-
Notifications
You must be signed in to change notification settings - Fork 0
/
MathUtils.cs
198 lines (174 loc) · 7.68 KB
/
MathUtils.cs
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
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace MissileDefence;
/// <summary>
/// Maths related utility functions.
/// </summary>
public static class MathUtils
{
/// <summary>
///
/// </summary>
/// <param name="p"></param>
/// <param name="p0"></param>
/// <param name="p1"></param>
/// <param name="p2"></param>
/// <returns></returns>
public static bool PtInTriangle2(PointF p, PointF p0, PointF p1, PointF p2)
{
float dX = p.X - p2.X;
float dY = p.Y - p2.Y;
float dX21 = p2.X - p1.X;
float dY12 = p1.Y - p2.Y;
float D = dY12 * (p0.X - p2.X) + dX21 * (p0.Y - p2.Y);
float s = dY12 * dX + dX21 * dY;
float t = (p2.Y - p0.Y) * dX + (p0.X - p2.X) * dY;
if (D < 0) return s <= 0 && t <= 0 && s + t >= D;
return s >= 0 && t >= 0 && s + t <= D;
}
/// <summary>
///
/// </summary>
/// <param name="pointToTestIsInTriangle"></param>
/// <param name="triangleVertex1"></param>
/// <param name="triangleVertex2"></param>
/// <param name="triangleVertex3"></param>
/// <returns></returns>
public static bool PtInTriangle(PointA pointToTestIsInTriangle, PointA triangleVertex1, PointA triangleVertex2, PointA triangleVertex3)
{
double det = (triangleVertex2.HorizontalInMissileCommandDisplayPX - triangleVertex1.HorizontalInMissileCommandDisplayPX) * (triangleVertex3.AltitudeInMissileCommandDisplayPX - triangleVertex1.AltitudeInMissileCommandDisplayPX) - (triangleVertex2.AltitudeInMissileCommandDisplayPX - triangleVertex1.AltitudeInMissileCommandDisplayPX) * (triangleVertex3.HorizontalInMissileCommandDisplayPX - triangleVertex1.HorizontalInMissileCommandDisplayPX);
return det * ((triangleVertex2.HorizontalInMissileCommandDisplayPX - triangleVertex1.HorizontalInMissileCommandDisplayPX) * (pointToTestIsInTriangle.AltitudeInMissileCommandDisplayPX - triangleVertex1.AltitudeInMissileCommandDisplayPX) - (triangleVertex2.AltitudeInMissileCommandDisplayPX - triangleVertex1.AltitudeInMissileCommandDisplayPX) * (pointToTestIsInTriangle.HorizontalInMissileCommandDisplayPX - triangleVertex1.HorizontalInMissileCommandDisplayPX)) >= 0 &&
det * ((triangleVertex3.HorizontalInMissileCommandDisplayPX - triangleVertex2.HorizontalInMissileCommandDisplayPX) * (pointToTestIsInTriangle.AltitudeInMissileCommandDisplayPX - triangleVertex2.AltitudeInMissileCommandDisplayPX) - (triangleVertex3.AltitudeInMissileCommandDisplayPX - triangleVertex2.AltitudeInMissileCommandDisplayPX) * (pointToTestIsInTriangle.HorizontalInMissileCommandDisplayPX - triangleVertex2.HorizontalInMissileCommandDisplayPX)) >= 0 &&
det * ((triangleVertex1.HorizontalInMissileCommandDisplayPX - triangleVertex3.HorizontalInMissileCommandDisplayPX) * (pointToTestIsInTriangle.AltitudeInMissileCommandDisplayPX - triangleVertex3.AltitudeInMissileCommandDisplayPX) - (triangleVertex1.AltitudeInMissileCommandDisplayPX - triangleVertex3.AltitudeInMissileCommandDisplayPX) * (pointToTestIsInTriangle.HorizontalInMissileCommandDisplayPX - triangleVertex3.HorizontalInMissileCommandDisplayPX)) >= 0;
}
/// <summary>
///
/// </summary>
/// <param name="angleInDegrees"></param>
/// <returns></returns>
public static double Clamp360(double angleInDegrees)
{
if (angleInDegrees < 0) angleInDegrees += 360;
if (angleInDegrees >= 360) angleInDegrees -= 360;
return angleInDegrees;
}
/// <summary>
/// Determine a point rotated by an angle around an origin.
