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@ruanitto
Created October 4, 2018 13:05
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  1. ruanitto created this gist Oct 4, 2018.
    1 change: 1 addition & 0 deletions index.html
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    <canvas id="c"></canvas>
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    Matrix rain animation using HTML5 canvas and javascript
    -------------------------------------------------------


    A [Pen](https://codepen.io/P3R0/pen/MwgoKv) by [Ebram Marzouk](https://codepen.io/P3R0) on [CodePen](https://codepen.io).

    [License](https://codepen.io/P3R0/pen/MwgoKv/license).
    53 changes: 53 additions & 0 deletions script.js
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    var c = document.getElementById("c");
    var ctx = c.getContext("2d");

    //making the canvas full screen
    c.height = window.innerHeight;
    c.width = window.innerWidth;

    //chinese characters - taken from the unicode charset
    var chinese = "田由甲申甴电甶男甸甹町画甼甽甾甿畀畁畂畃畄畅畆畇畈畉畊畋界畍畎畏畐畑";
    //converting the string into an array of single characters
    chinese = chinese.split("");

    var font_size = 10;
    var columns = c.width/font_size; //number of columns for the rain
    //an array of drops - one per column
    var drops = [];
    //x below is the x coordinate
    //1 = y co-ordinate of the drop(same for every drop initially)
    for(var x = 0; x < columns; x++)
    drops[x] = 1;

    //drawing the characters
    function draw()
    {
    //Black BG for the canvas
    //translucent BG to show trail
    ctx.fillStyle = "rgba(0, 0, 0, 0.05)";
    ctx.fillRect(0, 0, c.width, c.height);

    ctx.fillStyle = "#0F0"; //green text
    ctx.font = font_size + "px arial";
    //looping over drops
    for(var i = 0; i < drops.length; i++)
    {
    //a random chinese character to print
    var text = chinese[Math.floor(Math.random()*chinese.length)];
    //x = i*font_size, y = value of drops[i]*font_size
    ctx.fillText(text, i*font_size, drops[i]*font_size);

    //sending the drop back to the top randomly after it has crossed the screen
    //adding a randomness to the reset to make the drops scattered on the Y axis
    if(drops[i]*font_size > c.height && Math.random() > 0.975)
    drops[i] = 0;

    //incrementing Y coordinate
    drops[i]++;
    }
    }

    setInterval(draw, 33);



    1 change: 1 addition & 0 deletions scripts
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    <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
    5 changes: 5 additions & 0 deletions style.css
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    /*basic reset*/
    * {margin: 0; padding: 0;}
    /*adding a black bg to the body to make things clearer*/
    body {background: black;}
    canvas {display: block;}