1 files changed, 255 insertions, 0 deletions
diff --git a/vendor/github.com/golang/geo/r2/rect.go b/vendor/github.com/golang/geo/r2/rect.go
new file mode 100644
index 000000000..495545bba
--- /dev/null
+++ b/vendor/github.com/golang/geo/r2/rect.go
@@ -0,0 +1,255 @@
+// Copyright 2014 Google Inc. 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.
+
+package r2
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/golang/geo/r1"
+)
+
+// Point represents a point in ℝ².
+type Point struct {
+	X, Y float64
+}
+
+// Add returns the sum of p and op.
+func (p Point) Add(op Point) Point { return Point{p.X + op.X, p.Y + op.Y} }
+
+// Sub returns the difference of p and op.
+func (p Point) Sub(op Point) Point { return Point{p.X - op.X, p.Y - op.Y} }
+
+// Mul returns the scalar product of p and m.
+func (p Point) Mul(m float64) Point { return Point{m * p.X, m * p.Y} }
+
+// Ortho returns a counterclockwise orthogonal point with the same norm.
+func (p Point) Ortho() Point { return Point{-p.Y, p.X} }
+
+// Dot returns the dot product between p and op.
+func (p Point) Dot(op Point) float64 { return p.X*op.X + p.Y*op.Y }
+
+// Cross returns the cross product of p and op.
+func (p Point) Cross(op Point) float64 { return p.X*op.Y - p.Y*op.X }
+
+// Norm returns the vector's norm.
+func (p Point) Norm() float64 { return math.Hypot(p.X, p.Y) }
+
+// Normalize returns a unit point in the same direction as p.
+func (p Point) Normalize() Point {
+	if p.X == 0 && p.Y == 0 {
+		return p
+	}
+	return p.Mul(1 / p.Norm())
+}
+
+func (p Point) String() string { return fmt.Sprintf("(%.12f, %.12f)", p.X, p.Y) }
+
+// Rect represents a closed axis-aligned rectangle in the (x,y) plane.
+type Rect struct {
+	X, Y r1.Interval
+}
+
+// RectFromPoints constructs a rect that contains the given points.
+func RectFromPoints(pts ...Point) Rect {
+	// Because the default value on interval is 0,0, we need to manually
+	// define the interval from the first point passed in as our starting
+	// interval, otherwise we end up with the case of passing in
+	// Point{0.2, 0.3} and getting the starting Rect of {0, 0.2}, {0, 0.3}
+	// instead of the Rect {0.2, 0.2}, {0.3, 0.3} which is not correct.
+	if len(pts) == 0 {
+		return Rect{}
+	}
+
+	r := Rect{
+		X: r1.Interval{Lo: pts[0].X, Hi: pts[0].X},
+		Y: r1.Interval{Lo: pts[0].Y, Hi: pts[0].Y},
+	}
+
+	for _, p := range pts[1:] {
+		r = r.AddPoint(p)
+	}
+	return r
+}
+
+// RectFromCenterSize constructs a rectangle with the given center and size.
+// Both dimensions of size must be non-negative.
+func RectFromCenterSize(center, size Point) Rect {
+	return Rect{
+		r1.Interval{Lo: center.X - size.X/2, Hi: center.X + size.X/2},
+		r1.Interval{Lo: center.Y - size.Y/2, Hi: center.Y + size.Y/2},
+	}
+}
+
+// EmptyRect constructs the canonical empty rectangle. Use IsEmpty() to test
+// for empty rectangles, since they have more than one representation. A Rect{}
+// is not the same as the EmptyRect.
+func EmptyRect() Rect {
+	return Rect{r1.EmptyInterval(), r1.EmptyInterval()}
+}
+
+// IsValid reports whether the rectangle is valid.
+// This requires the width to be empty iff the height is empty.
+func (r Rect) IsValid() bool {
+	return r.X.IsEmpty() == r.Y.IsEmpty()
+}
+
+// IsEmpty reports whether the rectangle is empty.
+func (r Rect) IsEmpty() bool {
+	return r.X.IsEmpty()
+}
+
+// Vertices returns all four vertices of the rectangle. Vertices are returned in
+// CCW direction starting with the lower left corner.
+func (r Rect) Vertices() [4]Point {
+	return [4]Point{
+		{r.X.Lo, r.Y.Lo},
+		{r.X.Hi, r.Y.Lo},
+		{r.X.Hi, r.Y.Hi},
+		{r.X.Lo, r.Y.Hi},
+	}
+}
+
+// VertexIJ returns the vertex in direction i along the X-axis (0=left, 1=right) and
+// direction j along the Y-axis (0=down, 1=up).
+func (r Rect) VertexIJ(i, j int) Point {
+	x := r.X.Lo
+	if i == 1 {
+		x = r.X.Hi
+	}
+	y := r.Y.Lo
+	if j == 1 {
+		y = r.Y.Hi
+	}
+	return Point{x, y}
+}
+
+// Lo returns the low corner of the rect.
