown_83C7248
-_08081C48:
-	adds r0, r6, 0
-	b _08081C8C
-_08081C4C:
-	movs r5, 0
-_08081C4E:
-	ldr r0, _08081C98 @ =gUnknown_83C7248
-	lsls r4, r5, 2
-	adds r4, r0
-	ldrb r1, [r7, 0x1D]
-	mov r0, sp
-	movs r6, 0
-	ldrsh r2, [r0, r6]
-	mov r0, r8
-	movs r6, 0
-	ldrsh r3, [r0, r6]
-	ldr r4, [r4]
-	adds r0, r7, 0
-	bl _call_via_r4
-	lsls r0, 24
-	lsrs r6, r0, 24
-	adds r0, r5, 0x1
-	lsls r0, 24
-	lsrs r4, r0, 24
-	adds r0, r7, 0
-	adds r1, r6, 0
-	adds r2, r4, 0
-	bl CheckPathBetweenTrainerAndPlayer
-	lsls r0, 24
-	cmp r0, 0
-	bne _08081C48
-	adds r5, r4, 0
-	cmp r5, 0x3
-	bls _08081C4E
-	movs r0, 0
-_08081C8C:
-	add sp, 0x4
-	pop {r3}
-	mov r8, r3
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	.align 2, 0
-_08081C98: .4byte gUnknown_83C7248
-	thumb_func_end sub_8081BEC
-
-	thumb_func_start IsTrainerInRangeSouth
-IsTrainerInRangeSouth: @ 8081C9C
-	push {r4,r5,lr}
-	adds r4, r0, 0
-	lsls r1, 16
-	lsrs r1, 16
-	lsls r3, 16
-	lsrs r5, r3, 16
-	movs r3, 0x10
-	ldrsh r0, [r4, r3]
-	lsls r2, 16
-	asrs r2, 16
-	cmp r0, r2
-	bne _08081CE4
-	lsls r0, r5, 16
-	asrs r2, r0, 16
-	movs r3, 0x12
-	ldrsh r0, [r4, r3]
-	cmp r2, r0
-	ble _08081CE4
-	lsls r1, 16
-	asrs r1, 16
-	adds r0, r1
-	cmp r2, r0
-	bgt _08081CE4
-	cmp r1, 0x3
-	ble _08081CDA
-	bl sub_805DF30
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x10
-	beq _08081CE4
-_08081CDA:
-	ldrb r0, [r4, 0x12]
-	subs r0, r5, r0
-	lsls r0, 24
-	lsrs r0, 24
-	b _08081CE6
-_08081CE4:
-	movs r0, 0
-_08081CE6:
-	pop {r4,r5}
-	pop {r1}
-	bx r1
-	thumb_func_end IsTrainerInRangeSouth
-
-	thumb_func_start IsTrainerInRangeNorth
-IsTrainerInRangeNorth: @ 8081CEC
-	push {r4-r6,lr}
-	adds r4, r0, 0
-	lsls r1, 16
-	lsrs r6, r1, 16
-	lsls r3, 16
-	lsrs r5, r3, 16
-	movs r1, 0x10
-	ldrsh r0, [r4, r1]
-	lsls r2, 16
-	asrs r2, 16
-	cmp r0, r2
-	bne _08081D26
-	lsls r0, r5, 16
-	asrs r2, r0, 16
-	ldrh r3, [r4, 0x12]
-	movs r1, 0x12
-	ldrsh r0, [r4, r1]
-	cmp r2, r0
-	bge _08081D26
-	adds r1, r0, 0
-	lsls r0, r6, 16
-	asrs r0, 16
-	subs r1, r0
-	cmp r2, r1
-	blt _08081D26
-	subs r0, r3, r5
-	lsls r0, 24
-	lsrs r0, 24
-	b _08081D28
-_08081D26:
-	movs r0, 0
-_08081D28:
-	pop {r4-r6}
-	pop {r1}
-	bx r1
-	thumb_func_end IsTrainerInRangeNorth
-
-	thumb_func_start IsTrainerInRangeWest
-IsTrainerInRangeWest: @ 8081D30
-	push {r4-r6,lr}
-	adds r4, r0, 0
-	lsls r1, 16
-	lsrs r6, r1, 16
-	lsls r2, 16
-	lsrs r5, r2, 16
-	movs r1, 0x12
-	ldrsh r0, [r4, r1]
-	lsls r3, 16
-	asrs r3, 16
