How a cloud list engine works and how to use it

As i explained above, a cloud list engine works by encoding and decoding letters, numbers, or data you give it, you might not think that using a cloud list engine is necessary, but believe me it is :) This will allow us to keep track of their usernames, so you can see who you are playing with :). The engine i use has to main custom blocks, they are

Save [List... v] to [Variable... v] :: custom

Load () to  [List... v] :: custom

The Save block saves a list to the cloud, lets say you have a list with peoples name, and everytime someone clicked the flag, their name would be added, we would first load the list, which puts whatever is in the cloud to as it was before it was saved, so we have the latest data, then we would add the username to the list, and hen we would save it, it would look like this

when green flag clicked
Load (☁ Users) to  [Usernames v] :: custom
if <not <[Usernames v] contains (username)>> then
add (username) to [Usernames v]
Save [Username v] to [☁ Users v] ::custom
    
end

this script will check if the list does not contain your username, to avoid username spam, then it would load the data to a list i created called “Username” from the cloud variable “Users” it would add username to the list usernames, and save username to the cloud variable called “Users”, this is not found in your scratch inventory for those of you frantically searching, simply add the sprite located in this project to your backpack
https://scratch.mit.edu/projects/68788730/

Notice!
If you dont understand this, feel free to ask in the comments, id be happy to explain in more detail how a cloud list engine works

Multiplayer Game Setup

Lets setup your game, before we begin anything, lets make an average menu that has a button that says join, the join button should be one sprite, then make 4 sprites, called “Client” “Player 1” “Player 2” “Player 3” “Player4”, draw your character in the middle of the scratch art editor, be sure to create your first character before creating the other player sprites so you dont have to create the characters again, so basically just duplicate it three other times once you are finished with the first sprite, lets make a sprite called “Multiplayer” and the final sprite should be the one we just got called “Cloud list engine”, before continuing on to the first step, make sure that your menu works, and put when flag clicked, hide in all player sprites,make sure the button “Join” broadcasts “Join” and hides itself once clicked, but shows itself when the * is clicked, basic stuff

The Multiplayer Game

What this script will do is kick inactive players, start an inactive forever player checker (Checks that players are actually online), and find the ID of the player (This is so we know which player you are) based on who is online. Lets start with the activity checker, basically the client (You) will have a script which changes its check by one, we will have a list containing four items with 0, this list will be called

(Checker :: list)

This is where what we learned about cloud lists comes in handy, the activity reporter (Tells the project that you are alive) must look like this

On Client Sprite

when I receive [IdRec v]
forever
    
if <(ID) = [1 ]> then
    
replace item (4 v) of [Player1  v] with ((item (3 v) of [Player1  v]) + (1))
end
if <(ID) = [2]> then
    replace item (4 v) of [Player2  v] with ((item (3 v) of [Player2  v]) + (1))
end
 if <(ID) = [3]> then
    replace item (4 v) of [Player3  v] with ((item (3 v) of [Player3  v]) + (1))
end
 if <(ID) = [4]> then
    replace item (4 v) of [Player4  v] with ((item (3 v) of [Player4  v]) + (1))
end

end

This will basically replace the last item of your four item profile with the previous item plus 1, so the program knows if you are alive, but this needs to be put on dat cloud :P Here is how to do so, this does not broadcast anything to the cloud, the script that will will be on the moving (Plataformer) script, dat script is huge :P

On CloudList engine sprite

when I receive [LoadChecker v]
if <(ID)=[1]> then
Load (☁ Player2) to [Player2 v]  :: custom
Load (☁ Player3) to [Player3 v]  :: custom
Load (☁ Player4) to [Player4 v]  :: custom
else
if <(ID)=[2]> then
Load (☁ Player1) to [Player1 v]  :: custom
Load (☁ Player3) to [Player3 v]  :: custom
Load (☁ Player4) to [Player4 v]  :: custom
else
if <(ID)=[3]> then
Load (☁ Player1) to [Player1 v]  :: custom
Load (☁ Player2) to [Player2 v]  :: custom
Load (☁ Player4) to [Player4 v]  :: custom
else
if <(ID)=[4]> then
Load (☁ Player1) to [Player1 v]  :: custom
Load (☁ Player2) to [Player2 v]  :: custom
Load (☁ Player3) to [Player3 v]  :: custom

when I receive [SaveChecker v]
if <(ID)=[1]
Save [Player1 v] to [☁ Player1 v]  :: custom
else
if <(ID)=[2]
Save [Player2 v] to [☁ Player2 v]  :: custom
else
if <(ID)=[3]
Save [Player3 v] to [☁ Player3 v]  :: custom
else
if <(ID)=[4]
Save [Player4 v] to [☁ Player4 v]  :: custom

Cool! This does not do anything yet but it will soon :O Now lets head on over to the empty multiplayer sprite, This will check if people are alive,not report it, so this can be done by doing this, we will need only two scripts here and you never have to touch this again :D (On this sprite only)
and will make sure that new players dont join unless their is space available for them

