fabric.js 禁用在黑色像素上绘图

Question

I am making a drawing app in fabric.js. I want to ignore the black area of image to be colored in. Any suggestions please???? Click the link for image

Answer 1

You can use the image as overlay.Please check here: http://jsfiddle.net/mariusturcu93/s5wxbcde/19/
JS

 var canvas = new fabric.Canvas('canvas');
    canvas.backgroundColor = "blue";
    canvas.isDrawingMode=1;
    canvas.setOverlayImage('https://vignette.wikia.nocookie.net/fantendo/images/6/6e/Small-mario.png/revision/latest/scale-to-width-down/381?cb=20120718024112', canvas.renderAll.bind(canvas), {
        width: canvas.width,
        height: canvas.height
    });

HTML

<canvas id="canvas" width="800" height="800"></canvas>