ref: 9e368eee1f2f14e0d7e13f0d41dc89292051ec56
dir: /home/map_objects.asm/
; Functions handling map objects. GetSpritePalette:: ; 17ff push hl push de push bc ld c, a farcall _GetSpritePalette ld a, c pop bc pop de pop hl ret ; 180e GetSpriteVTile:: ; 180e push hl push bc ld hl, UsedSprites + 2 ld c, SPRITE_GFX_LIST_CAPACITY - 1 ld b, a ld a, [hMapObjectIndexBuffer] cp 0 jr z, .nope ld a, b .loop cp [hl] jr z, .found inc hl inc hl dec c jr nz, .loop ld a, [UsedSprites + 1] scf jr .done .nope ld a, [UsedSprites + 1] jr .done .found inc hl xor a ld a, [hl] .done pop bc pop hl ret ; 1836 DoesSpriteHaveFacings:: ; 1836 push de push hl ld b, a ld a, [hROMBank] push af ld a, BANK(_DoesSpriteHaveFacings) rst Bankswitch ld a, b call _DoesSpriteHaveFacings ld c, a pop de ld a, d rst Bankswitch pop hl pop de ret ; 184a GetPlayerStandingTile:: ; 184a ld a, [PlayerStandingTile] call GetTileCollision ld b, a ret ; 1852 CheckOnWater:: ; 1852 ld a, [PlayerStandingTile] call GetTileCollision sub WATERTILE ret z and a ret ; 185d GetTileCollision:: ; 185d ; Get the collision type of tile a. push de push hl ld hl, TileCollisionTable ld e, a ld d, 0 add hl, de ld a, [hROMBank] push af ld a, BANK(TileCollisionTable) rst Bankswitch ld e, [hl] pop af rst Bankswitch ld a, e and $f ; lo nybble only pop hl pop de ret ; 1875 CheckGrassTile:: ; 1875 ld d, a and $f0 cp HI_NYBBLE_TALL_GRASS jr z, .grass cp HI_NYBBLE_WATER jr z, .water scf ret .grass ld a, d and LO_NYBBLE_GRASS ret z scf ret ; For some reason, the above code is duplicated down here. .water ld a, d and LO_NYBBLE_GRASS ret z scf ret ; 188e CheckSuperTallGrassTile:: ; 188e cp COLL_LONG_GRASS ret z cp COLL_LONG_GRASS_1C ret ; 1894 CheckCutTreeTile:: ; 1894 cp COLL_CUT_TREE ret z cp COLL_CUT_TREE_1A ret ; 189a CheckHeadbuttTreeTile:: ; 189a cp COLL_HEADBUTT_TREE ret z cp COLL_HEADBUTT_TREE_1D ret ; 18a0 CheckCounterTile:: ; 18a0 cp COLL_COUNTER ret z cp COLL_COUNTER_98 ret ; 18a6 CheckPitTile:: ; 18a6 cp COLL_PIT ret z cp COLL_PIT_68 ret ; 18ac CheckIceTile:: ; 18ac cp COLL_ICE ret z cp COLL_ICE_2B ret z scf ret ; 18b4 CheckWhirlpoolTile:: ; 18b4 nop cp COLL_WHIRLPOOL ret z cp COLL_WHIRLPOOL_2C ret z scf ret ; 18bd CheckWaterfallTile:: ; 18bd cp COLL_WATERFALL ret z cp COLL_CURRENT_DOWN ret ; 18c3 CheckStandingOnEntrance:: ; 18c3 ld a, [PlayerStandingTile] cp COLL_DOOR ret z cp COLL_DOOR_79 ret z cp COLL_STAIRCASE ret z cp COLL_CAVE ret ; 18d2 GetMapObject:: ; 18d2 ; Return the location of map object a in bc. ld hl, MapObjects ld bc, OBJECT_LENGTH call AddNTimes ld b, h ld c, l ret ; 18de CheckObjectVisibility:: ; 18de ; Sets carry if the object is not visible on the screen. ld [hMapObjectIndexBuffer], a call GetMapObject ld hl, MAPOBJECT_OBJECT_STRUCT_ID add hl, bc ld a, [hl] cp -1 jr