File size: 2,760 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 | import { BufferGeometry } from '../core/BufferGeometry.js';
import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import { Vector2 } from '../math/Vector2.js';
import { Vector3 } from '../math/Vector3.js';
class RingGeometry extends BufferGeometry {
constructor( innerRadius = 0.5, outerRadius = 1, thetaSegments = 32, phiSegments = 1, thetaStart = 0, thetaLength = Math.PI * 2 ) {
super();
this.type = 'RingGeometry';
this.parameters = {
innerRadius: innerRadius,
outerRadius: outerRadius,
thetaSegments: thetaSegments,
phiSegments: phiSegments,
thetaStart: thetaStart,
thetaLength: thetaLength
};
thetaSegments = Math.max( 3, thetaSegments );
phiSegments = Math.max( 1, phiSegments );
// buffers
const indices = [];
const vertices = [];
const normals = [];
const uvs = [];
// some helper variables
let radius = innerRadius;
const radiusStep = ( ( outerRadius - innerRadius ) / phiSegments );
const vertex = new Vector3();
const uv = new Vector2();
// generate vertices, normals and uvs
for ( let j = 0; j <= phiSegments; j ++ ) {
for ( let i = 0; i <= thetaSegments; i ++ ) {
// values are generate from the inside of the ring to the outside
const segment = thetaStart + i / thetaSegments * thetaLength;
// vertex
vertex.x = radius * Math.cos( segment );
vertex.y = radius * Math.sin( segment );
vertices.push( vertex.x, vertex.y, vertex.z );
// normal
normals.push( 0, 0, 1 );
// uv
uv.x = ( vertex.x / outerRadius + 1 ) / 2;
uv.y = ( vertex.y / outerRadius + 1 ) / 2;
uvs.push( uv.x, uv.y );
}
// increase the radius for next row of vertices
radius += radiusStep;
}
// indices
for ( let j = 0; j < phiSegments; j ++ ) {
const thetaSegmentLevel = j * ( thetaSegments + 1 );
for ( let i = 0; i < thetaSegments; i ++ ) {
const segment = i + thetaSegmentLevel;
const a = segment;
const b = segment + thetaSegments + 1;
const c = segment + thetaSegments + 2;
const d = segment + 1;
// faces
indices.push( a, b, d );
indices.push( b, c, d );
}
}
// build geometry
this.setIndex( indices );
this.setAttribute( 'position', new Float32BufferAttribute( vertices, 3 ) );
this.setAttribute( 'normal', new Float32BufferAttribute( normals, 3 ) );
this.setAttribute( 'uv', new Float32BufferAttribute( uvs, 2 ) );
}
copy( source ) {
super.copy( source );
this.parameters = Object.assign( {}, source.parameters );
return this;
}
static fromJSON( data ) {
return new RingGeometry( data.innerRadius, data.outerRadius, data.thetaSegments, data.phiSegments, data.thetaStart, data.thetaLength );
}
}
export { RingGeometry };
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