shithub: pokecrystal

ref: 9af2aee640b555f9f52503233bc06d299b99974d
dir: /engine/routines/getsquareroot.asm/

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GetSquareRoot: ; 13b87
; Return the square root of de in b.

; Rather than calculating the result, we take the index of the
; first value in a table of squares that isn't lower than de.

	ld hl, .Squares
	ld b, 0
.loop
; Make sure we don't go past the end of the table.
	inc b
	ld a, b
	cp $ff
	ret z

; Iterate over the table until b**2 >= de.
	ld a, [hli]
	sub e
	ld a, [hli]
	sbc d

	jr c, .loop
	ret

.Squares: ; 13b98
root	set 1
	rept $ff
	dw root*root
root	set root+1
	endr