How to create the snowfall in html5 canvas using javascript

how to make snowfall effect in html5 canvas using javascript - Nibunan

how to create snowfall in html5 canvas using javascript - Nibunan

how to write program to display snowfall effect in html5 canvas using javascript - Nibunan

how to write program to create snowfall animation in html5 canvas using javascript - Nibunan

how to write code to create snowfall effect in html5 canvas using javascript - Nibunan

Html5 canvas is evolving to give the rich graphics on browser without using flash or other plugins. Html5 canvas is being used in many places like games animations and rich user interfaces on web and so on.This airticle explains how to create snowfall effect in html5 canvas using javascript.

Demo

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Source


      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
      <html xmlns="http://www.w3.org/1999/xhtml">
      <head>
      <title>Creating snowfall effect using html5 canvas - Nibunan</title>
      </head>
      <body style="margin: 0px">
      <canvas width="700" height="450" id="drawing-surface"></canvas>
      <script type="text/javascript">
      function Random(range) {
      return Math.floor((Math.random() * range) + 1);
      }
      function RandomFloat(range) {
      return (Math.random() * range) + 1;
      }
      var viewport = new Viewport()
      for (var i = 0; i < 1000; i++) {
      var snow = new Snow();
      viewport.addObject(snow);
      }
      viewport.init();
      </script>
      </body>
      </html>
    

Viewport


      function Viewport() {
      var me = this;
      me.objects = [];
      var canvas = document.getElementById("drawing-surface");
      function resizeCanvas() {
      canvas.width = window.innerWidth;
      canvas.height = window.innerHeight;
      }
      resizeCanvas();
      window.onresize = function () {
      resizeCanvas();
      }
      var drawingSurface = document.getElementById("drawing-surface").getContext("2d");
      var image = new Image();
      image.src = "background.png";
      image.onload = function () {
      me.backgroundImage = image;
      me.doPaint = true;
      }
      me.doPaint = true;
      function drawBackgroundImage() {
      if (me.backgroundImage) {
      drawingSurface.drawImage(me.backgroundImage, 0, 0, canvas.width, canvas.height);
      }
      }
      function drawObjects() {
      for (var i = 0; i < me.objects.length; i++) {
      me.objects[i].paint(drawingSurface);
      }
      }
      me.paintInit = function () {
      me.doPaint = true;
      }
      function paint() {
      me.paintInit();
      if (me.doPaint) {
      drawBackgroundImage();
      drawObjects();
      me.doPaint = false;
      }
      }
      var timer;
      me.init = function () {
      timer = setInterval(function () { paint(); }, 1000 / 30);
      };
      me.repaint = function () {
      me.doPaint = true;
      };
      me.addObject = function (obj) {
      me.objects.push(obj);
      }
      }
    

Snow


      function Snow() {
      var me = this;
      me.reset = function () {
      me.wind = RandomFloat(2);
      me.speed = RandomFloat(5) + 1;
      me.size = { width: RandomFloat(3) + 1, height: RandomFloat(3) + 1 };
      me.location = { x: RandomFloat(window.innerWidth), y: 0 };
      };
      me.reset();
      var image = new Image();
      image.src = "snow.png";
      image.onload = function () {
      me.image = image;
      }
      me.move = function () {
      if (me.location.y > window.innerWidth || me.location.x < 0 || me.location.x > window.innerWidth) {
      me.reset();
      }
      me.location.x += me.wind;
      me.location.y += me.speed;
      };
      me.paint = function (context) {
      if (!me.image) return;
      me.move();
      context.drawImage(me.image, me.location.x, me.location.y,me.size.width,me.size.height);
      };
      }