fabric.js/src/mixins/object_geometry.mixin.js

400 lines
13 KiB
JavaScript

(function() {
var degreesToRadians = fabric.util.degreesToRadians;
fabric.util.object.extend(fabric.Object.prototype, /** @lends fabric.Object.prototype */ {
/**
* Object containing coordinates of object's controls
* @type Object
* @default
*/
oCoords: null,
/**
* Checks if object intersects with an area formed by 2 points
* @param {Object} pointTL top-left point of area
* @param {Object} pointBR bottom-right point of area
* @return {Boolean} true if object intersects with an area formed by 2 points
*/
intersectsWithRect: function(pointTL, pointBR) {
var oCoords = this.oCoords,
tl = new fabric.Point(oCoords.tl.x, oCoords.tl.y),
tr = new fabric.Point(oCoords.tr.x, oCoords.tr.y),
bl = new fabric.Point(oCoords.bl.x, oCoords.bl.y),
br = new fabric.Point(oCoords.br.x, oCoords.br.y),
intersection = fabric.Intersection.intersectPolygonRectangle(
[tl, tr, br, bl],
pointTL,
pointBR
);
return intersection.status === 'Intersection';
},
/**
* Checks if object intersects with another object
* @param {Object} other Object to test
* @return {Boolean} true if object intersects with another object
*/
intersectsWithObject: function(other) {
// extracts coords
function getCoords(oCoords) {
return {
tl: new fabric.Point(oCoords.tl.x, oCoords.tl.y),
tr: new fabric.Point(oCoords.tr.x, oCoords.tr.y),
bl: new fabric.Point(oCoords.bl.x, oCoords.bl.y),
br: new fabric.Point(oCoords.br.x, oCoords.br.y)
};
}
var thisCoords = getCoords(this.oCoords),
otherCoords = getCoords(other.oCoords),
intersection = fabric.Intersection.intersectPolygonPolygon(
[thisCoords.tl, thisCoords.tr, thisCoords.br, thisCoords.bl],
[otherCoords.tl, otherCoords.tr, otherCoords.br, otherCoords.bl]
);
return intersection.status === 'Intersection';
},
/**
* Checks if object is fully contained within area of another object
* @param {Object} other Object to test
* @return {Boolean} true if object is fully contained within area of another object
*/
isContainedWithinObject: function(other) {
var boundingRect = other.getBoundingRect(),
point1 = new fabric.Point(boundingRect.left, boundingRect.top),
point2 = new fabric.Point(boundingRect.left + boundingRect.width, boundingRect.top + boundingRect.height);
return this.isContainedWithinRect(point1, point2);
},
/**
* Checks if object is fully contained within area formed by 2 points
* @param {Object} pointTL top-left point of area
* @param {Object} pointBR bottom-right point of area
* @return {Boolean} true if object is fully contained within area formed by 2 points
*/
isContainedWithinRect: function(pointTL, pointBR) {
var boundingRect = this.getBoundingRect();
return (
boundingRect.left >= pointTL.x &&
boundingRect.left + boundingRect.width <= pointBR.x &&
boundingRect.top >= pointTL.y &&
boundingRect.top + boundingRect.height <= pointBR.y
);
},
/**
* Checks if point is inside the object
* @param {fabric.Point} point Point to check against
* @return {Boolean} true if point is inside the object
*/
containsPoint: function(point) {
var lines = this._getImageLines(this.oCoords),
xPoints = this._findCrossPoints(point, lines);
// if xPoints is odd then point is inside the object
return (xPoints !== 0 && xPoints % 2 === 1);
},
/**
* Method that returns an object with the object edges in it, given the coordinates of the corners
* @private
* @param {Object} oCoords Coordinates of the object corners
*/
_getImageLines: function(oCoords) {
return {
topline: {
o: oCoords.tl,
d: oCoords.tr
},
rightline: {
o: oCoords.tr,
d: oCoords.br
},
bottomline: {
o: oCoords.br,
