Function getSourceCanvas

static/cropper/2.3.4/cropper.js:222–286

(image, data)

  }

  function getSourceCanvas(image, data) {
    var canvas = $('<canvas>')[0];
    var context = canvas.getContext('2d');
    var dstX = 0;
    var dstY = 0;
    var dstWidth = data.naturalWidth;
    var dstHeight = data.naturalHeight;
    var rotate = data.rotate;
    var scaleX = data.scaleX;
    var scaleY = data.scaleY;
    var scalable = isNumber(scaleX) && isNumber(scaleY) && (scaleX !== 1 || scaleY !== 1);
    var rotatable = isNumber(rotate) && rotate !== 0;
    var advanced = rotatable || scalable;
    var canvasWidth = dstWidth * abs(scaleX || 1);
    var canvasHeight = dstHeight * abs(scaleY || 1);
    var translateX;
    var translateY;
    var rotated;

    if (scalable) {
      translateX = canvasWidth / 2;
      translateY = canvasHeight / 2;
    }

    if (rotatable) {
      rotated = getRotatedSizes({
        width: canvasWidth,
        height: canvasHeight,
        degree: rotate
      });

      canvasWidth = rotated.width;
      canvasHeight = rotated.height;
      translateX = canvasWidth / 2;
      translateY = canvasHeight / 2;
    }

    canvas.width = canvasWidth;
    canvas.height = canvasHeight;

    if (advanced) {
      dstX = -dstWidth / 2;
      dstY = -dstHeight / 2;

      context.save();
      context.translate(translateX, translateY);
    }

    // Rotate should come first before scale as in the "getTransform" function
    if (rotatable) {
      context.rotate(rotate * Math.PI / 180);
    }

    if (scalable) {
      context.scale(scaleX, scaleY);
    }

    context.drawImage(image, floor(dstX), floor(dstY), floor(dstWidth), floor(dstHeight));