)
}
}
)
(
}
{
)
)
(
)
(
(
{
}
)
(
)
}
)
)
{
(
(
)
)
}
)
(
}

W3Schools Output Tag

  1. <!-- from w3schools.com -->
  2. <!DOCTYPE html>
  3. <html>
  4. <body>
  5.  
  6. <h1>The output element</h1>
  7.  
  8. <form oninput="x.value=parseInt(a.value)+parseInt(b.value)">
  9. <input type="range" id="a" value="50">
  10. +<input type="number" id="b" value="25">
  11. =<output name="x" for="a b"></output>
  12. </form>
  13.  
  14. <p><strong>Note:</strong> The output element is not supported in Edge 12 (or earlier).</p>
  15.  
  16. </body>
  17. </html>

I like w3Schools.

This code has some problems… but… for a cool little snippet to play with – I think that’s ok. SnippetZone certainly has tons of things like this…

Canvas Path2D

  1. const canvas = document.body.appendChild(
  2.   document.createElement('canvas')
  3. )
  4. const c = canvas.getContext('2d')
  5.  
  6. canvas.width = innerWidth
  7. canvas.height = innerHeight
  8.  
  9. c.translate(10, 10)
  10. const path = new Path2D('M 154.75 61.5 Q 169.75 63.8 184.8 69.35 173.15 68.3 161.7 69.4 173.1 73.85 184.8 75.95 173.1 77.15 161.65 75.95 173.05 80.45 184.8 82.55 173 83.75 160.05 82.35 173 87.05 184.8 89.15 172.95 90.35 161.65 89.1 172.9 93.65 184.8 95.75 172.8 96.9 161.65 95.7 172.8 100.2 184.8 102.35 172.75 103.5 163.7 102.7 172.7 106.8 184.8 110.3 172.7 110.1 161.65 108.85 172.6 113.35 184.8 118.85 171.05 116.05 158.35 114.65 167.3 126.9 174 141.45 166.5 132.45 157.65 125.1 162.55 136.3 169.35 146.1 160.2 138.65 152.95 129.7 157.85 141 164.7 150.75 155.5 143.25 147.3 133.15 153.15 145.6 160 155.45 150.75 147.9 143.65 139 148.45 150.2 155.35 160.1 146.05 152.4 139 143.65 143.7 154.75 150.7 164.75 141.3 157.05 135.5 150.05 139 159.35 145.05 170.4 136.65 161.7 129.7 152.95 134.25 163.9 139 176.45 131.3 164.75 123.3 154.8 121 169.8 115.45 184.8 116.5 173.15 115.4 161.7 110.95 173.1 108.85 184.8 107.65 173.1 108.85 161.65 104.35 173.05 102.25 184.8 101.05 173 102.45 160.05 97.75 173 95.65 184.8 94.45 172.95 95.7 161.65 91.15 172.9 89.05 184.8 87.9 172.8 89.1 161.65 84.6 172.8 82.45 184.8 81.3 172.75 82.1 163.7 78 172.7 74.5 