Skeetendo

Bump.

put it after  ld [wDoNotWaitForButtonPressAfterDisplayingText], a

Take a look at the rematch/phone call thread, I explained how to make events only run once over there.

Nevermind, worked it out after much trial and error.

DirectorText: ; 487b2 (12:47b2)
    TX_ASM

    ; check pokédex
    ld hl, wPokedexOwned
    ld b, wPokedexOwnedEnd - wPokedexOwned
    call CountSetBits
    ld a, [wNumSetBits]
    cp 150
    jr nz, .gotmew
    jr nc, .CompletedDex
    ld hl, .GameDesigner
    jr .done
.CompletedDex
    ld hl, .CompletedDexText
.done
    call PrintText
    jp TextScriptEnd

.GameDesigner ; 487d0 (12:47d0)
    TX_FAR _GameDesignerText
    db "@"

.CompletedDexText
    TX_FAR _CompletedDexText
    db $6
    TX_ASM
    ld a, [wd72e]
    and a ; got mew?
    jr z, .givemew
.givemew
    ld hl, .MeetMewGuyText
    call PrintText
    call z, WaitForTextScrollButtonPress
    lb bc, MEW, 5
    call GivePokemon
    ld a, [wSimulatedJoypadStatesEnd]
    and a
    call z, WaitForTextScrollButtonPress
    call EnableAutoTextBoxDrawing
    ld hl, .HeresYourMewText
    call PrintText
    ld hl, wd72e
    set 0, [hl]
    jr z, .gotmew
.gotmew
    ld hl, .GaveMewText
    call PrintText
       jp TextScriptEnd
    
.GaveMewText
    TX_FAR _GaveMewText
    db $6
    TX_ASM
    callab DisplayDiploma
    ld a, $1
    ld [wDoNotWaitForButtonPressAfterDisplayingText], a
    jp TextScriptEnd    
    
.MeetMewGuyText
    TX_FAR _MeetMewGuyText
    db "@"

.HeresYourMewText
    TX_FAR _HeresYourMewText
    db "@"
    jp TextScriptEnd

Turns out I just had to add "jr nz, .gotmew" to

cp 150
    jr nz, .gotmew
    jr nc, .CompletedDex
    ld hl, .GameDesigner
    jr .done

Speaking of Mew, I'm actually thinking of including an homage to the Mew glitch in my own hack. Specifically, after you beat the Swimmer in Cerulean Gym, after a set number of steps, you'll have a random wild encounter with Mew, and unless you're in a house, a Pokémon Center, or a Poké Mart, the whole map becomes like a less strong version of the Cave Tile Effect, i.e. every step has a chance of summoning wild Pokemon, only the appearances will be far less frequent and every wild encounter not in tall grass or water or cave will be a Lv. 5 Mew, which will not stop bothering you even if you defeat it in combat until you capture it successfully.

Or would there be a better way to go about this Mew glitch homage? (Do keep in mind that you can do the Mew glitch as it's traditionally performed as early as Cerulean City in the actual games.)

Ok, so I setup a fork of your copy on github, got it on my pc, and when I tried to build it, I just got a ton of "OPP_ already defined" errors. I thought it would be easier for me to work in out if I was playing with your actual code, but since clearly that isn't working, guess I'll have to do it the way I'd been doing.

Talked to Danny (since your project is based on his patch) and he suggested that my RGBDS is probably out of date. Sounds about right. I'll get that updated and see what I can come up with.

In the meantime, try moving the

jr nz, .gotMew

line, so that instead of being right after cp 150, it is REPLACING the "jr z, .giveMew" line further down.

That way, if you've already got mew, it goes to the GotMew line, otherwise it falls through to giving you mew the first time.

To be fair, that comment was actually off-topic, so I was focusing on the original question (how to make the man give Mew instead of just the Diploma) before moving on to that. And since that is completely unrelated to what we're figuring out in this thread, it would probably be better to discuss that in another thread, so it doesn't get lost by trying to have two unrelated discussions at the same time.

Also, the way you originally wanted to do it, I'm not sure of any good way to do that, so I would have to look into it.

I think the problem is what you are trying to use to set Mew as being received. wd72e is used by various other things, and is not a good choice to use for trying to permanantly mark an event as having happened. Kinda like how you added a new location to store the player's gender. You could just add

wExtraFlags::
ds 1

in wram.asm, (probably near wPlayerGender, but it doesn't really matter so long as it is inside the "main data" block so it will be saved) and replace wd72e with wExtraFlags and see if it works properly. Probably something else has already set the bit you are trying to check, so the game thinks you've already got Mew.