there are some changes but it did all | Official Unity Discord | Page 1

molten roost Jun 9, 2023, 5:12 PM

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because, if so, this does not make sense.

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public class PathNode

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note that it does not implement any interfaces and does not derive from anything

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the tutorial must have something like that

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and the GridSystem declaration must have some kind of constraint on the generic type

verbal thistle Jun 9, 2023, 5:14 PM

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public class GridSystem<TGridObject>
{

private int width;
private int length;
private float height;
private int floor;
private float floorHeight;
private TGridObject[,] gridObjectArray;



public GridSystem(int width, int length, int floor, float floorHeight, Func<GridSystem<TGridObject>, GridPosition, TGridObject> createGridObject)   that still looks the same

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the gridobject script seems unchanged aswell

molten roost Jun 9, 2023, 5:14 PM

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public abstract class GoesOnGrid {
  public GridPosition gridPosition;
}

public class GridSystem<T> where T : GoesOnGrid { }

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it has to look something like this

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so that anything you store in the GridSystem is guaranteed to have a gridPosition field

verbal thistle Jun 9, 2023, 5:15 PM

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do you mean the part where my gridsystem gets instantiated?

molten roost Jun 9, 2023, 5:15 PM

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No, I'm talking about the definition of GridSystem.

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The point of generics is to let you pick a type to use, rather than being forced to use a single specific type

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Sometimes, there are no limitations on what type you use

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List<T> lets you use whatever you want

verbal thistle Jun 9, 2023, 5:16 PM

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yeah i get that part of generics, but how its implemented here i really dont get

molten roost Jun 9, 2023, 5:17 PM

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However, that means that List can't really do anything with objects of the generic type

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because they could be literally anything

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your GridSystem needs to actually do things with its contents

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notably, it tries to get gridPosition out of the objects

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if you just define it like this

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public class GridSystem<T>

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then you can't do that, because maybe T is an int or something

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you can't write 3.gridPosition

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so you get an error

molten roost Jun 9, 2023, 5:17 PM

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molten roost ```cs public abstract class GoesOnGrid { public GridPosition gridPosition; } ...

that's where the constraint comes in

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Whatever T is, it must be compatible with GoesOnGrid

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that means that if you have an object of type T, you can get gridPosition from it

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because T has been constrained to be compatible with GoesOnGrid

verbal thistle Jun 9, 2023, 5:20 PM

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https://hastebin.com/share/gubehoviji.csharp if it helps, here is how the gridsystem worked before i started refactoring it

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molten roost Jun 9, 2023, 5:20 PM

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molten roost ```cs public abstract class GoesOnGrid { public GridPosition gridPosition; } ...

so, you could do something like this

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public abstract class GoesOnGrid {
  public GridPosition gridPosition;
}

public class GridObject : GoesOnGrid {
  public int health;
  public string label;
}

public class GridPathfindingInfo : GoesOnGrid {
  public bool passable;
}

public class GridSystem<T> where T : GoesOnGrid { }

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GridSystem<GridObject> and GridSystem<GridPathfindingInfo> would both be valid

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and GridSystem would be able to access gridPosition from

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one of two things is possible:

the tutorial never tries to access anything from the things the GridSystem is tracking
the tutorial constraints the type of things that GridSystem can track

verbal thistle Jun 9, 2023, 5:23 PM

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the gridobject does not hold stats like you typed, it holds the unit that holds the variables + the gridpositions

molten roost Jun 9, 2023, 5:23 PM

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sure, i just made some stuff up

verbal thistle Jun 9, 2023, 5:25 PM

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guess ill try asking the guy directly what functions exactly the Tgridobjects serve, otherwise ill try without them

molten roost Jun 9, 2023, 5:25 PM

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i'm still having a lot of trouble understanding what you are trying to do here

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let me put it this way: does GridSystem ever need to access any fields or methods on GridObject?

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I'm pretty sure you were trying to do that in your original question

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i think most of my issues come from that my old gridobject.gridposition does not work anymore

verbal thistle Jun 9, 2023, 5:27 PM

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i use gridobject.gridposition all the time, its for accessing all the x,y,z and floor data thats stored in my gridpositions inside the gridobjects

molten roost Jun 9, 2023, 5:27 PM

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but does GridSystem need to do that?

