// Copyright 2006 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview A utility class for representing rectangles.
*/
goog.provide('goog.math.Rect');
goog.require('goog.math.Box');
goog.require('goog.math.Coordinate');
goog.require('goog.math.Size');
/**
* Class for representing rectangular regions.
* @param {number} x Left.
* @param {number} y Top.
* @param {number} w Width.
* @param {number} h Height.
* @struct
* @constructor
*/
goog.math.Rect = function(x, y, w, h) {
/** @type {number} */
this.left = x;
/** @type {number} */
this.top = y;
/** @type {number} */
this.width = w;
/** @type {number} */
this.height = h;
};
/**
* @return {!goog.math.Rect} A new copy of this Rectangle.
*/
goog.math.Rect.prototype.clone = function() {
return new goog.math.Rect(this.left, this.top, this.width, this.height);
};
/**
* Returns a new Box object with the same position and dimensions as this
* rectangle.
* @return {!goog.math.Box} A new Box representation of this Rectangle.
*/
goog.math.Rect.prototype.toBox = function() {
var right = this.left + this.width;
var bottom = this.top + this.height;
return new goog.math.Box(this.top,
right,
bottom,
this.left);
};
/**
* Creates a new Rect object with the position and size given.
* @param {!goog.math.Coordinate} position The top-left coordinate of the Rect
* @param {!goog.math.Size} size The size of the Rect
* @return {!goog.math.Rect} A new Rect initialized with the given position and
* size.
*/
goog.math.Rect.createFromPositionAndSize = function(position, size) {
return new goog.math.Rect(position.x, position.y, size.width, size.height);
};
/**
* Creates a new Rect object with the same position and dimensions as a given
* Box. Note that this is only the inverse of toBox if left/top are defined.
* @param {goog.math.Box} box A box.
* @return {!goog.math.Rect} A new Rect initialized with the box's position
* and size.
*/
goog.math.Rect.createFromBox = function(box) {
return new goog.math.Rect(box.left, box.top,
box.right - box.left, box.bottom - box.top);
};
if (goog.DEBUG) {
/**
* Returns a nice string representing size and dimensions of rectangle.
* @return {string} In the form (50, 73 - 75w x 25h).
* @override
*/
goog.math.Rect.prototype.toString = function() {
return '(' + this.left + ', ' + this.top + ' - ' + this.width + 'w x ' +
this.height + 'h)';
};
}
/**
* Compares rectangles for equality.
* @param {goog.math.Rect} a A Rectangle.
* @param {goog.math.Rect} b A Rectangle.
* @return {boolean} True iff the rectangles have the same left, top, width,
* and height, or if both are null.
*/
goog.math.Rect.equals = function(a, b) {
if (a == b) {
return true;
}
if (!a || !b) {
return false;
}
return a.left == b.left && a.width == b.width &&
a.top == b.top && a.height == b.height;
};
/**
* Computes the intersection of this rectangle and the rectangle parameter. If
* there is no intersection, returns false and leaves this rectangle as is.
* @param {goog.math.Rect} rect A Rectangle.
* @return {boolean} True iff this rectangle intersects with the parameter.
*/
goog.math.Rect.prototype.intersection = function(rect) {
var x0 = Math.max(this.left, rect.left);
var x1 = Math.min(this.left + this.width, rect.left + rect.width);
if (x0 <= x1) {
var y0 = Math.max(this.top, rect.top);
var y1 = Math.min(this.top + this.height, rect.top + rect.height);
if (y0 <= y1) {
this.left = x0;
this.top = y0;
this.width = x1 - x0;
this.height = y1 - y0;
return true;
}
}
return false;
};
/**
* Returns the intersection of two rectangles. Two rectangles intersect if they
* touch at all, for example, two zero width and height rectangles would
* intersect if they had the same top and left.
* @param {goog.math.Rect} a A Rectangle.
* @param {goog.math.Rect} b A Rectangle.
* @return {goog.math.Rect} A new intersection rect (even if width and height
* are 0), or null if there is no intersection.
*/
goog.math.Rect.intersection = function(a, b) {
// There is no nice way to do intersection via a clone, because any such
// clone might be unnecessary if this function returns null. So, we duplicate
// code from above.
var x0 = Math.max(a.left, b.left);
var x1 = Math.min(a.left + a.width, b.left + b.width);
if (x0 <= x1) {
var y0 = Math.max(a.top, b.top);
var y1 = Math.min(a.top + a.height, b.top + b.height);
if (y0 <= y1) {
return new goog.math.Rect(x0, y0, x1 - x0, y1 - y0);
}
}
return null;
};
/**
* Returns whether two rectangles intersect. Two rectangles intersect if they
* touch at all, for example, two zero width and height rectangles would
* intersect if they had the same top and left.
