pokecrystal/engine/math/get_square_root.asm

DEF NUM_SQUARE_ROOTS EQU 255

GetSquareRoot:
; 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 NUM_SQUARE_ROOTS
	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:
for x, 1, NUM_SQUARE_ROOTS + 1
	dw x**2
endr
RGBDS syntax updates (#905) New MACRO and DEF syntax 2022-06-06 21:25:42 +00:00			`DEF NUM_SQUARE_ROOTS EQU 255`
Cleaner Pokédex code 2018-01-16 22:59:05 +00:00
Remove all address comments 2018-06-24 14:09:41 +00:00			`GetSquareRoot:`
Move more contiguous related code blocks from main.asm to engine/ and events/ 2017-12-16 01:10:54 +00:00			`; 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.`

Remove all code from main.asm (some labeled INCBINs, like out-of-context graphics, are still present) engine/routines/ stores isolated out-of-context routines as individual files. It might be preferable later to append them to their related engine/ files in unique little SECTIONs, relying on the linkerscript to place them appropriately; or some other organization method. In the meantime, they're now easily findable apart from main.asm's other content. 2017-12-25 00:35:35 +00:00			`ld hl, .Squares`
Move more contiguous related code blocks from main.asm to engine/ and events/ 2017-12-16 01:10:54 +00:00			`ld b, 0`
			`.loop`
			`; Make sure we don't go past the end of the table.`
			`inc b`
			`ld a, b`
Cleaner Pokédex code 2018-01-16 22:59:05 +00:00			`cp NUM_SQUARE_ROOTS`
Move more contiguous related code blocks from main.asm to engine/ and events/ 2017-12-16 01:10:54 +00:00			`ret z`

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

			`jr c, .loop`
			`ret`

Remove all address comments 2018-06-24 14:09:41 +00:00			`.Squares:`
Use rgbds 0.5.0 2021-04-19 20:31:37 +00:00			`for x, 1, NUM_SQUARE_ROOTS + 1`
			`dw x**2`
Cleaner Pokédex code 2018-01-16 22:59:05 +00:00			`endr`