+func (r Rect) Lo() Point {
+	return Point{r.X.Lo, r.Y.Lo}
+}
+
+// Hi returns the high corner of the rect.
+func (r Rect) Hi() Point {
+	return Point{r.X.Hi, r.Y.Hi}
+}
+
+// Center returns the center of the rectangle in (x,y)-space
+func (r Rect) Center() Point {
+	return Point{r.X.Center(), r.Y.Center()}
+}
+
+// Size returns the width and height of this rectangle in (x,y)-space. Empty
+// rectangles have a negative width and height.
+func (r Rect) Size() Point {
+	return Point{r.X.Length(), r.Y.Length()}
+}
+
+// ContainsPoint reports whether the rectangle contains the given point.
+// Rectangles are closed regions, i.e. they contain their boundary.
+func (r Rect) ContainsPoint(p Point) bool {
+	return r.X.Contains(p.X) && r.Y.Contains(p.Y)
+}
+
+// InteriorContainsPoint returns true iff the given point is contained in the interior
+// of the region (i.e. the region excluding its boundary).
+func (r Rect) InteriorContainsPoint(p Point) bool {
+	return r.X.InteriorContains(p.X) && r.Y.InteriorContains(p.Y)
+}
+
+// Contains reports whether the rectangle contains the given rectangle.
+func (r Rect) Contains(other Rect) bool {
+	return r.X.ContainsInterval(other.X) && r.Y.ContainsInterval(other.Y)
+}
+
+// InteriorContains reports whether the interior of this rectangle contains all of the
+// points of the given other rectangle (including its boundary).
+func (r Rect) InteriorContains(other Rect) bool {
+	return r.X.InteriorContainsInterval(other.X) && r.Y.InteriorContainsInterval(other.Y)
+}
+
+// Intersects reports whether this rectangle and the other rectangle have any points in common.
+func (r Rect) Intersects(other Rect) bool {
+	return r.X.Intersects(other.X) && r.Y.Intersects(other.Y)
+}
+
+// InteriorIntersects reports whether the interior of this rectangle intersects
+// any point (including the boundary) of the given other rectangle.
+func (r Rect) InteriorIntersects(other Rect) bool {
+	return r.X.InteriorIntersects(other.X) && r.Y.InteriorIntersects(other.Y)
+}
+
+// AddPoint expands the rectangle to include the given point. The rectangle is
+// expanded by the minimum amount possible.
+func (r Rect) AddPoint(p Point) Rect {
+	return Rect{r.X.AddPoint(p.X), r.Y.AddPoint(p.Y)}
+}
+
+// AddRect expands the rectangle to include the given rectangle. This is the
+// same as replacing the rectangle by the union of the two rectangles, but
+// is more efficient.
+func (r Rect) AddRect(other Rect) Rect {
+	return Rect{r.X.Union(other.X), r.Y.Union(other.Y)}
+}
+
+// ClampPoint returns the closest point in the rectangle to the given point.
+// The rectangle must be non-empty.
+func (r Rect) ClampPoint(p Point) Point {
+	return Point{r.X.ClampPoint(p.X), r.Y.ClampPoint(p.Y)}
+}
+
+// Expanded returns a rectangle that has been expanded in the x-direction
+// by margin.X, and in y-direction by margin.Y. If either margin is empty,
+// then shrink the interval on the corresponding sides instead. The resulting
+// rectangle may be empty. Any expansion of an empty rectangle remains empty.
+func (r Rect) Expanded(margin Point) Rect {
+	xx := r.X.Expanded(margin.X)
+	yy := r.Y.Expanded(margin.Y)
+	if xx.IsEmpty() || yy.IsEmpty() {
+		return EmptyRect()
+	}
+	return Rect{xx, yy}
+}
+
+// ExpandedByMargin returns a Rect that has been expanded by the amount on all sides.
+func (r Rect) ExpandedByMargin(margin float64) Rect {
+	return r.Expanded(Point{margin, margin})
+}
+
+// Union returns the smallest rectangle containing the union of this rectangle and
+// the given rectangle.
+func (r Rect) Union(other Rect) Rect {
+	return Rect{r.X.Union(other.X), r.Y.Union(other.Y)}
+}
+
+// Intersection returns the smallest rectangle containing the intersection of this
+// rectangle and the given rectangle.
+func (r Rect) Intersection(other Rect) Rect {
+	xx := r.X.Intersection(other.X)
+	yy := r.Y.Intersection(other.Y)
+	if xx.IsEmpty() || yy.IsEmpty() {
+		return EmptyRect()
+	}
+
+	return Rect{xx, yy}
+}
+
+// ApproxEqual returns true if the x- and y-intervals of the two rectangles are
+// the same up to the given tolerance.
+func (r Rect) ApproxEqual(r2 Rect) bool {
+	return r.X.ApproxEqual(r2.X) && r.Y.ApproxEqual(r2.Y)
+}
+
+func (r Rect) String() string { return fmt.Sprintf("[Lo%s, Hi%s]", r.Lo(), r.Hi()) }