/// </summary>
/// <param name="point"></param>
/// <param name="origin"></param>
/// <param name="angleInDegrees"></param>
/// <returns></returns>
internal static PointF RotatePointAboutOrigin(PointF point, PointF origin, double angleInDegrees)
{
return RotatePointAboutOriginInRadians(point, origin, DegreesInRadians(angleInDegrees));
}
/// <summary>
/// Determine a point rotated by an angle around an origin.
/// </summary>
/// <param name="point"></param>
/// <param name="origin"></param>
/// <param name="angleInRadians"></param>
/// <returns></returns>
public static PointF RotatePointAboutOriginInRadians(PointF point, PointF origin, double angleInRadians)
{
double cos = Math.Cos(angleInRadians);
double sin = Math.Sin(angleInRadians);
float dx = point.X - origin.X;
float dy = point.Y - origin.Y;
// standard maths for rotation.
return new PointF((float)(cos * dx - sin * dy + origin.X),
(float)(sin * dx + cos * dy + origin.Y)
);
}
/// <summary>
/// Logic requires radians but we track angles in degrees, this converts.
/// </summary>
/// <param name="angle"></param>
/// <returns></returns>
public static double DegreesInRadians(double angle)
{
// if (angle < 0 || angle > 360) Debugger.Break();
return (double)Math.PI * angle / 180;
}
/// <summary>
/// Converts radians into degrees.
/// One could argue, WHY not just use degrees? Preference. Degrees are more intuitive than 2*PI offset values.
/// </summary>
/// <param name="radians"></param>
/// <returns></returns>
public static double RadiansInDegrees(double radians)
{
// radians = PI * angle / 180
// radians * 180 / PI = angle
return radians * 180F / Math.PI;
}
/// <summary>
/// Computes the distance between 2 points using Pythagoras's theorem a^2 = b^2 + c^2.
/// </summary>
/// <param name="pt1">First point.</param>
/// <param name="pt2">Second point.</param>
/// <returns></returns>
public static float DistanceBetweenTwoPoints(PointF pt1, PointF pt2)
{
float dx = pt2.X - pt1.X;
float dy = pt2.Y - pt1.Y;
return (float)Math.Sqrt(dx * dx + dy * dy);
}
/// <summary>
/// Computes the distance between 2 points using Pythagoras's theorem a^2 = b^2 + c^2.
/// </summary>
/// <param name="pt1">First point.</param>
/// <param name="pt2">Second point.</param>
/// <returns></returns>
public static float DistanceBetweenTwoPoints(PointA pt1, PointA pt2)
{
float dx = pt2.HorizontalInMissileCommandDisplayPX - pt1.HorizontalInMissileCommandDisplayPX;
float dy = pt2.AltitudeInMissileCommandDisplayPX - pt1.AltitudeInMissileCommandDisplayPX;
return (float)Math.Sqrt(dx * dx + dy * dy);
}
/// <summary>
/// Returns a value between min and max (never outside of).
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="val"></param>
/// <param name="min"></param>
/// <param name="max"></param>
/// <returns></returns>
public static T Clamp<T>(this T val, T min, T max) where T : IComparable<T>
{
if (val.CompareTo(min) < 0)
{
return min;
}
if (val.CompareTo(max) > 0)
{
return max;
}
return val;
}
/// <summary>
///
/// </summary>
/// <param name="val"></param>
/// <param name="min"></param>
/// <param name="max"></param>
/// <returns></returns>
public static int Clamp(int val, int min, int max)
{
if (val.CompareTo(min) < 0)
{
return min;
}
if (val.CompareTo(max) > 0)
{
return max;
}
return val;
}
}