Extract all the maths

[rbdr/r.bdr.sh] / js / animation.js

diff --git a/js/animation.js b/js/animation.js
index b579fea1e0b197006ba05fc1bb9ea0dddf35cce0..f33198215d0e0e5947c03c5480d673b83e0d0433 100644 (file)
--- a/js/animation.js
+++ b/js/animation.js
@@ -1,87 +1,78 @@
 (function () {
 
-  var canvas = document.querySelector('canvas'),
-      r = Math.random,
-      pi = Math.PI,
-      cos = Math.cos,
-      sin = Math.sin,
-      context = canvas.getContext('2d'),
+  var K = document.querySelector('canvas'),
+      { random: r, PI, cos, sin, floor, atan2 } = Math,
+      ctx = K.getContext('2d'),
       fps = 24,
-      lastFrame = 0,
-      speed = 1,
-      size = 5 + rnd(10),
-      clear = !!(r() > 0.5),
-      changeColor = !!(r() > 0.5),
-      items = Array(rnd(10) + 6).fill(null).map(() => ({
+      lst = 0,
+      spd = 1,
+      siz = 5 + rnd(10),
+      clr = r() > 0.5,
+      ccl = r() > 0.5,
+      I = Array(rnd(10) + 6).fill(null).map(() => ({
         x: rnd(64),
         y: rnd(64),
-        angle: r() * 2 * pi,
-        color: Array(3).fill(rnd(256))
+        a: r() * 2 * PI,
+        c: Array(3).fill(rnd(256))
       })),
-      shapes = [sqr, crc, hrt, chs, lch],
-      positions = [id, spn(5), spn(15)],
-      draw = shapes[rnd(shapes.length)],
-      pos = positions[rnd(positions.length)];
+      SHP = [sqr, crc, hrt, chs, lch],
+      POS = [id, spn(5), spn(15)],
+      draw = SHP[rnd(SHP.length)],
+      pos = POS[rnd(POS.length)];
 
   function rnd (x) {
-    return Math.floor(r() * x);
+    return floor(r() * x);
   }
 
   function sqr(i) {
 
     var p = pos(i);
-    context.fillRect(p.x, p.y, size, size);
+    ctx.fillRect(p.x, p.y, siz, siz);
   }
 
   function crc(i) {
 
     var p = pos(i);
-    context.beginPath();
-    context.arc(p.x, p.y, size / 2, 0, 2 * pi);
-    context.fill();
+    ctx.beginPath();
+    ctx.arc(p.x, p.y, siz / 2, 0, 2 * PI);
+    ctx.fill();
   }
 
   function chs(i) {
 
     var p = pos(i);
-    context.beginPath();
-    context.moveTo(p.x, p.y);
-    context.lineTo(p.x * 10 * cos(i.angle), p.y * 10 * sin(i.angle));
-    context.lineTo(rnd(64), rnd(64));
-    context.fill();
+    ctx.beginPath();
+    ctx.moveTo(p.x, p.y);
+    ctx.lineTo(p.x * 10 * cos(i.a), p.y * 10 * sin(i.a));
+    ctx.lineTo(rnd(64), rnd(64));
+    ctx.fill();
   }
 
   function lch(i) {
 
     var p = pos(i);
-    context.beginPath();
-    context.lineWidth = 5;
-    context.strokeStyle = `rgb(${i.color.join(',')})`;
-    context.moveTo(p.x, p.y);
-    context.lineTo(p.x * 10 * cos(i.angle), p.y * 10 * sin(i.angle));
-    context.stroke();
-  }
-
-  function sqr(i) {
-
-    var p = pos(i);
-    context.fillRect(p.x, p.y, size, size);
+    ctx.beginPath();
+    ctx.lineWidth = 5;
+    ctx.strokeStyle = `rgb(${i.c.join(',')})`;
+    ctx.moveTo(p.x, p.y);
+    ctx.lineTo(p.x * 10 * cos(i.a), p.y * 10 * sin(i.a));
+    ctx.stroke();
   }
 
   function hrt(i) {
 
     var p = pos(i);
-    context.fillRect(p.x, p.y, size, size);
+    ctx.fillRect(p.x, p.y, siz, siz);
 
-    context.beginPath();
-    context.arc(p.x + size / 2, p.y, size / 2, 0, 2 * pi, false);
-    context.fill();
-    context.closePath();
+    ctx.beginPath();
+    ctx.arc(p.x + siz / 2, p.y, siz / 2, 0, 2 * PI, false);
+    ctx.fill();
+    ctx.closePath();
 
-    context.beginPath();
-    context.arc(p.x + size, p.y + size / 2, size / 2, 0, 2 * pi, false);
-    context.fill();
-    context.closePath();
+    ctx.beginPath();
+    ctx.arc(p.x + siz, p.y + siz / 2, siz / 2, 0, 2 * PI, false);
+    ctx.fill();
+    ctx.closePath();
   }
 
   function id(p) {
@@ -93,53 +84,53 @@
     return function (p) {
 
       return {
-        x: p.x + rad * cos(lastFrame),
-        y: p.y + rad * sin(lastFrame)
+        x: p.x + rad * cos(lst),
+        y: p.y + rad * sin(lst)
       }
     }
   }
 
   function mov(i) {
 
-    i.x = i.x + speed * cos(i.angle);
-    i.y = i.y + speed * sin(i.angle);
+    i.x = i.x + spd * cos(i.a);
+    i.y = i.y + spd * sin(i.a);
 
     if (i.x < 0 || i.x > 64) {
-      i.angle = Math.atan2(sin(i.angle), -cos(i.angle))
+      i.a = atan2(sin(i.a), -cos(i.a))
     }
 
     if (i.y < 0 || i.y > 64) {
-      i.angle = Math.atan2(-sin(i.angle), cos(i.angle))
+      i.a = atan2(-sin(i.a), cos(i.a))
     }
   }
 
-  function updateColor(i) {
+  function ucl(i) {
 
-    i.color = i.color.map((c) => {
+    i.c = i.c.map((c) => {
       c = c + 5;
       return c > 255 ? 0 : c;
     })
   }
 
-  function frame(time) {
+  function frm(t) {
 
-    window.requestAnimationFrame(frame);
+    window.requestAnimationFrame(frm);
 
-    var delta = time - lastFrame;
+    var dt = t - lst;
 
-    if (delta > 1000 / fps) {
-      clear && context.clearRect(0, 0, 64, 64);
-      for (var i of items) {
-        context.fillStyle = `rgb(${i.color.join(',')})`;
+    if (dt > 1000 / fps) {
+      clr && ctx.clearRect(0, 0, 64, 64);
+      for (var i of I) {
+        ctx.fillStyle = `rgb(${i.c.join(',')})`;
         draw(i);
-        changeColor && updateColor(i);
+        ccl && ucl(i);
         mov(i);
       }
 
-      lastFrame = time;
+      lst = t;
     }
   }
 
-  frame();
+  frm();
 }
 )();