Pokemon XD PID/IV Relationship Uncovered

[Kaphotics]

After a bunch of time spent with Dolphin and collaborating with OmegaDonut, here's the call structure of and the PRNG it uses.

0	Initial
1	Opponent TID
2	Opponent SID
3	1st ???
4	2nd ???
5	IV Block 1 (Def/Atk/HP)
6	IV Block 2 (SpD/SpA/SpE)
7	3rd ???
8	Upper Half of PID
9	Lower Half of PID

note that the upper is generated before the lower, a common trait of non-GBA originated Pokemon 
like the BACD Restricted Pokemon that are generated from a header on the save file

0x000343FD*seed+0x00269EC3

=====

To check the PID/IV legality of an (and possibly Colosseum) originated Pokemon, you can't use the current version of Legal.exe. For Pokemon, it is a reverse BADE (call it DEBA) but with a different Linear Congruential Random Number Generator.

1	IV Block 1 (Def/Atk/HP)
2	IV Block 2 (SpD/SpA/SpE)
3	3rd ???
4	Upper Half of PID
5	Lower Half of PID

Here's an example:

Frame	RNG Value
1	171EA3F5	171E in binary: 0|00101|11000|11110 (Defense 5, Attack 24, HP 30)
2	CA36C6E4	CA36 in binary: 1|10010|10001|10110 (SpDef 18, SpAtk 17, Speed 22)
3	8302DA17	ignored
4	C7512C7E	C751 forms the upper half of the PID
5	BF7E9149	BF7E forms the lower half of the PID

We are then left with the following Pokemon:

C751BF7E 30/24/5/17/18/22
Common GC (DEBA)

[OmegaDonut]

Also, Pokémon are never shiny. The game will continue to roll over to the next PID until the Pokémon is not shiny. Here's an example:

Frame	RNG Value
1	EDA5FFE8	IV Block 1
2	4EE63F0B	IV Block 2
3	F953CDA2	ignored
4	BFB03DDD	frames 4 and 5 form a PID that should be shiny (BFB04B1B) 
5	4B1B992C	but we know it rerolls to frames 6 and 7
6	3F07833F	frames 6 and 7 also form a PID that should also be shiny with our ID\SID (3F07CBA9).  
7	CBA9D106	we want to know if it only rerolls once, or if it keeps rerolling until not shiny
8	[b]2BC0[/b]C3B1
9	[b]FBF2[/b]57B0	final PID 2BC0FBF2, so the game rerolled until a non-shiny PID occurred on frame 8 and 9.

I guess we could call it Uncommon GC (HIBA).

[froggy25]

Good job

[Poryhack]

Awesome work you guys.

[Guest]

Great job for finally settling up the matter about the Ageto Celebi.

You deserve a prize, but I have nothing I could offer except my congratulations.

[Kaphotics]

XDC-Legal

Checks the GC method Pokemon. Essentially it's every Pokemon that fits into the Unknown GBA type, except Channel. Every Pokemon that is given out through a GameCube interface that isn't BACD should be checkable.

[Bond697]

XDC-Legal

Checks the GC method Pokemon. Essentially it's every Pokemon that fits into the Unknown GBA type, except Channel. Every Pokemon that is given out through a GameCube interface that isn't BACD should be checkable.

i'm not sure if the worst part of this is that you

a. ripped off shaym.in entirely(http://shaym.in/apps/iv_checker - have a look)

b. deleted both the author's credits and copyright

c. after changing a very small bit of the javascript, you tried to make someone else's code unreadable after it was released openly in shaym.in(hint: minify is not obfuscation)

d. put this crap tucked away in the middle of the shaym.in guy's source:

// This calculator is a modified version of Alex Smith's Method 1/J/K PIDIV calculator. It may only be used by Kaphotics' Dropbox.

// http://dl.dropbox.com/u/12206225/RNG/xdc-legal.html

// If this is uploaded to another site, then you are an asshole and a good for nothing. I will hunt you down.

i'm also not at all sure what has to be wrong with you to do that, but here's a fully open version with all functions readable and everything restored as it should be:

http://hack.thundaga.com/doc.html