* @param {goog.math.Rect} a A Rectangle.
* @param {goog.math.Rect} b A Rectangle.
* @return {boolean} Whether a and b intersect.
*/
goog.math.Rect.intersects = function(a, b) {
return (a.left <= b.left + b.width && b.left <= a.left + a.width &&
a.top <= b.top + b.height && b.top <= a.top + a.height);
};
/**
* Returns whether a rectangle intersects this rectangle.
* @param {goog.math.Rect} rect A rectangle.
* @return {boolean} Whether rect intersects this rectangle.
*/
goog.math.Rect.prototype.intersects = function(rect) {
return goog.math.Rect.intersects(this, rect);
};
/**
* Computes the difference regions between two rectangles. The return value is
* an array of 0 to 4 rectangles defining the remaining regions of the first
* rectangle after the second has been subtracted.
* @param {goog.math.Rect} a A Rectangle.
* @param {goog.math.Rect} b A Rectangle.
* @return {!Array<!goog.math.Rect>} An array with 0 to 4 rectangles which
* together define the difference area of rectangle a minus rectangle b.
*/
goog.math.Rect.difference = function(a, b) {
var intersection = goog.math.Rect.intersection(a, b);
if (!intersection || !intersection.height || !intersection.width) {
return [a.clone()];
}
var result = [];
var top = a.top;
var height = a.height;
var ar = a.left + a.width;
var ab = a.top + a.height;
var br = b.left + b.width;
var bb = b.top + b.height;
// Subtract off any area on top where A extends past B
if (b.top > a.top) {
result.push(new goog.math.Rect(a.left, a.top, a.width, b.top - a.top));
top = b.top;
// If we're moving the top down, we also need to subtract the height diff.
height -= b.top - a.top;
}
// Subtract off any area on bottom where A extends past B
if (bb < ab) {
result.push(new goog.math.Rect(a.left, bb, a.width, ab - bb));
height = bb - top;
}
// Subtract any area on left where A extends past B
if (b.left > a.left) {
result.push(new goog.math.Rect(a.left, top, b.left - a.left, height));
}
// Subtract any area on right where A extends past B
if (br < ar) {
result.push(new goog.math.Rect(br, top, ar - br, height));
}
return result;
};
/**
* Computes the difference regions between this rectangle and {@code rect}. The
* return value is an array of 0 to 4 rectangles defining the remaining regions
* of this rectangle after the other has been subtracted.
* @param {goog.math.Rect} rect A Rectangle.
* @return {!Array<!goog.math.Rect>} An array with 0 to 4 rectangles which
* together define the difference area of rectangle a minus rectangle b.
*/
goog.math.Rect.prototype.difference = function(rect) {
return goog.math.Rect.difference(this, rect);
};
/**
* Expand this rectangle to also include the area of the given rectangle.
* @param {goog.math.Rect} rect The other rectangle.
*/
goog.math.Rect.prototype.boundingRect = function(rect) {
// We compute right and bottom before we change left and top below.
var right = Math.max(this.left + this.width, rect.left + rect.width);
var bottom = Math.max(this.top + this.height, rect.top + rect.height);
this.left = Math.min(this.left, rect.left);
this.top = Math.min(this.top, rect.top);
this.width = right - this.left;
this.height = bottom - this.top;
};
/**
* Returns a new rectangle which completely contains both input rectangles.
* @param {goog.math.Rect} a A rectangle.
* @param {goog.math.Rect} b A rectangle.
* @return {goog.math.Rect} A new bounding rect, or null if either rect is
* null.
*/
goog.math.Rect.boundingRect = function(a, b) {
if (!a || !b) {
return null;
}
var clone = a.clone();
clone.boundingRect(b);
return clone;
};
/**
* Tests whether this rectangle entirely contains another rectangle or
* coordinate.
*
* @param {goog.math.Rect|goog.math.Coordinate} another The rectangle or
* coordinate to test for containment.
* @return {boolean} Whether this rectangle contains given rectangle or
* coordinate.