184.8 74.7 172.7 75.95 161.65 71.45 172.6 65.95 184.8 68.75 171.05 70.15 158.4 57.9 167.35 43.35 174.05 52.35 166.55 59.7 157.7 48.5 162.6 38.7 169.4 46.15 160.25 55.1 153 43.8 157.9 34.05 164.75 41.55 155.55 51.65 147.35 39.2 153.2 29.35 160.05 36.9 150.8 45.8 143.7 34.6 148.5 24.7 155.4 32.4 146.1 41.15 139.05 30.05 143.75 20.05 150.75 27.75 141.35 34.75 135.55 25.45 139.05 14.4 145.1 23.1 136.7 31.85 129.75 20.9 134.3 8.35 139.05 20.05 131.3 30.05 123.3 15.05 121 0 115.45 11.65 116.5 23.1 115.4 11.7 110.95 0 108.85 11.7 107.65 23.15 108.85 11.75 104.35 0 102.25 11.8 101.05 24.75 102.45 11.8 97.75 0 95.65 11.85 94.45 23.15 95.7 11.9 91.15 0 89.05 12 87.9 23.15 89.1 12 84.6 0 82.45 12.05 81.3 21.1 82.1 12.1 78 0 74.5 12.1 74.7 23.15 75.95 12.2 71.45 0 65.95 13.75 68.75 26.45 70.15 17.45 57.9 10.75 43.35 18.25 52.35 27.1 59.7 22.2 48.5 15.4 38.7 24.55 46.15 31.8 55.1 26.9 43.8 20.05 34.05 29.25 41.55 37.45 51.65 31.6 39.2 24.75 29.35 34 36.9 41.1 45.8 36.3 34.6 29.4 24.7 38.7 32.4 45.75 41.15 41.05 30.05 34.05 20.05 43.45 27.75 49.25 34.75 45.75 25.45 39.7 14.4 48.1 23.1 55.05 31.85 50.5 20.9 45.75 8.35 53.5 20.05 61.5 30.05 63.8 15.05 69.35 0 68.3 11.65 69.4 23.1 73.85 11.7 75.95 0 77.15 11.7 75.95 23.15 80.45 11.75 82.55 0 83.75 11.8 82.35 24.75 87.05 11.8 89.15 0 90.35 11.85 89.1 23.15 93.65 11.9 95.75 0 96.9 12 95.7 23.15 100.2 12 102.35 0 103.5 12.05 102.7 21.1 106.8 12.1 110.3 0 110.1 12.1 108.85 23.15 113.35 12.2 118.85 0 116.05 13.75 114.65 26.45 126.9 17.45 141.45 10.75 132.45 18.25 125.1 27.1 136.3 22.2 146.1 15.4 138.65 24.55 129.7 31.8 141 26.9 150.75 20.05 143.25 29.25 133.15 37.45 145.6 31.6 155.45 24.75 147.9 34 139 41.1 150.2 36.3 160.1 29.4 152.4 38.7 143.65 45.75 154.75 41.05 164.75 34.05 157.05 43.45 150.05 49.25 159.35 45.75 170.4 39.7 161.7 48.1 152.95 55.05 163.9 50.5 176.45 45.75 164.75 53.5 154.75 61.5 140.2 73.15 129.35 85.4 146 97.85 158.35 114.65 M 61.5 30.05 Q 73.15 44.6 85.4 55.45 97.8 38.8 114.65 26.45 M 30.05 123.3 Q 44.6 111.65 55.45 99.45 38.8 87 26.45 70.15 M 123.3 154.8 Q 111.65 140.25 99.4 129.4 86.95 146.05 70.15 158.4');
  11.  
  12. c.stroke(path);

