ref: edf939a07be9e0553a3ef91dd66291806dd3ad50
parent: 3b70005fb07750959a86c464a8a423a94f98f04b
author: yenatch <yenatch@gmail.com>
date: Sat Sep 7 22:47:52 EDT 2013
split Random into common/random.asm
--- /dev/null
+++ b/common/random.asm
@@ -1,0 +1,76 @@
+Random: ; 2f8c
+; A simple hardware-based random number generator (RNG).
+
+; Two random numbers are generated by adding and subtracting
+; the divider to the respective values every time it's called.
+
+; The divider is a register that increments at a rate of 16384Hz.
+; For comparison, the Game Boy operates at a clock speed of 4.2MHz.
+
+; Additionally, an equivalent function is executed in VBlank.
+
+; This leaves a with the value in hRandomSub.
+
+ push bc
+
+ ld a, [rDIV]
+ ld b, a
+ ld a, [hRandomAdd]
+ adc b
+ ld [hRandomAdd], a
+
+ ld a, [rDIV]
+ ld b, a
+ ld a, [hRandomSub]
+ sbc b
+ ld [hRandomSub], a
+
+ pop bc
+ ret
+; 2f9f
+
+BattleRandom: ; 2f9f
+; _BattleRandom lives in another bank.
+
+; It handles all RNG calls in the battle engine, allowing
+; link battles to remain in sync using a shared PRNG.
+
+ ld a, [hROMBank]
+ push af
+ ld a, BANK(_BattleRandom)
+ rst Bankswitch
+
+ call _BattleRandom
+
+ ld [$cfb6], a
+ pop af
+ rst Bankswitch
+ ld a, [$cfb6]
+ ret
+; 2fb1
+
+
+Function2fb1: ; 2fb1
+ push bc
+ ld c, a
+ xor a
+ sub c
+.asm_2fb5
+ sub c
+ jr nc, .asm_2fb5
+ add c
+ ld b, a
+ push bc
+.asm_2fbb
+ call Random
+ ld a, [hRandomAdd]
+ ld c, a
+ add b
+ jr c, .asm_2fbb
+ ld a, c
+ pop bc
+ call SimpleDivide
+ pop bc
+ ret
+; 2fcb
+
--- a/main.asm
+++ b/main.asm
@@ -810,82 +810,8 @@
INCLUDE "common/item.asm"
+INCLUDE "common/random.asm"
-Random: ; 2f8c
-; A simple hardware-based random number generator (RNG).
-
-; Two random numbers are generated by adding and subtracting
-; the divider to the respective values every time it's called.
-
-; The divider is a register that increments at a rate of 16384Hz.
-; For comparison, the Game Boy operates at a clock speed of 4.2MHz.
-
-; Additionally, an equivalent function is executed in VBlank.
-
-; This leaves a with the value in hRandomSub.
-
- push bc
-
- ld a, [rDIV]
- ld b, a
- ld a, [hRandomAdd]
- adc b
- ld [hRandomAdd], a
-
- ld a, [rDIV]
- ld b, a
- ld a, [hRandomSub]
- sbc b
- ld [hRandomSub], a
-
- pop bc
- ret
-; 2f9f
-
-BattleRandom: ; 2f9f
-; _BattleRandom lives in another bank.
-
-; It handles all RNG calls in the battle engine, allowing
-; link battles to remain in sync using a shared PRNG.
-
- ld a, [hROMBank]
- push af
- ld a, BANK(_BattleRandom)
- rst Bankswitch
-
- call _BattleRandom
-
- ld [$cfb6], a
- pop af
- rst Bankswitch
- ld a, [$cfb6]
- ret
-; 2fb1
-
-
-Function2fb1: ; 2fb1
- push bc
- ld c, a
- xor a
- sub c
-.asm_2fb5
- sub c
- jr nc, .asm_2fb5
- add c
- ld b, a
- push bc
-.asm_2fbb
- call Random
- ld a, [hRandomAdd]
- ld c, a
- add b
- jr c, .asm_2fbb
- ld a, c
- pop bc
- call SimpleDivide
- pop bc
- ret
-; 2fcb
GetSRAMBank: ; 2fcb
; load sram bank a