ref: 2910b9a6c21862ed422227846481fafff15a8f7c
dir: /engine/overworld/npc_movement.asm/
CanObjectMoveInDirection: ld hl, OBJECT_PALETTE add hl, bc bit SWIMMING_F, [hl] jr z, .not_swimming ld hl, OBJECT_FLAGS1 add hl, bc bit NOCLIP_TILES_F, [hl] ; lost, uncomment next line to fix ; jr nz, .noclip_tiles push hl push bc call WillObjectBumpIntoLand pop bc pop hl ret c jr .continue .not_swimming ld hl, OBJECT_FLAGS1 add hl, bc bit NOCLIP_TILES_F, [hl] jr nz, .noclip_tiles push hl push bc call WillObjectBumpIntoWater pop bc pop hl ret c .noclip_tiles .continue bit NOCLIP_OBJS_F, [hl] jr nz, .noclip_objs push hl push bc call WillObjectBumpIntoSomeoneElse pop bc pop hl ret c .noclip_objs bit MOVE_ANYWHERE_F, [hl] jr nz, .move_anywhere push hl call HasObjectReachedMovementLimit pop hl ret c push hl call IsObjectMovingOffEdgeOfScreen pop hl ret c .move_anywhere and a ret WillObjectBumpIntoWater: call CanObjectLeaveTile ret c ld hl, OBJECT_NEXT_MAP_X add hl, bc ld d, [hl] ld hl, OBJECT_NEXT_MAP_Y add hl, bc ld e, [hl] ld hl, OBJECT_PALETTE add hl, bc bit OAM_PRIORITY, [hl] jp nz, WillObjectRemainOnWater ld hl, OBJECT_NEXT_TILE add hl, bc ld a, [hl] ld d, a call GetTileCollision and a ; LAND_TILE jr z, WillObjectBumpIntoTile scf ret WillObjectBumpIntoLand: call CanObjectLeaveTile ret c ld hl, OBJECT_NEXT_TILE add hl, bc ld a, [hl] call GetTileCollision cp WATER_TILE jr z, WillObjectBumpIntoTile scf ret WillObjectBumpIntoTile: ld hl, OBJECT_NEXT_TILE add hl, bc ld a, [hl] call GetSideWallDirectionMask ret nc push af ld hl, OBJECT_DIRECTION_WALKING add hl, bc ld a, [hl] maskbits NUM_DIRECTIONS ld e, a ld d, 0 ld hl, .dir_masks add hl, de pop af and [hl] ret z scf ret .dir_masks db DOWN_MASK ; DOWN db UP_MASK ; UP db RIGHT_MASK ; LEFT db LEFT_MASK ; RIGHT CanObjectLeaveTile: ld hl, OBJECT_STANDING_TILE add hl, bc ld a, [hl] call GetSideWallDirectionMask ret nc push af ld hl, OBJECT_DIRECTION_WALKING add hl, bc maskbits NUM_DIRECTIONS ld e, a ld d, 0 ld hl, .dir_masks add hl, de pop af and [hl] ret z scf ret .dir_masks db UP_MASK ; DOWN db DOWN_MASK ; UP db LEFT_MASK ; LEFT db RIGHT_MASK ; RIGHT GetSideWallDirectionMask: ld d, a and $f0 cp HI_NYBBLE_SIDE_WALLS jr z, .continue cp HI_NYBBLE_SIDE_BUOYS jr z, .continue xor a ret .continue ld a, d and $7 ld e, a ld d, 0 ld hl, .side_wall_masks add hl, de ld a, [hl] scf ret .side_wall_masks db RIGHT_MASK ; COLL_RIGHT_WALL/BUOY db LEFT_MASK ; COLL_LEFT_WALL/BUOY db DOWN_MASK ; COLL_UP_WALL/BUOY db UP_MASK ; COLL_DOWN_WALL/BUOY db UP_MASK | RIGHT_MASK ; COLL_DOWN_RIGHT_WALL/BUOY db UP_MASK | LEFT_MASK ; COLL_DOWN_LEFT_WALL/BUOY db DOWN_MASK | RIGHT_MASK ; COLL_UP_RIGHT_WALL/BUOY db DOWN_MASK | LEFT_MASK ; COLL_UP_LEFT_WALL/BUOY WillObjectRemainOnWater: ld hl, OBJECT_DIRECTION_WALKING add hl, bc ld a, [hl] maskbits NUM_DIRECTIONS jr z, .down dec a jr z, .up dec a jr z, .left jr .right .down inc e push de inc d jr .continue .up push de inc d jr .continue .left push de inc e jr .continue .right inc d push de inc e .continue call GetCoordTile call GetTileCollision pop de and a ; LAND_TILE jr nz, .not_land call GetCoordTile call GetTileCollision and a ; LAND_TILE jr nz, .not_land xor a ret .not_land scf ret CheckFacingObject:: call GetFacingTileCoord ; Double the distance for counter tiles. call CheckCounterTile jr nz, .not_counter ld a, [wPlayerStandingMapX] sub d cpl inc a add d ld d, a ld a, [wPlayerStandingMapY] sub e cpl inc a add e ld e, a .not_counter ld bc, wObjectStructs ; redundant ld a, 0 ldh [hMapObjectIndex], a call IsNPCAtCoord ret nc ld hl, OBJECT_DIRECTION_WALKING add