Organize the engine/ directory

This is an informed attempt at reorganizing the engine/ directory by
creating categorized subdirectories, in order to make it easier to
navigate and find things.

The directories created are as follows:
* engine/game: Contains all "minigames", things like the unown puzzle
and slot machine.
* engine/gfx: Contains all handling of graphics. From loading palettes
to playing animations.
* engine/link: Contains all multiplayer functionality.
* engine/menu: Contains all generic/misc. menus and menu code.
Other, more specialized menus are in their own subdirectories (pokedex,
pokegear, party menu, etc).
* engine/overworld: Contains all handling of the overworld. From loading
and connecting maps to wild encounters and the scripting engine.
* engine/pokegear: In the same vein as engine/pokedex, except it could
use some more splitting up.
* engine/pokemon: Contains everything related to manipulating pokemon
data. From the pokemon storage system to evolution and mail.
* engine/printer: Contains everything related to printing things as well
as the printer communication.
* engine/title: Contains intro sequences, title screens and credits.

engine/overworld/player_object.asm

@@ -0,0 +1,856 @@
+BlankScreen: ; 8000
+	call DisableSpriteUpdates
+	xor a
+	ld [hBGMapMode], a
+	call ClearBGPalettes
+	call ClearSprites
+	hlcoord 0, 0
+	ld bc, wTileMapEnd - wTileMap
+	ld a, " "
+	call ByteFill
+	hlcoord 0, 0, wAttrMap
+	ld bc, wAttrMapEnd - wAttrMap
+	ld a, $7
+	call ByteFill
+	call WaitBGMap2
+	call SetPalettes
+	ret
+
+SpawnPlayer: ; 8029
+	ld a, -1
+	ld [wObjectFollow_Leader], a
+	ld [wObjectFollow_Follower], a
+	ld a, $0
+	ld hl, PlayerObjectTemplate
+	call CopyPlayerObjectTemplate
+	ld b, $0
+	call PlayerSpawn_ConvertCoords
+	ld a, PLAYER_OBJECT
+	call GetMapObject
+	ld hl, MAPOBJECT_COLOR
+	add hl, bc
+	ln e, PAL_NPC_RED, OBJECTTYPE_SCRIPT
+	ld a, [wPlayerSpriteSetupFlags]
+	bit PLAYERSPRITESETUP_FEMALE_TO_MALE_F, a
+	jr nz, .ok
+	ld a, [wPlayerGender]
+	bit PLAYERGENDER_FEMALE_F, a
+	jr z, .ok
+	ln e, PAL_NPC_BLUE, OBJECTTYPE_SCRIPT
+
+.ok
+	ld [hl], e
+	ld a, PLAYER_OBJECT
+	ld [hMapObjectIndexBuffer], a
+	ld bc, wMapObjects
+	ld a, PLAYER_OBJECT
+	ld [hObjectStructIndexBuffer], a
+	ld de, wObjectStructs
+	call CopyMapObjectToObjectStruct
+	ld a, PLAYER
+	ld [wCenteredObject], a
+	ret
+
+PlayerObjectTemplate: ; 8071
+; A dummy map object used to initialize the player object.
+; Shorter than the actual amount copied by two bytes.
+; Said bytes seem to be unused.