Use SVG style paths in canvas…

Proxy Constants

  1. const spec = {
  2.   get(o, key) { 
  3.     return o[key] != null ? 
  4.       o[key] : o[key] = Objector()
  5.   }
  6. };
  7.  
  8. const Objector = () => new Proxy({}, spec);
  9.  
  10. const events = Objector();
  11.  
  12. events.graphics.RENDERED;
  13. events.graphics.ERASED;
  14. events.ui.LOADING;
  15. events.ui.LOADED;
  16. events.files.OPENED;
  17. events.files.CLOSED;
  18.  
  19. const { ERASED } = events.graphics;
  20. console.log('a', ERASED === events.graphics.ERASED);
  21. console.log('b', ERASED === events.files.CLOSED);

This is somewhat evil… I’ve never liked these java style constants. Maybe I’ll write up a detailed alternative method some time.

// humor // proxies // tricks

Two Circles Explode

  1. const { random, min, sqrt, cos, sin, PI } = Math
  2. let TWO_PI = PI * 2
  3. let minSize
  4.  
  5. document.body.style.margin = 0
  6. document.body.style.background = 'black'
  7. const canvas = document.body.appendChild(
  8.   document.createElement('canvas')
  9. )
  10. const c = canvas.getContext('2d')
  11.  
  12. addEventListener('resize', resize)
  13. resize()
  14.  
  15. function resize() {
  16.   canvas.width = innerWidth
  17.   canvas.height = innerHeight
  18.   minSize = min(innerWidth, innerHeight)
  19.   clear()
  20. }
  21.  
  22. function clear() {
  23.   c.fillStyle = 'rgba(0, 0, 0, .15)'
  24.   c.fillRect(0, 0, innerWidth, innerHeight)
  25. }
  26.  
  27. let dots = []
  28. function dot({x, y, vx, vy, rad, grav = .15}) {
  29.   let sx = x
  30.   let sy = y
  31.   let svx = vx
  32.   let svy = vy
  33.   let intersected
  34.   let partsNum = 20
  35.   let parts = []
  36.   let delay = random() * 5
  37.   let time = 0
  38.  
  39.   dots.push(() => y > innerHeight)
  40.  
  41.   return {
  42.     step() {
  43.       time++
  44.       if (time < delay) return
  45.       if (intersected) {
  46.         for (let i = 0; i < partsNum; i++) {
  47.           parts[i].step()
  48.         }
  49.         return
  50.       }
  51.       x += vx
  52.       y += vy
  53.       vy += grav;
  54.       c.beginPath()
  55.       c.arc(x, y, rad(), 0, 7)
  56.       c.fill()
  57.     },
  58.     reset() {
  59.       x = sx;
  60.       y = sy;
  61.       vx = svx;
  62.       vy = svy;
  63.       intersected = false
  64.     },
  65.     hit() {
  66.       if (!intersected) {
  67.         partsNum = rad() / 3
  68.         for (let i = 0; i < partsNum; i++) {
  69.           let t = random() * TWO_PI
  70.           let r = 5 + random() * 5
  71.           let size = random() * 10
  72.  
  73.           parts.push(
  74.             dot({
  75.               x, y,
  76.               vx: r * cos(t),
  77.               vy: r * sin(t),
  78.               rad: () => size
  79.             })
  80.           )
  81.         }
  82.       }
  83.       intersected = true
  84.     },
  85.     get x() {
  86.       return x
  87.     },
  88.     get y() {
  89.       return y
  90.     }
  91.   }
  92. }
  93.  
  94. const bigRad = () => minSize * .14;
  95.  
  96. let leftDot
  97. let rightDot
  98.  
  99. function start() {
  100.  
  101.   rightDot = dot({
  102.     x: innerWidth, 
  103.     y: innerHeight / 2, 
  104.     vx: -innerWidth * .005, 
  105.     vy: -6, rad: bigRad
  106.   })
  107.  
  108.   leftDot = dot({
  109.     x: 0, 
  110.     y: innerHeight / 2, 
  111.     vx: innerWidth * .005, 
  112.     vy: -6, rad: bigRad
  113.   })
  114. }
  115. start()
  116.  
  117. function collide(a, b) {
  118.   const dx = a.x - b.x
  119.   const dy = a.y - b.y
  120.   const dist = sqrt(dx**2 + dy**2)
  121.   return dist <= bigRad() * 1.8
  122. }
  123.  
  124. function loop() {
  125.   let inc = 2
  126.  
  127.   clear()
  128.   c.fillStyle = 'white'
  129.   if (collide(leftDot, rightDot)) {
  130.  
  131.     leftDot.hit()
  132.     rightDot.hit()
  133.   }
  134.  
  135.   leftDot.step()
  136.   rightDot.step()
  137.  
  138.   dots.forEach(done => {
  139.     if (done()) inc++;
  140.   }) 
  141.  
  142.   if (dots.length > 2 && inc == dots.length)  {
  143.     dots = []
  144.     start()
  145.   }
  146.  
  147.   requestAnimationFrame(loop)
  148. }
  149. loop()

