| Index: sdk/lib/math/point.dart
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| diff --git a/sdk/lib/math/point.dart b/sdk/lib/math/point.dart
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| new file mode 100644
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| index 0000000000000000000000000000000000000000..6644a590cdbe8da98e5acc1cc51ed7b1a3f7d171
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| --- /dev/null
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| +++ b/sdk/lib/math/point.dart
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| @@ -0,0 +1,81 @@
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| +// 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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| +
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| + const Point([T x = 0, T y = 0]): this.x = x, this.y = y;
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| +
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| + String toString() => 'Point($x, $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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| +
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| + int get hashCode => _JenkinsSmiHash.hash2(x.hashCode, y.hashCode);
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| +
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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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| + /**
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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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| + /**
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| + * Scale this point by [factor] as if it was 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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| + /**
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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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| + /**
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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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| + /**
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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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|