z, .not_visible ld [hObjectStructIndexBuffer], a call GetObjectStruct and a ret .not_visible scf ret ; 18f5 CheckObjectTime:: ; 18f5 ld hl, MAPOBJECT_HOUR add hl, bc ld a, [hl] cp -1 jr nz, .check_hour ld hl, MAPOBJECT_TIMEOFDAY add hl, bc ld a, [hl] cp -1 jr z, .timeofday_always ld hl, .TimeOfDayValues_191e ld a, [TimeOfDay] add l ld l, a jr nc, .ok inc h .ok ld a, [hl] ld hl, MAPOBJECT_TIMEOFDAY add hl, bc and [hl] jr nz, .timeofday_always scf ret .timeofday_always and a ret .TimeOfDayValues_191e: ; entries correspond to TimeOfDay values db MORN db DAY db NITE .check_hour ld hl, MAPOBJECT_HOUR add hl, bc ld d, [hl] ld hl, MAPOBJECT_TIMEOFDAY add hl, bc ld e, [hl] ld hl, hHours ld a, d cp e jr z, .yes jr c, .check_timeofday ld a, [hl] cp d jr nc, .yes cp e jr c, .yes jr z, .yes jr .no .check_timeofday ld a, e cp [hl] jr c, .no ld a, [hl] cp d jr nc, .yes jr .no .yes and a ret .no scf ret ; 194d ; unused ld [hMapObjectIndexBuffer], a call GetMapObject call CopyObjectStruct ret ; 1956 _CopyObjectStruct:: ; 1956 ld [hMapObjectIndexBuffer], a call UnmaskObject ld a, [hMapObjectIndexBuffer] call GetMapObject farcall CopyObjectStruct ret ; 1967 ApplyDeletionToMapObject:: ; 1967 ld [hMapObjectIndexBuffer], a call GetMapObject ld hl, MAPOBJECT_OBJECT_STRUCT_ID add hl, bc ld a, [hl] cp -1 ret z ; already hidden ld [hl], -1 push af call .CheckStopFollow pop af call GetObjectStruct farcall DeleteMapObject ret .CheckStopFollow: ld hl, wObjectFollow_Leader cp [hl] jr z, .ok ld hl, wObjectFollow_Follower cp [hl] ret nz .ok farcall StopFollow ld a, -1 ld [wObjectFollow_Leader], a ld [wObjectFollow_Follower], a ret ; 199f DeleteObjectStruct:: ; 199f call ApplyDeletionToMapObject call MaskObject ret ; 19a6 CopyPlayerObjectTemplate:: ; 19a6 push hl call GetMapObject ld d, b ld e, c ld a, -1 ld [de], a inc de pop hl ld bc, OBJECT_LENGTH - 1 call CopyBytes ret ; 19b8 Unreferenced_Function19b8: call GetMapObject ld hl, MAPOBJECT_OBJECT_STRUCT_ID add hl, bc ld a, [hl] push af ld [hl], -1 inc hl ld bc, OBJECT_LENGTH - 1 xor a call ByteFill pop af cp -1 ret z cp $d ret nc ld b, a ld a, [wObjectFollow_Leader] cp b jr nz, .ok ld a, -1 ld [wObjectFollow_Leader], a .ok ld a, b call GetObjectStruct farcall DeleteMapObject ret ; 19e9 LoadMovementDataPointer:: ; 19e9 ; Load the movement data pointer for object a. ld [wMovementObject], a ld a, [hROMBank] ld [wMovementDataPointer], a ld a, l ld [wMovementDataPointer + 1], a ld a, h ld [wMovementDataPointer + 2], a ld a, [wMovementObject] call CheckObjectVisibility ret c ld hl, OBJECT_MOVEMENTTYPE add hl, bc ld [hl], SPRITEMOVEDATA_SCRIPTED ld hl, OBJECT_STEP_TYPE add hl, bc ld [hl], STEP_TYPE_00 ld hl, VramState set 7, [hl] and a ret ; 1a13 FindFirstEmptyObjectStruct:: ; 1a13 ; Returns the index of