alex/beta-minecraft-rust

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

//! Ports of `WorldGenTrees`, `WorldGenForest`, `WorldGenTaiga1` and `WorldGenTaiga2`.

use common::JavaRandom;
use common::biome::Biome;
use common::world::Block;

use super::big_tree;
use crate::level::Level;

#[derive(Clone, Copy, Debug)]
pub enum Kind {
    Oak,
    Birch,
    BigOak,
    /// `WorldGenBigTree` as saplings grow it, unscaled.
    SaplingBigOak,
    /// `WorldGenTaiga1`.
    Pine,
    /// `WorldGenTaiga2`.
    Spruce,
}

impl Kind {
    /// `BiomeGenBase.getRandomWorldGenForTrees`.
    pub fn pick(biome: Biome, rand: &mut JavaRandom) -> Self {
        match biome {
            Biome::Forest if rand.next_int(5) == 0 => Self::Birch,
            Biome::Forest | Biome::Rainforest if rand.next_int(3) == 0 => Self::BigOak,
            Biome::Forest | Biome::Rainforest => Self::Oak,
            Biome::Taiga if rand.next_int(3) == 0 => Self::Pine,
            Biome::Taiga => Self::Spruce,
            _ if rand.next_int(10) == 0 => Self::BigOak,
            _ => Self::Oak,
        }
    }

    pub fn generate(self, level: &mut Level, pos: [i32; 3], rand: &mut JavaRandom) -> bool {
        match self {
            Self::Oak => small(level, pos, rand, 4, None),
            Self::Birch => small(level, pos, rand, 5, Some(2)),
            Self::BigOak => big_tree::generate(level, pos, rand, 5),
            Self::SaplingBigOak => big_tree::generate(level, pos, rand, 4),
            Self::Pine => pine(level, pos, rand),
            Self::Spruce => spruce(level, pos, rand),
        }
    }
}

/// Whether the tree fits: in height, with each layer's square of `radius(y)` around the column
/// only air or leaves. If so, turns the soil below into dirt, or fails if it is not grass or dirt.
fn plant(level: &mut Level, [x, y, z]: [i32; 3], height: i32, radius: impl Fn(i32) -> i32) -> bool {
    if y < 1 || y + height + 1 > 128 {
        return false;
    }
    for cy in y..=y + 1 + height {
        if cy >= 128 {
            return false;
        }
        let radius = radius(cy);
        for cx in x - radius..=x + radius {
            for cz in z - radius..=z + radius {
                if !matches!(level.block(cx, cy, cz), Block::AIR | Block::LEAVES) {
                    return false;
                }
            }
        }
    }
    let soil = level.block(x, y - 1, z);
    if !matches!(soil, Block::GRASS | Block::DIRT) || y >= 128 - height - 1 {
        return false;
    }
    level.set_block(x, y - 1, z, Block::DIRT);
    true
}

fn trunk(level: &mut Level, [x, y, z]: [i32; 3], height: i32, metadata: Option<u8>) {
    for dy in 0..height {
        if matches!(level.block(x, y + dy, z), Block::AIR | Block::LEAVES) {
            level.change_block(x, y + dy, z, Block::LOG, metadata);
        }
    }
}

/// `WorldGenTrees` (oak) and `WorldGenForest` (birch).
fn small(
    level: &mut Level,
    [x, y, z]: [i32; 3],
    rand: &mut JavaRandom,
    base_height: i32,
    metadata: Option<u8>,
) -> bool {
    let height = rand.next_int(3) + base_height;
    let radius = |cy| match cy - y {
        dy if dy >= height - 1 => 2,
        0 => 0,
        _ => 1,
    };
    if !plant(level, [x, y, z], height, radius) {
        return false;
    }
    for cy in y - 3 + height..=y + height {
        let offset = cy - (y + height);
        let radius = 1 - offset / 2;
        for cx in x - radius..=x + radius {
            for cz in z - radius..=z + radius {
                let corner = (cx - x).abs() == radius && (cz - z).abs() == radius;
                if (!corner || (rand.next_int(2) != 0 && offset != 0))
                    && !level.block(cx, cy, cz).is_opaque_cube()
                {
                    level.change_block(cx, cy, cz, Block::LEAVES, metadata);
                }
            }
        }
    }
    trunk(level, [x, y, z], height, metadata);
    true
}

/// `WorldGenTaiga1`: a tall trunk with a single narrow cone at the top.
fn pine(level: &mut Level, [x, y, z]: [i32; 3], rand: &mut JavaRandom) -> bool {
    let height = rand.next_int(5) + 7;
    let bare = height - rand.next_int(2) - 3;
    let crown = height - bare;
    let max_radius = 1 + rand.next_int(crown + 1);
    let radius = |cy| if cy - y < bare { 0 } else { max_radius };
    if !plant(level, [x, y, z], height, radius) {
        return false;
    }
    let mut radius = 0;
    for cy in (y + bare..=y + height).rev() {
        leaf_square(level, [x, cy, z], radius);
        if radius >= 1 && cy == y + bare + 1 {
            radius -= 1;
        } else if radius < max_radius {
            radius += 1;
        }
    }
    trunk(level, [x, y, z], height - 1, Some(1));
    true
}

/// `WorldGenTaiga2`: stacked rings of alternating width.
fn spruce(level: &mut Level, [x, y, z]: [i32; 3], rand: &mut JavaRandom) -> bool {
    let height = rand.next_int(4) + 6;
    let bare = 1 + rand.next_int(2);
    let crown = height - bare;
    let max_radius = 2 + rand.next_int(2);
    let radius = |cy| if cy - y < bare { 0 } else { max_radius };
    if !plant(level, [x, y, z], height, radius) {
        return false;
    }
    let mut radius = rand.next_int(2);
    let mut limit = 1;
    let mut restart = 0;
    for i in 0..=crown {
        leaf_square(level, [x, y + height - i, z], radius);
        if radius >= limit {
            radius = restart;
            restart = 1;
            limit = (limit + 1).min(max_radius);
        } else {
            radius += 1;
        }
    }
    let cut = rand.next_int(3);
    trunk(level, [x, y, z], height - cut, Some(1));
    true
}

/// A square of spruce leaves without its corners, or a single block for radius 0.
fn leaf_square(level: &mut Level, [x, y, z]: [i32; 3], radius: i32) {
    for cx in x - radius..=x + radius {
        for cz in z - radius..=z + radius {
            let corner = (cx - x).abs() == radius && (cz - z).abs() == radius;
            if (!corner || radius <= 0) && !level.block(cx, y, cz).is_opaque_cube() {
                level.set_block_with_metadata(cx, y, cz, Block::LEAVES, 1);
            }
        }
    }
}