CODEWITHSUNDEEP
javascripthtmlcanvaskineticjs
sianabanana
sianabanana

Reputation: 910

KineticJS Fill with pattern

I previously asked how to fill a shape with a checkerboard effect using html5 canvas. HTML5 Canvas Fill with two colours

and i was given a jsfiddle to show how to do this. http://jsfiddle.net/NdUcv/2/

var can = document.getElementById('canvas1');
var ctx = can.getContext('2d');

// set up a pattern, something really elaborate!
var pattern = document.createElement('canvas');
pattern.width = 40;
pattern.height = 40;
var pctx = pattern.getContext('2d');

pctx.fillStyle = "rgb(188, 222, 178)";
pctx.fillRect(0,0,20,20);
pctx.fillRect(20,20,20,20);

// Now we draw that pattern to a custom shape:

var pattern = ctx.createPattern(pattern, "repeat");
ctx.beginPath();
ctx.moveTo(30, 30);
ctx.lineTo(300, 30);
ctx.lineTo(400, 60);
ctx.lineTo(300, 150);
ctx.lineTo(200, 50);
ctx.lineTo(100, 450);
//ctx.closePath();
ctx.fillStyle = pattern;
ctx.fill();

I would like to know know how its possible to convert this syntax to KineticJS? I notice from the kineticjs doc and examples, that you can fill with an image or a gradient, but there is no mention of filling with a pattern.

Surely this can be done if it can be done natively with html5?

Upvotes: 0

Views: 2113

Answers (1)

markE
markE

Reputation: 105015

Yes, you can use similar code to create a kinetic polygon filled with your pattern

enter image description here

Fill a canvas with your pattern just as you do in native html canvas:

    // use a temp canvas to create a pattern
    var pattern = document.createElement('canvas');
    pattern.width = 40;
    pattern.height = 40;
    var pctx = pattern.getContext('2d');
    pctx.fillStyle = "rgb(188, 222, 178)";
    pctx.fillRect(0,0,20,20);
    pctx.fillRect(20,20,20,20);

Now use that temp canvas to create an image object

    var img=new Image();
    img.onload=function(){
            // img now contains your pattern
    }
    img.src=pattern.toDataURL();

Finally, use fillPatternImage to fill a kinetic polygon with your pattern:

        // make a kinetic polygon filled with the pattern
        var polyPattern = new Kinetic.Polygon({
          points: [30,30, 300,30, 400,60, 300,150, 200,50, 100,450],
          fillPatternImage: img,
          stroke: 'black',
          strokeWidth: 3
        });

Here is code and a Fiddle: http://jsfiddle.net/m1erickson/uW8xz/

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Prototype</title>
    <script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
    <script src="http://d3lp1msu2r81bx.cloudfront.net/kjs/js/lib/kinetic-v4.7.0.min.js"></script>

<style>
#container{
  border:solid 1px #ccc;
  margin-top: 10px;
  width:400px;
  height:400px;
}
</style>        
<script>
$(function(){

    var stage = new Kinetic.Stage({
        container: 'container',
        width: 450,
        height: 450
    });
    var layer = new Kinetic.Layer();
    stage.add(layer);

    // use a temp canvas to create a pattern
    var pattern = document.createElement('canvas');
    pattern.width = 40;
    pattern.height = 40;
    var pctx = pattern.getContext('2d');
    pctx.fillStyle = "rgb(188, 222, 178)";
    pctx.fillRect(0,0,20,20);
    pctx.fillRect(20,20,20,20);

    // make an image from the temp canvas pattern
    var img=new Image();
    img.onload=function(){

        // make a kinetic polygon filled with the pattern
        var polyPattern = new Kinetic.Polygon({
          points: [30,30, 300,30, 400,60, 300,150, 200,50, 100,450],
          fillPatternImage: img,
          stroke: 'black',
          strokeWidth: 3
        });
        // add the shape to the layer and layer.draw()
        layer.add(polyPattern);
        layer.draw();

    }
    img.src=pattern.toDataURL();


}); // end $(function(){});

</script>       
</head>

<body>
    <div id="container"></div>
</body>
</html>

Upvotes: 2

Related Questions