1 files changed, 494 insertions, 0 deletions
diff --git a/engine/overworld/overworld.asm b/engine/overworld/overworld.asm
new file mode 100644
index 00000000..05b15ea9
--- /dev/null
+++ b/engine/overworld/overworld.asm
@@ -0,0 +1,494 @@
+_ReplaceChrisSprite::
+	call GetChrisSprite
+	ld a, [wUsedSprites]
+	ld c, a
+	ld a, [wUsedSprites + 1]
+	ld b, a
+	call GetUsedSprite
+	ret
+
+_RefreshSprites::
+	ld hl, wSpriteFlags
+	ld a, [hl]
+	push af
+	res 7, [hl]
+	set 6, [hl]
+	call LoadUsedSpritesGFX
+	pop af
+	ld [wSpriteFlags], a
+	ret
+
+_ClearSprites::
+	ld hl, wSpriteFlags
+	ld a, [hl]
+	push af
+	set 7, [hl]
+	res 6, [hl]
+	call LoadUsedSpritesGFX
+	pop af
+	ld [wSpriteFlags], a
+	ret
+
+RefreshSprites::
+	call .Refresh
+	call LoadUsedSpritesGFX
+	ret
+
+.Refresh:
+	xor a
+	ld bc, SPRITE_GFX_LIST_CAPACITY * 2
+	ld hl, wUsedSprites
+	call ByteFill
+	call GetChrisSprite
+	call AddMapSprites
+	ret
+
+GetChrisSprite:
+	ld a, [wPlayerState]
+	ld c, a
+; Get Chris's sprite.
+	ld hl, ChrisStateSprites
+.loop
+	ld a, [hli]
+	cp c
+	jr z, .good
+	inc hl
+	cp -1
+	jr nz, .loop
+
+; Any player state not in the array defaults to Chris's sprite.
+	xor a ; ld a, PLAYER_NORMAL
+	ld [wPlayerState], a
+	ld a, SPRITE_CHRIS
+	jr .finish
+
+.good
+	ld a, [hl]
+
+.finish
+	ld [wUsedSprites + 0], a
+	ld [wPlayerSprite], a
+	ld [wPlayerObjectSprite], a
+	ret
+
+INCLUDE "data/sprites/player_sprites.asm"
+
+AddMapSprites:
+	call GetMapEnvironment
+	call CheckOutdoorMap
+	jr z, .outdoor
+	call AddIndoorSprites
+	ret
+
+.outdoor
+	call AddOutdoorSprites
+	ret
+
+AddIndoorSprites:
+	ld hl, wMap2ObjectSprite
+	ld a, 2
+.loop
+	push af
+	ld a, [hl]
+	call AddSpriteGFX
+	ld de, MAPOBJECT_LENGTH
+	add hl, de
+	pop af
+	inc a
+	cp NUM_OBJECTS
+	jr nz, .loop
+	ret
+
+AddOutdoorSprites:
+	ld a, [wMapGroup]
+	dec a
+	ld c, a
+	ld b, 0
+	ld hl, OutdoorSprites
+	add hl, bc
+	add hl, bc
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld c, MAX_OUTDOOR_SPRITES
+.loop
+	push bc
+	ld a, [hli]
+	call AddSpriteGFX
+	pop bc
+	dec c
+	jr nz, .loop
+
+	ld a, [wUnusedD05A]
+	ld c, a
+	ret
+
+AddSpriteGFX:
+	and a
+	ret z
+	ld c, a
+	call _DoesSpriteHaveFacings
+	jr nc, .nope
+	ld de, wUsedSprites + (SPRITE_GFX_LIST_CAPACITY - 2) * 2
+	ld b, 2
+	call .Loop
+	jr nc, .ok
+.nope
+	ld de, wUsedSprites + 2
+	ld b, SPRITE_GFX_LIST_CAPACITY - 3
+	call .Loop
+	jr .ok
+.ok:
+	ret
+
+.Loop:
+	ld a, [de]
+	and a
+	jr z, .new
+	cp c
+	jr z, .exists
+	inc de
+	inc de
+	dec b
+	jr nz, .Loop
+	scf
+	ret
+.new:
+	ld a, c
+	ld [de], a
+	xor a
+	ret
+.exists:
+	xor a
+	ret
+
