three
Version:
JavaScript 3D library
159 lines (99 loc) • 3.9 kB
JavaScript
import { Geometry } from '../core/Geometry.js';
import { BufferGeometry } from '../core/BufferGeometry.js';
import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import { Vector3 } from '../math/Vector3.js';
// SphereGeometry
function SphereGeometry( radius, widthSegments, heightSegments, phiStart, phiLength, thetaStart, thetaLength ) {
Geometry.call( this );
this.type = 'SphereGeometry';
this.parameters = {
radius: radius,
widthSegments: widthSegments,
heightSegments: heightSegments,
phiStart: phiStart,
phiLength: phiLength,
thetaStart: thetaStart,
thetaLength: thetaLength
};
this.fromBufferGeometry( new SphereBufferGeometry( radius, widthSegments, heightSegments, phiStart, phiLength, thetaStart, thetaLength ) );
this.mergeVertices();
}
SphereGeometry.prototype = Object.create( Geometry.prototype );
SphereGeometry.prototype.constructor = SphereGeometry;
// SphereBufferGeometry
function SphereBufferGeometry( radius, widthSegments, heightSegments, phiStart, phiLength, thetaStart, thetaLength ) {
BufferGeometry.call( this );
this.type = 'SphereBufferGeometry';
this.parameters = {
radius: radius,
widthSegments: widthSegments,
heightSegments: heightSegments,
phiStart: phiStart,
phiLength: phiLength,
thetaStart: thetaStart,
thetaLength: thetaLength
};
radius = radius || 1;
widthSegments = Math.max( 3, Math.floor( widthSegments ) || 8 );
heightSegments = Math.max( 2, Math.floor( heightSegments ) || 6 );
phiStart = phiStart !== undefined ? phiStart : 0;
phiLength = phiLength !== undefined ? phiLength : Math.PI * 2;
thetaStart = thetaStart !== undefined ? thetaStart : 0;
thetaLength = thetaLength !== undefined ? thetaLength : Math.PI;
const thetaEnd = Math.min( thetaStart + thetaLength, Math.PI );
let index = 0;
const grid = [];
const vertex = new Vector3();
const normal = new Vector3();
// buffers
const indices = [];
const vertices = [];
const normals = [];
const uvs = [];
// generate vertices, normals and uvs
for ( let iy = 0; iy <= heightSegments; iy ++ ) {
const verticesRow = [];
const v = iy / heightSegments;
// special case for the poles
let uOffset = 0;
if ( iy == 0 && thetaStart == 0 ) {
uOffset = 0.5 / widthSegments;
} else if ( iy == heightSegments && thetaEnd == Math.PI ) {
uOffset = - 0.5 / widthSegments;
}
for ( let ix = 0; ix <= widthSegments; ix ++ ) {
const u = ix / widthSegments;
// vertex
vertex.x = - radius * Math.cos( phiStart + u * phiLength ) * Math.sin( thetaStart + v * thetaLength );
vertex.y = radius * Math.cos( thetaStart + v * thetaLength );
vertex.z = radius * Math.sin( phiStart + u * phiLength ) * Math.sin( thetaStart + v * thetaLength );
vertices.push( vertex.x, vertex.y, vertex.z );
// normal
normal.copy( vertex ).normalize();
normals.push( normal.x, normal.y, normal.z );
// uv
uvs.push( u + uOffset, 1 - v );
verticesRow.push( index ++ );
}
grid.push( verticesRow );
}
// indices
for ( let iy = 0; iy < heightSegments; iy ++ ) {
for ( let ix = 0; ix < widthSegments; ix ++ ) {
const a = grid[ iy ][ ix + 1 ];
const b = grid[ iy ][ ix ];
const c = grid[ iy + 1 ][ ix ];
const d = grid[ iy + 1 ][ ix + 1 ];
if ( iy !== 0 || thetaStart > 0 ) indices.push( a, b, d );
if ( iy !== heightSegments - 1 || thetaEnd < Math.PI ) 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 ) );
}
SphereBufferGeometry.prototype = Object.create( BufferGeometry.prototype );
SphereBufferGeometry.prototype.constructor = SphereBufferGeometry;
export { SphereGeometry, SphereBufferGeometry };