javascript - Creating a path from a PNG in fabricjs -


  • i have png image transparent area.
  • i have photo.
  • i using fabricjs

i need create new image cropped transparent area of png.

i understand can use clipto(path) function create new image.

however, problem creating path in first place. how can create path transparent area of png?

thanks in advance.

as strange may seem, wasn't able find correct duplicate this...

you don't need calculate path bitmap. canvasrenderingcontext2d api offers compositing , blending options, allow work directly bitmaps.

fabricjs offers option: http://fabricjs.com/docs/fabric.object.html#globalcompositeoperation

var c = new fabric.canvas('c', {    imagesmoothingenabled: false  });  fabric.image.fromurl(    'https://dl.dropboxusercontent.com/s/4e90e48s5vtmfbd/aaa.png',    function(image1) {     fabric.image.fromurl(      'https://upload.wikimedia.org/wikipedia/commons/5/55/john_william_waterhouse_a_mermaid.jpg',      function(image2) { // 1 clipped        c.add(image1);        c.add(image2);        c.renderall();     }, {      globalcompositeoperation: 'source-in', // drawn pixels drawn      top: -300,      left: -400    });    }, {    width: 200,    height: 200  });
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.18/fabric.js"></script>  <canvas id="c" width="500" height="500"></canvas>


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