+LoadUsedSpritesGFX:
+	ld a, MAPCALLBACK_SPRITES
+	call RunMapCallback
+	call GetUsedSprites
+	ret c
+
+	call _LoadMiscTiles
+	call LoadMiscTiles
+	ret
+
+GetUsedSprites:
+	xor a
+	ldh [hUsedSpriteTile], a
+	ld hl, wUsedSprites
+	ld a, SPRITE_GFX_LIST_CAPACITY - 2
+
+.loop
+	push af
+	ld a, [hli]
+	ldh [hUsedSpriteIndex], a
+	and a
+	jr z, .dont_set
+
+	call GetSprite
+	push hl
+	push bc
+	ldh a, [hUsedSpriteTile]
+	call CopyToVram
+	pop bc
+	pop hl
+	ldh a, [hUsedSpriteTile]
+	ld [hl], a
+	add c
+	ldh [hUsedSpriteTile], a
+	cp $80
+	jr nc, .done
+
+.dont_set
+	inc hl
+	pop af
+	dec a
+	jr nz, .loop
+
+	xor a
+	ret
+
+.done
+	pop af
+	scf
+	ret
+
+_LoadMiscTiles:
+	ld a, [wUsedSprites + (SPRITE_GFX_LIST_CAPACITY - 2) * 2]
+	and a
+	jr z, .asm_14274
+
+	call GetSprite
+	ld hl, vTiles0 tile $78
+	call Get2bpp
+
+.asm_14274
+	ld a, $78
+	ld [wUsedSprites + (SPRITE_GFX_LIST_CAPACITY - 2) * 2 + 1], a
+	ld a, [wUsedSprites + (SPRITE_GFX_LIST_CAPACITY - 1) * 2]
+	and a
+	jr z, .asm_14288
+
+	call GetSprite
+	ld hl, vTiles0 tile $7c
+	call Get2bpp
+
+.asm_14288
+	ld a, $7c
+	ld [wUsedSprites + (SPRITE_GFX_LIST_CAPACITY - 1) * 2 + 1], a
+	ret
+
+LoadMiscTiles:
+	ld a, [wSpriteFlags]
+	bit 6, a
+	ret nz
+
+	ld c, EMOTE_SHADOW
+	farcall LoadEmote
+	call GetMapEnvironment
+	call CheckOutdoorMap
+	ld c, EMOTE_GRASS_RUSTLE
+	jr z, .outdoor
+	ld c, EMOTE_BOULDER_DUST
+.outdoor
+	farcall LoadEmote
+	ret
+
+GetSprite:
+	call GetMonSprite
+	ret c
+
+	push hl
+	ld hl, OverworldSprites + SPRITEDATA_ADDR
+	dec a
+	ld c, a
+	ld b, 0
+	ld a, NUM_SPRITEDATA_FIELDS
+	call AddNTimes
+	ld a, [hli]
+	ld e, a
+	ld a, [hli]
+	ld d, a
+	ld a, [hli]
+	swap a
+	ld c, a
+	ld b, [hl]
+	pop hl
+	ret
+
+GetMonSprite:
+; Return carry if a monster sprite was loaded.
+
+	cp SPRITE_POKEMON
+	jr c, .Normal
+	cp SPRITE_DAY_CARE_MON_1
+	jr z, .BreedMon1
+	cp SPRITE_DAY_CARE_MON_2
+	jr z, .BreedMon2
+	cp SPRITE_VARS
+	jr nc, .Variable
+	jr .Icon
+
+.Normal:
+	and a
+	ret
+
+.Icon:
+	push hl
+	sub SPRITE_POKEMON
+	ld e, a
+	ld d, 0
+	ld hl, SpriteMons
+	add hl, de
+	ld a, [hl]
+	pop hl
+	jr .Mon
+
+.BreedMon1
+	ld a, [wBreedMon1Species]
+	jr .Mon
+
+.BreedMon2
+	ld a, [wBreedMon2Species]
+
+.Mon:
+	ld e, a
+	and a
+	jr z, .NoBreedmon
+
+	push hl
+	farcall LoadOverworldMonIcon
+	pop hl
+
+	scf
+	ret
+
+.Variable:
+	push hl
+	sub SPRITE_VARS
+	ld e, a
+	ld d, 0
+	ld hl, wVariableSprites
+	add hl, de
+	ld a, [hl]
+	pop hl
+	and a
+	jp nz, GetMonSprite
+
+.NoBreedmon:
+	ld a, 1
+	and a
+	ret
+
+_DoesSpriteHaveFacings::
+; Checks to see whether we can apply a facing to a sprite.
