First Commit

Upload literally everything from the pokecrystal16 expand-move-ID branch

home/movement.asm

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+InitMovementBuffer::
+	ld [wMovementBufferObject], a
+	xor a
+	ld [wMovementBufferCount], a
+	ld [wUnusedMovementBufferBank], a
+	ld a, LOW(wMovementBuffer)
+	ld [wUnusedMovementBufferPointer], a
+	ld a, HIGH(wMovementBuffer)
+	ld [wUnusedMovementBufferPointer + 1], a
+	ret
+
+DecrementMovementBufferCount::
+	ld a, [wMovementBufferCount]
+	and a
+	ret z
+	dec a
+	ld [wMovementBufferCount], a
+	ret
+
+AppendToMovementBuffer::
+	push hl
+	push de
+	ld hl, wMovementBufferCount
+	ld e, [hl]
+	inc [hl]
+	ld d, 0
+	ld hl, wMovementBuffer
+	add hl, de
+	ld [hl], a
+	pop de
+	pop hl
+	ret
+
+AppendToMovementBufferNTimes::
+	push af
+	ld a, c
+	and a
+	jr nz, .okay
+	pop af
+	ret
+
+.okay
+	pop af
+.loop
+	call AppendToMovementBuffer
+	dec c
+	jr nz, .loop
+	ret
+
+ComputePathToWalkToPlayer::
+	push af
+; compare x coords, load left/right into h, and x distance into d
+	ld a, b
+	sub d
+	ld h, LEFT
+	jr nc, .got_x_distance
+	dec a
+	cpl
+	ld h, RIGHT
+
+.got_x_distance
+	ld d, a
+; compare y coords, load up/down into l, and y distance into e
+	ld a, c
+	sub e
+	ld l, UP
+	jr nc, .got_y_distance
+	dec a
+	cpl
+	ld l, DOWN
+
+.got_y_distance
+	ld e, a
+; if the x distance is less than the y distance, swap h and l, and swap d and e
+	cp d
+	jr nc, .done
+	ld a, h
+	ld h, l
+	ld l, a
+	ld a, d
+	ld d, e
+	ld e, a
+
+.done
+	pop af
+	ld b, a
+; Add movement in the longer direction first...
+	ld a, h
+	call .GetMovementData
+	ld c, d
+	call AppendToMovementBufferNTimes
+; ... then add the shorter direction.
+	ld a, l
+	call .GetMovementData
+	ld c, e
+	call AppendToMovementBufferNTimes
+	ret
+
+.GetMovementData:
+	push de
+	push hl
+	ld l, b
+	ld h, 0
+	add hl, hl
+	add hl, hl
+	ld e, a
+	ld d, 0
+	add hl, de
+	ld de, .MovementData
+	add hl, de
+	ld a, [hl]
+	pop hl
+	pop de
+	ret
+
+.MovementData:
+	slow_step DOWN
+	slow_step UP
+	slow_step LEFT
+	slow_step RIGHT
+	step DOWN
+	step UP
+	step LEFT
+	step RIGHT
+	big_step DOWN
+	big_step UP
+	big_step LEFT
+	big_step RIGHT