Organize the engine/ directory, take 3

Renamed `title` to `movies`.
Moved some functions from `engine/routines/` to their fitting
directories, and cleaned up the base `engine/` directory.
Moved `engine/pokemon/tmhm.asm` back to `engine/items/`.

Made a new subdirectory:
* engine/tilesets: Contains all map-related graphics routines.

engine/events/checksave.asm

@@ -0,0 +1,20 @@
+CheckSave:: ; 4cffe
+	ld a, BANK(sCheckValue1) ; BANK(sCheckValue2)
+	call GetSRAMBank
+	ld a, [sCheckValue1]
+	ld b, a
+	ld a, [sCheckValue2]
+	ld c, a
+	call CloseSRAM
+	ld a, b
+	cp SAVE_CHECK_VALUE_1
+	jr nz, .ok
+	ld a, c
+	cp SAVE_CHECK_VALUE_2
+	jr nz, .ok
+	ld c, $1
+	ret
+
+.ok
+	ld c, $0
+	ret

engine/events/checktime.asm

@@ -0,0 +1,19 @@
+CheckTime:: ; c000
+	ld a, [wTimeOfDay]
+	ld hl, .TimeOfDayTable
+	ld de, 2
+	call IsInArray
+	inc hl
+	ld c, [hl]
+	ret c
+
+	xor a
+	ld c, a
+	ret
+
+.TimeOfDayTable: ; c012
+	db MORN_F, MORN
+	db DAY_F,  DAY
+	db NITE_F, NITE
+	db NITE_F, NITE
+	db -1

engine/events/engine_flags.asm

@@ -0,0 +1,86 @@
+EngineFlagAction:: ; 80430
+; Do action b on engine flag de
+;
+;   b = 0: reset flag
+;     = 1: set flag
+;     > 1: check flag, result in c
+;
+; Setting/resetting does not return a result.
+
+
+; 16-bit flag ids are considered invalid, but it's nice
+; to know that the infrastructure is there.
+
+	ld a, d
+	cp 0
+	jr z, .ceiling
+	jr c, .read ; cp 0 can't set carry!
+	jr .invalid
+
+; There are only $a2 engine flags, so
+; anything beyond that is invalid too.
+
+.ceiling
+	ld a, e
+	cp NUM_ENGINE_FLAGS
+	jr c, .read
+
+; Invalid flags are treated as flag 00.
+
+.invalid
+	xor a
+	ld e, a
+	ld d, a
+
+; Get this flag's location.
+
+.read
+	ld hl, EngineFlags
+; location
+	add hl, de
+	add hl, de
+; bit
+	add hl, de
+
+; location
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+	inc hl
+; bit
+	ld c, [hl]
+
+; What are we doing with this flag?
+
+	ld a, b
+	cp 1
+	jr c, .reset ; b = 0
+	jr z, .set   ; b = 1
+
+; Return the given flag in c.
+.check
+	ld a, [de]
+	and c
+	ld c, a
+	ret
+
+; Set the given flag.
+.set
+	ld a, [de]
+	or c
+	ld [de], a
+	ret
+
+; Reset the given flag.
+.reset
+	ld a, c
+	cpl ; AND all bits except the one in question
+	ld c, a
+	ld a, [de]
+	and c
+	ld [de], a
+	ret
+; 80462
+
+
+INCLUDE "data/engine_flags.asm"