hl, bc ld a, [hl] cp STANDING jr z, .standing xor a ret .standing scf ret WillObjectBumpIntoSomeoneElse: ld hl, OBJECT_NEXT_MAP_X add hl, bc ld d, [hl] ld hl, OBJECT_NEXT_MAP_Y add hl, bc ld e, [hl] jr IsNPCAtCoord IsObjectFacingSomeoneElse: ; unreferenced ldh a, [hMapObjectIndex] call GetObjectStruct call .GetFacingCoords call IsNPCAtCoord ret .GetFacingCoords: ld hl, OBJECT_NEXT_MAP_X add hl, bc ld d, [hl] ld hl, OBJECT_NEXT_MAP_Y add hl, bc ld e, [hl] call GetSpriteDirection and a ; OW_DOWN? jr z, .down cp OW_UP jr z, .up cp OW_LEFT jr z, .left ; OW_RIGHT inc d ret .down inc e ret .up dec e ret .left dec d ret IsNPCAtCoord: ld bc, wObjectStructs xor a .loop ldh [hObjectStructIndex], a call DoesObjectHaveASprite jr z, .next ld hl, OBJECT_FLAGS1 add hl, bc bit 7, [hl] jr nz, .next ld hl, OBJECT_PALETTE add hl, bc bit BIG_OBJECT_F, [hl] jr z, .not_big call WillObjectIntersectBigObject jr nc, .check_current_coords jr .continue .not_big ld hl, OBJECT_NEXT_MAP_X add hl, bc ld a, [hl] cp d jr nz, .check_current_coords ld hl, OBJECT_NEXT_MAP_Y add hl, bc ld a, [hl] cp e jr nz, .check_current_coords .continue ldh a, [hMapObjectIndex] ld l, a ldh a, [hObjectStructIndex] cp l jr nz, .yes .check_current_coords ld hl, OBJECT_MAP_X add hl, bc ld a, [hl] cp d jr nz, .next ld hl, OBJECT_MAP_Y add hl, bc ld a, [hl] cp e jr nz, .next ldh a, [hMapObjectIndex] ld l, a ldh a, [hObjectStructIndex] cp l jr nz, .yes .next ld hl, OBJECT_LENGTH add hl, bc ld b, h ld c, l ldh a, [hObjectStructIndex] inc a cp NUM_OBJECT_STRUCTS jr nz, .loop and a ret .yes scf ret HasObjectReachedMovementLimit: ld hl, OBJECT_RADIUS add hl, bc ld a, [hl] and a jr z, .nope and $f jr z, .check_y ld e, a ld d, a ld hl, OBJECT_INIT_X add hl, bc ld a, [hl] sub d ld d, a ld a, [hl] add e ld e, a ld hl, OBJECT_NEXT_MAP_X add hl, bc ld a, [hl] cp d jr z, .yes cp e jr z, .yes .check_y ld hl, OBJECT_RADIUS add hl, bc ld a, [hl] swap a and $f jr z, .nope ld e, a ld d, a ld hl, OBJECT_INIT_Y add hl, bc ld a, [hl] sub d ld d, a ld a, [hl] add e ld e, a ld hl, OBJECT_NEXT_MAP_Y add hl, bc ld a, [hl] cp d jr z, .yes cp e jr z, .yes .nope xor a ret .yes scf ret IsObjectMovingOffEdgeOfScreen: ld hl, OBJECT_NEXT_MAP_X add hl, bc ld a, [wXCoord] cp [hl] jr z, .check_y jr nc, .yes add $9 cp [hl] jr c, .yes .check_y ld hl, OBJECT_NEXT_MAP_Y add hl, bc ld a, [wYCoord] cp [hl] jr z, .nope jr nc, .yes add $8 cp [hl] jr c, .yes .nope and a ret .yes scf ret IsNPCAtPlayerCoord: ; unreferenced ld a, [wPlayerStandingMapX] ld d, a ld a, [wPlayerStandingMapY] ld e, a ld bc, wObjectStructs xor a .loop ldh [hObjectStructIndex], a call DoesObjectHaveASprite jr z, .next ld hl, OBJECT_MOVEMENTTYPE add hl, bc ld a, [hl] cp SPRITEMOVEDATA_BIGDOLLSYM jr nz, .not_big call WillObjectIntersectBigObject jr c, .yes jr .next .not_big ld hl, OBJECT_NEXT_MAP_Y add hl, bc ld a, [hl] cp e jr nz, .check_current_coords ld hl, OBJECT_NEXT_MAP_X add hl, bc ld a, [hl] cp d jr nz, .check_current_coords ldh a, [hObjectStructIndex] cp PLAYER_OBJECT jr z, .next jr .yes .check_current_coords ld hl, OBJECT_MAP_Y add hl, bc ld a, [hl] cp e jr nz, .next ld hl, OBJECT_MAP_X add hl, bc ld a, [hl] cp d jr nz, .next jr .yes .next ld hl, OBJECT_LENGTH add hl, bc ld b, h ld c, l ldh a, [hObjectStructIndex] inc a cp NUM_OBJECT_STRUCTS jr nz, .loop xor a ret .yes scf ret WillObjectIntersectBigObject: ld hl, OBJECT_NEXT_MAP_X add hl, bc ld a, d sub [hl] jr c, .nope cp 2 ; big doll width jr nc, .nope ld hl, OBJECT_NEXT_MAP_Y add hl, bc ld a, e sub [hl] jr c, .nope cp 2 ; big doll height jr nc, .nope scf ret .nope and a ret