Fun With Circles

Code Sharing
1

I was in a project yesterday and gave a circle a negative value. The result was a cool shape, so I figured I would share a small project showcasing the result.

function setup()
    print("Hello World!")
    x = 0
    pos = vec2(WIDTH/2,HEIGHT/2)
    parameter.integer("size",20,400,225)
end

-- This function gets called once every frame
function draw()
    -- This sets a dark background color 
    background(0, 0, 0, 255)
    fill(255, 81, 0, 255)
    translate(pos.x,pos.y)
    blendMode(ADDITIVE)
    pushMatrix()
        rotate(x)
        ellipse(0,0,-1*size)
    popMatrix()
    fill(0, 153, 255, 255)
    pushMatrix()
        rotate(2*x)
        ellipse(0,0,-1*size)
    popMatrix()
    x = x + 0.75
end
function touched(t)
    pos.x = t.x
    pos.y = t.y
end
2

@thebombdiggity You also get some odd circles by having a large circle size. I posted this back in April 2014. Changing the circle size gives different images, but not all values show something. This is for a Retina display. I don’t know if anything will show on a non Retina display.

displayMode(OVERLAY)

function setup()
    parameter.integer("size",20000000,90000000,64659584)
end

function draw()
    background(0)
    noFill()
    stroke(255)
    strokeWidth(2)
    ellipse(WIDTH/2,HEIGHT/2,size)
end
3

@dave1707 My iPad has a Retina display, but nothing shows up. Strange…

4

@thebombdiggity Do you see anything when you use the slider to change values. I’m using an iPad Air. Maybe it’s seen only on an iPad Air, because I get different images as I use the slider.

5

No, I don’t see anything when I use the slider. I’m on an iPad 4th generation so maybe it’s just the fact that the iPad is older

6

Just have to wait and see if anyone else can see something and what they’re using.

7

Non retina, iPad mini 1, latest codea release, just get a black screen.

8

iPad Air 2, dave’s not imagining things, I get a grainy black and white circular pattern

9

Here’s a video of what I see. The image changes as I move the slider. Not all slider values creates an image.

https://m.youtube.com/watch?v=dUbf8k8rrdc
10

yep, I get that too

not sure what you can do with it, though

11

@Ignatz If I’m drawing a circle with a radius of 64,000,000 , why should I be seeing something on the screen at all. @thebombdiggity Sorry for hijacking your discussion. Your program shows that giving functions unusual values sometimes gives interesting results. Try setting up 2 parameters for the 2 sizes of an ellipse in your program. Set the 2 size values to run from -400 to 400 and see what you get as you change the values.

12

@dave1707 Wow! There are some amazing designs that can be gotten from messing with those parameters! I added more colors and it looks even more amazing. I can’t believe I hadn’t already tried that.

13

The reason for the differences is because the GPU in the iPad Air 2 and previous generations differ. The extreme size of the circle is probably causing floating-point overflows, and different GPUs handle it differently.

14

@Simeon Thanks for the explanation. @thebombdiggity Can you post your new program when you get finished.

15

funny and interesting, a circle a negative value, extreme size

16

@dave1707 Here you go

displayMode(OVERLAY)
function setup()
    print("Hello World!")
    x = 0
    pos = vec2(WIDTH/2,HEIGHT/2)
    parameter.watch("math.floor(1/DeltaTime)")
    parameter.integer("size",-400,400,225)
    parameter.integer("size2",-400,400,225)
    colors = {
    color(255, 81, 0, 255),
    color(0, 153, 255, 255),
    color(215, 0, 255, 255),
    color(0, 255, 64, 255),
    color(0, 255, 205, 255),
    color(107, 0, 255, 255),
    }
    parameter.integer("amount",1,#colors,2)
end
-- This function gets called once every frame
function draw()
    -- This sets a dark background color 
    background(0, 0, 0, 255)
    translate(pos.x,pos.y)
    blendMode(ADDITIVE)
    for i = 1,amount do
        create(0,0,i*x,colors[i])
    end
    x = x + 0.75
end
function create(x1,y1,r,c)
    pushMatrix()
    pushStyle()
        fill(c)
        rotate(r)
        ellipse(x1,y1,-1*size,-1*size2)
    popStyle()
    popMatrix()
end
function touched(t)
    pos.x = t.x
    pos.y = t.y
end
17

Nice job. Really shows some interesting designs.

18

I need help with a delay fx, PGM runs at 60fps a sec. I would like to slow it down with a time elapsed fx

-- Ellipse

function setup()
    ellipseMode(CENTER)
    displayMode(FULLSCREEN)
    t=ElapsedTime
end

function draw()
    background(0)
    t=t+2
    -- Draw a random color 
    fill(math.random(255),math.random(255),math.random(255))
    -- Line thickness
    strokeWidth(3)
    -- Color stroke(41, 21, 196)
    -- Shape location along the x, y axis ;
    -- Size along the x, y axis
    ellipse(400,200,300,200)
end
19

Here your code with a 2 second delay.

displayMode(FULLSCREEN)

function setup()
    ellipseMode(CENTER) 
    strokeWidth(3)
    t=ElapsedTime
end

function draw()
    background(0)
    if ElapsedTime>t+2 then      -- 2 second delay
        colr=color(math.random(255),math.random(255),math.random(255))
        fill(colr)
        t=ElapsedTime
    end
    ellipse(400,200,300,200)
end
20

Is there any trick to make the ellipse stay on the screen instead of being cleared away by the background CMD ?..