Need help with touch events.

Questions
1

Hello, I was watching a Patrick Coxall’s Codea tutorial on YouTube. In lesson 4 he was talking about touch events.
The code listed below must check, if I am touching inside the sprite’s hitbox, but no…It actually doesn’t.

Here is the code.

if (touch.state == MOVING) then
        if ( (imagePosition.x - imageSize.x/2) < currentTouchPosition.x and
            (imagePosition.x + imageSize.x/2) > currentTouchPosition.x and
            (imagePosition.y - imageSize.y/2) < currentTouchPosition.y and
            (imagePosition.y + imageSize.y/2) > currentTouchPosition.y) then 
            
            imagePosition = currentTouchPosition 
       end
end
2

Oh and actually after the first if statement you’ll see in the code there is an indent, it was there, but it didn’t browse when I copied the code.

3

The code seems ok, except it will only trigger if your finger moves. Simply touching the screen won’t do it.

If you want to just trap simple touches, rather use

if touch.state==ENDEd then
4

@Ignatz the guy who did the tutorial had everything work, watch the video, and you’ll see why am I so mad that his code works, but mine doesn’t, even while I’m moving my finger. I’m soooo mad!!

5

Well, check all your code carefully. Programming can be frustrating sometimes.

6

@Ignatz here is the video link:
https://m.youtube.com/watch?v=B3k0saVH5uA

7

Do you probably have a typo somewhere?

I did the series during the last weeks as well. I modified some names and added print()'s here and there, but maybe my code helps you by using a diff:

http://pastebin.com/c55GxJjB

8

@Ignatz Thanks, that’s such a motivation!

9

@HappyProgrammer11 It doesn’t take a lot of code to select a Sprite and move it around the screen.

displayMode(FULLSCREEN)

function setup()
    img=readImage("SpaceCute:Beetle Ship")
    w2=img.width/2  -- image width / 2
    h2=img.height/2 -- image height / 2
    x=300   -- starting x position
    y=300   -- starting y position
end

function draw()
    background(40, 40, 50)
    sprite(img,x,y)
end

function touched(t)
    if t.x>x-w2 and t.x<x+w2 and t.y>y-h2 and t.y<y+h2 then -- touch area
        if t.state==BEGAN or t.state==MOVING then
            x=t.x
            y=t.y
        end
    end   
end
10

@HappyProgrammer11 what we would need to see would be your code, that doesn’t work, not a video of his that does.

11

Here’s what I did just for fun:

-- S2ratch

function setup()
    Image = readImage("Planet Cute:Heart")
    ImagePosition = vec2(WIDTH/2, HEIGHT/2)
end

function draw()
    background(40, 40, 50)
    translate(ImagePosition:unpack())
    sprite(Image)
end

function touched(touchID)
    if touchID.state == BEGAN or touchID.state == MOVING then
        if nearEnough(touchID.x, touchID.y, ImagePosition) then
            ImagePosition = vec2(touchID.x, touchID.y)
        end
    end
end

function nearEnough(x, y, touch)
    return vec2(x,y):dist(vec2(touch.x, touch.y)) < 50
end