+	object_event -4, -4, SPRITE_CHRIS, SPRITEMOVEDATA_PLAYER, 15, 15, -1, -1, 0, OBJECTTYPE_SCRIPT, 0, 0, -1
+
+CopyDECoordsToMapObject:: ; 807e
+	push de
+	ld a, b
+	call GetMapObject
+	pop de
+	ld hl, MAPOBJECT_X_COORD
+	add hl, bc
+	ld [hl], d
+	ld hl, MAPOBJECT_Y_COORD
+	add hl, bc
+	ld [hl], e
+	ret
+
+PlayerSpawn_ConvertCoords: ; 808f
+	push bc
+	ld a, [wXCoord]
+	add 4
+	ld d, a
+	ld a, [wYCoord]
+	add 4
+	ld e, a
+	pop bc
+	call CopyDECoordsToMapObject
+	ret
+
+WriteObjectXY:: ; 80a1
+	ld a, b
+	call CheckObjectVisibility
+	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 a, [hMapObjectIndexBuffer]
+	ld b, a
+	call CopyDECoordsToMapObject
+	and a
+	ret
+
+RefreshPlayerCoords: ; 80b8
+	ld a, [wXCoord]
+	add 4
+	ld d, a
+	ld hl, wPlayerStandingMapX
+	sub [hl]
+	ld [hl], d
+	ld hl, wMapObjects + MAPOBJECT_X_COORD
+	ld [hl], d
+	ld hl, wPlayerLastMapX
+	ld [hl], d
+	ld d, a
+	ld a, [wYCoord]
+	add 4
+	ld e, a
+	ld hl, wPlayerStandingMapY
+	sub [hl]
+	ld [hl], e
+	ld hl, wMapObjects + MAPOBJECT_Y_COORD
+	ld [hl], e
+	ld hl, wPlayerLastMapY
+	ld [hl], e
+	ld e, a
+	ld a, [wObjectFollow_Leader]
+	cp $0
+	ret nz ; wtf
+	ret
+
+CopyObjectStruct:: ; 80e7
+	call CheckObjectMask
+	and a
+	ret nz ; masked
+
+	ld hl, wObjectStructs + OBJECT_STRUCT_LENGTH * 1
+	ld a, 1
+	ld de, OBJECT_STRUCT_LENGTH
+.loop
+	ld [hObjectStructIndexBuffer], a
+	ld a, [hl]
+	and a
+	jr z, .done
+	add hl, de
+	ld a, [hObjectStructIndexBuffer]
+	inc a
+	cp NUM_OBJECT_STRUCTS
+	jr nz, .loop
+	scf
+	ret ; overflow
+
+.done
+	ld d, h
+	ld e, l
+	call CopyMapObjectToObjectStruct
+	ld hl, wVramState
+	bit 7, [hl]
+	ret z
+
+	ld hl, OBJECT_FLAGS2
+	add hl, de
+	set 5, [hl]
+	ret
+
+CopyMapObjectToObjectStruct: ; 8116
+	call .CopyMapObjectToTempObject
+	call CopyTempObjectToObjectStruct
+	ret
+
+.CopyMapObjectToTempObject: ; 811d
+	ld a, [hObjectStructIndexBuffer]
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld [hl], a
+
+	ld a, [hMapObjectIndexBuffer]
+	ld [wTempObjectCopyMapObjectIndex], a
+
+	ld hl, MAPOBJECT_SPRITE
+	add hl, bc
+	ld a, [hl]
+	ld [wTempObjectCopySprite], a
+
+	call GetSpriteVTile
+	ld [wTempObjectCopySpriteVTile], a
+
+	ld a, [hl]
+	call GetSpritePalette
+	ld [wTempObjectCopyPalette], a
+
+	ld hl, MAPOBJECT_COLOR
+	add hl, bc
+	ld a, [hl]
+	and $f0
+	jr z, .skip_color_override
+	swap a
+	and PALETTE_MASK
+	ld [wTempObjectCopyPalette], a
+
+.skip_color_override
+	ld hl, MAPOBJECT_MOVEMENT
+	add hl, bc
+	ld a, [hl]
+	ld [wTempObjectCopyMovement], a
+
+	ld hl, MAPOBJECT_RANGE
+	add hl, bc
+	ld a, [hl]
+	ld [wTempObjectCopyRange], a
+
+	ld hl, MAPOBJECT_X_COORD
+	add hl, bc
+	ld a, [hl]
+	ld [wTempObjectCopyX], a
+
+	ld hl, MAPOBJECT_Y_COORD
+	add hl, bc
+	ld a, [hl]
+	ld [wTempObjectCopyY], a
+
+	ld hl, MAPOBJECT_RADIUS
+	add hl, bc
+	ld a, [hl]
+	ld [wTempObjectCopyRadius], a
+	ret
+
+InitializeVisibleSprites: ; 8177
+	ld bc, wMapObjects + OBJECT_LENGTH
+	ld a, 1
+.loop
+	ld [hMapObjectIndexBuffer], a
+	ld hl, MAPOBJECT_SPRITE
+	add hl, bc
+	ld a, [hl]
+	and a
+	jr z, .next
+
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	cp -1
+	jr nz, .next
+
+	ld a, [wXCoord]
+	ld d, a
+	ld a, [wYCoord]
+	ld e, a
+
+	ld hl, MAPOBJECT_X_COORD
+	add hl, bc
+	ld a, [hl]
+	add 1
+	sub d
+	jr c, .next
+
+	cp MAPOBJECT_SCREEN_WIDTH
+	jr nc, .next
+
+	ld hl, MAPOBJECT_Y_COORD
+	add hl, bc
+	ld a, [hl]
+	add 1
+	sub e
+	jr c, .next
+
+	cp MAPOBJECT_SCREEN_HEIGHT
