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Scale fabric.js canvas objects

I have a fabric.js canvas on my page, that I'd like to be responsive. My code works for scaling the canvas itself, but not the objects I've drawn on it. Any idea? I've searched SO but couldn't find a solution that worked for me.

var resizeCanvas;

resizeCanvas = function() {
  var height, ratio, width;
  ratio = 800 / 1177;
  width = tmpl.$('.canvas-wrapper').width();
  height = width / ratio;

  canvas.setDimensions({
    width: width,
    height: height
  });
};

Meteor.setTimeout(function() {
  return resizeCanvas();
}, 100);

$(window).resize(resizeCanvas);
like image 700
zimt28 Avatar asked Feb 03 '15 14:02

zimt28


1 Answers

Here's my zoom function - We zoom the canvas, and then loop over all objects and scale them as well.

Call like zoomIt(2.2)

function zoomIt(factor) {
canvas.setHeight(canvas.getHeight() * factor);
canvas.setWidth(canvas.getWidth() * factor);
if (canvas.backgroundImage) {
    // Need to scale background images as well
    var bi = canvas.backgroundImage;
    bi.width = bi.width * factor; bi.height = bi.height * factor;
}
var objects = canvas.getObjects();
for (var i in objects) {
    var scaleX = objects[i].scaleX;
    var scaleY = objects[i].scaleY;
    var left = objects[i].left;
    var top = objects[i].top;

    var tempScaleX = scaleX * factor;
    var tempScaleY = scaleY * factor;
    var tempLeft = left * factor;
    var tempTop = top * factor;

    objects[i].scaleX = tempScaleX;
    objects[i].scaleY = tempScaleY;
    objects[i].left = tempLeft;
    objects[i].top = tempTop;

    objects[i].setCoords();
}
canvas.renderAll();
canvas.calcOffset();
}
like image 73
Jason Maggard Avatar answered Nov 11 '22 02:11

Jason Maggard