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does it care about the gridposition field?

verbal thistle Jun 9, 2023, 5:29 PM

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yeah, since the grid is created in this script, other scripts access the positions here thorugh functions such as create debugobjects() and getgridposition()

molten roost Jun 9, 2023, 5:30 PM

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verbal thistle https://hastebin.com/share/gubehoviji.csharp if it helps, here is how the gridsy...

I see zero places in this code where GridSystem needs to access the gridposition field of GridObject

verbal thistle Jun 9, 2023, 5:31 PM

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are you checking from before my refactor or after?

molten roost Jun 9, 2023, 5:31 PM

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verbal thistle https://hastebin.com/share/gubehoviji.csharp if it helps, here is how the gridsy...

Whatever this is.

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I noticed that it has generics in it, though, so I'm not sure that's from before the refactor...

verbal thistle Jun 9, 2023, 5:32 PM

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thats from before the refactor, the original code that worked

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https://hastebin.com/share/kiduheziva.java line 176

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molten roost Jun 9, 2023, 5:33 PM

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ok, so now you are trying to access a member of TGridObject

verbal thistle Jun 9, 2023, 5:33 PM

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this is from my current script

molten roost Jun 9, 2023, 5:33 PM

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which does not work, because TGridObject could be anything

verbal thistle Jun 9, 2023, 5:35 PM

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i noticed that in this refactor, some of the other scripts where still referencing the old gridobject instead of a tgridobject, is the difference that the normal gridobject holds the current data and tgridobject something else?

molten roost Jun 9, 2023, 5:36 PM

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TGridObject is just whatever type you choose to use with GridSystem.

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It has nothing to do with GridObject whatsoever

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GridSystem should not reference GridObject anywhere if you want to be able to use GridSystem with many different types.

verbal thistle Jun 9, 2023, 5:38 PM

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private List<GridSystem<PathNode> < i took this from the pathfinding script. im guessing he's reusing the gridsystem functions( dimensions) here to make a copy of the grid but fill it with pathnodes instead?

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so aTgridobject could be either a gridobject or a pathnode

molten roost Jun 9, 2023, 5:40 PM

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Right.

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I would rename TGridObject to just T

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it has no relationship to GridObject

verbal thistle Jun 9, 2023, 5:41 PM

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that would clear some confusions yeah, ill try doing that

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thanks for all the help btw, sorry i cant explain it better

molten roost Jun 9, 2023, 5:43 PM

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the idea is to add just enough constraints to do the work you need to

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and nothing more

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a too-extreme constraint would be

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public class GridSystem<T> where T : GridObject

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that would not allow you to use PathNode

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a too-loose constraint would be

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public class GridSystem<T>

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T is too vague

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public abstract class OnGrid {
  public GridPosition gridPosition;
}

public class GridSystem<T> where T : OnGrid

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that's the sweet spot

verbal thistle Jun 9, 2023, 5:48 PM

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i guess i would have to add my units aswell to that ongrid class if i understand it correctly?

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or can different T's take different amount of parameters?

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@molten roost first time using a thread, i guess it doesnt ping automatically

molten roost Jun 9, 2023, 5:55 PM

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OnGrid will define what everything that goes on the grid must provide

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GridSystem will only be able to see members of OnGrid

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however, the users of GridSystem will be working with the specific type they want

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if I have a GridSystem<GridObject>, it will give me GridObject, and I'll have access to everything on GridObject

verbal thistle Jun 9, 2023, 5:56 PM

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allright ty

molten roost Jun 9, 2023, 5:59 PM

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So, GridSystem will have to stick with the common functionality of all of the types it supports

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like how List<T> can't really do anything with its items

verbal thistle Jun 9, 2023, 6:02 PM

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@molten roost made a screenshot so you could see the error here im trying to acces the gridobjects instead of the T now, but it seems since the [,][] array gets declared as a T i cant acces it here anymore

molten roost Jun 9, 2023, 6:03 PM

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Yes, since that array holds T.