+; Returns carry unless the sprite is a Pokemon or a Still Sprite.
+	cp SPRITE_POKEMON
+	jr nc, .only_down
+
+	push hl
+	push bc
+	ld hl, OverworldSprites + SPRITEDATA_TYPE
+	dec a
+	ld c, a
+	ld b, 0
+	ld a, NUM_SPRITEDATA_FIELDS
+	call AddNTimes
+	ld a, [hl]
+	pop bc
+	pop hl
+	cp STILL_SPRITE
+	jr nz, .only_down
+	scf
+	ret
+
+.only_down
+	and a
+	ret
+
+_GetSpritePalette::
+	ld a, c
+	call GetMonSprite
+	jr c, .is_pokemon
+
+	ld hl, OverworldSprites + SPRITEDATA_PALETTE
+	dec a
+	ld c, a
+	ld b, 0
+	ld a, NUM_SPRITEDATA_FIELDS
+	call AddNTimes
+	ld c, [hl]
+	ret
+
+.is_pokemon
+	xor a
+	ld c, a
+	ret
+
+CopyToVram:
+	ld l, a
+	ld h, 0
+rept 4
+	add hl, hl
+endr
+	ld a, l
+	add LOW(vTiles0)
+	ld l, a
+	ld a, h
+	adc HIGH(vTiles0)
+	ld h, a
+	push hl
+	push de
+	push bc
+	ld a, [wSpriteFlags]
+	bit 7, a
+	jr nz, .skip
+	call Get2bpp
+
+.skip:
+	pop bc
+	ld l, c
+	ld h, 0
+rept 4
+	add hl, hl
+endr
+	pop de
+	add hl, de
+	ld e, l
+	ld d, h
+	pop hl
+	ld a, h
+	add HIGH(vTiles1 - vTiles0)
+	ld h, a
+	ldh a, [hUsedSpriteIndex]
+	call _DoesSpriteHaveFacings
+	jr c, .done
+
+	ld a, [wSpriteFlags]
+	bit 6, a
+	jr nz, .done
+
+	call Get2bpp
+
+.done:
+	ret
+
+Unreferenced_Function1438a:
+	ld a, c
+	jr GetUsedSprite
+
+	ld a, c
+	ld b, 0
+	jr GetUsedSprite
+
+	ld a, c
+	ld b, SPRITE_GFX_LIST_CAPACITY
+	jr GetUsedSprite
+
+GetUsedSprite:
+	push bc
+	ld a, c
+	ldh [hUsedSpriteIndex], a
+	call GetSprite
+	pop af
+	call CopyToVram
+	ret
+
+LoadEmote::
+; Get the address of the pointer to emote c.
+	ld a, c
+	ld bc, 6 ; sizeof(emote)
+	ld hl, Emotes
+	call AddNTimes
+; Load the emote address into de
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+; load the length of the emote (in tiles) into c
+	inc hl
+	ld c, [hl]
+	swap c
+; load the emote pointer bank into b
+	inc hl
+	ld b, [hl]
+; load the VRAM destination into hl
+	inc hl
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+; if the emote has a length of 0, do not proceed (error handling)
+	ld a, c
+	and a
+	ret z
+	call Get2bpp
+	ret
+
+INCLUDE "data/sprites/emotes.asm"
+
+INCLUDE "gfx/emotes.asm"
+
+INCLUDE "data/sprites/sprite_mons.asm"
+
+INCLUDE "data/maps/outdoor_sprites.asm"
+
+INCLUDE "data/sprites/sprites.asm"