Dweets awesomed by u/13thptr

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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Current theme challenge: #Food

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pavel

remix of d/11487 by u/pavel

function u(t) {

for(r=c.width|=0,x.font='30px"';--r;)x.fillText(r,960+r*C(a=(r+~~(99*t)-t/9)*5**.5/2),540+r*S(a))

Dec 19 2018 1:24 AM UTC

}// 97/140

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Explanation of d/11487

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pavel

remix of d/11455 by u/pavel

function u(t) {

for(r=c.width|=0;--r;)x.stroke(p=new Path2D,p.arc(960,540,r,a=(r+~~(99*t)-t/9)*5**.5/2%(2*Math.PI),a+(x.lineWidth=32)/r))

Dec 19 2018 1:13 AM UTC

}// 121/140

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Black Hole

u/pavel

Deleting %(2*Math.PI) works in Chrome but not in Safari.
u/pavel

Notice that the radius does not change with time. The inward motion is achieved by drawing a smaller radius square next to where the larger radius square was a frame ago.
u/pavel

If the squares were numbered you'd see that the numbers jump around every frame.
u/pavel

I've made an explanation dweet d/11488

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pavel

remix of d/11472 by u/cantelope

function u(t) {

for(k=c.width|=0;j=--k>>7;x.lineTo(960*(z+4*S(t)+.43*d*((k&120)-62)+S(a))/z,1e3/z))d=.5-(j+4*t&1),z=j+.6-4*t%1+C(a=k%8*d*2.1)*2/3;x.stroke()

Dec 18 2018 11:22 PM UTC

}// 140/140

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k=[4 bits for y][4 bits for x][3 bits for hexagon vertex]

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u/pavel

16*16*8=2048~=1920 so using width
u/pavel

.43~=3**.5/4, 2.1~=2*Math.PI/3
u/pavel

120=0b1111000 so k&120=x*8
u/pavel

I'm using a single stroke and no moveTo. This is a single curve, just lined everything up.
u/pavel

d is horizontal offset, even rows are offset from odd rows. Using +4*t&1 to explicitly cycle the animation every second instead of implicitly cycling every 2 seconds. Longer cycle leads to z<0 and glitches or hexagons that don't reach the camera.
u/magna

Wow!
u/aleamb

awesome!!!
u/pavel

#uncompressed with one plane

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pavel

remix of d/11463 by u/cantelope

function u(t) {

with(x)for(c.width|=i=6,scale(9,9),q=C(4*t);i--;stroke(),fill())moveTo(X=64+17*i,0),arc(X-60*S(a=(q>0?i:i-5)?0:q),60*C(a),8,a-Math.PI/2,9)

Dec 18 2018 12:32 AM UTC

}// 138/140

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u/cantelope

ah! of course. i knew there had to be an easier way ;P
u/katkip

Haha nice
u/iverjo

#newtonscradle
u/pavel

For a more realistic look replace (q>0?i:i-5)?0:q with (q>0?i:i-5)?q/50:q

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pavel

function u(t) {

c.width|=t||(i=j=.3,X=9,Y=60)
with(x)scale(9,9),fillText("DVD",X+=i=X<9|X>200?-i:i,Y+=j=Y<9|Y>99?-j:j),ellipse(X+10,Y+3,11,2,0,0,7),stroke()

Dec 18 2018 12:01 AM UTC

}// 140/140

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pavel

remix of d/11448 by u/carolinaphoenix

function u(t) {

for(w=i=c.width|=0;--i;x.fillRect(960+r*C(a=(i+i*5**.5)*Math.PI),540+r*S(a),9,9))r=(i+60*t)%w

Dec 17 2018 8:12 AM UTC

}// 93/140

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Sunflower seeds. The angles are integer multiples of the golden ratio. https://youtu.be/sj8Sg8qnjOg

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pavel

function u(t) {

with(x)for(j=512;j--;fill())for(beginPath(l=3);l--;arc(325*((j>>6)+j%2/3)+r*S(9*t),j%8*165,r*4,a=(l+j/2%1)*2.09,a))fillStyle=R(r=j&56,r*4)

Dec 17 2018 2:13 AM UTC

}// 138/140

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u/magna

Nice!
u/cantelope

supercool

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pavel

remix of d/11426 by u/Quant1um

function u(t) {

t?w=c.width|=onclick=e=>{i+=e.x/7-X/s,j+=e.y/7-Y/s}:s=i=j=X=Y=20
x.fillRect(X+=i*=(i<0?X>0:X<w)||-.7,Y=++j+Y>1e3?(i*=.9,j*=-.7,1e3):Y+j,s,s)

Dec 16 2018 3:34 AM UTC

}// 140/140

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pavel

remix of d/11421 by u/pavel

function u(t) {

for(x.fillRect(0,0,k=2e3,k);j=--k>>6;x.fillRect((i-j+4)*g,(8+C(i/4)*C((t*30-j|0)/4)*3)*g,s=g*g/200,s))i=k%64,x.fillStyle=R(4*i,g=960/(35-j))

Dec 15 2018 10:08 AM UTC

}// 140/140

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u/cantelope

impressive
u/iverjo

#perspective

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pavel

remix of d/11391 by u/pavel

function u(t) {

for(a=t?b:{8256:1},i=frame%9==1&t<9.5&&(c.width|=b={},2e5);i--;x.fillRect(i&1017,i>>7,8,a[q]*8))k=i%8+5,b[q=i>>3]^=a[q+k%3*128+k/3%3-129|0]

Dec 15 2018 2:32 AM UTC

}// 139/140

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Fredkin Replicator (non-minified version)

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u/pavel

Using div/mod to store 128x128 pixel coordinates in a. 8256=128*64+64 is the middle pixel.
u/pavel

Using frame%9==1 to update the automata once every nine frames. Frames are 1 indexed.
u/pavel

i encodes three variables: lowest 3 bits is neighbor cell 'index', middle 7 is x, and upper 7 is y.
u/pavel

To get neighbor cells I do the div/mod trick on the 'index' but need to exclude (0,0) which has index 4. So I map cell index to i%8+5 which %9 is [5,6,7,8,0,1,2,3]
u/pavel

A cell is 'on' iff the parity of its 'on' neighbors is odd which is the same as the xor of neighbor states
u/pavel

I cheat a little. Y=i>>10 so my rect should use (i>>10)*8 but to save chars I use i>>7. The cells are slightly off-place vertically but its hard to notice.
u/pavel

i&1017 is a mistake, oops, should be i&1016, causes tiny visual glitch. 1016=0b1111111000 which is X*8
u/pavel

#uncompressed

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