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You can't assume it holds GridObject anymore. It could be anything compatible with the generic type

verbal thistle Jun 9, 2023, 6:04 PM

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so for a function that wants to acces the gridobjects. how can i make that distinction?

molten roost Jun 9, 2023, 6:04 PM

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does it really need GridObjects

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or does it just need to know about all of the things this GridSystem is tracking, and their grid positions?

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it sounds like the latter to me

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you may also need to change GridDebugObject to reference an OnGrid instead of a GridObject

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(assuming you called that abstract class OnGrid)

verbal thistle Jun 9, 2023, 6:05 PM

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i can convert it to use T instead cause the dimensions are the same but than i cant acces the gridobject.gridpositions anymore

molten roost Jun 9, 2023, 6:06 PM

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molten roost ```cs public abstract class OnGrid { public GridPosition gridPosition; } publ...

because you haven't constrained T, have you?

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if T can be anything, then you can't do anything with it

verbal thistle Jun 9, 2023, 6:06 PM

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molten roost because you haven't constrained `T`, have you?

ah no not yet, i figured it would work without. ill do that now

molten roost Jun 9, 2023, 6:07 PM

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without a constraint, the compiler cannot assume anything about T

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this isn't like c++ templates, where you just kinda substitute stuff in when you use it

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(meaning that you'd get an error when you try to use a T that doesn't have a gridPosition field)

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you must constrain T so that it has everything you need

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does GridDebugObject need anything other than the position of something?

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you use SetGridObject to tell it about a specific GridObject

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If it only cares about the position of something, then it can also be changed to use an OnGrid

verbal thistle Jun 9, 2023, 6:18 PM

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@molten roost sorry didnt notice your messages here i managed to clear all the errors in the gridsystem. now im left with how all the other scripts are calling it

verbal thistle Jun 9, 2023, 6:44 PM

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public abstract class OnGrid
{
    public GridPosition gridPosition;
    public GridObject [,][] gridObjectArray;
    public Unit unit;
   
}
``` ive added gridobject to the abstract class but the errors persist

molten roost Jun 9, 2023, 7:02 PM

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I don't understand your design.

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OnGrid is an abstraction of what used to be GridObject, but now OnGrid contains GridObject?

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please explain what these things mean

verbal thistle Jun 9, 2023, 7:06 PM

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i added it in an attempt to figure out what was causing the errors in the picture i send above

molten roost Jun 9, 2023, 7:07 PM

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you can't just add stuff at random..

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OnGrid only contains things that everything on a grid needs

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If a field or method isn't needed by GridSystem, then it does not belong on OnGrid

verbal thistle Jun 9, 2023, 7:15 PM

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i used to call it with a gridobject, im guessing that should still be the case for all my current scripts, i followed ティナ's advice i just got and my game compiles now

molten roost Jun 9, 2023, 7:16 PM

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"used to call it with a gridobject"?

molten roost Jun 9, 2023, 7:16 PM

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molten roost If a field or method isn't needed by `GridSystem`, then it does not belong on `O...

A script that works with GridObjects should use the GridObject type, not the OnGrid type

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Only GridSystem should really need to use the OnGrid type.

verbal thistle Jun 9, 2023, 7:16 PM

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molten roost "used to call it with a gridobject"?

#1116776820390498376 message i mean with how i call it here

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ティナ told me gridobjects should inherit from ongrid and that fixed the errors i was getting

molten roost Jun 9, 2023, 7:25 PM

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molten roost ```cs public abstract class GoesOnGrid { public GridPosition gridPosition; } ...

right, like this

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each of these various classes derive from OnGrid

verbal thistle Jun 9, 2023, 7:27 PM

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molten roost ```cs public abstract class OnGrid { public GridPosition gridPosition; } publ...

ahh i see, i implemented it like you wrote here^

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@molten roost how can i properly thank you guys? the help is really appreciated a lot and i feel bad i dont always understand the solutions you guys give me

molten roost Jun 9, 2023, 7:29 PM

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by making your game :p

#there are some changes but it did all