1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package draw
// A Point is an X, Y coordinate pair.
type Point struct {
X, Y int;
}
// ZP is the zero Point.
var ZP Point
// A Rectangle contains the Points with Min.X <= X < Max.X, Min.Y <= Y < Max.Y.
type Rectangle struct {
Min, Max Point;
}
// ZR is the zero Rectangle.
var ZR Rectangle
// Pt is shorthand for Point{X, Y}.
func Pt(X, Y int) Point {
return Point{X, Y};
}
// Rect is shorthand for Rectangle{Pt(x0, y0), Pt(x1, y1)}.
func Rect(x0, y0, x1, y1 int) Rectangle {
return Rectangle{Point{x0, y0}, Point{x1, y1}};
}
// Rpt is shorthand for Rectangle{min, max}.
func Rpt(min, max Point) Rectangle {
return Rectangle{min, max};
}
// Add returns the sum of p and q: Pt(p.X+q.X, p.Y+q.Y).
func (p Point) Add(q Point) Point {
return Point{p.X + q.X, p.Y + q.Y};
}
// Sub returns the difference of p and q: Pt(p.X-q.X, p.Y-q.Y).
func (p Point) Sub(q Point) Point {
return Point{p.X - q.X, p.Y - q.Y};
}
// Mul returns p scaled by k: Pt(p.X*k p.Y*k).
func (p Point) Mul(k int) Point {
return Point{p.X * k, p.Y * k};
}
// Div returns p divided by k: Pt(p.X/k, p.Y/k).
func (p Point) Div(k int) Point {
return Point{p.X / k, p.Y / k};
}
// Eq returns true if p and q are equal.
func (p Point) Eq(q Point) bool {
return p.X == q.X && p.Y == q.Y;
}
// Inset returns the rectangle r inset by n: Rect(r.Min.X+n, r.Min.Y+n, r.Max.X-n, r.Max.Y-n).
func (r Rectangle) Inset(n int) Rectangle {
return Rectangle{Point{r.Min.X + n, r.Min.Y + n}, Point{r.Max.X - n, r.Max.Y - n}};
}
// Add returns the rectangle r translated by p: Rpt(r.Min.Add(p), r.Max.Add(p)).
func (r Rectangle) Add(p Point) Rectangle {
return Rectangle{r.Min.Add(p), r.Max.Add(p)};
}
// Sub returns the rectangle r translated by -p: Rpt(r.Min.Sub(p), r.Max.Sub(p)).
func (r Rectangle) Sub(p Point) Rectangle {
return Rectangle{r.Min.Sub(p), r.Max.Sub(p)};
}
// Canon returns a canonical version of r: the returned rectangle
// has Min.X <= Max.X and Min.Y <= Max.Y.
func (r Rectangle) Canon() Rectangle {
if r.Max.X < r.Min.X {
r.Max.X = r.Min.X;
}
if r.Max.Y < r.Min.Y {
r.Max.Y = r.Min.Y;
}
return r;
}
// Overlaps returns true if r and r1 cross; that is, it returns true if they share any point.
func (r Rectangle) Overlaps(r1 Rectangle) bool {
return r.Min.X < r1.Max.X && r1.Min.X < r.Max.X &&
r.Min.Y < r1.Max.Y && r1.Min.Y < r.Max.Y;
}
// Empty retruns true if r contains no points.
func (r Rectangle) Empty() bool {
return r.Max.X <= r.Min.X || r.Max.Y <= r.Min.Y;
}
// InRect returns true if all the points in r are also in r1.
func (r Rectangle) In(r1 Rectangle) bool {
if r.Empty() {
return true;
}
if r1.Empty() {
return false;
}
return r1.Min.X <= r.Min.X && r.Max.X <= r1.Max.X &&
r1.Min.Y <= r.Min.Y && r.Max.Y <= r1.Max.Y;
}
// Combine returns the smallest rectangle containing all points from r and from r1.
func (r Rectangle) Combine(r1 Rectangle) Rectangle {
if r.Empty() {
return r1;
}
if r1.Empty() {
return r;
}
if r.Min.X > r1.Min.X {
r.Min.X = r1.Min.X;
}
if r.Min.Y > r1.Min.Y {
r.Min.Y = r1.Min.Y;
}
if r.Max.X < r1.Max.X {
r.Max.X = r1.Max.X;
}
if r.Max.Y < r1.Max.Y {
r.Max.Y = r1.Max.Y;
}
return r;
}
// Clip returns the largest rectangle containing only points shared by r and r1.
func (r Rectangle) Clip(r1 Rectangle) Rectangle {
if r.Empty() {
return r;
}
if r1.Empty() {
return r1;
}
if r.Min.X < r1.Min.X {
r.Min.X = r1.Min.X;
}
if r.Min.Y < r1.Min.Y {
r.Min.Y = r1.Min.Y;
}
if r.Max.X > r1.Max.X {
r.Max.X = r1.Max.X;
}
if r.Max.Y > r1.Max.Y {
r.Max.Y = r1.Max.Y;
}
return r;
}
// Dx returns the width of the rectangle r: r.Max.X - r.Min.X.
func (r Rectangle) Dx() int {
return r.Max.X - r.Min.X;
}
// Dy returns the width of the rectangle r: r.Max.Y - r.Min.Y.
func (r Rectangle) Dy() int {
return r.Max.Y - r.Min.Y;
}
|