+	jr nc, .next
+
+	push bc
+	call CopyObjectStruct
+	pop bc
+	jp c, .ret
+
+.next
+	ld hl, OBJECT_LENGTH
+	add hl, bc
+	ld b, h
+	ld c, l
+	ld a, [hMapObjectIndexBuffer]
+	inc a
+	cp NUM_OBJECTS
+	jr nz, .loop
+	ret
+
+.ret ; 81c9
+	ret
+
+CheckObjectEnteringVisibleRange:: ; 81ca
+	nop
+	ld a, [wPlayerStepDirection]
+	cp STANDING
+	ret z
+	ld hl, .dw
+	rst JumpTable
+	ret
+
+.dw ; 81d6
+	dw .Down
+	dw .Up
+	dw .Left
+	dw .Right
+
+.Up: ; 81de
+	ld a, [wYCoord]
+	sub 1
+	jr .Vertical
+
+.Down: ; 81e5
+	ld a, [wYCoord]
+	add 9
+.Vertical: ; 81ea
+	ld d, a
+	ld a, [wXCoord]
+	ld e, a
+	ld bc, wMapObjects + OBJECT_LENGTH
+	ld a, 1
+.loop_v
+	ld [hMapObjectIndexBuffer], a
+	ld hl, MAPOBJECT_SPRITE
+	add hl, bc
+	ld a, [hl]
+	and a
+	jr z, .next_v
+	ld hl, MAPOBJECT_Y_COORD
+	add hl, bc
+	ld a, d
+	cp [hl]
+	jr nz, .next_v
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	cp -1
+	jr nz, .next_v
+	ld hl, MAPOBJECT_X_COORD
+	add hl, bc
+	ld a, [hl]
+	add 1
+	sub e
+	jr c, .next_v
+	cp MAPOBJECT_SCREEN_WIDTH
+	jr nc, .next_v
+	push de
+	push bc
+	call CopyObjectStruct
+	pop bc
+	pop de
+
+.next_v
+	ld hl, OBJECT_LENGTH
+	add hl, bc
+	ld b, h
+	ld c, l
+	ld a, [hMapObjectIndexBuffer]
+	inc a
+	cp NUM_OBJECTS
+	jr nz, .loop_v
+	ret
+
+.Left: ; 8232
+	ld a, [wXCoord]
+	sub 1
+	jr .Horizontal
+
+.Right: ; 8239
+	ld a, [wXCoord]
+	add 10
+.Horizontal: ; 823e
+	ld e, a
+	ld a, [wYCoord]
+	ld d, a
+	ld bc, wMapObjects + OBJECT_LENGTH
+	ld a, 1
+.loop_h
+	ld [hMapObjectIndexBuffer], a
+	ld hl, MAPOBJECT_SPRITE
+	add hl, bc
+	ld a, [hl]
+	and a
+	jr z, .next_h
+	ld hl, MAPOBJECT_X_COORD
+	add hl, bc
+	ld a, e
+	cp [hl]
+	jr nz, .next_h
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	cp -1
+	jr nz, .next_h
+	ld hl, MAPOBJECT_Y_COORD
+	add hl, bc
+	ld a, [hl]
+	add 1
+	sub d
+	jr c, .next_h
+	cp MAPOBJECT_SCREEN_HEIGHT
+	jr nc, .next_h
+	push de
+	push bc
+	call CopyObjectStruct
+	pop bc
+	pop de
+
+.next_h
+	ld hl, OBJECT_LENGTH
+	add hl, bc
+	ld b, h
+	ld c, l
+	ld a, [hMapObjectIndexBuffer]
+	inc a
+	cp NUM_OBJECTS
+	jr nz, .loop_h
+	ret
+
+CopyTempObjectToObjectStruct: ; 8286
+	ld a, [wTempObjectCopyMapObjectIndex]
+	ld hl, OBJECT_MAP_OBJECT_INDEX
+	add hl, de
+	ld [hl], a
+
+	ld a, [wTempObjectCopyMovement]
+	call CopySpriteMovementData
+
+	ld a, [wTempObjectCopyPalette]
+	ld hl, OBJECT_PALETTE
+	add hl, de
+	or [hl]
+	ld [hl], a
+
+	ld a, [wTempObjectCopyY]
+	call .InitYCoord
+
+	ld a, [wTempObjectCopyX]
+	call .InitXCoord
+
+	ld a, [wTempObjectCopySprite]
+	ld hl, OBJECT_SPRITE
+	add hl, de
+	ld [hl], a
+
+	ld a, [wTempObjectCopySpriteVTile]
+	ld hl, OBJECT_SPRITE_TILE
+	add hl, de
+	ld [hl], a
+
+	ld hl, OBJECT_STEP_TYPE
+	add hl, de
+	ld [hl], STEP_TYPE_00
+
+	ld hl, OBJECT_FACING_STEP
+	add hl, de
+	ld [hl], STANDING
+
+	ld a, [wTempObjectCopyRadius]
+	call .InitRadius
+
+	ld a, [wTempObjectCopyRange]
+	ld hl, OBJECT_RANGE
+	add hl, de
+	ld [hl], a
+
+	and a
+	ret
+
+.InitYCoord: ; 82d5
+	ld hl, OBJECT_INIT_Y
+	add hl, de
+	ld [hl], a
+
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, de
+	ld [hl], a
+
+	ld hl, wYCoord
+	sub [hl]
+	and $f
+	swap a
+	ld hl, wPlayerBGMapOffsetY
+	sub [hl]
+	ld hl, OBJECT_SPRITE_Y
+	add hl, de
+	ld [hl], a
+	ret
+
+.InitXCoord: ; 82f1
+	ld hl, OBJECT_INIT_X
+	add hl, de
+	ld [hl], a
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, de
+	ld [hl], a
+	ld hl, wXCoord
+	sub [hl]
+	and $f
+	swap a
