[Other] Changing the base shiny odds

[0lle]

Hi, I've been looking to change the shiny odds in Pokeemerald. I found this line in \include\contstants\pokemon.h :

#define SHINY_ODDS 8 // Actual probability is SHINY_ODDS/65536

However, there are a bunch of other files (mainly in \src) that contain strings/references to a Pokemon being shiny, like this block in \src\pokemon.c :

bool8 IsMonShiny(struct Pokemon *mon)
{
    u32 otId = GetMonData(mon, MON_DATA_OT_ID, 0);
    u32 personality = GetMonData(mon, MON_DATA_PERSONALITY, 0);
    return IsShinyOtIdPersonality(otId, personality);
}

bool8 IsShinyOtIdPersonality(u32 otId, u32 personality)
{
    bool8 retVal = FALSE;
    u32 shinyValue = HIHALF(otId) ^ LOHALF(otId) ^ HIHALF(personality) ^ LOHALF(personality);
    if (shinyValue < SHINY_ODDS)
        retVal = TRUE;
    return retVal;
}

I'd like to change it to something like 1/512, so I figured I could change the value in pokemon.h to 64. Can anyone tell me if this actually affects the odds of a pokemon being shiny? If it matters: I applied the RNG fix. Thanks in advance.

 

[mgriffin]

I think the number you're looking for is 128 (if you want exactly 1/512), but yeah, I think changing that number should work.

 

[Lunos]

Hi, I've been looking to change the shiny odds in Pokeemerald. I found this line in \include\contstants\pokemon.h :

#define SHINY_ODDS 8 // Actual probability is SHINY_ODDS/65536

However, there are a bunch of other files (mainly in \src) that contain strings/references to a Pokemon being shiny, like this block in \src\pokemon.c :

bool8 IsMonShiny(struct Pokemon *mon)
{
    u32 otId = GetMonData(mon, MON_DATA_OT_ID, 0);
    u32 personality = GetMonData(mon, MON_DATA_PERSONALITY, 0);
    return IsShinyOtIdPersonality(otId, personality);
}

bool8 IsShinyOtIdPersonality(u32 otId, u32 personality)
{
    bool8 retVal = FALSE;
    u32 shinyValue = HIHALF(otId) ^ LOHALF(otId) ^ HIHALF(personality) ^ LOHALF(personality);
    if (shinyValue < SHINY_ODDS)
        retVal = TRUE;
    return retVal;
}

I'd like to change it to something like 1/512, so I figured I could change the value in pokemon.h to 64. Can anyone tell me if this actually affects the odds of a pokemon being shiny? If it matters: I applied the RNG fix. Thanks in advance.

Setting SHINY_ODDS to 64 would change the rate from 1/8191 to 1/1024.
If you want the shiny rate to become 1/512, you want to set it to 128 instead I believe.

But yes, that does modify the chance of a wild Pokémon to be generated as a shiny Pokémon.

 

[0lle]

Alright, thanks! Messed up my math for a second there.