/
EdgesGeometry.js
141 lines (95 loc) · 3.9 KB
/
EdgesGeometry.js
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
import { BufferGeometry } from '../core/BufferGeometry.js';
import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import * as MathUtils from '../math/MathUtils.js';
import { Triangle } from '../math/Triangle.js';
import { Vector3 } from '../math/Vector3.js';
const _v0 = /*@__PURE__*/ new Vector3();
const _v1 = /*@__PURE__*/ new Vector3();
const _normal = /*@__PURE__*/ new Vector3();
const _triangle = /*@__PURE__*/ new Triangle();
class EdgesGeometry extends BufferGeometry {
constructor( geometry = null, thresholdAngle = 1 ) {
super();
this.type = 'EdgesGeometry';
this.parameters = {
geometry: geometry,
thresholdAngle: thresholdAngle
};
if ( geometry !== null ) {
const precisionPoints = 4;
const precision = Math.pow( 10, precisionPoints );
const thresholdDot = Math.cos( MathUtils.DEG2RAD * thresholdAngle );
const indexAttr = geometry.getIndex();
const positionAttr = geometry.getAttribute( 'position' );
const indexCount = indexAttr ? indexAttr.count : positionAttr.count;
const indexArr = [ 0, 0, 0 ];
const vertKeys = [ 'a', 'b', 'c' ];
const hashes = new Array( 3 );
const edgeData = {};
const vertices = [];
for ( let i = 0; i < indexCount; i += 3 ) {
if ( indexAttr ) {
indexArr[ 0 ] = indexAttr.getX( i );
indexArr[ 1 ] = indexAttr.getX( i + 1 );
indexArr[ 2 ] = indexAttr.getX( i + 2 );
} else {
indexArr[ 0 ] = i;
indexArr[ 1 ] = i + 1;
indexArr[ 2 ] = i + 2;
}
const { a, b, c } = _triangle;
a.fromBufferAttribute( positionAttr, indexArr[ 0 ] );
b.fromBufferAttribute( positionAttr, indexArr[ 1 ] );
c.fromBufferAttribute( positionAttr, indexArr[ 2 ] );
_triangle.getNormal( _normal );
// create hashes for the edge from the vertices
hashes[ 0 ] = `${ Math.round( a.x * precision ) },${ Math.round( a.y * precision ) },${ Math.round( a.z * precision ) }`;
hashes[ 1 ] = `${ Math.round( b.x * precision ) },${ Math.round( b.y * precision ) },${ Math.round( b.z * precision ) }`;
hashes[ 2 ] = `${ Math.round( c.x * precision ) },${ Math.round( c.y * precision ) },${ Math.round( c.z * precision ) }`;
// skip degenerate triangles
if ( hashes[ 0 ] === hashes[ 1 ] || hashes[ 1 ] === hashes[ 2 ] || hashes[ 2 ] === hashes[ 0 ] ) {
continue;
}
// iterate over every edge
for ( let j = 0; j < 3; j ++ ) {
// get the first and next vertex making up the edge
const jNext = ( j + 1 ) % 3;
const vecHash0 = hashes[ j ];
const vecHash1 = hashes[ jNext ];
const v0 = _triangle[ vertKeys[ j ] ];
const v1 = _triangle[ vertKeys[ jNext ] ];
const hash = `${ vecHash0 }_${ vecHash1 }`;
const reverseHash = `${ vecHash1 }_${ vecHash0 }`;
if ( reverseHash in edgeData && edgeData[ reverseHash ] ) {
// if we found a sibling edge add it into the vertex array if
// it meets the angle threshold and delete the edge from the map.
if ( _normal.dot( edgeData[ reverseHash ].normal ) <= thresholdDot ) {
vertices.push( v0.x, v0.y, v0.z );
vertices.push( v1.x, v1.y, v1.z );
}
edgeData[ reverseHash ] = null;
} else if ( ! ( hash in edgeData ) ) {
// if we've already got an edge here then skip adding a new one
edgeData[ hash ] = {
index0: indexArr[ j ],
index1: indexArr[ jNext ],
normal: _normal.clone(),
};
}
}
}
// iterate over all remaining, unmatched edges and add them to the vertex array
for ( const key in edgeData ) {
if ( edgeData[ key ] ) {
const { index0, index1 } = edgeData[ key ];
_v0.fromBufferAttribute( positionAttr, index0 );
_v1.fromBufferAttribute( positionAttr, index1 );
vertices.push( _v0.x, _v0.y, _v0.z );
vertices.push( _v1.x, _v1.y, _v1.z );
}
}
this.setAttribute( 'position', new Float32BufferAttribute( vertices, 3 ) );
}
}
}
export { EdgesGeometry };