Dweets awesomed by u/camel_case

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.

Try the new frontend: beta.dwitter.net
Current theme challenge: #Food

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KilledByAPixel

function u(t) {

c.style.background='black'

Jun 2 2020 5:13 PM UTC

}// 26/140

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#BlackoutTueday #BlackLivesMatter

u/katkip

c.style.background=R() is shorter

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pavel

remix of d/13495 by u/pavel

function u(t) {

for(i=t?c.width|=C=_=>u[j=q+n&-n|p/n]=-!u[j]|1:p=q=r=s=571;i--;u[i]||x.fillRect(i?i%n*n:p+=r*=C(p+=r),i?i&-n:q+=s*=C(q+=s),z=i?n:15,-z))n=64

Apr 11 2020 10:31 PM UTC

}// 140/140

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#breakout

Show more comments…
u/pavel

Fixed the tilted look, the missing upper left block, and increased the size of the ball.
u/pavel

Why does changing 571 break the code for most values? :)
u/pavel

472, 582, 593 work well though
u/iznax

The code seems to work with most starting values if you change it to "C=_=>(p|q)<0?-1:u[j=q+n&-n|p/n]=-!u[j]|1" and handle negative coordinates as blockers?
u/KilledByAPixel

👍
u/pavel

Its shorter to init positions and velocities to same number but makes velocities too fast. Another problem is that init needs to happen once and shortest way to do that is t?<spot>:init which creates a spot to do something every non-first frame. I solve both problems by naming my collision detection function C and defining it on every non-first frame. On the first frame C is Math.cos so the velocity update code does r = r*C(p+=r) = 571*Math.cos(571+571) = 17.7 which is a reasonable speed.
u/pavel

The ball needs to be updated once per frame. Since I am iterating with a single index its easiest to check for index 0. This corresponds to the upper left block which is why it was missing in the original. A short fix is to shift everything up one block by using negative height for the blocks and adding a row to ball position encoding. The +n in q+n&-n|p/n.
u/pavel

I encode and decode 2d co-ordinates into one number. The block coordinates are (i%n,i/n|0) and their width is n making their real positions (i%n*n,(i/n|0)*n). Lets simplify the second one. If we choose n=2**k then (i/n|0)*n = (i/2**k|0)*2**k = (i>>k)<<k so we are zeroing out the last k binary digits. But if n=2**k then -n is a bunch of ones followed by k zeroes (https://en.wikipedia.org/wiki/Two%27s_comple…)! Therefore (i/n|0)*n = i&-n.
u/pavel

Need to check if ball pos (p,q) touches a new block. Ball is always in some block, find that blocks pos index. Dividing ball position by n gives the virtual coords and blocks are 1x1 so truncating gives 2d block coordinates (p/n|0,q/n|0). Want to encode this into index j where (x,y)=(j%n,j/n|0). Therefore j=(q/n|0)*n+(p/n|0). If n=2**k then in binary j=[32-k binary digits y-coord][k binary digits of x-coord] so we can use bitwise-or which also auto-truncates so j=(q/n|0)*n|p/n. And as we saw (q/n|0)*n=q&-n so j=q&-n|p/n! Real code uses j=q+n&-n|p/n to add one row to ball pos to account for shift up to hide missing (0,0)` block.
u/pavel

p+=r*=C(p+=r) encodes an unbelievable trick that is perfect for collision detection. For detection we need to independently try advancing vertically and horizontally, check for collision, and reverse course if hit. The temporary state involved in trying can cost a lot of chars. p+=r*=C(p+=r) does it all and C doesn't even read its argument! When C is invoked the global p it sees was already incremented by r. However, the outer p+= will eventually discard that increment. Magic!
u/rep_movsd

Un-effing-believable
u/hvianna

Wow, this is insane!
u/jylikangas

Masterclass in code golfing!
u/13thptr

awesome, looks like the ball escapes without breaking everything after a while though. will read the explanation more thoroughly.
u/pavel

No chars left for bounds checks! It freaks out with negative positions. If I find a way to shorten I will add bounds.
u/ersagun

I need to read and reread that explanation on a loop until I get this. This is incredible.
u/Qwitter

Just wow.

