scion 0.7.0

Game making library on top of wgpu, winit, hecs
Documentation 
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


use serde::{Deserialize, Serialize};
use crate::core::components::maths::coordinates::Coordinates;

/// The standard way to communicate a position in 3 dimensions in `Scion`
#[derive(Eq, PartialEq, Hash, Clone, Debug, Serialize, Deserialize)]
pub struct Position {
    x: usize,
    y: usize,
    z: usize,
}

impl Position {
    pub fn new(x: usize, y: usize, z: usize) -> Self {
        Self { x, y, z }
    }

    pub fn x(&self) -> usize {
        self.x
    }

    pub fn y(&self) -> usize {
        self.y
    }

    pub fn z(&self) -> usize {
        self.z
    }
}

/// The standard way to communicate 3D sizes in `Scion`
pub struct Dimensions {
    width: usize,
    height: usize,
    depth: usize,
}

impl Dimensions {
    pub fn new(width: usize, height: usize, depth: usize) -> Self {
        Self { width, height, depth }
    }

    pub fn width(&self) -> usize {
        self.width
    }

    pub fn height(&self) -> usize {
        self.height
    }

    pub fn depth(&self) -> usize {
        self.depth
    }
}

/// Struct used in all `Scion` to specify any 2D movement.
#[derive(Default, Debug, Copy, Clone)]
pub struct Vector {
    pub(crate) x: f32,
    pub(crate) y: f32,
}

impl Vector {
    pub fn new(x: f32, y: f32) -> Self {
        Self { x, y }
    }

    pub fn x(&self) -> f32 {
        self.x
    }

    pub fn y(&self) -> f32 {
        self.y
    }

    pub fn set_x(&mut self, x: f32) {
        self.x = x
    }

    pub fn set_y(&mut self, y: f32) {
        self.y = y;
    }
}


// https://www.omnicalculator.com/math/centroid#what-is-the-formula-for-the-centroid
pub fn centroid_polygon(vertices: &Vec<Coordinates>) -> Coordinates {
    let (mut x, mut y) = (0., 0.);
    let mut signed_area: f32 = 0.;

    for i in 0..vertices.len() {
        let current_vertice = vertices.get(i).unwrap();
        let next_vertice = vertices.get((i + 1) % vertices.len()).unwrap();
        let current_area = (current_vertice.x * next_vertice.y) - (next_vertice.x * current_vertice.y);
        signed_area += current_area;
        x += (current_vertice.x + next_vertice.x) * current_area;
        y += (current_vertice.y + next_vertice.y) * current_area;
    }
    signed_area *= 0.5;
    x /= 6. * signed_area;
    y /= 6. * signed_area;
    Coordinates::new(x, y)
}

// https://www.omnicalculator.com/math/centroid#what-is-the-formula-for-the-centroid
pub fn centroid_points(vertices: &Vec<Coordinates>) -> Coordinates {
    let sum = vertices.iter().fold(Coordinates::default(),
                                   |acc, current|
                                       Coordinates::new(acc.x + current.x, current.y + acc.y));
    Coordinates::new(sum.x / vertices.len() as f32, sum.y / vertices.len() as f32)
}

pub fn rotate_point_around_pivot(point: &Coordinates, pivot: &Coordinates, angle: f32) -> Coordinates{
    if angle != 0.{
        let angle_rad = angle;
        let x2 = pivot.x + (point.x - pivot.x) * angle_rad.cos() - (point.y - pivot.y) * angle_rad.sin();
        let y2 = pivot.y + (point.x - pivot.x) * angle_rad.sin() + (point.y - pivot.y) * angle_rad.cos();
        Coordinates::new(x2, y2)
    }else{
        Coordinates::new(point.x, point.y)
    }

}

#[cfg(test)]
mod test {
    use crate::core::components::maths::coordinates::Coordinates;
    use crate::utils::maths::{centroid_points, centroid_polygon, rotate_point_around_pivot};

    #[test]
    fn test_centroid() {
        let vertices = vec![Coordinates::new(1., 1.), Coordinates::new(2., 4.), Coordinates::new(5., 4.), Coordinates::new(11., 1.)];
        println!("Centre par polygone : {:?}", centroid_polygon(&vertices));
    }

    #[test]
    fn test_centroid2() {
        let vertices = vec![Coordinates::new(1., 1.), Coordinates::new(2., 4.), Coordinates::new(5., 4.), Coordinates::new(11., 1.)];
        println!("Centre par points : {:?}", centroid_points(&vertices));
    }

    #[test]
    fn test_pivot() {
        let angle :f32 = 45.;
        let angle = angle.to_radians();
        let r = rotate_point_around_pivot(&Coordinates::new(128.,681.), &Coordinates::new(96., 681.), angle );
        println!("{:?}", r);
    }
}