draco-oxide 0.1.0-alpha.5

draco-oxide is a rust rewrite of Google's draco mesh compression 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

use super::PredictionSchemeImpl;
use crate::{
    core::{
        attribute::Attribute,
        corner_table::GenericCornerTable,
        shared::{CornerIdx, VertexIdx},
    },
    prelude::{NdVector, Vector},
};
use std::mem;

pub struct DeltaPrediction<'parents, C, const N: usize> {
    faces: &'parents [[usize; 3]],
    corner_table: &'parents C,
    _marker: std::marker::PhantomData<&'parents C>,
}

impl<'parents, C, const N: usize> PredictionSchemeImpl<'parents, C, N>
    for DeltaPrediction<'parents, C, N>
where
    C: GenericCornerTable,
    NdVector<N, i32>: Vector<N, Component = i32>,
{
    const ID: u32 = 1;

    type AdditionalDataForMetadata = ();

    fn new(_parents: &[&'parents Attribute], corner_table: &'parents C) -> Self {
        // Note: Connectivity is now passed via conn_att parameter instead of parent attributes
        // For now, use an empty slice as this prediction scheme needs to be updated for the new architecture
        let faces: &[[usize; 3]] = &[];

        Self {
            faces,
            corner_table,
            _marker: std::marker::PhantomData,
        }
    }

    fn get_values_impossible_to_predict(
        &mut self,
        value_indices: &mut Vec<std::ops::Range<usize>>,
    ) -> Vec<std::ops::Range<usize>> {
        let mut self_ = Vec::new();
        let mut out = Vec::new();
        for r in value_indices.iter() {
            for i in r.clone() {
                if i == 0 {
                    out.push(i);
                }
                // ToDo: Optimize this: 'self.faces' are the sorted array of sorted arrays.
                else if self
                    .faces
                    .iter()
                    .any(|f| f.contains(&(i - 1)) && f.contains(&i))
                {
                    self_.push(i);
                } else {
                    out.push(i);
                }
            }
        }
        let mut self_ = into_ranges(self_);
        mem::swap(&mut self_, value_indices);
        into_ranges(out)
    }

    fn predict(
        &mut self,
        _i: CornerIdx,
        vertices_up_till_now: &[VertexIdx],
        att: &Attribute,
    ) -> NdVector<N, i32> {
        let prev_v = if let Some(prev_v) = vertices_up_till_now.last() {
            *prev_v
        } else {
            // If there are no previous vertices, we cannot predict the value.
            return NdVector::zero();
        };
        let prev_pt = self
            .corner_table
            .point_idx(self.corner_table.left_most_corner(prev_v));
        att.get(prev_pt)
    }
}

fn into_ranges(v: Vec<usize>) -> Vec<std::ops::Range<usize>> {
    let mut out = Vec::new();
    if v.is_empty() {
        return out;
    }
    let mut start = v[0];
    let mut end = v[0];
    for &val in &v[1..] {
        if val != end + 1 {
            out.push(start..end + 1);
            start = val;
        }
        end = val;
    }
    out.push(start..end + 1);
    out
}

// ToDo: recover this test.
// #[cfg(test)]
// mod tests {
// 	use crate::{core::attribute::AttributeId, prelude::NdVector};

// use super::*;

// 	#[test]
// 	fn test_into_ranges() {
// 		let v = vec![1, 3, 6, 7, 8, 10, 11, 12, 15];
// 		let r = into_ranges(v);
// 		assert_eq!(r.len(), 5);
// 		assert_eq!(r[0], 1..2);
// 		assert_eq!(r[1], 3..4);
// 		assert_eq!(r[2], 6..9);
// 		assert_eq!(r[3], 10..13);
// 		assert_eq!(r[4], 15..16);
// 	}

// 	#[test]
// 	fn test_get_values_impossible_to_predict() {
// 		let faces = vec![[0, 1, 2], [1, 2, 3], [4, 5, 6], [5, 6, 7]];
// 		let conn_att = Attribute::from_faces(
// 			AttributeId::new(0),
// 			faces.clone(),
// 			Vec::new()
// 		);
// 		let mut delta = DeltaPrediction::<NdVector<3, f32>>::new(&[&conn_att]);
// 		let mut value_indices = vec![0..8];
// 		let impossible = delta.get_values_impossible_to_predict(&mut value_indices);
// 		assert_eq!(impossible.len(), 2);
// 		assert_eq!(impossible[0], 0..1);
// 		assert_eq!(impossible[1], 4..5);

// 		assert_eq!(value_indices.len(), 2);
// 		assert_eq!(value_indices[0], 1..4);
// 		assert_eq!(value_indices[1], 5..8);
// 	}
// }