Optimize

1 files changed, 30 insertions, 1 deletions

diff --git a/Improve-the-event-initialization-system.md b/Improve-the-event-initialization-system.md
index 78f42dd..5b5f509 100644
--- a/Improve-the-event-initialization-system.md
+++ b/Improve-the-event-initialization-system.md
@@ -207,4 +207,33 @@ $ tools/free_space.awk pokecrystal.map
 Free space: 455295/2097152 (21.71%)
 ```
 
-That's 72 more ROM bytes than before. It's not a whole lot, but every bit helps. You can eke out a few more by applying the tricks from the [assembly optimization tutorial](Optimizing-assembly-code) to `InitializeEvents`: it was written more for clarity than to save space. (For example, all three `cp -1` can become `inc a` to save three bytes *and* run a little faster.)
+That's 72 more ROM bytes than before. It's not a whole lot, but every bit helps. You can eke out a few more by applying the tricks from the [assembly optimization tutorial](Optimizing-assembly-code) to `InitializeEvents`: it was written more for clarity than to save space. For example, all three `cp -1` can become `inc a` to save three bytes *and* run a little faster. Or you can optimize the entire `.sprites_loop` using the "[Add `a` to an address](Optimizing-assembly-code#add-a-to-an-address)" technique:
+
+```diff
+ .sprites_loop
+ 	ld a, [hli]
+-	ld e, a
+-	ld d, 0
+-	cp -1
+-	jr z, .sprites_done
+-	ld a, [hli]
+-	push hl
+-	ld hl, wVariableSprites
+-	add hl, de
+-	ld [hl], a
+-	pop hl
++	ld a, [hli]
++	cp -1
++	ret z
++	add LOW(wVariableSprites)
++	ld e, a
++	adc HIGH(wVariableSprites)
++	sub e
++	ld d, a
++	ld a, [hli]
++	ld [de], a
+ 	jr .sprites_loop
+-.sprites_done
+-
+-	ret
+```