Ribose

Nobody reads these anyways so here's how I make/verify G/S/C BACKsprites.

I'm using Script-Fu (GIMP) to crop and transparentize, Visual Boy Advance screenshots (I say it isn't illegal because I own all Gen I and II game carts), and Python to compare images.

The longest part is sitting here with GameShark codes and 3 VBA emulators (G, S, C) and modifying the species, switching the Pkmn out and taking screenshots every turn... 251 times x 2 for shinies (even though I've determined so far that G/S are almost always the same and G/S/C shiny are almost always the same, but I've found a couple exceptions!). Here are my notes:

GAMESHARK CODES G/S/C
=====================
PkMn Data Structure

[00] Species
[01] Held Item
[02] Attack 1
[03] Attack 2
[04] Attack 3
[05] Attack 4
[06] OT ID (2)
[07]
[08] Experience (3)
[09]
[0A]
[0B] EV data (10)
[0C]
[0D]
[0E]
[0F]
[10]
[11]
[12]
[13]
[14]
[15] DVs (2)
[16]
[17] PP1
[18] PP2
[19] PP3
[1A] PP4
[1B] Happiness
[1C] Pokérus
[1D] Caught data (2)
[1E]
[1F] Level
[20] Status
[21] ?
[22] Current HP (2)
[23]
[24] Total HP (2)
[25]
[26] Attack (2)
[27]
[28] Defense (2)
[29]
[2A] Speed (2)
[2B]
[2C] Sp. Attack (2)
[2D]
[2E] Sp. Defense (2)
[2F]

Offsets:
Poké 1    2    3    4    5    6
GS: DA2A DA5A DA8A DABA DAEA DB1A
C:  DCDF DD0F DD3F DD6F DD9F DDEF

Codes:
GAME/POKé: GS/1     GS/2      C/1      C/2
SPECIES:   01XX2ADA 01XX5ADA  91XXDFDC 91XX0FDD
HP 100:    01644DDA 01647DDA  916402DD 916432DD  
HPMAX 100: 01644FDA 01647FDA  916404DD 916434DD
DV NORMAL: 01FF3FDA           91FFF4DC 
           01FF40DA           91FFF5DC
DV SHINY:           01EA6FDA           91EA24DD
                    01AA70DA           91AA25DD

Generated:
gs:init
01644DDA 01647DDA 01644FDA 01647FDA 01FF3FDA 01FF40DA 01EA6FDA 01AA70DA
c:init
916402DD 916432DD 916404DD 916434DD 91FFF4DC 91FFF5DC 91EA24DD 91AA25DD

gs
01162ADA 01165ADA
c
9116DFDC 91160FDD

Script-Fu is Scheme:

(define (crop-sprite input) (let* (
   (img (car (file-png-load RUN-NONINTERACTIVE input input)))
   (dsp (car (gimp-display-new img)))
   (drw (car (gimp-image-get-active-drawable img)))
   (lyr (car (gimp-image-get-active-layer img)))
   )
   (gimp-image-crop img 58 57 7 39)
   (gimp-layer-add-alpha lyr)
   (gimp-fuzzy-select drw 0 0 15 CHANNEL-OP-ADD FALSE FALSE 0 FALSE)
   (gimp-edit-clear drw)
   ; actual position: 56x56, at x=8px y=40px
   (gimp-image-crop img 56 56 1 1)
   (file-png-save-defaults 1 img drw input input)
   (gimp-display-delete dsp)
   ;(gimp-image-delete img)
))

Python (with PIL) for compares (takes command line args for each image to compare "g_100" -> Spr b 2g 100.png, "c_100_s" -> Spr b 2c 100 s.png, etc):

import Image
import ImageChops
import sys

im_name = "Spr b 2"
ims = []

args = sys.argv
i = 0
if len(args) > 1:
    for arg in args:
        if i > 0:
            ims = ims + ["Spr_b_2" + arg + ".png"]
        i = i + 1

i = 0
for im in ims:
    ims[i] = ims[i].replace("_", " ")
    i = i + 1

imo = []
i = 0
for im in ims:
    imo = imo + [Image.open(im)]
    print ims[i],imo[i]
    i = i + 1

diffs = []
i = 0
for im in ims:
    if i > 0:
        diffs = diffs + [ImageChops.difference(imo[i - 1], imo[i])]
        if len(diffs[i-1].getcolors()) > 1:
            print ims[i-1]," and ",ims[i]," do not match: color count = ", len(diffs[i-1].getcolors())
            print diffs[i-1].getcolors()[0][0],diffs[i-1].getcolors()[1][0]
            diffs[i-1].show()
    i = i + 1

Sprites that need correction:

• File:Spr b 2c 002.png (I can't overwrite the redirect with an image)