d: oCoords.bl
},
leftline: {
o: oCoords.bl,
d: oCoords.tl
}
};
},
/**
* Helper method to determine how many cross points are between the 4 object edges
* and the horizontal line determined by a point on canvas
* @private
* @param {fabric.Point} point Point to check
* @param {Object} oCoords Coordinates of the object being evaluated
*/
_findCrossPoints: function(point, oCoords) {
var b1, b2, a1, a2, xi, yi,
xcount = 0,
iLine;
for (var lineKey in oCoords) {
iLine = oCoords[lineKey];
// optimisation 1: line below point. no cross
if ((iLine.o.y < point.y) && (iLine.d.y < point.y)) {
continue;
}
// optimisation 2: line above point. no cross
if ((iLine.o.y >= point.y) && (iLine.d.y >= point.y)) {
continue;
}
// optimisation 3: vertical line case
if ((iLine.o.x === iLine.d.x) && (iLine.o.x >= point.x)) {
xi = iLine.o.x;
yi = point.y;
}
// calculate the intersection point
else {
b1 = 0;
b2 = (iLine.d.y - iLine.o.y) / (iLine.d.x - iLine.o.x);
a1 = point.y - b1 * point.x;
a2 = iLine.o.y - b2 * iLine.o.x;
xi = - (a1 - a2) / (b1 - b2);
yi = a1 + b1 * xi;
}
// dont count xi < point.x cases
if (xi >= point.x) {
xcount += 1;
}
// optimisation 4: specific for square images
if (xcount === 2) {
break;
}
}
return xcount;
},
/**
* Returns width of an object's bounding rectangle
* @deprecated since 1.0.4
* @return {Number} width value
*/
getBoundingRectWidth: function() {
return this.getBoundingRect().width;
},
/**
* Returns height of an object's bounding rectangle
* @deprecated since 1.0.4
* @return {Number} height value
*/
getBoundingRectHeight: function() {
return this.getBoundingRect().height;
},
/**
* Returns coordinates of object's bounding rectangle (left, top, width, height)
* @return {Object} Object with left, top, width, height properties
*/
getBoundingRect: function() {
this.oCoords || this.setCoords();
var xCoords = [this.oCoords.tl.x, this.oCoords.tr.x, this.oCoords.br.x, this.oCoords.bl.x],
minX = fabric.util.array.min(xCoords),
maxX = fabric.util.array.max(xCoords),
width = Math.abs(minX - maxX),
yCoords = [this.oCoords.tl.y, this.oCoords.tr.y, this.oCoords.br.y, this.oCoords.bl.y],
minY = fabric.util.array.min(yCoords),
maxY = fabric.util.array.max(yCoords),
height = Math.abs(minY - maxY);
return {
left: minX,
top: minY,
width: width,
height: height
};
},
/**
* Returns width of an object
* @return {Number} width value
*/
getWidth: function() {
return this.width * this.scaleX;
},
/**
* Returns height of an object
* @return {Number} height value
*/
getHeight: function() {
return this.height * this.scaleY;
},
/**
* Makes sure the scale is valid and modifies it if necessary
* @private
* @param {Number} value
* @return {Number}
*/
_constrainScale: function(value) {
if (Math.abs(value) < this.minScaleLimit) {
if (value < 0) {
return -this.minScaleLimit;
}
else {
return this.minScaleLimit;
}
}
return value;
},
/**
* Scales an object (equally by x and y)
* @param {Number} value Scale factor
* @return {fabric.Object} thisArg
* @chainable
*/
scale: function(value) {
value = this._constrainScale(value);
if (value < 0) {
this.flipX = !this.flipX;
this.flipY = !this.flipY;
value *= -1;
}
this.scaleX = value;
this.scaleY = value;
this.setCoords();
return this;
},
/**
* Scales an object to a given width, with respect to bounding box (scaling by x/y equally)
* @param {Number} value New width value
* @return {fabric.Object} thisArg
* @chainable
*/
scaleToWidth: function(value) {
// adjust to bounding rect factor so that rotated shapes would fit as well
var boundingRectFactor = this.getBoundingRectWidth() / this.getWidth();
