[Pokeemerald] Scripting Tutorial

Inmortal · Mar 9, 2019

Your way to explain is pretty good.

I'm not a native English speaker, and I've understood everything. I know how to script in binary hacking, but read this is very useful to introduce myself to the decomp scripting. I hope you will continue writing this tutorials. A loop tutorial would be great :)

Avara · Mar 26, 2019

Display Pokémon Sprite

You might not use it too often throughout your hack, but showing a Pokémon's sprite can add a little something extra to scripts where the Pokémon is being discussed.

Code:

showmonpic [Pokémon], [X-Co-ord], [Y-Co-ord]

So you need to specify the sprite you want to display and the X/Y co-ordinates of the screen where you want the box containing the sprite to be drawn. The Pokémon species list is in "include\constants\species.h" if you need it. And to hide the box again:

Code:

hidemonpic

Nice and straight forward. A full script example:

Code:

Script_DisplaySpriteDemo::
	lock
	faceplayer
	showmonpic SPECIES_DRATINI, 10, 3
	msgbox Text_DisplaySpriteDemo, MSGBOX_DEFAULT
	hidemonpic
	release
	end

Text_DisplaySpriteDemo:
	.string "Have you seen this Pokémon?$"

Co-ordinates of 10, 3 will display the box containing the specified sprite in the middle of the screen. And that's pretty much it!

Avara · Mar 26, 2019

Screen Fading Effects

It's easy to give the overworld a "fading out" effect - useful for cutscenes and such - by using the fadescreen command which looks like this:

Code:

fadescreen [Fade Type Number]

What do I mean by "fade type number"? Here are the numbers for fading out to black and then reverting to normal:

Avara said:
fadescreen 1 – Screen fades to black.
fadescreen 0 - Screen fades from black back to normal.

Time for an example script and gif so you can see how it looks in-game!

Code:

Script_FadescreenExample::
	msgbox Text_FadescreenExample, MSGBOX_DEFAULT
	fadescreen 1
	fadescreen 0
	end

Text_FadescreenExample:
	.string "Screen fading to black.$"

It's also possible to create a white version of the same effect by swapping out the 1 and 0 for 3 and 2 respectively.

Code:

Script_FadescreenExample::
	msgbox Text_FadescreenExample, MSGBOX_DEFAULT
	fadescreen 3
	fadescreen 2
	end

Text_FadescreenExample:
	.string "Screen fading to white.$"

To serve as a reminder, here is a list of all the fadescreen types for quick reference:

Avara said:
fadescreen 3 – Screen fades to white.
fadescreen 2 – Screen fades from white back to normal.

fadescreen 1 – Screen fades to black.
fadescreen 0 - Screen fades from black back to normal.

Avara · May 13, 2019

Play Pokémon Cry

Using Pokémon cries as a sound effect is another super easy thing to do, all you need is the playmoncry command:

Code:

playmoncry [Pokémon], 0

Followed by waitmoncry, which doesn't have any arguments. Just as it looks, it simply means the script will continue after the cry has finished playing.

Code:

Script_CryDemo::
	lock
	faceplayer
	playmoncry SPECIES_ARBOK, 0
	msgbox Text_CryDemo, MSGBOX_DEFAULT
	waitmoncry
        closemessage
	release
	end

Text_CryDemo:
	.string "Arbok: Hisssss!$"

Shouldn't need much explanation, but I'll break it down just in case: Arbok's cry will play, a message box will appear as the cry plays and will close once the cry has finished playing.

Diego Mertens · Dec 12, 2019

Now, i have to say
This is truly amazing, but there's also a "addobject [id]" and a "hideobjectat [id], [mapname]" functions. both of them are very useful and both helped me with a Wally event that i was doing

Avara · Jan 12, 2020

Diego Mertens said:
Now, i have to say
This is truly amazing, but there's also a "addobject [id]" and a "hideobjectat [id], [mapname]" functions. both of them are very useful and both helped me with a Wally event that i was doing

Definitely true! This amongst many other things was something I'd planned to add on to this tutorial. However, seeing as other scripting systems have recently been created for the decomps - such as PoryScript and Dragonsbreath - I decided it might not be worth updating this guide as much if those were to be more widely used, in case I was wasting my time writing a tutorial for something that'd soon be obsolete and not relevant. Will wait a little while and see what happens. Here's to the future!

