Trainer EV system

; this has been made over the routine that loads an enemy Pokemon
; had to find a point to break the routine where
; 1: stats had already been loaded into RAM
; 2: working with registers bc, de, and hl was not a problem (for convenience)

#org 3EB10
jp Main ; jumps to the new stuff

#org 3FE88
Main:
ld a,(D22D)
cp a, 2 ; are we in a trainer battle?
jp z, ApplyStatBoosts ; if so the stat boosts are applied, otherwise fallthrough

#org 3FE90
Original:
; original routine stuff, that is, original 3EB10-3EB37
ld hl,D073
ld de,C616
ld bc,000B
call Label3026
ld a,(D204)
dec a
ld c,a
ld b,01
ld hl,DEB9
ld a,03
call Label2D83
ld hl,D21A
ld de,C6C1
ld bc,000A
call Label3026
ret ; the original routine finishes at this point

ApplyStatBoosts:
;   [1,32]: no boost
;  [33,34]: boost = level/16 = 2
;  [35,54]: boost = level/16 + level/32
;  [55,73]: boost = level/8
;  [74,77]: boost = level/8 + level/16
; [78,100]: boost = level/4

ld hl,D21B ; point to the first stat LSB (attack)
ld c,5 ; there are five stats
ld a,(D143) ; get enemy's level

level78to100:
cp a,4E
jr c,level74to77 ; if not between 78 and 100, skip
ld d,2 ; level will be halved twice
call boost ; boost the stats
jr Original ; we are done

level74to77:
cp a,4A
jr c,level55to73
ld d,3
call boost ; level/(2^3) = level/8
ld hl,D21B
ld c,5
ld d,4
call boost ; level/(2^4) = level/16 --> level/8 + level/16
jr Original ;

level55to73:
cp a,37
jr c,level36to54
ld d,3
call boost
jr Original

level35to54:
cp a,23
jr c,level33to34
ld d,4
call boost
ld hl,D21B
ld c,5
ld d,5
call boost
jr Original

level33to34:
cp a,21
jr c,level0to32
ld d,4
call boost ; fallthrough

level0to32:
jr Original ; no boost if level<33

#org 3EB13
boost:
ld a,(D143) ; get enemy's level (a gets overwritten on every loop)
ld b,a
ld e,d ; save d for later
halve: ; halve level d times
srl b
dec d
jr nz,halve
ld a,(hl) ; a = attack LSB before boost has been applied
add a,b
ld (hl),a ; load a+b into the stat
jr nc,finish ; overflow check
dec hl ; if overflow, add 0x100 to the stat
inc (hl) ; inc MSB
inc hl ; point to LSB again
finish:
inc hl
inc hl ; point to the next stat LSB
dec c ; one less stat left
ld d,e
jr nz,boost ; loop if not done
ret ; otherwise return