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

#[cfg(test)]
use core::f32::consts::FRAC_PI_2;

use vec3;
use number_traits::Num;

use length::{dot, length, length_values};

#[inline]
pub fn transform_angle<'a, T: Copy + Num>(
    out: &'a mut [T; 2],
    a: &[T; 2],
    angle: T,
) -> &'a mut [T; 2] {
    let c = angle.cos();
    let s = angle.sin();

    out[0] = a[0] * c - a[1] * s;
    out[1] = a[0] * s + a[1] * c;
    out
}
#[test]
fn test_transform_angle() {
    use misc::eq;

    let mut out = [0f32, 0f32];
    let v = [0f32, 1f32];

    transform_angle(&mut out, &v, FRAC_PI_2);
    assert_eq!(eq(&out, &[-1f32, 0f32]), true);
}

#[inline]
pub fn transform_mat2<'a, T: Copy + Num>(
    out: &'a mut [T; 2],
    a: &[T; 2],
    m: &[T; 4],
) -> &'a mut [T; 2] {
    out[0] = a[0] * m[0] + a[1] * m[2];
    out[1] = a[0] * m[1] + a[1] * m[3];
    out
}

#[inline]
pub fn transform_mat32<'a, T: Copy + Num>(
    out: &'a mut [T; 2],
    a: &[T; 2],
    m: &[T; 6],
) -> &'a mut [T; 2] {
    out[0] = a[0] * m[0] + a[1] * m[2] + m[4];
    out[1] = a[0] * m[1] + a[1] * m[3] + m[5];
    out
}

#[inline]
pub fn transform_mat3<'a, T: Copy + Num>(
    out: &'a mut [T; 2],
    a: &[T; 2],
    m: &[T; 9],
) -> &'a mut [T; 2] {
    out[0] = a[0] * m[0] + a[1] * m[3];
    out[1] = a[0] * m[1] + a[1] * m[4];
    out
}

#[inline]
pub fn transform_mat4<'a, T: Copy + Num>(
    out: &'a mut [T; 2],
    a: &[T; 2],
    m: &[T; 16],
) -> &'a mut [T; 2] {
    out[0] = a[0] * m[0] + a[1] * m[4] + m[12];
    out[1] = a[0] * m[1] + a[1] * m[5] + m[13];
    out
}

#[inline]
pub fn transform_projection<'a, T: Copy + Num>(
    out: &'a mut [T; 2],
    a: &[T; 2],
    m: &[T; 16],
) -> &'a mut [T; 2] {
    let mut d = a[0] * m[3] + a[1] * m[7] + m[11] + m[15];
    d = if d != T::zero() { T::one() / d } else { d };

    out[0] = (a[0] * m[0] + a[1] * m[4] + m[8] + m[12]) * d;
    out[1] = (a[0] * m[1] + a[1] * m[5] + m[9] + m[13]) * d;
    out
}

#[inline]
pub fn transform_projection_no_position<'a, T: Copy + Num>(
    out: &'a mut [T; 2],
    a: &[T; 2],
    m: &[T; 16],
) -> &'a mut [T; 2] {
    let mut d = a[0] * m[3] + a[1] * m[7] + m[11] + m[15];
    d = if d != T::zero() { T::one() / d } else { d };

    out[0] = (a[0] * m[0] + a[1] * m[4] + m[8]) * d;
    out[1] = (a[0] * m[1] + a[1] * m[5] + m[9]) * d;
    out
}

#[inline]
pub fn position_mat32<'a, T: Copy + Num>(out: &'a mut [T; 2], m: &[T; 6]) -> &'a mut [T; 2] {
    out[0] = m[4];
    out[1] = m[5];
    out
}

#[inline]
pub fn position_mat4<'a, T: Copy + Num>(out: &'a mut [T; 2], m: &[T; 16]) -> &'a mut [T; 2] {
    out[0] = m[12];
    out[1] = m[13];
    out
}

#[inline]
pub fn scale_mat2<'a, T: Copy + Num>(out: &'a mut [T; 2], m: &[T; 4]) -> &'a mut [T; 2] {
    out[0] = length_values(m[0], m[2]);
    out[1] = length_values(m[1], m[3]);
    out
}

#[inline]
pub fn scale_mat32<'a, T: Copy + Num>(out: &'a mut [T; 2], m: &[T; 6]) -> &'a mut [T; 2] {
    out[0] = length_values(m[0], m[2]);
    out[1] = length_values(m[1], m[3]);
    out
}

#[inline]
pub fn scale_mat3<'a, T: Copy + Num>(out: &'a mut [T; 2], m: &[T; 9]) -> &'a mut [T; 2] {
    out[0] = vec3::length_values(m[0], m[3], m[6]);
    out[1] = vec3::length_values(m[1], m[4], m[7]);
    out
}

#[inline]
pub fn scale_mat4<'a, T: Copy + Num>(out: &'a mut [T; 2], m: &[T; 16]) -> &'a mut [T; 2] {
    out[0] = vec3::length_values(m[0], m[4], m[8]);
    out[1] = vec3::length_values(m[1], m[5], m[9]);
    out
}

#[inline]
pub fn angle<T: Copy + Num>(a: &[T; 2], b: &[T; 2]) -> T {
    (dot(a, b) / (length(a) * length(b))).acos()
}
#[test]
fn angle_test() {
    let rad = angle(&[0f32, 1f32], &[1f32, 0f32]);
    assert_eq!(rad, FRAC_PI_2);
}