-	cmp r0, r3
-	bne _08081D6A
-	lsls r0, r5, 16
-	asrs r3, r0, 16
-	ldrh r2, [r4, 0x10]
-	movs r1, 0x10
-	ldrsh r0, [r4, r1]
-	cmp r3, r0
-	bge _08081D6A
-	adds r1, r0, 0
-	lsls r0, r6, 16
-	asrs r0, 16
-	subs r1, r0
-	cmp r3, r1
-	blt _08081D6A
-	subs r0, r2, r5
-	lsls r0, 24
-	lsrs r0, 24
-	b _08081D6C
-_08081D6A:
-	movs r0, 0
-_08081D6C:
-	pop {r4-r6}
-	pop {r1}
-	bx r1
-	thumb_func_end IsTrainerInRangeWest
-
-	thumb_func_start IsTrainerInRangeEast
-IsTrainerInRangeEast: @ 8081D74
-	push {r4-r6,lr}
-	adds r4, r0, 0
-	lsls r1, 16
-	lsrs r6, r1, 16
-	lsls r2, 16
-	lsrs r5, r2, 16
-	movs r1, 0x12
-	ldrsh r0, [r4, r1]
-	lsls r3, 16
-	asrs r3, 16
-	cmp r0, r3
-	bne _08081DAE
-	lsls r0, r5, 16
-	asrs r3, r0, 16
-	ldrh r2, [r4, 0x10]
-	movs r1, 0x10
-	ldrsh r0, [r4, r1]
-	cmp r3, r0
-	ble _08081DAE
-	adds r1, r0, 0
-	lsls r0, r6, 16
-	asrs r0, 16
-	adds r1, r0
-	cmp r3, r1
-	bgt _08081DAE
-	subs r0, r5, r2
-	lsls r0, 24
-	lsrs r0, 24
-	b _08081DB0
-_08081DAE:
-	movs r0, 0
-_08081DB0:
-	pop {r4-r6}
-	pop {r1}
-	bx r1
-	thumb_func_end IsTrainerInRangeEast
-
-	thumb_func_start CheckPathBetweenTrainerAndPlayer
-CheckPathBetweenTrainerAndPlayer: @ 8081DB8
-	push {r4-r7,lr}
-	mov r7, r9
-	mov r6, r8
-	push {r6,r7}
-	sub sp, 0x4
-	adds r6, r0, 0
-	lsls r1, 24
-	lsrs r1, 24
-	mov r9, r1
-	lsls r2, 24
-	lsrs r7, r2, 24
-	cmp r1, 0
-	beq _08081E54
-	ldrh r1, [r6, 0x10]
-	mov r0, sp
-	strh r1, [r0]
-	ldrh r0, [r6, 0x12]
-	mov r1, sp
-	adds r1, 0x2
-	strh r0, [r1]
-	movs r4, 0
-	mov r8, r1
-	mov r5, r9
-	subs r5, 0x1
-	cmp r4, r5
-	bgt _08081E26
-_08081DEC:
-	mov r0, sp
-	movs r2, 0
-	ldrsh r1, [r0, r2]
-	mov r3, r8
-	movs r0, 0
-	ldrsh r2, [r3, r0]
-	adds r0, r6, 0
-	adds r3, r7, 0
-	bl sub_8063770
-	lsls r0, 24
-	lsrs r1, r0, 24
-	cmp r1, 0
-	beq _08081E12
-	movs r0, 0x2
-	negs r0, r0
-	ands r1, r0
-	cmp r1, 0
-	bne _08081E54
-_08081E12:
-	adds r0, r4, 0x1
-	lsls r0, 24
-	lsrs r4, r0, 24
-	adds r0, r7, 0
-	mov r1, sp
-	mov r2, r8
-	bl MoveCoords
-	cmp r4, r5
-	ble _08081DEC
-_08081E26:
-	ldrb r4, [r6, 0x19]
-	lsls r5, r4, 28
-	lsrs r5, 28
-	lsrs r4, 4
-	movs r0, 0
-	strb r0, [r6, 0x19]
-	mov r0, sp
-	movs r2, 0
-	ldrsh r1, [r0, r2]
-	mov r3, r8
-	movs r0, 0
-	ldrsh r2, [r3, r0]
-	adds r0, r6, 0
-	adds r3, r7, 0
-	bl npc_block_way
-	lsls r0, 24
-	lsrs r1, r0, 24
-	lsls r4, 4
-	orrs r5, r4
-	strb r5, [r6, 0x19]
-	cmp r1, 0x4
-	beq _08081E58
-_08081E54:
-	movs r0, 0
-	b _08081E5A
-_08081E58:
-	mov r0, r9
-_08081E5A:
