Need help with lua? - LunaLua General Help

[cato]

How to make autoscroll in other sections ? If possible......

[Novarender]

How can you determine the distance between the player and the nearest block underneath them? Or at least detect if they are in mid-air?

[PixelPest]

How can you determine the distance between the player and the nearest block underneath them? Or at least detect if they are in mid-air?

You can check:

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not player:isGroundTouching()

[Novarender]

How can you determine the distance between the player and the nearest block underneath them? Or at least detect if they are in mid-air?

You can check:

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not player:isGroundTouching()

Specifically what does this represent? (Slopes? NPCs?)

[PixelPest]

How can you determine the distance between the player and the nearest block underneath them? Or at least detect if they are in mid-air?

You can check:

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not player:isGroundTouching()

Specifically what does this represent? (Slopes? NPCs?)

All of them

[Novarender]

If I define a variable without using "local", which other .lua files can access it? Is it the ones in the same level folder, episode folder, or the entirety of SMBX?

[Mr Boboo]

Is it possible to despawn an NPC (without killing it) using Lua events?

[Hoeloe]

Absolutely. That's how the magikoopa works if I remember correctly.

[PixelPest]

Is it possible to despawn an NPC (without killing it) using Lua events?

Most definitely. If you look on the PGE Wiki you'll find some documentation of NPC memory fields. You'll need to set the NPC's offscreen timer to 0 iirc and make sure you set the respawn identity (another NPC field, set it to the NPC's ID)

[The0x539]

If I define a variable without using "local", which other .lua files can access it? Is it the ones in the same level folder, episode folder, or the entirety of SMBX?

So... if you declare something not as local, with the current Beta 4 code.... it depends where you do it.
1) If you do it in luna.lua/lunadll.lua/etc:
- If the non-local var matches the name of an event handler, it will be quarantined to JUST exist in that file
- Otherwise, it will be shared with all Lua code within the episode, but quarantined so it's not visible from basegame lua files
2) If you do it in libraries in episode/level folders:
- It is always shared with all Lua code within the episode, but quarantined so it's not visible from basegame lua files
3) If you do it in basegame lua code:
- It is always quarantined to JUST exist in that file

Typically in Lua, global variables go in a table called _G. If you explicitly put something in _G, like

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_G.myVar = 2

, then it'll be accessible everywhere, under most circumstances.

Currently, if you write _G.foo it'll go everywhere in basically all cases.... BUT before beta 4 release I'm strongly considering locking it down so from episode/level code, _G only writes to the context for episode/level stuff

to keep episode/level code messing with _G from affecting core and basegame code

In Beta 3, globals in libraries are shared through the whole Lua shebang, and globals in lunadll.lua and the like aren't shared at all.

[Taycamgame]

So if you want a global collectible, say a special type of coin, you'd have to use global variables for it?
And where would you put the code for that - in the episode lunadll file, or in each level's lunadll file?

[Hoeloe]

No, you wouldn't use global variables for that. The Lua state resets every time you change levels or return to the overworld, so even if you had it saved in a global variable, the value would disappear.

You'd need to use the Data class in beta 3.

[Novarender]

So, how could I add to the save file of the episode using global variables? Or would I have to create my own save file? For instance, what if I want to save which Star Coins the player has collected so that when they save, close and exit it's still saved?

Also, unrelated, how can you "loop until"?

[The0x539]

So, how could I add to the save file of the episode using global variables? Or would I have to create my own save file? For instance, what if I want to save which Star Coins the player has collected so that when they save, close and exit it's still saved?

Also, unrelated, how can you "loop until"?

You wouldn't use global variables. Like Hoeloe said, you'd use the Data class.

[Novarender]

How do I set the player's animation?

[PixelPest]

How do I set the player's animation?

Check out the SMBX Player Offsets page on the PGE Wiki. You'll need to use the player:mem function to set the value at the address 0x114

[Novarender]

How do I set the player's animation?

Check out the SMBX Player Offsets page on the PGE Wiki. You'll need to use the player:mem function to set the value at the address 0x114

I tried that, but I can't set it. In fact, I can't set any of the player offsets.

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player:mem(0x114, FIELD_WORD) = 24

[PixelPest]

How do I set the player's animation?

Check out the SMBX Player Offsets page on the PGE Wiki. You'll need to use the player:mem function to set the value at the address 0x114

I tried that, but I can't set it. In fact, I can't set any of the player offsets.

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player:mem(0x114, FIELD_WORD) = 24

If you look at the documentation that's not how it works. player:mem(0x114, FIELD_WORD) returns the value at the address 0x114 in the player memory struct. Basically you're trying to tell the code to set a number to another number. The player:mem (and all other mem functions in LunaLua) work a special way; put in two arguments and it'll return the associated value, add a third argument to set the value at the mem address.

>player:mem(0x114, FIELD_WORD)

a number

>player:mem(0x114, FIELD_WORD, 24)

address 0x114 set to 24

[Novarender]

Ok, I tried that but it's not doing anything.

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player:mem(0x114,FIELD_WORD,24)

At least it's not giving me an error.

EDIT: It's setting it to 24 every tick but then it's overidden by normal player animations. How can I stop this?

[PixelPest]

Ok, I tried that but it's not doing anything.

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player:mem(0x114,FIELD_WORD,24)

At least it's not giving me an error.

EDIT: It's setting it to 24 every tick but then it's overidden by normal player animations. How can I stop this?

Perform anything graphics-related in onDraw