Stereographic Projection by @noel

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 2 remixes fullscreen

@noel

function u(t) {

eval(unescape(escape`󩭯󬬨󪬽󛜱󞽪󟌨󭼽󜬵󝜩󞽩󚼫󚝦󫽲󚍹󟜭󜜫󜬪󪬫󚼯󭼬󪜽󛜱󞽩󟍷󞽩󚼫󚝻󪼽󛜱󚼲󚭩󛽷󒭤󟝍󨝴󪌮󬽱󬭴󚍫󚭫󚽹󚭹󚜊󨜽󣝡󭍨󛭡󭍡󫬲󚍹󛍫󚜊󮬽󭼪󠼨󨜩󛽤󚽴󚭷󧬨󭼪󤼨󨜩󛽤󚽴󚭷󚜊󮌮󩭩󫍬󤽴󮝬󩜽󤬨󩌬󮬦󭼬󮬦󭼩󒭸󛭦󪝬󫍒󩝣󭌨󪜬󪬬󜜬󜜩󯜻`.replace(/u../g,'')))

Jun 1 2023 6:02 PM UTC

}// 133/140

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

Stereographic Projection

Show more comments…
u/@noel

My first dwitter. I reduced the drawn area, but it still runs very slow
u/@noel

for(j=-1;j<(w=255);i++)for(y=-1+2*j++/w,i=-1;i<w;i++){k=-1+2*i/w d=Math.sqrt(k*k+y*y) a=Math.atan2(y,k) z=w*C(a)/d+t*w^(w*S(a)/d+t*w) x.fillStyle=R(d,z&w,z&w) x.fillRect(i,j,1,1)}
u/@noel

In java this runs smoothly.
u/@noel

A bit of a disappointment. I am going to try to do this with bigger rectangles now.
u/Xen

nicely done! welcome to the dwitter family
u/KilledByAPixel

fillStyle can be slow when called this often (60,000+ times per frame), you can make a faster/smaller version in grayscale by removing the fillStyle and doing this x.fillRect(i,j,1,(z&w)/w)
u/danny@hille.dk

uncompressed using grayscale and some other golfing tricks ->c.width=w=255;for(m=4e4;m--;x.fillRect(i,j,((C(a=Math.atan2(y,k))*w/d+t*w^S(a)*w/d+t*w)&w)/w,1))i=m%w,j=m/w,d=Math.hypot(k=i/w-.5,y=j/w-.3)
u/danny@hille.dk

Great first Dweet, by the way :-)
u/@noel

u/danny@hille.dk Thank you. Your solution is really nice. I am playing right now with it.


      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