-	add sp, 0x4
-	pop {r3,r4}
-	mov r8, r3
-	mov r9, r4
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	thumb_func_end CheckPathBetweenTrainerAndPlayer
-
 	thumb_func_start sub_8081E68
 sub_8081E68: @ 8081E68
 	push {r4,r5,lr}
diff --git a/data/trainer_see.s b/data/trainer_see.s
index 3014d8ba0..13641f259 100644
--- a/data/trainer_see.s
+++ b/data/trainer_see.s
@@ -4,15 +4,6 @@
 	.section .rodata
 	.align 2
 
-gUnknown_83C6AC8::
-	.incbin "graphics/object_events/emoticons.4bpp"
-
-gUnknown_83C7248:: @ 83C7248
-	.4byte IsTrainerInRangeSouth
-	.4byte IsTrainerInRangeNorth
-	.4byte IsTrainerInRangeWest
-	.4byte IsTrainerInRangeEast
-
 gUnknown_83C7258:: @ 83C7258
 	.4byte sub_8081F34
 	.4byte sub_8081F38
diff --git a/include/event_object_movement.h b/include/event_object_movement.h
index 650f137d9..b5acd4bbb 100644
--- a/include/event_object_movement.h
+++ b/include/event_object_movement.h
@@ -76,7 +76,7 @@ u8 GetStepInPlaceDelay4AnimId(u32);
 u8 GetStepInPlaceDelay8AnimId(u32);
 u8 GetStepInPlaceDelay16AnimId(u32);
 u8 GetStepInPlaceDelay32AnimId(u32);
-u8 npc_block_way(struct ObjectEvent *, s16, s16, u32);
+u8 GetCollisionAtCoords(struct ObjectEvent *, s16, s16, u32);
 void MoveCoords(u8, s16 *, s16 *);
 bool8 ObjectEventIsSpecialAnimActive(struct ObjectEvent *);
 u8 ObjectEventClearHeldMovementIfFinished(struct ObjectEvent *);
@@ -98,6 +98,9 @@ u8 GetTrainerFacingDirectionMovementType(u8 direction);
 void CameraObjectSetFollowedObjectId(u8 spriteId);
 void UnfreezeObjectEvents(void);
 void TurnObjectEvent(u8, u8);
+const u8 *GetObjectEventScriptPointerByObjectEventId(u8 objectEventId);
+u8 sub_805DF30(void);
+u8 GetCollisionFlagsAtCoords(struct ObjectEvent * objectEvent, s16 x, s16 y, u8 direction);
 
 // Exported data declarations
 
diff --git a/include/global.fieldmap.h b/include/global.fieldmap.h
index e0053fe88..c599b68ab 100644
--- a/include/global.fieldmap.h
+++ b/include/global.fieldmap.h
@@ -205,9 +205,9 @@ struct ObjectEvent
     /*0x0A*/        u8 mapGroup;
     /*0x0B*/        u8 mapobj_unk_0B_0:4;
                     u8 elevation:4;
-    /*0x0C*/        struct Coords16 coords1;
-    /*0x10*/        struct Coords16 coords2;
-    /*0x14*/        struct Coords16 coords3;
+    /*0x0C*/        struct Coords16 initialCoords;
+    /*0x10*/        struct Coords16 currentCoords;
+    /*0x14*/        struct Coords16 previousCoords;
     /*0x18*/        u8 facingDirection:4;  //current direction?