engine/events/money.asm

@@ -0,0 +1,221 @@
+GiveMoney:: ; 15fd7
+	ld a, 3
+	call AddMoney
+	ld bc, MaxMoney
+	ld a, 3
+	call CompareMoney
+	jr z, .not_maxed_out
+	jr c, .not_maxed_out
+	ld hl, MaxMoney
+	ld a, [hli]
+	ld [de], a
+	inc de
+	ld a, [hli]
+	ld [de], a
+	inc de
+	ld a, [hli]
+	ld [de], a
+	scf
+	ret
+
+.not_maxed_out
+	and a
+	ret
+; 15ff7
+
+MaxMoney: ; 15ff7
+	dt MAX_MONEY
+; 15ffa
+
+
+TakeMoney:: ; 15ffa
+	ld a, 3
+	call SubtractMoney
+	jr nc, .okay
+	; leave with 0 money
+	xor a
+	ld [de], a
+	inc de
+	ld [de], a
+	inc de
+	ld [de], a
+	scf
+	ret
+
+.okay
+	and a
+	ret
+; 1600b
+
+CompareMoney:: ; 1600b
+	ld a, 3
+CompareFunds: ; 1600d
+; a: number of bytes
+; bc: start addr of amount (big-endian)
+; de: start addr of account (big-endian)
+	push hl
+	push de
+	push bc
+	ld h, b
+	ld l, c
+	ld c, 0
+	ld b, a
+.loop1
+	dec a
+	jr z, .done
+	inc de
+	inc hl
+	jr .loop1
+
+.done
+	and a
+.loop2
+	ld a, [de]
+	sbc [hl]
+	jr z, .okay
+	inc c
+
+.okay
+	dec de
+	dec hl
+	dec b
+	jr nz, .loop2
+	jr c, .set_carry
+	ld a, c
+	and a
+	jr .skip_carry
+
+.set_carry
+	ld a, 1
+	and a
+	scf
+.skip_carry
+	pop bc
+	pop de
+	pop hl
+	ret
+; 16035
+
+SubtractMoney: ; 16035
+	ld a, 3
+SubtractFunds: ; 16037
+; a: number of bytes
+; bc: start addr of amount (big-endian)
+; de: start addr of account (big-endian)
+	push hl
+	push de
+	push bc
+	ld h, b
+	ld l, c
+	ld b, a
+	ld c, 0
+.loop
+	dec a
+	jr z, .done
+	inc de
+	inc hl
+	jr .loop
+
+.done
+	and a
+.loop2
+	ld a, [de]
+	sbc [hl]
+	ld [de], a
+	dec de
+	dec hl
+	dec b
+	jr nz, .loop2
+	pop bc
+	pop de
+	pop hl
+	ret
+; 16053
+
+AddMoney: ; 16053
+	ld a, 3
+AddFunds: ; 16055
+; a: number of bytes
+; bc: start addr of amount (big-endian)
+; de: start addr of account (big-endian)
+	push hl
+	push de
+	push bc
+
+	ld h, b
+	ld l, c
+	ld b, a
+.loop1
+	dec a
+	jr z, .done
+	inc de
+	inc hl
+	jr .loop1
+
+.done
+	and a
+.loop2
+	ld a, [de]
+	adc [hl]
+	ld [de], a
+	dec de
+	dec hl
+	dec b
+	jr nz, .loop2
+
+	pop bc
+	pop de
+	pop hl
+	ret
+; 1606f
+
+GiveCoins:: ; 1606f
+	ld a, 2
+	ld de, wCoins
+	call AddFunds
+	ld a, 2
+	ld bc, .maxcoins
+	call CompareFunds
+	jr c, .not_maxed
+	ld hl, .maxcoins
+	ld a, [hli]
+	ld [de], a
+	inc de
+	ld a, [hli]
+	ld [de], a
+	scf
+	ret
+
+.not_maxed
+	and a
+	ret
+; 1608d
+
+.maxcoins ; 1608d
+	bigdw MAX_COINS
+; 1608f
+
+
+TakeCoins:: ; 1608f
+	ld a, 2
+	ld de, wCoins
+	call SubtractFunds
+	jr nc, .okay
+	; leave with 0 coins
+	xor a
+	ld [de], a
+	inc de
+	ld [de], a
+	scf
+	ret
+
+.okay
+	and a
+	ret
+; 160a1
+
+CheckCoins:: ; 160a1
+	ld a, 2
+	ld de, wCoins
+	jp CompareFunds
+; 160a9

engine/events/playslowcry.asm

@@ -0,0 +1,31 @@
+PlaySlowCry: ; fb841
+	ld a, [wScriptVar]
+	call LoadCry
+	jr c, .done
+
+	ld hl, wCryPitch
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld bc, -$140
+	add hl, bc
+	ld a, l
+	ld [wCryPitch], a
+	ld a, h
+	ld [wCryPitch + 1], a
+	ld hl, wCryLength
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld bc, $60
+	add hl, bc
+	ld a, l
+	ld [wCryLength], a
+	ld a, h
+	ld [wCryLength + 1], a
+	farcall _PlayCry
+	call WaitSFX
+
+.done
+	ret
+; fb877