Help with multiple touches

Questions
1

Hello, I’m new to Codea and found it very accessible, but I have been stuck for days with a touch issue. I have set up a d-pad interface with other buttons for shoot/dash/etc and I’m having trouble understanding how to make a button press-able while holding a direction and vice versa. It seems that “touch” is the only built in variable, so how do you differentiate between one touch being held and another touch beginning - or 2 touches beginning at the same time?

2

@n0ogit The touch function also uses a touch id. Each time you touch the screen, you get a different id. By using the id, you can differentiate between multiple touches. If you need an example, I have one someplace, I just have to find it.

3

@n0ogit I found it. You can hold down any one of the direction keys and press the shoot button.

function setup()
    rectMode(CENTER)
    dir=""
    stab=""
    btn={}
    table.insert(btn,buttons(300,300,100,50,"UP"))
    table.insert(btn,buttons(300,100,100,50,"DOWN"))
    table.insert(btn,buttons(200,200,100,50,"LEFT"))
    table.insert(btn,buttons(400,200,100,50,"RIGHT"))
    table.insert(btn,buttons(300,400,100,50,"SHOOT"))
end

function draw()
    background(40, 40, 50)
    for a,b in pairs(btn) do
        b:draw()
        if b.pressed then
            if b.text=="SHOOT" then
                stab=b.text
            elseif dir=="" then
                dir=b.text
            end
        end
    end
    fill(255)
    text(dir,WIDTH/2,HEIGHT-50)
    text(stab,WIDTH/2,HEIGHT-100)
end

function touched(t)
    for a,b in pairs(btn) do
        b:touched(t)
    end
end

buttons=class()

function buttons:init(x,y,w,h,txt)
    self.x=x
    self.y=y
    self.w=w
    self.h=h
    self.text=txt
    self.left=x-w/2
    self.right=x+w/2
    self.bottom=y-h/2
    self.top=y+h/2
    self.pressed=false  
    self.id=0 
end

function buttons:draw()
    fill(255)
    if self.pressed then
        fill(255, 158, 0, 255)
    end
    rect(self.x,self.y,self.w,self.h)   
    fill(255,0,0) 
    text(self.text,self.x,self.y)
end

function buttons:touched(t)
    if t.state==BEGAN or t.state==MOVING and self.id==0 then
        if t.x>self.left and t.x<self.right and 
                    t.y>self.bottom and t.y<self.top then
            self.pressed=true
            self.id=t.id
        end
    end
    if t.state==MOVING and self.id==t.id then
        if t.x>self.left and t.x<self.right and 
                    t.y>self.bottom and t.y<self.top then
            self.pressed=true
        else
            self.pressed=false
            self.id=0
            dir=""
            stab=""
        end
    end
    if t.state==ENDED and self.id==t.id then
        self.pressed=false
        self.id=0
        dir=""
        stab=""
    end
end
4

There are also a couple of sample projects which have examples of handling multiple touches. In my projects, I use a touch handler which gathers the touch information and then delegates it out to various objects that want to use the touch information. You can find my code on github. I’m not particularly recommending you use my code as-is, but it might show you a way to work with multiple touches.

5

Thank you! That makes complete sense.