nucleation 0.3.3

A high-performance Minecraft schematic parser and utility library
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
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

use super::{ParametricShape, Shape};

#[derive(Clone)]
pub struct Line {
    pub start: (f64, f64, f64),
    pub end: (f64, f64, f64),
    pub thickness: f64,
    length_sq: f64,
}

impl Line {
    pub fn new(start: (f64, f64, f64), end: (f64, f64, f64), thickness: f64) -> Self {
        let dx = end.0 - start.0;
        let dy = end.1 - start.1;
        let dz = end.2 - start.2;
        Self {
            start,
            end,
            thickness,
            length_sq: dx * dx + dy * dy + dz * dz,
        }
    }

    fn project_t(&self, x: i32, y: i32, z: i32) -> f64 {
        if self.length_sq == 0.0 {
            return 0.0;
        }
        let dx = self.end.0 - self.start.0;
        let dy = self.end.1 - self.start.1;
        let dz = self.end.2 - self.start.2;
        let vx = x as f64 - self.start.0;
        let vy = y as f64 - self.start.1;
        let vz = z as f64 - self.start.2;
        let dot = vx * dx + vy * dy + vz * dz;
        (dot / self.length_sq).clamp(0.0, 1.0)
    }

    fn distance_to_segment(&self, x: i32, y: i32, z: i32) -> f64 {
        let t = self.project_t(x, y, z);
        let dx = self.end.0 - self.start.0;
        let dy = self.end.1 - self.start.1;
        let dz = self.end.2 - self.start.2;
        let closest_x = self.start.0 + t * dx;
        let closest_y = self.start.1 + t * dy;
        let closest_z = self.start.2 + t * dz;
        let rx = x as f64 - closest_x;
        let ry = y as f64 - closest_y;
        let rz = z as f64 - closest_z;
        (rx * rx + ry * ry + rz * rz).sqrt()
    }
}

impl Shape for Line {
    fn contains(&self, x: i32, y: i32, z: i32) -> bool {
        // Bresenham fast path for thin lines
        if self.thickness <= 0.5 {
            return self.distance_to_segment(x, y, z) <= 0.87; // ~sqrt(3)/2 for voxel diag
        }
        self.distance_to_segment(x, y, z) <= self.thickness / 2.0
    }

    fn points(&self) -> Vec<(i32, i32, i32)> {
        // For thin lines, use Bresenham's algorithm
        if self.thickness <= 0.5 {
            return bresenham_3d(
                self.start.0.round() as i32,
                self.start.1.round() as i32,
                self.start.2.round() as i32,
                self.end.0.round() as i32,
                self.end.1.round() as i32,
                self.end.2.round() as i32,
            );
        }
        let mut points = Vec::new();
        self.for_each_point(|x, y, z| points.push((x, y, z)));
        points
    }

    fn normal_at(&self, x: i32, y: i32, z: i32) -> (f64, f64, f64) {
        let t = self.project_t(x, y, z);
        let dx = self.end.0 - self.start.0;
        let dy = self.end.1 - self.start.1;
        let dz = self.end.2 - self.start.2;
        let closest_x = self.start.0 + t * dx;
        let closest_y = self.start.1 + t * dy;
        let closest_z = self.start.2 + t * dz;
        let rx = x as f64 - closest_x;
        let ry = y as f64 - closest_y;
        let rz = z as f64 - closest_z;
        let len = (rx * rx + ry * ry + rz * rz).sqrt();
        if len == 0.0 {
            (0.0, 1.0, 0.0)
        } else {
            (rx / len, ry / len, rz / len)
        }
    }

    fn bounds(&self) -> (i32, i32, i32, i32, i32, i32) {
        let r = (self.thickness / 2.0).ceil() as i32 + 1;
        let min_x = (self.start.0.min(self.end.0)).floor() as i32 - r;
        let min_y = (self.start.1.min(self.end.1)).floor() as i32 - r;
        let min_z = (self.start.2.min(self.end.2)).floor() as i32 - r;
        let max_x = (self.start.0.max(self.end.0)).ceil() as i32 + r;
        let max_y = (self.start.1.max(self.end.1)).ceil() as i32 + r;
        let max_z = (self.start.2.max(self.end.2)).ceil() as i32 + r;
        (min_x, min_y, min_z, max_x, max_y, max_z)
    }

    fn for_each_point<F>(&self, mut f: F)
    where
        F: FnMut(i32, i32, i32),
    {
        if self.thickness <= 0.5 {
            for (x, y, z) in bresenham_3d(
                self.start.0.round() as i32,
                self.start.1.round() as i32,
                self.start.2.round() as i32,
                self.end.0.round() as i32,
                self.end.1.round() as i32,
                self.end.2.round() as i32,
            ) {
                f(x, y, z);
            }
            return;
        }
        let (min_x, min_y, min_z, max_x, max_y, max_z) = self.bounds();
        let half_t = self.thickness / 2.0;
        for x in min_x..=max_x {
            for y in min_y..=max_y {
                for z in min_z..=max_z {
                    if self.distance_to_segment(x, y, z) <= half_t {
                        f(x, y, z);
                    }
                }
            }
        }
    }
}

impl ParametricShape for Line {
    fn parameter_at(&self, x: i32, y: i32, z: i32) -> f64 {
        self.project_t(x, y, z)
    }
}

fn bresenham_3d(x0: i32, y0: i32, z0: i32, x1: i32, y1: i32, z1: i32) -> Vec<(i32, i32, i32)> {
    let mut points = Vec::new();
    let dx = (x1 - x0).abs();
    let dy = (y1 - y0).abs();
    let dz = (z1 - z0).abs();
    let sx = if x0 < x1 { 1 } else { -1 };
    let sy = if y0 < y1 { 1 } else { -1 };
    let sz = if z0 < z1 { 1 } else { -1 };

    let dm = dx.max(dy).max(dz);
    let mut x = x0;
    let mut y = y0;
    let mut z = z0;

    let mut err_x = dm / 2;
    let mut err_y = dm / 2;
    let mut err_z = dm / 2;

    for _ in 0..=dm {
        points.push((x, y, z));
        err_x -= dx;
        err_y -= dy;
        err_z -= dz;
        if err_x < 0 {
            err_x += dm;
            x += sx;
        }
        if err_y < 0 {
            err_y += dm;
            y += sy;
        }
        if err_z < 0 {
            err_z += dm;
            z += sz;
        }
    }
    points
}