+	ld hl, wPlayerBGMapOffsetX
+	sub [hl]
+	ld hl, OBJECT_SPRITE_X
+	add hl, de
+	ld [hl], a
+	ret
+
+.InitRadius: ; 830d
+	ld h, a
+	inc a
+	and $f
+	ld l, a
+	ld a, h
+	add $10
+	and $f0
+	or l
+	ld hl, OBJECT_RADIUS
+	add hl, de
+	ld [hl], a
+	ret
+
+TrainerWalkToPlayer: ; 831e
+	ld a, [hLastTalked]
+	call InitMovementBuffer
+	ld a, movement_step_sleep
+	call AppendToMovementBuffer
+	ld a, [wd03f]
+	dec a
+	jr z, .TerminateStep
+	ld a, [hLastTalked]
+	ld b, a
+	ld c, PLAYER
+	ld d, 1
+	call .GetPathToPlayer
+	call DecrementMovementBufferCount
+
+.TerminateStep:
+	ld a, movement_step_end
+	call AppendToMovementBuffer
+	ret
+
+.GetPathToPlayer: ; 8341
+	push de
+	push bc
+; get player object struct, load to de
+	ld a, c
+	call GetMapObject
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	call GetObjectStruct
+	ld d, b
+	ld e, c
+
+; get last talked object struct, load to bc
+	pop bc
+	ld a, b
+	call GetMapObject
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	call GetObjectStruct
+
+; get last talked coords, load to bc
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, bc
+	ld a, [hl]
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, bc
+	ld c, [hl]
+	ld b, a
+
+; get player coords, load to de
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, de
+	ld a, [hl]
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, de
+	ld e, [hl]
+	ld d, a
+
+	pop af
+	call ComputePathToWalkToPlayer
+	ret
+
+SurfStartStep: ; 8379
+	call InitMovementBuffer
+	call .GetMovementData
+	call AppendToMovementBuffer
+	ld a, movement_step_end
+	call AppendToMovementBuffer
+	ret
+
+.GetMovementData: ; 8388
+	ld a, [wPlayerDirection]
+	srl a
+	srl a
+	maskbits NUM_DIRECTIONS
+	ld e, a
+	ld d, 0
+	ld hl, .movement_data
+	add hl, de
+	ld a, [hl]
+	ret
+
+.movement_data
+	slow_step DOWN
+	slow_step UP
+	slow_step LEFT
+	slow_step RIGHT
+
+FollowNotExact:: ; 839e
+	push bc
+	ld a, c
+	call CheckObjectVisibility
+	ld d, b
+	ld e, c
+	pop bc
+	ret c
+
+	ld a, b
+	call CheckObjectVisibility
+	ret c
+
+; object 2 is now in bc, object 1 is now in de
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, bc
+	ld a, [hl]
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, bc
+	ld c, [hl]
+	ld b, a
+
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, de
+	ld a, [hl]
+	cp b
+	jr z, .same_x
+	jr c, .to_the_left
+	inc b
+	jr .continue
+
+.to_the_left
+	dec b
+	jr .continue
+
+.same_x
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, de
+	ld a, [hl]
+	cp c
+	jr z, .continue
+	jr c, .below
+	inc c
+	jr .continue
+
+.below
+	dec c
+
+.continue
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, de
+	ld [hl], b
+	ld a, b
+	ld hl, wXCoord
+	sub [hl]
+	and $f
+	swap a
+	ld hl, wPlayerBGMapOffsetX
+	sub [hl]
+	ld hl, OBJECT_SPRITE_X
+	add hl, de
+	ld [hl], a
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, de
+	ld [hl], c
+	ld a, c
+	ld hl, wYCoord
+	sub [hl]
+	and $f
+	swap a
+	ld hl, wPlayerBGMapOffsetY
+	sub [hl]
+	ld hl, OBJECT_SPRITE_Y
+	add hl, de
+	ld [hl], a
+	ld a, [hObjectStructIndexBuffer]
+	ld hl, OBJECT_RANGE
+	add hl, de
+	ld [hl], a
+	ld hl, OBJECT_MOVEMENTTYPE
+	add hl, de
+	ld [hl], SPRITEMOVEDATA_FOLLOWNOTEXACT
+	ld hl, OBJECT_STEP_TYPE
+	add hl, de
+	ld [hl], STEP_TYPE_00
+	ret
+
+GetRelativeFacing:: ; 8417
+; Determines which way map object e would have to turn to face map object d.  Returns carry if it's impossible for whatever reason.