     /*0x18*/        u8 placeholder18:4;
     /*0x19*/        union ObjectEventRange range;
diff --git a/include/quest_log.h b/include/quest_log.h
index eddd4c02a..25d0d5871 100644
--- a/include/quest_log.h
+++ b/include/quest_log.h
@@ -49,5 +49,6 @@ void *QuestLogGetFlagOrVarPtr(bool8 isFlag, u16 idx);
 void QuestLogSetFlagOrVar(bool8 isFlag, u16 idx, u16 value);
 void sub_8110840(void *oldSave);
 void sub_8112F18(u8 windowId);
+bool8 sub_8111C2C(void);
 
 #endif //GUARD_QUEST_LOG_H
diff --git a/ld_script.txt b/ld_script.txt
index d15778e06..a11f859f9 100644
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -122,6 +122,7 @@ SECTIONS {
         src/field_screen_effect.o(.text);
         src/battle_setup.o(.text);
         asm/cable_club.o(.text);
+        src/trainer_see.o(.text);
         asm/trainer_see.o(.text);
         src/wild_encounter.o(.text);
         asm/field_effect.o(.text);
@@ -444,6 +445,7 @@ SECTIONS {
         src/field_screen_effect.o(.rodata);
         src/battle_setup.o(.rodata);
         data/cable_club.o(.rodata);
+        src/trainer_see.o(.rodata);
         data/trainer_see.o(.rodata);
         src/wild_encounter.o(.rodata);
         data/field_effect.o(.rodata);
diff --git a/src/quest_log_objects.c b/src/quest_log_objects.c
index aecc5fd68..e029632f3 100644
--- a/src/quest_log_objects.c
+++ b/src/quest_log_objects.c
@@ -39,8 +39,8 @@ void SetQuestLogObjectEventsData(struct QuestLog * questLog)
         questLog->unk_008[i].localId = gObjectEvents[i].localId;
         questLog->unk_008[i].mapNum = gObjectEvents[i].mapNum;
         questLog->unk_008[i].mapGroup = gObjectEvents[i].mapGroup;
-        questLog->unk_008[i].x = gObjectEvents[i].coords2.x;
-        questLog->unk_008[i].y = gObjectEvents[i].coords2.y;
+        questLog->unk_008[i].x = gObjectEvents[i].currentCoords.x;
+        questLog->unk_008[i].y = gObjectEvents[i].currentCoords.y;
         questLog->unk_008[i].trainerRange_berryTreeId = gObjectEvents[i].trainerRange_berryTreeId;
         questLog->unk_008[i].mapobj_unk_1F = gObjectEvents[i].mapobj_unk_1F;
         questLog->unk_008[i].mapobj_unk_21 = gObjectEvents[i].mapobj_unk_21;
@@ -83,8 +83,8 @@ void sub_815A1F8(const struct QuestLog * questLog, const struct ObjectEventTempl
         gObjectEvents[i].localId = questLogObjectEvents[i].localId;
         gObjectEvents[i].mapNum = questLogObjectEvents[i].mapNum;
         gObjectEvents[i].mapGroup = questLogObjectEvents[i].mapGroup;
-        gObjectEvents[i].coords2.x = questLogObjectEvents[i].x;
-        gObjectEvents[i].coords2.y = questLogObjectEvents[i].y;
+        gObjectEvents[i].currentCoords.x = questLogObjectEvents[i].x;
+        gObjectEvents[i].currentCoords.y = questLogObjectEvents[i].y;
         gObjectEvents[i].trainerRange_berryTreeId = questLogObjectEvents[i].trainerRange_berryTreeId;
         gObjectEvents[i].mapobj_unk_1F = questLogObjectEvents[i].mapobj_unk_1F;
         gObjectEvents[i].mapobj_unk_21 = questLogObjectEvents[i].mapobj_unk_21;
@@ -94,38 +94,38 @@ void sub_815A1F8(const struct QuestLog * questLog, const struct ObjectEventTempl
         {
             if (gObjectEvents[i].localId == templates[j].localId)
             {
-                gObjectEvents[i].coords1.x = templates[j].x + 7;
-                gObjectEvents[i].coords1.y = templates[j].y + 7;
+                gObjectEvents[i].initialCoords.x = templates[j].x + 7;
+                gObjectEvents[i].initialCoords.y = templates[j].y + 7;
                 gObjectEvents[i].range.as_nybbles.x = templates[j].movementRangeX;
                 gObjectEvents[i].range.as_nybbles.y = templates[j].movementRangeY;
             }
         }
 
-        gObjectEvents[i].mapobj_unk_1E = MapGridGetMetatileBehaviorAt(gObjectEvents[i].coords2.x, gObjectEvents[i].coords2.y);
-        if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].coords2.x), (s16)(gObjectEvents[i].coords2.y)))