return this.scale(value / this.width / boundingRectFactor);
},
/**
* Scales an object to a given height, with respect to bounding box (scaling by x/y equally)
* @param {Number} value New height value
* @return {fabric.Object} thisArg
* @chainable
*/
scaleToHeight: function(value) {
// adjust to bounding rect factor so that rotated shapes would fit as well
var boundingRectFactor = this.getBoundingRectHeight() / this.getHeight();
return this.scale(value / this.height / boundingRectFactor);
},
/**
* Sets corner position coordinates based on current angle, width and height
* See https://github.com/kangax/fabric.js/wiki/When-to-call-setCoords
* @return {fabric.Object} thisArg
* @chainable
*/
setCoords: function() {
var strokeWidth = this.strokeWidth,
theta = degreesToRadians(this.angle),
vpt = this.getViewportTransform(),
f = function (p) {
return fabric.util.transformPoint(p, vpt);
},
w = this.width, currentWidth,
h = this.height, currentHeight,
capped = this.strokeLineCap === 'round' || this.strokeLineCap === 'square',
vLine = this.type === 'line' && this.width === 0,
hLine = this.type === 'line' && this.height === 0,
sLine = vLine || hLine,
strokeW = (capped && hLine) || !sLine,
strokeH = (capped && vLine) || !sLine;
if (vLine) {
w = strokeWidth;
}
else if (hLine) {
h = strokeWidth;
}
if (strokeW) {
w += w > 0 ? strokeWidth : -strokeWidth;
}
if (strokeH) {
h += h > 0 ? strokeWidth : -strokeWidth;
}
currentWidth = w * this.scaleX + 2 * this.padding;
currentHeight = h * this.scaleY + 2 * this.padding;
// If width is negative, make postive. Fixes path selection issue
if (currentWidth < 0) {
currentWidth = Math.abs(currentWidth);
}
var _hypotenuse = Math.sqrt(
Math.pow(currentWidth / 2, 2) +
Math.pow(currentHeight / 2, 2)),
_angle = Math.atan(
isFinite(currentHeight / currentWidth)
? currentHeight / currentWidth
: 0),
// offset added for rotate and scale actions
offsetX = Math.cos(_angle + theta) * _hypotenuse,
offsetY = Math.sin(_angle + theta) * _hypotenuse,
sinTh = Math.sin(theta),
cosTh = Math.cos(theta),
coords = this.getCenterPoint(),
wh = new fabric.Point(currentWidth, currentHeight),
_tl = new fabric.Point(coords.x - offsetX, coords.y - offsetY),
_tr = new fabric.Point(_tl.x + (wh.x * cosTh), _tl.y + (wh.x * sinTh)),
_bl = new fabric.Point(_tl.x - (wh.y * sinTh), _tl.y + (wh.y * cosTh)),
_mt = new fabric.Point(_tl.x + (wh.x/2 * cosTh), _tl.y + (wh.x/2 * sinTh)),
tl = f(_tl),
tr = f(_tr),
br = f(new fabric.Point(_tr.x - (wh.y * sinTh), _tr.y + (wh.y * cosTh))),
bl = f(_bl),
ml = f(new fabric.Point(_tl.x - (wh.y/2 * sinTh), _tl.y + (wh.y/2 * cosTh))),
mt = f(_mt),
mr = f(new fabric.Point(_tr.x - (wh.y/2 * sinTh), _tr.y + (wh.y/2 * cosTh))),
mb = f(new fabric.Point(_bl.x + (wh.x/2 * cosTh), _bl.y + (wh.x/2 * sinTh))),
mtr = f(new fabric.Point(_mt.x, _mt.y));
// debugging
// setTimeout(function() {
// canvas.contextTop.fillStyle = 'green';
// canvas.contextTop.fillRect(mb.x, mb.y, 3, 3);
// canvas.contextTop.fillRect(bl.x, bl.y, 3, 3);
// canvas.contextTop.fillRect(br.x, br.y, 3, 3);
// canvas.contextTop.fillRect(tl.x, tl.y, 3, 3);
// canvas.contextTop.fillRect(tr.x, tr.y, 3, 3);
// canvas.contextTop.fillRect(ml.x, ml.y, 3, 3);
// canvas.contextTop.fillRect(mr.x, mr.y, 3, 3);
// canvas.contextTop.fillRect(mt.x, mt.y, 3, 3);
// }, 50);
this.oCoords = {
// corners
tl: tl, tr: tr, br: br, bl: bl,
// middle
ml: ml, mt: mt, mr: mr, mb: mb,
// rotating point
mtr: mtr
};
// set coordinates of the draggable boxes in the corners used to scale/rotate the image
this._setCornerCoords && this._setCornerCoords();
return this;
}
});
})();