javascript - Text Masking not working with HTML canvas -

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i trying text masking in javascript.

below code :-

if(this.image!==null) {    canvascontext.drawimage(this.image, 0, 0, this.width, this.height); }  canvascontext.font = "55px arial"; canvascontext.textalign = "center"; canvascontext.textbaseline = "middle";    canvascontext.globalcompositeoperation = 'destination-out'; canvascontext.filltext("censored", 250, 250);

but not working. please me resolve issues.

i’m not sure “not working” means, but…

there 2 common kinds of text masking in canvas

destination-out: text act cookie-cutter , remove drawn underneath text, text not show on transparent pixels.

xor: text cut out non-transparent drawings on canvas, text otherwise drawn normally.

here code , fiddle: http://jsfiddle.net/m1erickson/n836n/ 

<style>     body{ background-color: purple; }     canvas{background-color: white; border:1px solid red;} </style>  <script> $(function(){      var canvas1=document.getelementbyid("canvas1");     var canvascontext1=canvas1.getcontext("2d");     var canvas2=document.getelementbyid("canvas2");     var canvascontext2=canvas2.getcontext("2d");      // destination-out      // text cuts-out under     // background revealed in cut-out     makegradientandfont(canvascontext1,canvas1);     canvascontext1.globalcompositeoperation = 'destination-out';     canvascontext1.filltext("censored", 175, 50);      // xor     // text cuts-out overlaps     // text drawn canvas transparent     // background revealed in cut-out     makegradientandfont(canvascontext2,canvas2);     canvascontext2.globalcompositeoperation = 'xor';     canvascontext2.filltext("censored", 175, 50);      function makegradientandfont(ctx,canvas){         var grad = ctx.createlineargradient(0, 0, canvas.width, canvas.height);         grad.addcolorstop( 0, '#0000ff');            grad.addcolorstop(.3, '#00ffff');         grad.addcolorstop(.4, '#99ffff');            grad.addcolorstop(.5, '#00ff00');         grad.addcolorstop(.6, '#ffff00');         grad.addcolorstop(.8, '#f00000');         ctx.rect(115, 0, canvas.width-115, canvas.height);         ctx.fillstyle=grad;         ctx.fill();         ctx.fillstyle="black";         ctx.font = "55px arial";         ctx.textalign = "center";         ctx.textbaseline = "middle";      }   }); // end $(function(){}); </script>  </head>  <body>     <canvas id="canvas1" width=350 height=100></canvas><br/>     <canvas id="canvas2" width=350 height=100></canvas> </body> </html>

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