1 files changed, 88 insertions, 0 deletions
diff --git a/engine/pokeball_wobble.asm b/engine/pokeball_wobble.asm
new file mode 100755
index 000000000..7fb4d3e38
--- /dev/null
+++ b/engine/pokeball_wobble.asm
@@ -0,0 +1,88 @@
+GetPokeBallWobble: ; f971 (3:7971)
+; Returns whether a Poke Ball will wobble in the catch animation.
+; Whether a Pokemon is caught is determined beforehand.
+
+	push de
+
+	ld a, [rSVBK]
+	ld d, a
+	push de
+
+	ld a, 1 ; BANK(Buffer2)
+	ld [rSVBK], a
+
+	ld a, [Buffer2]
+	inc a
+	ld [Buffer2], a
+
+; Wobble up to 3 times.
+	cp 3 + 1
+	jr z, .finished
+
+	ld a, [wWildMon]
+	and a
+	ld c, 0 ; next
+	jr nz, .done
+
+	ld hl, .WobbleProbabilities
+	ld a, [Buffer1]
+	ld b, a
+.loop
+	ld a, [hli]
+	cp b
+	jr nc, .checkwobble
+	inc hl
+	jr .loop
+
+.checkwobble
+	ld b, [hl]
+	call Random
+	cp b
+	ld c, 0 ; next
+	jr c, .done
+	ld c, 2 ; escaped
+	jr .done
+
+.finished
+	ld a, [wWildMon]
+	and a
+	ld c, 1 ; caught
+	jr nz, .done
+	ld c, 2 ; escaped
+
+.done
+	pop de
+	ld e, a
+	ld a, d
+	ld [rSVBK], a
+	ld a, e
+	pop de
+	ret
+
+.WobbleProbabilities: ; f9ba
+; catch rate, chance of wobbling / 255
+; nLeft/255 = (nRight/255) ** 4
+	db   1,  63
+	db   2,  75
+	db   3,  84
+	db   4,  90
+	db   5,  95
+	db   7, 103
+	db  10, 113
+	db  15, 126
+	db  20, 134
+	db  30, 149
+	db  40, 160
+	db  50, 169
+	db  60, 177
+	db  80, 191
+	db 100, 201
+	db 120, 211
+	db 140, 220
+	db 160, 227
+	db 180, 234
+	db 200, 240
+	db 220, 246
+	db 240, 251
+	db 254, 253
+	db 255, 255