+	ld a, d
+	call GetMapObject
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	cp NUM_OBJECT_STRUCTS
+	jr nc, .carry
+	ld d, a
+	ld a, e
+	call GetMapObject
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	cp NUM_OBJECT_STRUCTS
+	jr nc, .carry
+	ld e, a
+	call .GetFacing_e_relativeto_d
+	ret
+
+.carry
+	scf
+	ret
+
+.GetFacing_e_relativeto_d: ; 8439
+; Determines which way object e would have to turn to face object d.  Returns carry if it's impossible.
+; load the coordinates of object d into bc
+	ld a, d
+	call GetObjectStruct
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, bc
+	ld a, [hl]
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, bc
+	ld c, [hl]
+	ld b, a
+	push bc
+; load the coordinates of object e into de
+	ld a, e
+	call GetObjectStruct
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, bc
+	ld d, [hl]
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, bc
+	ld e, [hl]
+	pop bc
+; |x1 - x2|
+	ld a, b
+	sub d
+	jr z, .same_x_1
+	jr nc, .b_right_of_d_1
+	cpl
+	inc a
+
+.b_right_of_d_1
+; |y1 - y2|
+	ld h, a
+	ld a, c
+	sub e
+	jr z, .same_y_1
+	jr nc, .c_below_e_1
+	cpl
+	inc a
+
+.c_below_e_1
+; |y1 - y2| - |x1 - x2|
+	sub h
+	jr c, .same_y_1
+
+.same_x_1
+; compare the y coordinates
+	ld a, c
+	cp e
+	jr z, .same_x_and_y
+	jr c, .c_directly_below_e
+; c directly above e
+	ld d, DOWN
+	and a
+	ret
+
+.c_directly_below_e
+	ld d, UP
+	and a
+	ret
+
+.same_y_1
+	ld a, b
+	cp d
+	jr z, .same_x_and_y
+	jr c, .b_directly_right_of_d
+; b directly left of d
+	ld d, RIGHT
+	and a
+	ret
+
+.b_directly_right_of_d
+	ld d, LEFT
+	and a
+	ret
+
+.same_x_and_y
+	scf
+	ret
+
+QueueFollowerFirstStep: ; 848a
+	call .QueueFirstStep
+	jr c, .same
+	ld [wFollowMovementQueue], a
+	xor a
+	ld [wFollowerMovementQueueLength], a
+	ret
+
+.same
+	ld a, -1
+	ld [wFollowerMovementQueueLength], a
+	ret
+
+.QueueFirstStep:
+	ld a, [wObjectFollow_Leader]
+	call GetObjectStruct
+	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 a, [wObjectFollow_Follower]
+	call GetObjectStruct
+	ld hl, OBJECT_NEXT_MAP_X
+	add hl, bc
+	ld a, d
+	cp [hl]
+	jr z, .check_y
+	jr c, .left
+	and a
+	ld a, movement_step + RIGHT
+	ret
+
+.left
+	and a
+	ld a, movement_step + LEFT
+	ret
+
+.check_y
+	ld hl, OBJECT_NEXT_MAP_Y
+	add hl, bc
+	ld a, e
+	cp [hl]
+	jr z, .same_xy
+	jr c, .up
+	and a
+	ld a, movement_step + DOWN
+	ret
+
+.up
+	and a
+	ld a, movement_step + UP
+	ret
+
+.same_xy
+	scf
+	ret