Some nice math for the 270 initial radi… by pavel

function u(t) {

c.width=1920 // clear the canvas
for(i=0;i<9;i++)
x.fillRect(400+i*100+S(t)*300,400,50,200) // draw 50x200 rects

} // 122/140

Please log in (or register) to post a dweet (copy-paste the code somewhere safe to save it meanwhile)


    u(t) is called 60 times per second.
    t: Elapsed time in seconds.
    S: Shorthand for Math.sin.
    C: Shorthand for Math.cos.
    T: Shorthand for Math.tan.
    R: Function that generates rgba-strings, usage ex.: R(255, 255, 255, 0.5)
    c: A 1920x1080 canvas.
    x: A 2D context for that canvas.

show FPS hide FPS share fullscreen

pavel

remix of [deleted]

function u(t) {

c.width|=f=(X,Y,r)=>r>1&&x.moveTo(X+r,Y)+x.arc(X,Y,r,0,7)+f(X+r*C(a=(S(b=5*t)-b)/4),Y,r/2)+f(X,Y+r*S(a),r/2)
f(960,540,270)
x.fill`evenodd`

Oct 13 2021 9:44 PM UTC

}// 139/140

Please log in (or register) to post as a new dweet (copy-paste code somewhere safe to save it meanwhile).

Some nice math for the 270 initial radius: The half-height is 540, this must equal r+r/2+r/4+r/8+...=r(1+1/2+1/4+1/8+...). Think about the bit in the brackets in terms of pizzas. You have a whole pizza, plus half a pizza, plus a quarter (half the remaining half), plus an eighth (half the remaining), etc. You have two pizzas! So 540=r*2.

u/pavel

Remix of d/11587. I remixed my other remix but that one was boring so I deleted it.
u/ciaccodavide

nice!
u/cantelope

i think about everything in terms of pizzas


      u(t) is called 60 times per second.
      t: elapsed time in seconds.
      c: A 1920x1080 canvas.
      x: A 2D context for that canvas.
      S: Math.sin
      C: Math.cos
      T: Math.tan
      R: Generates rgba-strings, ex.: R(255, 255, 255, 0.5)

dwitter.net