*/
goog.math.Rect.prototype.contains = function(another) {
if (another instanceof goog.math.Rect) {
return this.left <= another.left &&
this.left + this.width >= another.left + another.width &&
this.top <= another.top &&
this.top + this.height >= another.top + another.height;
} else { // (another instanceof goog.math.Coordinate)
return another.x >= this.left &&
another.x <= this.left + this.width &&
another.y >= this.top &&
another.y <= this.top + this.height;
}
};
/**
* @param {!goog.math.Coordinate} point A coordinate.
* @return {number} The squared distance between the point and the closest
* point inside the rectangle. Returns 0 if the point is inside the
* rectangle.
*/
goog.math.Rect.prototype.squaredDistance = function(point) {
var dx = point.x < this.left ?
this.left - point.x : Math.max(point.x - (this.left + this.width), 0);
var dy = point.y < this.top ?
this.top - point.y : Math.max(point.y - (this.top + this.height), 0);
return dx * dx + dy * dy;
};
/**
* @param {!goog.math.Coordinate} point A coordinate.
* @return {number} The distance between the point and the closest point
* inside the rectangle. Returns 0 if the point is inside the rectangle.
*/
goog.math.Rect.prototype.distance = function(point) {
return Math.sqrt(this.squaredDistance(point));
};
/**
* @return {!goog.math.Size} The size of this rectangle.
*/
goog.math.Rect.prototype.getSize = function() {
return new goog.math.Size(this.width, this.height);
};
/**
* @return {!goog.math.Coordinate} A new coordinate for the top-left corner of
* the rectangle.
*/
goog.math.Rect.prototype.getTopLeft = function() {
return new goog.math.Coordinate(this.left, this.top);
};
/**
* @return {!goog.math.Coordinate} A new coordinate for the center of the
* rectangle.
*/
goog.math.Rect.prototype.getCenter = function() {
return new goog.math.Coordinate(
this.left + this.width / 2, this.top + this.height / 2);
};
/**
* @return {!goog.math.Coordinate} A new coordinate for the bottom-right corner
* of the rectangle.
*/
goog.math.Rect.prototype.getBottomRight = function() {
return new goog.math.Coordinate(
this.left + this.width, this.top + this.height);
};
/**
* Rounds the fields to the next larger integer values.
* @return {!goog.math.Rect} This rectangle with ceil'd fields.
*/
goog.math.Rect.prototype.ceil = function() {
this.left = Math.ceil(this.left);
this.top = Math.ceil(this.top);
this.width = Math.ceil(this.width);
this.height = Math.ceil(this.height);
return this;
};
/**
* Rounds the fields to the next smaller integer values.
* @return {!goog.math.Rect} This rectangle with floored fields.
*/
goog.math.Rect.prototype.floor = function() {
this.left = Math.floor(this.left);
this.top = Math.floor(this.top);
this.width = Math.floor(this.width);
this.height = Math.floor(this.height);
return this;
};
/**
* Rounds the fields to nearest integer values.
* @return {!goog.math.Rect} This rectangle with rounded fields.
*/
goog.math.Rect.prototype.round = function() {
this.left = Math.round(this.left);
this.top = Math.round(this.top);
this.width = Math.round(this.width);
this.height = Math.round(this.height);
return this;
};
/**
* Translates this rectangle by the given offsets. If a
* {@code goog.math.Coordinate} is given, then the left and top values are
* translated by the coordinate's x and y values. Otherwise, top and left are
* translated by {@code tx} and {@code opt_ty} respectively.
* @param {number|goog.math.Coordinate} tx The value to translate left by or the
* the coordinate to translate this rect by.
* @param {number=} opt_ty The value to translate top by.
* @return {!goog.math.Rect} This rectangle after translating.
*/
goog.math.Rect.prototype.translate = function(tx, opt_ty) {
if (tx instanceof goog.math.Coordinate) {
this.left += tx.x;
this.top += tx.y;
} else {
this.left += tx;
if (goog.isNumber(opt_ty)) {
this.top += opt_ty;
}
}
return this;
};
/**
* Scales this rectangle by the given scale factors. The left and width values
* are scaled by {@code sx} and the top and height values are scaled by
* {@code opt_sy}. If {@code opt_sy} is not given, then all fields are scaled
* by {@code sx}.
* @param {number} sx The scale factor to use for the x dimension.
* @param {number=} opt_sy The scale factor to use for the y dimension.
* @return {!goog.math.Rect} This rectangle after scaling.
*/
goog.math.Rect.prototype.scale = function(sx, opt_sy) {
var sy = goog.isNumber(opt_sy) ? opt_sy : sx;
this.left *= sx;
this.width *= sx;
this.top *= sy;
this.height *= sy;
return this;
};
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