File size: 1,960 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 | import { BufferGeometry } from '../core/BufferGeometry.js';
import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import { Vector3 } from '../math/Vector3.js';
import { Vector2 } from '../math/Vector2.js';
class CircleGeometry extends BufferGeometry {
constructor( radius = 1, segments = 32, thetaStart = 0, thetaLength = Math.PI * 2 ) {
super();
this.type = 'CircleGeometry';
this.parameters = {
radius: radius,
segments: segments,
thetaStart: thetaStart,
thetaLength: thetaLength
};
segments = Math.max( 3, segments );
// buffers
const indices = [];
const vertices = [];
const normals = [];
const uvs = [];
// helper variables
const vertex = new Vector3();
const uv = new Vector2();
// center point
vertices.push( 0, 0, 0 );
normals.push( 0, 0, 1 );
uvs.push( 0.5, 0.5 );
for ( let s = 0, i = 3; s <= segments; s ++, i += 3 ) {
const segment = thetaStart + s / segments * 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 );
// uvs
uv.x = ( vertices[ i ] / radius + 1 ) / 2;
uv.y = ( vertices[ i + 1 ] / radius + 1 ) / 2;
uvs.push( uv.x, uv.y );
}
// indices
for ( let i = 1; i <= segments; i ++ ) {
indices.push( i, i + 1, 0 );
}
// 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 CircleGeometry( data.radius, data.segments, data.thetaStart, data.thetaLength );
}
}
export { CircleGeometry };
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