Underwater #cavern 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

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    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.

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pavel

function u(t) {

with(x)for(i=999;i--;fillRect(~setTransform(s=24e3/i,0,0,4*s,960-i+9*s*C(a=i+60*t),540+8*s*S(a)),~rotate(T(a*a)),2,2))fillStyle=R(9,i/4,i/3)

May 4 2020 7:34 PM UTC

}// 140/140

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Underwater #cavern

Show more comments…
u/KilledByAPixel

sick
u/KilledByAPixel

looped https://twitter.com/KilledByAPixel/status/12…
u/pavel

One trick here is f();g();h(-1,-1) is the same as h(~f(),~g()) when f and g return a falsy value, undefined in this case.
u/pavel

Notice how none of the distance variables are based on time, only angles are, yet the distances are changing and nothing is rotating...
u/pavel

Try making the moving a little faster :)
u/pavel

After I wrote this I looked for other dweets using a similar technique and this is the earliest one I've found, and it includes an explanation d/10212
u/KilledByAPixel

Amazing work! I have not seen the ~ before, will be using it a lot now. I tried to explain the 60*t trick in one of my blog posts, https://frankforce.com/?p=7160
u/pavel

That is an amazingly detailed explanation with great visual aids.
u/pavel

To clarify your explanation, any integer time works. 60*t is naturally an integer (ish). frame is one char longer without numerical errors. In general, (n*t|0) works for any n.
u/AndrewK

privet
u/katkip

masterpiece
u/joeytwiddle

I think this also counts as a #tunnel
u/Qwitter

Awesome!


      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)

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