+        gObjectEvents[i].mapobj_unk_1E = MapGridGetMetatileBehaviorAt(gObjectEvents[i].currentCoords.x, gObjectEvents[i].currentCoords.y);
+        if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].currentCoords.x), (s16)(gObjectEvents[i].currentCoords.y)))
         {
-            gObjectEvents[i].coords3.x = gObjectEvents[i].coords2.x;
-            gObjectEvents[i].coords3.y = gObjectEvents[i].coords2.y;
+            gObjectEvents[i].previousCoords.x = gObjectEvents[i].currentCoords.x;
+            gObjectEvents[i].previousCoords.y = gObjectEvents[i].currentCoords.y;
         }
-        else if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].coords2.x - 1), (s16)(gObjectEvents[i].coords2.y)))
+        else if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].currentCoords.x - 1), (s16)(gObjectEvents[i].currentCoords.y)))
         {
-            gObjectEvents[i].coords3.x = gObjectEvents[i].coords2.x - 1;
-            gObjectEvents[i].coords3.y = gObjectEvents[i].coords2.y;
+            gObjectEvents[i].previousCoords.x = gObjectEvents[i].currentCoords.x - 1;
+            gObjectEvents[i].previousCoords.y = gObjectEvents[i].currentCoords.y;
         }
-        else if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].coords2.x + 1), (s16)(gObjectEvents[i].coords2.y)))
+        else if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].currentCoords.x + 1), (s16)(gObjectEvents[i].currentCoords.y)))
         {
-            gObjectEvents[i].coords3.x = gObjectEvents[i].coords2.x + 1;
-            gObjectEvents[i].coords3.y = gObjectEvents[i].coords2.y;
+            gObjectEvents[i].previousCoords.x = gObjectEvents[i].currentCoords.x + 1;
+            gObjectEvents[i].previousCoords.y = gObjectEvents[i].currentCoords.y;
         }
-        else if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].coords2.x), (s16)(gObjectEvents[i].coords2.y - 1)))
+        else if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].currentCoords.x), (s16)(gObjectEvents[i].currentCoords.y - 1)))
         {
-            gObjectEvents[i].coords3.x = gObjectEvents[i].coords2.x;
-            gObjectEvents[i].coords3.y = gObjectEvents[i].coords2.y - 1;
+            gObjectEvents[i].previousCoords.x = gObjectEvents[i].currentCoords.x;
+            gObjectEvents[i].previousCoords.y = gObjectEvents[i].currentCoords.y - 1;
         }
-        else if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].coords2.x), (s16)(gObjectEvents[i].coords2.y + 1)))
+        else if (gObjectEvents[i].mapobj_unk_1F == MapGridGetMetatileBehaviorAt((s16)(gObjectEvents[i].currentCoords.x), (s16)(gObjectEvents[i].currentCoords.y + 1)))
         {
-            gObjectEvents[i].coords3.x = gObjectEvents[i].coords2.x;
-            gObjectEvents[i].coords3.y = gObjectEvents[i].coords2.y + 1;
+            gObjectEvents[i].previousCoords.x = gObjectEvents[i].currentCoords.x;
+            gObjectEvents[i].previousCoords.y = gObjectEvents[i].currentCoords.y + 1;
         }
     }
 
diff --git a/src/quest_log_player.c b/src/quest_log_player.c
index 0d7a2bb50..d66c677d8 100644
--- a/src/quest_log_player.c
+++ b/src/quest_log_player.c
@@ -145,8 +145,8 @@ static void sub_8150708(void)
         sub_81507BC(objectEvent, sub_805C808(2));
         ObjectEventTurn(objectEvent, objectEvent->placeholder18);
         SetPlayerAvatarStateMask(PLAYER_AVATAR_FLAG_SURFING);
-        gFieldEffectArguments[0] = objectEvent->coords2.x;
-        gFieldEffectArguments[1] = objectEvent->coords2.y;
+        gFieldEffectArguments[0] = objectEvent->currentCoords.x;
+        gFieldEffectArguments[1] = objectEvent->currentCoords.y;
         gFieldEffectArguments[2] = gPlayerAvatar.objectEventId;
         fieldEffectId = FieldEffectStart(FLDEFF_SURF_BLOB);
         objectEvent->mapobj_unk_1A = fieldEffectId;
diff --git a/src/trainer_see.c b/src/trainer_see.c
new file mode 100644
index 000000000..a04fe83ec