UltimaSoul · Jan 22, 2020

Avara said:
Definitely true! This amongst many other things was something I'd planned to add on to this tutorial. However, seeing as other scripting systems have recently been created for the decomps - such as PoryScript and Dragonsbreath - I decided it might not be worth updating this guide as much if those were to be more widely used, in case I was wasting my time writing a tutorial for something that'd soon be obsolete and not relevant. Will wait a little while and see what happens. Here's to the future!

Poryscript still uses these same commands with just parentheses to enclose the arguments, so it's well-worth maybe even slightly gearing your tutorial towards it as the main difference lies in easier conditional checking.

Hestia · Jan 26, 2020

Poryscript still uses these same commands with just parentheses to enclose the arguments, so it's well-worth maybe even slightly gearing your tutorial towards it as the main difference lies in easier conditional checking.

Well, it does a little more than that. Adding branch controls and loop and making goto obsolate for example. With the same mindset one could say the same about decomp scripting and classical XSE scripts, since the default commands stay the same.

Diego Mertens · Feb 16, 2020

Avara said:
Giving Eggs
This section will cover how to give your player a Pokémon Egg.

Code:

giveegg [Pokémon]

Super easy.

Code:

Script_GiveEggDemo:: lock faceplayer msgbox Text_EggQuestion, MSGBOX_YESNO compare VAR_RESULT, 0 goto_if_eq Script_PlayerAnsweredNo getpartysize compare VAR_RESULT, 6 goto_if_eq Script_PlayerHasFullParty giveegg SPECIES_LARVITAR playfanfare MUS_FANFA4 msgbox Text_ReceivedEgg, MSGBOX_DEFAULT waitfanfare release end Script_PlayerHasFullParty:: msgbox Text_PlayerHasFullParty, MSGBOX_DEFAULT release end Script_PlayerAnsweredNo:: msgbox Text_PlayerAnsweredNo, MSGBOX_DEFAULT release end Text_EggQuestion: .string "Will you take this Egg?$" Text_PlayerAnsweredNo: .string "Oh, that's too bad.$" Text_ReceivedEgg: .string "{PLAYER} received the Egg!$" Text_PlayerHasFullParty: .string "Your party is full.\n" .string "There's no room for this Egg.$"

If you've read the other sections of the tutorial, you'll see that this script asks the player whether or not they would like to accept the Egg. After that, if the player responds with "YES", it'll check if they have space in their party before giving it to them. I also already explained how to use getpartysize in the Giving Pokémon section, so I won't bother going over that again.

How do I set up Egg moves for them?
Like, I want to give the player X Pokémon that knows moves that can only be learned via breeding... How can I do this?

Lunos · Feb 16, 2020

Diego Mertens said:
How do I set up Egg moves for them?
Like, I want to give the player X Pokémon that knows moves that can only be learned via breeding... How can I do this?

There's the setmonmove command which you can probably use for that task. By default, it's used to give a Pichu Egg via Mystery Event that knows Surf, apparently.
At first glance, it looks like the arguments the macro needs seem to be the Party Slot where your Egg is in, followed by the move slot you want the move to be set in and then stating the desired move.

For more information, look into the data/scripts/mevent_pichu.inc file if you're using Pokeemerald.

wilikily2205 · Feb 17, 2020

Is there a way to find out which Offsets in the compiled rom belongs to which data in the disassembly?
I ask that becuse I try to fix Emeralds faulty PRNG in pokeemerald.
I found a fix from HackMew (Search in your Browser for 'Pokemon Emerald RNG fix' (Sorry, I can't post links because I haven't made 5 posts)).
The problem is that the fix is for a compiled rom and I don't now where the routines are in pokeemerald that I must edit.

TetsuyaGR · Feb 17, 2020

wilikily2205 said:
Is there a way to find out which Offsets in the compiled rom belongs to which data in the disassembly?
I ask that becuse I try to fix Emeralds faulty PRNG in pokeemerald.
I found a fix from HackMew (Search in your Browser for 'Pokemon Emerald RNG fix' (Sorry, I can't post links because I haven't made 5 posts)).
The problem is that the fix is for a compiled rom and I don't now where the routines are in pokeemerald that I must edit.

You can fix the RNG by editing main.c and specifically putting the line

Code:

SeedRngWithRtc();

below

Code:

InitMapMusic();

Diego Mertens · Feb 19, 2020

How do I move the camera?
Like, I want to show something that the player can't usually see, and I want to move the camera...

