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
199
200
201
202

/*
 * // Copyright (c) 2021 Feng Yang
 * //
 * // I am making my contributions/submissions to this project solely in my
 * // personal capacity and am not conveying any rights to any intellectual
 * // property of any third parties.
 */

use num::Float;

// MARK: Zero

/// Zero size_t.
pub const K_ZERO_SIZE: usize = 0;

/// Zero ssize_t.
pub const K_ZERO_SSIZE: isize = 0;

/// Zero for type T.
pub fn zero<T: Float>() -> T {
    return T::from(0.0).unwrap();
}

// MARK: One

/// One size_t.
pub const K_ONE_SIZE: usize = 1;

/// One ssize_t.
pub const K_ONE_SSIZE: isize = 1;

/// One for type T.
pub fn one<T: Float>() -> T {
    return T::from(1.0).unwrap();
}

// MARK: Epsilon

/// Float-type epsilon.
pub const K_EPSILON_F: f32 = f32::EPSILON;

/// Double-type epsilon.
pub const K_EPSILON_D: f64 = f64::EPSILON;

// MARK: Max

/// Max size_t.
pub const K_MAX_SIZE: usize = usize::MAX;

/// Max ssize_t.
pub const K_MAX_SSIZE: isize = isize::MAX;

/// Max float.
pub const K_MAX_F: f32 = f32::MAX;

/// Max double.
pub const K_MAX_D: f64 = f64::MAX;

// MARK: Pi

/// Float-type pi.
pub const K_PI_F: f32 = std::f32::consts::PI;

/// Double-type pi.
pub const K_PI_D: f64 = std::f64::consts::PI;

/// Pi for type T.
pub fn pi<T: Float>() -> T {
    return T::from(K_PI_D).unwrap();
}

// MARK: Pi/2

/// Float-type pi/2.
pub const K_HALF_PI_F: f32 = std::f32::consts::FRAC_PI_2;

/// Double-type pi/2.
pub const K_HALF_PI_D: f64 = std::f64::consts::FRAC_PI_2;

/// Pi/2 for type T.
pub fn half_pi<T: Float>() -> T {
    return T::from(K_HALF_PI_D).unwrap();
}

// MARK: Pi/4

/// Float-type pi/4.
pub const K_QUARTER_PI_F: f32 = std::f32::consts::FRAC_PI_4;

/// Double-type pi/4.
pub const K_QUARTER_PI_D: f64 = std::f64::consts::FRAC_PI_4;

/// Pi/4 for type T.
pub fn quarter_pi<T: Float>() -> T {
    return T::from(K_QUARTER_PI_D).unwrap();
}

// MARK: 2*Pi

/// Float-type 2*pi.
pub const K_TWO_PI_F: f32 = std::f32::consts::TAU;

/// Double-type 2*pi.
pub const K_TWO_PI_D: f64 = std::f64::consts::TAU;

/// 2*pi for type T.
pub fn two_pi<T: Float>() -> T {
    return T::from(K_TWO_PI_D).unwrap();
}

// MARK: 4*Pi

/// Float-type 4*pi.
pub const K_FOUR_PI_F: f32 = 2.0 * std::f32::consts::TAU;

/// Double-type 4*pi.
pub const K_FOUR_PI_D: f64 = 2.0 * std::f64::consts::TAU;

/// 4*pi for type T.
pub fn four_pi<T: Float>() -> T {
    return T::from(K_FOUR_PI_D).unwrap();
}

// MARK: 1/Pi

/// Float-type 1/pi.
pub const K_INV_PI_F: f32 = std::f32::consts::FRAC_1_PI;

/// Double-type 1/pi.
pub const K_INV_PI_D: f64 = std::f64::consts::FRAC_1_PI;

/// 1/pi for type T.
pub fn inv_pi<T: Float>() -> T {
    return T::from(K_INV_PI_D).unwrap();
}

// MARK: 1/2*Pi

/// Float-type 1/2*pi.
pub const K_INV_TWO_PI_F: f32 = std::f32::consts::FRAC_1_PI * 0.5;

/// Double-type 1/2*pi.
pub const K_INV_TWO_PI_D: f64 = std::f64::consts::FRAC_1_PI * 0.5;

/// 1/2*pi for type T.
pub fn inv_two_pi<T: Float>() -> T {
    return T::from(K_INV_TWO_PI_D).unwrap();
}

// MARK: 1/4*Pi

/// Float-type 1/4*pi.
pub const K_INV_FOUR_PI_F: f32 = std::f32::consts::FRAC_1_PI * 0.25;

/// Double-type 1/4*pi.
pub const K_INV_FOUR_PI_D: f64 = std::f64::consts::FRAC_1_PI * 0.25;

/// 1/4*pi for type T.
pub fn inv_four_pi<T: Float>() -> T {
    return T::from(K_INV_FOUR_PI_D).unwrap();
}

// MARK: Physics

/// Gravity.
pub const K_GRAVITY: f64 = -9.8;

/// Water density.
pub const K_WATER_DENSITY: f64 = 1000.0;

/// Speed of sound in water at 20 degrees Celsius.
pub const K_SPEED_OF_SOUND_IN_WATER: f64 = 1482.0;

// MARK: Common enums

/// No direction.
pub const K_DIRECTION_NONE: i32 = 0;

/// Left direction.
pub const K_DIRECTION_LEFT: i32 = 1 << 0;

/// Right direction.
pub const K_DIRECTION_RIGHT: i32 = 1 << 1;

/// Down direction.
pub const K_DIRECTION_DOWN: i32 = 1 << 2;

/// Up direction.
pub const K_DIRECTION_UP: i32 = 1 << 3;

/// Back direction.
pub const K_DIRECTION_BACK: i32 = 1 << 4;

/// Front direction.
pub const K_DIRECTION_FRONT: i32 = 1 << 5;

/// All direction.
pub const K_DIRECTION_ALL: i32 = K_DIRECTION_LEFT | K_DIRECTION_RIGHT |
    K_DIRECTION_DOWN | K_DIRECTION_UP | K_DIRECTION_BACK |
    K_DIRECTION_FRONT;