John Messerly
807d3b3b22
it's all under input_sdk now: lib -> the lib folder private -> the dart:_* libs patch -> the files with @patch I imagine we'll try and focus changes on the last two
89 lines
2.4 KiB
Dart
89 lines
2.4 KiB
Dart
// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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part of dart.math;
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/**
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* A utility class for representing two-dimensional positions.
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*/
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class Point<T extends num> {
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final T x;
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final T y;
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const Point(T x, T y): this.x = x, this.y = y;
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String toString() => 'Point($x, $y)';
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/**
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* A `Point` is only equal to another `Point` with the same coordinates.
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*
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* This point is equal to `other` if, and only if,
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* `other` is a `Point` with
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* [x] equal to `other.x` and [y] equal to `other.y`.
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*/
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bool operator ==(other) {
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if (other is !Point) return false;
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return x == other.x && y == other.y;
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}
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int get hashCode => _JenkinsSmiHash.hash2(x.hashCode, y.hashCode);
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/**
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* Add [other] to `this`, as if both points were vectors.
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*
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* Returns the resulting "vector" as a Point.
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*/
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Point<T> operator +(Point<T> other) {
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return new Point<T>(x + other.x, y + other.y);
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}
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/**
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* Subtract [other] from `this`, as if both points were vectors.
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*
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* Returns the resulting "vector" as a Point.
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*/
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Point<T> operator -(Point<T> other) {
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return new Point<T>(x - other.x, y - other.y);
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}
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/**
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* Scale this point by [factor] as if it were a vector.
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*
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* *Important* *Note*: This function accepts a `num` as its argument only so
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* that you can scale Point<double> objects by an `int` factor. Because the
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* star operator always returns the same type of Point that originally called
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* it, passing in a double [factor] on a `Point<int>` _causes_ _a_
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* _runtime_ _error_ in checked mode.
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*/
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Point<T> operator *(num factor) {
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return new Point<T>(x * factor, y * factor);
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}
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/**
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* Get the straight line (Euclidean) distance between the origin (0, 0) and
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* this point.
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*/
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double get magnitude => sqrt(x * x + y * y);
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/**
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* Returns the distance between `this` and [other].
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*/
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double distanceTo(Point<T> other) {
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var dx = x - other.x;
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var dy = y - other.y;
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return sqrt(dx * dx + dy * dy);
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}
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/**
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* Returns the squared distance between `this` and [other].
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*
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* Squared distances can be used for comparisons when the actual value is not
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* required.
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*/
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T squaredDistanceTo(Point<T> other) {
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var dx = x - other.x;
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var dy = y - other.y;
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return dx * dx + dy * dy;
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}
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}
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