Scale fabric.js canvas objects

问题

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);

回答1:

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();
}

来源：https://stackoverflow.com/questions/28301286/scale-fabric-js-canvas-objects