the first empty object struct in A and its address in HL, then sets carry. ; If all object structs are occupied, A = 0 and Z is set. ; Preserves BC and DE. push bc push de ld hl, ObjectStructs ld de, OBJECT_STRUCT_LENGTH ld c, NUM_OBJECT_STRUCTS .loop ld a, [hl] and a jr z, .break add hl, de dec c jr nz, .loop xor a jr .done .break ld a, NUM_OBJECT_STRUCTS sub c scf .done pop de pop bc ret ; 1a2f GetSpriteMovementFunction:: ; 1a2f ld hl, OBJECT_MOVEMENTTYPE add hl, bc ld a, [hl] cp NUM_SPRITEMOVEDATA jr c, .ok xor a .ok ld hl, SpriteMovementData ld e, a ld d, 0 rept SPRITEMOVEDATA_FIELDS add hl, de endr ld a, [hl] ret ; 1a47 GetInitialFacing:: ; 1a47 push bc push de ld e, a ld d, 0 ld hl, SpriteMovementData + 1 ; init facing rept SPRITEMOVEDATA_FIELDS add hl, de endr ld a, BANK(SpriteMovementData) call GetFarByte add a add a and $c pop de pop bc ret ; 1a61 CopySpriteMovementData:: ; 1a61 ld l, a ld a, [hROMBank] push af ld a, BANK(SpriteMovementData) rst Bankswitch ld a, l push bc call .CopyData pop bc pop af rst Bankswitch ret ; 1a71 .CopyData: ; 1a71 ld hl, OBJECT_MOVEMENTTYPE add hl, de ld [hl], a push de ld e, a ld d, 0 ld hl, SpriteMovementData + 1 ; init facing rept SPRITEMOVEDATA_FIELDS add hl, de endr ld b, h ld c, l pop de ld a, [bc] inc bc rlca rlca and %00001100 ld hl, OBJECT_FACING add hl, de ld [hl], a ld a, [bc] inc bc ld hl, OBJECT_ACTION add hl, de ld [hl], a ld a, [bc] inc bc ld hl, OBJECT_FLAGS1 add hl, de ld [hl], a ld a, [bc] inc bc ld hl, OBJECT_FLAGS2 add hl, de ld [hl], a ld a, [bc] inc bc ld hl, OBJECT_PALETTE add hl, de ld [hl], a ret ; 1aae _GetMovementByte:: ; 1aae ; Switch to the movement data bank ld a, [hROMBank] push af ld a, [hli] rst Bankswitch ; Load the current script byte as given by OBJECT_MOVEMENT_BYTE_INDEX, and increment OBJECT_MOVEMENT_BYTE_INDEX ld a, [hli] ld d, [hl] ld hl, OBJECT_MOVEMENT_BYTE_INDEX add hl, bc add [hl] ld e, a ld a, d adc 0 ld d, a inc [hl] ld a, [de] ld h, a pop af rst Bankswitch ld a, h ret ; 1ac6 SetVramState_Bit0:: ; 1ac6 ld hl, VramState set 0, [hl] ret ; 1acc ResetVramState_Bit0:: ; 1acc ld hl, VramState res 0, [hl] ret ; 1ad2 UpdateSprites:: ; 1ad2 ld a, [VramState] bit 0, a ret z farcall Function55e0 farcall _UpdateSprites ret ; 1ae5 GetObjectStruct:: ; 1ae5 ld bc, OBJECT_STRUCT_LENGTH ld hl, ObjectStructs call AddNTimes ld b, h ld c, l ret ; 1af1 DoesObjectHaveASprite:: ; 1af1 ld hl, OBJECT_SPRITE add hl, bc ld a, [hl] and a ret ; 1af8 SetSpriteDirection:: ; 1af8 ; preserves other flags push af ld hl, OBJECT_FACING add hl, bc ld a, [hl] and %11110011 ld e, a pop af and %00001100 or e ld [hl], a ret ; 1b07 GetSpriteDirection:: ; 1b07 ld hl, OBJECT_FACING add hl, bc ld a, [hl] and %00001100 ret ; 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