Artifacts on phone version

General
1

Hi all,

1st of all, excellent work on the phone version!

Very happy with it overall, but there are some artifacts in one of my projects where I draw a scaled and/or rotated img of the screen back onto itself.

I added a couple of pics, the 1st 2 pics are from the phone version, where you can see these purple artifacts, even if I draw nothing, the last pic is from the ipad, how it is supposed to look.

I only get the artifacts when the screen is being rotated and/or scaled, the strength of which is determined by how you hold the device. I included the relevant bit of code below, there is another setcontext() before I draw the final img to the screen.

    setContext(screenImg)
    pushMatrix()
    translate(WIDTH/2,HEIGHT/2)
    zooml = 1-(Gravity.y+.8) / 20--1-((Gravity.y+1)*2/10)
    rotate(-Gravity.x*3)
    sprite(screenImg, 0,0, screenImg.width*zooml,screenImg.height*zooml)
    popMatrix()
2

Thanks for the detailed report. What iPhone model are you using?

Do you have a very short example that reproduces the problem?

3

Im using a 12 mini, sample code below, thanks! =)

You can scale up or down by ‘tilting’ and rotate by ‘rolling’ the device.
You can draw something on the screen by touching, but the artifacts show up regardless.

-- Artifact Xmple

function setup()
    rnd = math.random
    img = image(WIDTH, HEIGHT)

    noStroke()
    setContext(img)
        fill(55+rnd(200), 55+rnd(200), 55+rnd(200))
        rect(WIDTH/2-150,HEIGHT/2-150, 300, 300)
    setContext()
end

function draw()
    background(0, 0, 0, 255)

    -- draw scaled & rotated img onto itself
    zoom = 1-(Gravity.y+.8) / 20
    setContext(img)
        pushMatrix()
        translate(WIDTH/2, HEIGHT/2)
        rotate(-Gravity.x*6)
        sprite(img, 0,0, img.width*zoom, img.height*zoom)
        popMatrix()
    
        -- fade to black
        fill(0,2)
        rect(0,0,WIDTH, HEIGHT)   
    setContext()
    
    -- draw img to screen
    sprite(img, img.width/2, img.height/2)
    
    fill(255)
    text(1//DeltaTime, WIDTH/2,HEIGHT-20)
end

function touched(t)
    setContext(img)
        ellipse(t.x,t.y, 50)
    setContext()
end
4

Thank you! Will use it for debugging. I wonder if it’s due to the 3x scale factor of iPhone screens and some assumption in the Codea rendering code

5

Hi simon,

I got this problem on a new ipad as well, is this still on the fix list?