Diego Mertens · Feb 19, 2020

TetsuyaGR said:
You can fix the RNG by editing main.c and specifically putting the line

Code:

SeedRngWithRtc();

below

Code:

InitMapMusic();

It generates me an error, saying that it's not definied

wilikily2205 · Feb 20, 2020

Diego Mertens said:
It generates me an error, saying that it's not definied

.
That happens because SeedRngWithRtc(); is defined only in Ruby and Sapphire.
In Emerald the developers removed the routine and replaced by SeedRngAndSetTrainerId(), which they copied from Firered/Leafgreen.
Interestingly SeedRngAndSetTrainerId(); isn't used in src/main.c in pokefirered.
Instead it is used in main/title_screen.c, in the routine SetTitleScreenScene_Cry(s16 * data) in case 2.
This was forgotten in pokeemerald and causes the bug. The routine SetTitleScreenScene_Cry(s16 * data) doesn't exist in main/title_screen.c in pokeemerald.
so to fix that put SeedRngAndSetTrainerId() between static void Task_TitleScreenPhase3(u8 taskId)
{ and if ((gMain.newKeys & A_BUTTON) || (gMain.newKeys & START_BUTTON)).
Alternatively you could do what TetsuyaGR did, just with SeedRngAndSetTrainerId(); instead of SeedRngWithRtc();, that would work as well.
Edit: That fix is not working.

Diego Mertens · Mar 10, 2020

wilikily2205 said:
.
That happens because SeedRngWithRtc(); is defined only in Ruby and Sapphire.
In Emerald the developers removed the routine and replaced by SeedRngAndSetTrainerId(), which they copied from Firered/Leafgreen.
Interestingly SeedRngAndSetTrainerId(); isn't used in src/main.c in pokefirered.
Instead it is used in main/title_screen.c, in the routine SetTitleScreenScene_Cry(s16 * data) in case 2.
This was forgotten in pokeemerald and causes the bug. The routine SetTitleScreenScene_Cry(s16 * data) doesn't exist in main/title_screen.c in pokeemerald.
so to fix that put SeedRngAndSetTrainerId() between static void Task_TitleScreenPhase3(u8 taskId)
{ and if ((gMain.newKeys & A_BUTTON) || (gMain.newKeys & START_BUTTON)).
Alternatively you could do what TetsuyaGR did, just with SeedRngAndSetTrainerId(); instead of SeedRngWithRtc();, that would work as well.
Edit: That fix is not working.

i already fixed it, and it's as simple as adding also the RS function and calling it where you described, since is what was left abandoned... and also a little tweaks in the SeedRngAndSetTrainerId thing, but it easy.

felipenx · Apr 29, 2020

Hi. I copy and past the script for givemon but when i complie. Giveme a error in the line of the givemon saying it has to many parameters. Do yo know what could happens?

Buffel Saft · Apr 30, 2020

felipenx said:
Hi. I copy and past the script for givemon but when i complie. Giveme a error in the line of the givemon saying it has to many parameters. Do yo know what could happens?

Hey, givemon has less been changed to take less input parameters, so instead of:

Code:

givemon SPECIES_DRATINI, 5, ITEM_DRAGON_FANG, 0x0, 0x0, 0

you'd just do:

Code:

givemon SPECIES_DRATINI, 5, ITEM_DRAGON_FANG

felipenx · May 1, 2020

Thanks but When i do that. And compile the script, give me another error saying my script has no reference to event_script. When i go to the event file in the map theres the script listed but still cant do it work.

Buffel Saft · May 1, 2020

felipenx said:
Thanks but When i do that. And compile the script, give me another error saying my script has no reference to event_script. When i go to the event file in the map theres the script listed but still cant do it work.

Could you post your whole script, or the lines that are giving you the error? Can't tell you exactly what that means without seeing your code.

[Pokeemerald] Scripting Tutorial

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Inmortal

Avara

Avara

Avara

Diego Mertens

Avara

UltimaSoul

Hestia

Diego Mertens

Lunos

Random Uruguayan User

wilikily2205

TetsuyaGR

Diego Mertens

Diego Mertens

wilikily2205

Diego Mertens

felipenx

Buffel Saft

felipenx

Buffel Saft