Two circles intersect and explode repeatedly… works at any browser size…

ES5 Canvas Thing

  1. var canvas = document.body.appendChild(
  2.   document.createElement('canvas')
  3. ),
  4. c = canvas.getContext("2d"),
  5. size = canvas.width,
  6. quarterSize = size / 4,
  7. eightSize = size / 8,
  8. halfSize = size / 2,
  9. TWO_PI = Math.PI * 2,
  10. bombNum = 3,
  11. bombs = [],
  12. wanderers = {}, 
  13. wandererIndex = 0,
  14. particles = {},
  15. particleIndex = 0;
  16.  
  17. canvas.width = canvas.height = 300
  18.  
  19. c.fillStyle = "rgb(100,100,100)";
  20. c.fillRect(0,0,size,size);
  21.  
  22. function Particle(x, y){
  23.   this.x = x;
  24.   this.y = y;
  25.   var rad = 3 + Math.random() * 6;
  26.   var theta = Math.random() * TWO_PI;
  27.   this.vx = rad * Math.cos(theta);
  28.   this.vy = rad * Math.sin(theta);
  29.   this.alpha = 1;
  30.   particleIndex++;
  31.   this.index = particleIndex;
  32.   particles[this.index] = this;
  33. }
  34. Particle.prototype.draw = function(){
  35.   this.x += this.vx;
  36.   this.y += this.vy;
  37.   this.vx *= 0.9;
  38.   this.vy *= 0.9;
  39.   this.alpha -= 0.05;
  40.  
  41.   if (this.alpha <= 0){
  42.     this.alpha = 0;
  43.     delete particles[this.index];
  44.  
  45.   }
  46.  
  47.   c.fillStyle = "rgba(255,255,255,"+this.alpha+")";
  48.   c.beginPath();
  49.   c.arc(this.x, this.y, 1, 0, TWO_PI, false);
  50.   c.fill();
  51. };
  52.  
  53. function Bomb(){
  54.   this.x = quarterSize + Math.random() * halfSize;
  55.   this.y = quarterSize + Math.random() * halfSize;
  56.   this.radius = 15 + Math.random() * 20;
  57. }
  58. Bomb.prototype.draw = function(){
  59.   c.fillStyle = "#e64c25";
  60.   c.beginPath();
  61.   c.arc(this.x, this.y, this.radius, 0, TWO_PI, false);
  62.   c.fill();
  63. };
  64.  
  65. function Wanderer(x, y){
  66.   this.x = x;
  67.   this.y = y;
  68.   this.vx = Math.random() * 4 - 2;
  69.   this.vy = Math.random() * 4 - 2;
  70.   particleIndex++;
  71.   this.index = particleIndex;
  72.   particles[this.index] = this;
  73. }
  74. Wanderer.prototype.die = function(){
  75.   for (var j = 0; j < 4; j++){
  76.     new Particle(this.x, this.y);
  77.   }
  78.  
  79.   delete particles[this.index];
  80. };
  81. Wanderer.prototype.draw = function(){
  82.   this.x += this.vx;
  83.   this.y += this.vy;
  84.  
  85.   if (Math.random() < 0.1){
  86.     this.vx = Math.random() * 4 - 2;
  87.     this.vy = Math.random() * 4 - 2;
  88.   }
  89.  
  90.   if (this.x < 0) this.x = size;
  91.   if (this.x > size) this.x = 0;
  92.   if (this.y < 0) this.y = size;
  93.   if (this.y > size) this.y = 0;
  94.  
  95.   c.fillStyle = "white";
  96.   c.beginPath();
  97.   c.arc(this.x, this.y, 2, 0, TWO_PI, false);
  98.   c.closePath();
  99.   c.fill();
  100.  
  101.   for (var i = 0; i < bombNum; i++){
  102.     var bomb = bombs[i];
  103.     var dx = this.x - bomb.x;
  104.     var dy = this.y - bomb.y;
  105.     if (Math.sqrt(dx * dx + dy * dy) < bomb.radius){
  106.       this.die();
  107.     }
  108.   }
  109. };
  110.  
  111. for (var i = 0; i < bombNum; i++){
  112.   bombs[i] = new Bomb();
  113. }
  114.  
  115. new Wanderer(eightSize, eightSize); 
  116.  
  117. setInterval(function(){
  118.   c.fillStyle = "rgba(100,100,100, 0.2)";
  119.   c.fillRect(0,0,size,size);
  120.   c.strokeStyle = "white";
  121.   c.beginPath();
  122.   c.arc(eightSize, eightSize, 5, 0, TWO_PI, false);
  123.   c.stroke();
  124.  
  125.   if (Math.random() < 0.02){
  126.     new Wanderer(eightSize, eightSize); 
  127.   }
  128.  
  129.   for (var i = 0; i < bombNum; i++){
  130.     bombs[i].draw();
  131.   }
  132.  
  133.   for (var i in wanderers){
  134.     wanderers[i].draw(); 
  135.   }
  136.  
  137.   for (var i in particles){
  138.     particles[i].draw();
  139.   }
  140. }, 16);

An old es5 speedcoded thing…

snippet.zone ~ 2021-24 /// {s/z}