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camel_case

function u(t) {

S=z=>Math.round(Math.random()*z)*30
x.fillStyle=R(S(9),S(9),S(9))
x.fillRect(S(64),S(36),60+S(4),60+S(6))

Apr 8 2020 9:40 AM UTC

}// 105/140

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100% not an original idea - More blocky

u/joeytwiddle

Little remix: for(i=1e3;i--;){S=z=>Math.random()*z*90|0,x.fillStyle='hsla('+S(4)+',99%,63%,.01)',x.fillRect(S(64),S(36),60+S(8),60+S(6))}

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camel_case

function u(t) {

S=z=>Math.random()*z*100
x.fillStyle=R(S(3),S(3),S(3))
x.fillRect(S(19),S(11),S(2),S(3))

Apr 8 2020 9:10 AM UTC

}// 88/140

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100% not an original idea

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BriSeven

remix of d/18166 by u/BriSeven

function u(t) {

c.width=1920 // clear the canvas
for(i=0;i<256;i++)
x.fillRect(i*10,(i&(S(i/t+t)*t)+t)*10+500,10,15) // draw 50x200 rects

Apr 7 2020 4:05 AM UTC

}// 121/140

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sinewave serving samples of sierpinski

u/camel_case

I could watch this forever *.*
u/BriSeven

can you? i haven’t watched long enough to know for sure but i think the math should run down eventually
u/Xen

love it!

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Kirjava

function u(t) {

eval(unescape(escape`𭁼𯀨𬰽𦰮𛠮𘠠𜐳𡁜𫡆𞀲𠱜𫡅𠐵𝁜𫠶𞑂𝰢𧐬𥀽𜀩𛁯𫡫𩑹𭑰👮🐾𚁑👳𦱶👔𚱛𛐱𛀵𛀱𛀭𝑝𦰳𙡮𛡷𪁩𨱨𧑝𚐾𘠰𘠿𬱛𬱛𥁝👑𛁔👶𧐽𘠠𘠺𜀬𩀽𩁯𨱵𫑥𫡴𛡢𫱤𮐬𩀮𪑮𫡥𬡈𥁍𣀽𘠼𬁲𩐾𘠫𬰮𪡯𪑮𨁠𛁤𛡳𭁹𫁥𛡦𫱮𭁓𪑺𩐽𙰵𩑭𙰻`.replace(/u../g,'')))

Apr 2 2020 9:23 AM UTC

}// 132/140

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15 puzzle #game #interactive

u/Kirjava

control with IJKL
u/katkip

Works on light theme

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rodrigo.siqueira

remix of d/17508 by u/rodrigo.siqueira

function u(t) {

c.style='filter:invert(1'
for(X=Y=i=1e4*(t<6);i--;x.fillRect(960+900*X,560+300*Y,.1,1)){if(i%99==0)X=S(t*i**8)
Y=S(X)*+C(Y*2.4)*1.4}

Feb 8 2020 12:38 AM UTC

}// 132/140

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Link of Symmetry #bifurcation (Period-halving bifurcations leading to order, followed by period doubling bifurcations leading to chaos)

u/Xen

love it!

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camel_case

function u(t) {

d="123f;145o;245u;345i;125l;000 ".split`;`
x.font='4em"'
x.fillText(w+=d[n=d[n].charAt(new Date%3)].charAt(3),9,t*3300)
}var w="f",n=0
{

Dec 14 2019 5:30 PM UTC

}// 136/140

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dadaist-esque poem generator

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camel_case

function u(t) {

x.font='9em"'
v="walk0see0make me0fear0love0art0something0nothing0the sky".split(0)
x.fillText(v[c%5]+" "+v[c%6+3],99,99)}var c=new Date;{

Dec 12 2019 11:04 AM UTC

}// 138/140

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Make Something

u/katkip

this is nice!

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katkip

function u(t) {

/*‮*/eval(atob`dGhyb3cgIk1vdGl2YXRpb25FcnJvcjogRXhwZWN0ZWQgbW9yZSBsaWtlcyI=`)///////////////////////////////////////////////////////////////

Dec 1 2019 6:08 PM UTC

}// 140/140

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u/tomxor

I'm so torn, should I click awesome?
u/katkip

yes. #obfuscated
u/CalSch

What is this, why is "eval" backwards? Why is the text after the opening comment highlighted like a string instead of a comment? So confusing...

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