--- /dev/null
+++ b/src/trainer_see.c
@@ -0,0 +1,174 @@
+#include "global.h"
+#include "battle_setup.h"
+#include "field_player_avatar.h"
+#include "event_object_movement.h"
+#include "quest_log.h"
+#include "constants/battle_setup.h"
+
+static bool8 CheckTrainer(u8 objectEventId);
+static u8 GetTrainerApproachDistance(struct ObjectEvent * objectEvent);
+static u8 GetTrainerApproachDistanceSouth(struct ObjectEvent * objectEvent, s16 range, s16 x, s16 y);
+static u8 GetTrainerApproachDistanceNorth(struct ObjectEvent * objectEvent, s16 range, s16 x, s16 y);
+static u8 GetTrainerApproachDistanceWest(struct ObjectEvent * objectEvent, s16 range, s16 x, s16 y);
+static u8 GetTrainerApproachDistanceEast(struct ObjectEvent * objectEvent, s16 range, s16 x, s16 y);
+static u8 CheckPathBetweenTrainerAndPlayer(struct ObjectEvent * objectEvent, u8 approachDistance, u8 facingDirection);
+void sub_8081E68(struct ObjectEvent * objectEvent, u8 approachDistance);
+
+const u16 gUnknown_83C6AC8[] = INCBIN_U16("graphics/object_events/emoticons.4bpp");
+
+u8 (*const sDirectionalApproachDistanceFuncs[])(struct ObjectEvent *, s16 range, s16 x, s16 y) = {
+    GetTrainerApproachDistanceSouth,
+    GetTrainerApproachDistanceNorth,
+    GetTrainerApproachDistanceWest,
+    GetTrainerApproachDistanceEast
+};
+
+bool8 CheckForTrainersWantingBattle(void)
+{
+    u8 i;
+    if (sub_8111C2C() == TRUE)
+        return FALSE;
+
+    for (i = 0; i < OBJECT_EVENTS_COUNT; i++)
+    {
+        if (gObjectEvents[i].active
+         && (
+             gObjectEvents[i].trainerType == 1
+          || gObjectEvents[i].trainerType == 3
+         )
+         && CheckTrainer(i)
+      )
+            return TRUE;
+    }
+    return FALSE;
+}
+
+static bool8 CheckTrainer(u8 objectEventId)
+{
+    const u8 *script = GetObjectEventScriptPointerByObjectEventId(objectEventId);
+    u8 approachDistance;
+    if (GetTrainerFlagFromScriptPointer(script))
+        return FALSE;
+    approachDistance = GetTrainerApproachDistance(&gObjectEvents[objectEventId]);
+    if (approachDistance != 0)
+    {
+        if (script[1] == TRAINER_BATTLE_DOUBLE && GetMonsStateToDoubles())
+            return FALSE;
+        ConfigureAndSetUpOneTrainerBattle(objectEventId, script);
+        sub_8081E68(&gObjectEvents[objectEventId], approachDistance - 1);
+        return TRUE;
+    }
+    return FALSE;
+}
+
+static u8 GetTrainerApproachDistance(struct ObjectEvent *trainerObj)
+{
+    s16 x, y;
+    u8 i;
+    u8 approachDistance;
+
+    PlayerGetDestCoords(&x, &y);
+    if (trainerObj->trainerType == 1)  // can only see in one direction
+    {
+        approachDistance = sDirectionalApproachDistanceFuncs[trainerObj->facingDirection - 1](trainerObj, trainerObj->trainerRange_berryTreeId, x, y);
+        return CheckPathBetweenTrainerAndPlayer(trainerObj, approachDistance, trainerObj->facingDirection);
+    }
+    else  // can see in all directions
+    {
+        for (i = 0; i < 4; i++)
+        {
+            approachDistance = sDirectionalApproachDistanceFuncs[i](trainerObj, trainerObj->trainerRange_berryTreeId, x, y);
+            if (CheckPathBetweenTrainerAndPlayer(trainerObj, approachDistance, i + 1)) // directions are 1-4 instead of 0-3. south north west east
+                return approachDistance;
+        }
+    }
+
+    return 0;
+}
+
+// Returns how far south the player is from trainer. 0 if out of trainer's sight.
+static u8 GetTrainerApproachDistanceSouth(struct ObjectEvent *trainerObj, s16 range, s16 x, s16 y)
+{
+    if (trainerObj->currentCoords.x == x
+        && y > trainerObj->currentCoords.y
+        && y <= trainerObj->currentCoords.y + range)
+    {
+        if (range > 3 && sub_805DF30() == OBJECT_EVENTS_COUNT)
+            return 0;
+        return (y - trainerObj->currentCoords.y);
+    }
+    else
+        return 0;
+}
+
+// Returns how far north the player is from trainer. 0 if out of trainer's sight.
