dunge 0.1.4

Simple and portable 3d render 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

use {
    crate::{layout::Plain, vertex::Vertex},
    std::borrow::Cow,
    wgpu::{Buffer, Device, Queue},
};

/// A data struct for a mesh creation.
pub struct Data<'a, V> {
    verts: &'a [V],
    indxs: Cow<'a, [[u16; 3]]>,
}

impl<'a, V> Data<'a, V> {
    /// Creates a new [`MeshData`](crate::MeshData) from given vertices and indices.
    ///
    /// Returns `Some` if a data length fits in `u16` and all indices point to the data,
    /// otherwise returns `None`.
    pub fn new(verts: &'a [V], indxs: &'a [[u16; 3]]) -> Option<Self> {
        verts
            .len()
            .try_into()
            .ok()
            .filter(|len| indxs.iter().flatten().all(|i| i < len))
            .map(|_| Self {
                verts,
                indxs: indxs.into(),
            })
    }

    /// Creates a new [`MeshData`](crate::MeshData) from given triangles.
    ///
    /// Returns `Some` if a data length fits in `u16` and is multiple by 3,
    /// otherwise returns `None`.
    pub fn from_triangles(verts: &'a [V]) -> Option<Self> {
        verts
            .len()
            .try_into()
            .ok()
            .filter(|len| len % 3 == 0)
            .map(|len| {
                let indxs = (0..len).step_by(3).map(|i| [i, i + 1, i + 2]).collect();

                Self { verts, indxs }
            })
    }

    /// Creates a new [`MeshData`](crate::MeshData) from given quadrangles.
    ///
    /// Returns `Some` if a data length fits in `u16` and is multiple by 4,
    /// otherwise returns `None`.
    pub fn from_quads(verts: &'a [V]) -> Option<Self> {
        verts
            .len()
            .try_into()
            .ok()
            .filter(|len| len % 4 == 0)
            .map(|len| {
                let indxs = (0..len)
                    .step_by(4)
                    .flat_map(|i| [[i, i + 1, i + 2], [i + 2, i + 1, i + 3]])
                    .collect();

                Self { verts, indxs }
            })
    }
}

impl<'a, V> Clone for Data<'a, V> {
    fn clone(&self) -> Self {
        Self {
            verts: self.verts,
            indxs: self.indxs.clone(),
        }
    }
}

pub(crate) struct Mesh {
    vertex_buffer: Buffer,
    index_buffer: Buffer,
    n_indices: u32,
}

impl Mesh {
    pub(crate) fn new<V>(data: &Data<V>, device: &Device) -> Self
    where
        V: Vertex,
    {
        use wgpu::{
            util::{BufferInitDescriptor, DeviceExt},
            BufferUsages,
        };

        let vertex_buffer = device.create_buffer_init(&BufferInitDescriptor {
            label: Some("vertex buffer"),
            contents: data.verts.as_bytes(),
            usage: BufferUsages::VERTEX,
        });

        let index_buffer = device.create_buffer_init(&BufferInitDescriptor {
            label: Some("index buffer"),
            contents: data.indxs.as_ref().as_bytes(),
            usage: BufferUsages::INDEX,
        });

        let n_indices = (data.indxs.len() * 3).try_into().expect("too many indexes");

        Self {
            vertex_buffer,
            index_buffer,
            n_indices,
        }
    }

    pub(crate) fn update_data<V>(&mut self, data: &Data<V>, queue: &Queue)
    where
        V: Vertex,
    {
        queue.write_buffer(&self.vertex_buffer, 0, data.verts.as_bytes());
        queue.write_buffer(&self.index_buffer, 0, data.indxs.as_ref().as_bytes());
        self.n_indices = (data.indxs.len() * 3).try_into().expect("too many indexes");
    }

    pub(crate) fn vertex_buffer(&self) -> &Buffer {
        &self.vertex_buffer
    }

    pub(crate) fn index_buffer(&self) -> &Buffer {
        &self.index_buffer
    }

    pub(crate) fn n_indices(&self) -> u32 {
        self.n_indices
    }
}