File size: 3,004 Bytes
b797337 | 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 | import { BufferGeometry } from '../core/BufferGeometry.js';
import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import { Vector3 } from '../math/Vector3.js';
class WireframeGeometry extends BufferGeometry {
constructor( geometry = null ) {
super();
this.type = 'WireframeGeometry';
this.parameters = {
geometry: geometry
};
if ( geometry !== null ) {
// buffer
const vertices = [];
const edges = new Set();
// helper variables
const start = new Vector3();
const end = new Vector3();
if ( geometry.index !== null ) {
// indexed BufferGeometry
const position = geometry.attributes.position;
const indices = geometry.index;
let groups = geometry.groups;
if ( groups.length === 0 ) {
groups = [ { start: 0, count: indices.count, materialIndex: 0 } ];
}
// create a data structure that contains all edges without duplicates
for ( let o = 0, ol = groups.length; o < ol; ++ o ) {
const group = groups[ o ];
const groupStart = group.start;
const groupCount = group.count;
for ( let i = groupStart, l = ( groupStart + groupCount ); i < l; i += 3 ) {
for ( let j = 0; j < 3; j ++ ) {
const index1 = indices.getX( i + j );
const index2 = indices.getX( i + ( j + 1 ) % 3 );
start.fromBufferAttribute( position, index1 );
end.fromBufferAttribute( position, index2 );
if ( isUniqueEdge( start, end, edges ) === true ) {
vertices.push( start.x, start.y, start.z );
vertices.push( end.x, end.y, end.z );
}
}
}
}
} else {
// non-indexed BufferGeometry
const position = geometry.attributes.position;
for ( let i = 0, l = ( position.count / 3 ); i < l; i ++ ) {
for ( let j = 0; j < 3; j ++ ) {
// three edges per triangle, an edge is represented as (index1, index2)
// e.g. the first triangle has the following edges: (0,1),(1,2),(2,0)
const index1 = 3 * i + j;
const index2 = 3 * i + ( ( j + 1 ) % 3 );
start.fromBufferAttribute( position, index1 );
end.fromBufferAttribute( position, index2 );
if ( isUniqueEdge( start, end, edges ) === true ) {
vertices.push( start.x, start.y, start.z );
vertices.push( end.x, end.y, end.z );
}
}
}
}
// build geometry
this.setAttribute( 'position', new Float32BufferAttribute( vertices, 3 ) );
}
}
copy( source ) {
super.copy( source );
this.parameters = Object.assign( {}, source.parameters );
return this;
}
}
function isUniqueEdge( start, end, edges ) {
const hash1 = `${start.x},${start.y},${start.z}-${end.x},${end.y},${end.z}`;
const hash2 = `${end.x},${end.y},${end.z}-${start.x},${start.y},${start.z}`; // coincident edge
if ( edges.has( hash1 ) === true || edges.has( hash2 ) === true ) {
return false;
} else {
edges.add( hash1 );
edges.add( hash2 );
return true;
}
}
export { WireframeGeometry };
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