The Multiplayer Sprite

when I receive [Join v]
delete (all v) of [.Check v]
add (☁ Player1) to [.Check  v]
add (☁ Player2) to [.Check  v]
add (☁ Player3) to [.Check  v]
add (☁ Player4) to [.Check  v]
wait (2) secs
if < not <(☁ Player4) = (item (4 v) of [.check  v])>>
if  <(☁ Player1) = (item (1 v) of [.check  v])> then
    set [ID v] to [ 1]
else
if  <(☁ Player2) = (item (2 v) of [.check  v])> then
    set [ID v] to [ 2]
else
if  <(☁ Player3) = (item (3 v) of [.check  v])> then    
set [ID v] to [ 3]
else
if  <(☁ Player4) = (item (4 v) of [.check  v])>  then
    set [ID v] to [ 4]
end



    
end
end
end
broadcast [IdRec v]
when I receive [IdRec v]
delete (all v) of [Inactive v]
forever
delete (all v) of [.Check v]
add (☁ Player1) to [.Check  v]
add (☁ Player2) to [.Check  v]
add (☁ Player3) to [.Check  v]
add (☁ Player4) to [.Check  v]
wait (2) secs
if  <(☁ Player1) = (item (1 v) of [.check  v])> then
    set [ID v] to [ 1]
else
add [1] to [ Inactive v]
if  <(☁ Player2) = (item (2 v) of [.check  v])> then
    set [ID v] to [ 2]
else
add [2] to [ Inactive v]
if  <(☁ Player3) = (item (3 v) of [.check  v])> then

    set [ID v] to [ 3]
else
add [3] to [ Inactive v]

if  <(☁ Player4) = (item (4 v) of [.check  v])> then
    set [ID v] to [ 4]
else
add [4] to [ Inactive v]

end



    
end
end

We are almost done! Nah im messing with you, but we are doing good :P Now for the client, add this script to your client sprite (A platformer script is what makes your character move, a greaaaaaat platformer script can be found here: https://scratch.mit.edu/projects/34429446/, now lets consider the plataformer script is all in a block, called plataform (Simply because I do not want to type a very long script right now, take out the forever loop in the plataform script and put it in with a new one, and then we will add a tiny script below the plataformer script that will check the ID of the users and add the x and y positions to their profile

The Client Sprite

when I receive [IdRec v]
forever
    
-PlataformerScriptOfYourChoice- :: pen
if  <(ID) =[1]> then
    replace item [1] of [Player1  v] with (x position)
   replace item [2] of [Player1 v] with (y position)
replace item [3] of [Player1  v] with (Username)
else
if  <(ID) =[2]> then
       replace item [1] of [Player2  v] with (x position)
   replace item [2] of [Player2 v] with (y position)
replace item [3] of [Player2  v] with (Username)
else
if  <(ID) =[3]> then
       replace item [1] of [Player3  v] with (x position)
   replace item [2] of [Player3 v] with (y position)
replace item [3] of [Player3  v] with (Username)
else
if  <(ID) =[4]> then
    replace item [1] of [Player4  v] with (x position)
   replace item [2] of [Player4  v] with (y position)
replace item [3] of [Player4  v] with (Username)
end
end
end
end

broadcast [SaveChecker v] and wait

if you got through that then congratz, now if not done already build a platform where your players will be on, just a flat one, and now we are almost done, not joking this time, now there is one script you have to add to all players sprites, for example the scripts will use the last letter of the players sprite, so for example this would be the script in the first player sprite

when green flag clicked
forever
    
if <not <(ID) = [ 1]>> then
if <not <[Inactive v] contains [1]>> then
show
go to x: (item (1 v) of [Player1  v]) y: (item (2 v) of [Player1  v])
say (item (3 v) of [Player1  v])
    
else
hide
    
end

end

and for player two, replace the not id = 1 to not Id = 2 and not inactive contains one to not inactive contains 2 and replace all the player one lists two player 2 lists, if you did this successfully you have th simplest script weve ever made and were finished for real, add this where ever you want, preferabbly in the multplayer sprite, it has to say

when I receive [Join v]
forever
    
broadcast [LoadChecker v] and wait
end

and theyre you go! you have a fully working multiplayer project, tell me in the comments if you are having trouble so i can help :)
Good day!

~EncloCreations

ZozaTech wrote:

Hi. It is nice you like to help others! But the help with scripts is only for helping other people with their problems
Thanks though

EncloCreations wrote:

ZozaTech wrote:

Hi. It is nice you like to help others! But the help with scripts is only for helping other people with their problems
Thanks though

Oh okey, thankyou i was confused

EncloCreations wrote:

Actually it says you are allowed to post guides here
Thats what a lot of people do

EncloCreations wrote:

bump

EncloCreations wrote:

i can bump it if i want to,

EncloCreations wrote:

Whut, lol im joking xD But seriously, its part of this thread

EnderScout_77 wrote:

This is a GREAT tutorial. So, um, how do you report topics to be stickied? (You know what I mean )

when green flag clicked