Check If Point Is Walkable

[Dynasti]

Tutorial: Check If Point Is Walkable

For this you will need:

1. The latest version of JNGP, can be found here
2. Jass and vJass knowledge

The system im going to teach you is a simple system that allows you to check if the point is blocked by a wall, tree or doodad. ( This is more accurate than the IsTerrainPathable )

I recommend to use this simple func because of it's accuracy.

First thing you are going to is to open your converted trigger and create a library, lets call it CheckSystem

library CheckSystem initializer Init
endlibrary

Now for the globals:

library CheckSystem initializer Init

    globals
        // This item id 'sehr' is just a random item id,
        // you can use whatever you want
        private constant integer I_ID = 'sehr'
        private item I = null
    endglobals

endlibrary

When the globals are done the rest is pretty easy to do. First, we are going to add the "Init" function that we declared in the library's initializer

library CheckSystem initializer Init

    globals
        private constant integer I_ID = 'sehr'
        private item I = null
    endglobals

    private function Init takes nothing returns nothing
        // Creating the item
        set I = CreateItem(I_ID, 0, 0)
        // We turn off the visibility for the item because we dont
        // want it to show up in game.
        call SetItemVisible(I, false)
    endfunction
endlibrary

We made a private function because we dont want it to be shared with other systems

Now for the final function in this system. This is the function you will be calling to check that the point is walkable. Lets call the function "IsPointWalkable".

library CheckSystem initializer Init

    globals
        private constant integer I_ID = 'sehr'
        private item I = null
    endglobals

    function IsPointWalkable takes real x, real y returns boolean
        // What we do is that we set the item to the point that is given.
        // Then we check if the item's position after moving is what it
        // should be.
        call SetItemPosition(I, x, y)
        // We set the item's visible off again because it is turned 
        // on whenever it is moved
        call SetItemVisible(I, false)
        return GetItemX(I) == x and GetItemY(I) == y
    endfunction

    private function Init takes nothing returns nothing
        set I = CreateItem(I_ID, 0, 0)
        call SetItemVisible(I, false)
    endfunction
endlibrary

Remmember to always use "function" or "public function" for usage outside the library/scope. A "private function" cannot be accessed outside the system

The final code:

library CheckSystem initializer Init

    globals
        // This item id 'sehr' is just a random item id,
        // you can use whatever you want
        private constant integer I_ID = 'sehr'
        private item I = null
    endglobals

    function IsPointWalkable takes real x, real y returns boolean
        // What we do is that we set the item to the point that is given.
        // Then we check if the item's position after moving is what it
        // should be.
        call SetItemPosition(I, x, y)
        // We set the item's visible off again because it is turned 
        // on whenever it is moved
        call SetItemVisible(I, false)
        return GetItemX(I) == x and GetItemY(I) == y
    endfunction

    private function Init takes nothing returns nothing
        // Creating the Item
        set I = CreateItem(I_ID, 0, 0) 
        // We turn off the visibility for the item because we dont
        // want it to show up in game.
        call SetItemVisible(I, false)
    endfunction
endlibrary

This system is really easy to use.

Example:

function Test takes nothing returns nothing
    local real x = 47
    local real y = 19

    if IsPointWalkable(x, y) then
        call BJDebugMsg("Point is walkable!")
    endif
endfunction

Final Note

This sytem only applies for doodads, destructables and buildings( Things that normal land units cannot walk on )​

 

[TheBlooddancer]

*Cough* you know what i am gonna say.

But besides that, seems pretty usefull, and you didn't waste thoose 20 mins then

 

[Dynasti]

*Cough* you know what i am gonna say.

But besides that, seems pretty usefull, and you didn't waste thoose 20 mins then

^^ hehe

 

[Kwah]

It's not really a tutorial. Add more explanation.

 

[Dynasti]

It's not really a tutorial. Add more explanation.

like what?

 

[Kwah]

Explain what each thing is in detail, why it's there and what it means.

EDIT: Although there isn't much more to say. This should be a "How To", not a tutorial.

 

[Dynasti]

Explain what each thing is in detail, why it's there and what it means.

EDIT: Although there isn't much more to say. This should be a "How To", not a tutorial.

Tutorial = How To

-.-

 

[Kwah]

Tutorials are normally more in depth. And I'd still call this code snippets/script. But meh.

 

[Dynasti]

Tutorials are normally more in depth. And I'd still call this code snippets/script. But meh.

yay ^^

 

[scorpion182]

you can use native IsTerrainPathable
native IsTerrainPathable takes real x, real y, pathingtype t returns boolean

 

[Dynasti]

you can use native IsTerrainPathable
native IsTerrainPathable takes real x, real y, pathingtype t returns boolean

that goes for terrain, not walls

 

[TheBlooddancer]

Meh, i vote for this' approval.

 

[Dynasti]

you can use native IsTerrainPathable
native IsTerrainPathable takes real x, real y, pathingtype t returns boolean

that goes for terrain, not walls

And the IsTerrainPathable isn't as accurate as the IsPointWalkable func

 

[PurplePoot]

While you go, explain why you do what you do so that people learn rather than just copy/pasting the code, lacking any understanding of what they just did.

 

[Linaze]

I agree with what Poot said above. Since I'm not a JASSer I can't tell whatever this works at all or not. But what I can say is that you are telling people how to do something, not how it works etc. A real tutorial should be about explaining and teaching something to someone, instead of just giving them an already finished code. For that, they could just go to the JASS resource section. My suggestion is to add some more explanations to what the different steps and the code in them actually mean.

 

[PurplePoot]

It doesn't work properly anyways.

 

[Linaze]

All right. Then this should be graveyarded. I'll notify Pyritie about it.

 

[Pyritie]

Graveyard'd