+static u8 GetTrainerApproachDistanceNorth(struct ObjectEvent *trainerObj, s16 range, s16 x, s16 y)
+{
+    if (trainerObj->currentCoords.x == x
+        && y < trainerObj->currentCoords.y
+        && y >= trainerObj->currentCoords.y - range)
+        return (trainerObj->currentCoords.y - y);
+    else
+        return 0;
+}
+
+// Returns how far west the player is from trainer. 0 if out of trainer's sight.
+static u8 GetTrainerApproachDistanceWest(struct ObjectEvent *trainerObj, s16 range, s16 x, s16 y)
+{
+    if (trainerObj->currentCoords.y == y
+        && x < trainerObj->currentCoords.x
+        && x >= trainerObj->currentCoords.x - range)
+        return (trainerObj->currentCoords.x - x);
+    else
+        return 0;
+}
+
+// Returns how far east the player is from trainer. 0 if out of trainer's sight.
+static u8 GetTrainerApproachDistanceEast(struct ObjectEvent *trainerObj, s16 range, s16 x, s16 y)
+{
+    if (trainerObj->currentCoords.y == y
+        && x > trainerObj->currentCoords.x
+        && x <= trainerObj->currentCoords.x + range)
+        return (x - trainerObj->currentCoords.x);
+    else
+        return 0;
+}
+
+#define COLLISION_MASK (~1)
+
+static u8 CheckPathBetweenTrainerAndPlayer(struct ObjectEvent *trainerObj, u8 approachDistance, u8 direction)
+{
+    s16 x, y;
+    u8 unk19_temp;
+    u8 unk19b_temp;
+    u8 i;
+    u8 collision;
+
+    if (approachDistance == 0)
+        return 0;
+
+    x = trainerObj->currentCoords.x;
+    y = trainerObj->currentCoords.y;
+
+    for (i = 0; i <= approachDistance - 1; i++, MoveCoords(direction, &x, &y))
+    {
+        collision = GetCollisionFlagsAtCoords(trainerObj, x, y, direction);
+        if (collision != 0 && (collision & COLLISION_MASK))
+            return 0;
+    }
+
+    // preserve mapobj_unk_19 before clearing.
+    unk19_temp = trainerObj->range.as_nybbles.x;
+    unk19b_temp = trainerObj->range.as_nybbles.y;
+    trainerObj->range.as_nybbles.x = 0;
+    trainerObj->range.as_nybbles.y = 0;
+
+    collision = GetCollisionAtCoords(trainerObj, x, y, direction);
+
+    trainerObj->range.as_nybbles.x = unk19_temp;
+    trainerObj->range.as_nybbles.y = unk19b_temp;
+    if (collision == 4)
+        return approachDistance;
+
+    return 0;
+}
diff --git a/src/vs_seeker.c b/src/vs_seeker.c
index 9c9a4d67f..221108a8f 100644
--- a/src/vs_seeker.c
+++ b/src/vs_seeker.c
@@ -798,8 +798,8 @@ static void GatherNearbyTrainerInfo(void)
             sVsSeeker->trainerInfo[vsSeekerObjectIdx].localId = templates[objectEventIdx].localId;
             TryGetObjectEventIdByLocalIdAndMap(templates[objectEventIdx].localId, gSaveBlock1Ptr->location.mapNum, gSaveBlock1Ptr->location.mapGroup, &objectEventId);
             sVsSeeker->trainerInfo[vsSeekerObjectIdx].objectEventId = objectEventId;
-            sVsSeeker->trainerInfo[vsSeekerObjectIdx].xCoord = gObjectEvents[objectEventId].coords2.x - 7;
-            sVsSeeker->trainerInfo[vsSeekerObjectIdx].yCoord = gObjectEvents[objectEventId].coords2.y - 7;
+            sVsSeeker->trainerInfo[vsSeekerObjectIdx].xCoord = gObjectEvents[objectEventId].currentCoords.x - 7;
+            sVsSeeker->trainerInfo[vsSeekerObjectIdx].yCoord = gObjectEvents[objectEventId].currentCoords.y - 7;
             sVsSeeker->trainerInfo[vsSeekerObjectIdx].graphicsId = templates[objectEventIdx].graphicsId;
             vsSeekerObjectIdx++;
         }