import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import { BufferGeometry } from '../core/BufferGeometry.js';
import { Vector3 } from '../math/Vector3.js';
import { Vector2 } from '../math/Vector2.js';
import { clamp } from '../math/MathUtils.js';
class LatheGeometry extends BufferGeometry {
constructor( points = [ new Vector2( 0, - 0.5 ), new Vector2( 0.5, 0 ), new Vector2( 0, 0.5 ) ], segments = 12, phiStart = 0, phiLength = Math.PI * 2 ) {
super();
this.type = 'LatheGeometry';
this.parameters = {
points: points,
segments: segments,
phiStart: phiStart,
phiLength: phiLength
};
segments = Math.floor( segments );
// clamp phiLength so it's in range of [ 0, 2PI ]
phiLength = clamp( phiLength, 0, Math.PI * 2 );
// buffers
const indices = [];
const vertices = [];
const uvs = [];
const initNormals = [];
const normals = [];
// helper variables
const inverseSegments = 1.0 / segments;
const vertex = new Vector3();
const uv = new Vector2();
const normal = new Vector3();
const curNormal = new Vector3();
const prevNormal = new Vector3();
let dx = 0;
let dy = 0;
// pre-compute normals for initial "meridian"
for ( let j = 0; j <= ( points.length - 1 ); j ++ ) {
switch ( j ) {
case 0: // special handling for 1st vertex on path
dx = points[ j + 1 ].x - points[ j ].x;
dy = points[ j + 1 ].y - points[ j ].y;
normal.x = dy * 1.0;
normal.y = - dx;
normal.z = dy * 0.0;
prevNormal.copy( normal );
normal.normalize();
initNormals.push( normal.x, normal.y, normal.z );
break;
case ( points.length - 1 ): // special handling for last Vertex on path
initNormals.push( prevNormal.x, prevNormal.y, prevNormal.z );
break;
default: // default handling for all vertices in between
dx = points[ j + 1 ].x - points[ j ].x;
dy = points[ j + 1 ].y - points[ j ].y;
normal.x = dy * 1.0;
normal.y = - dx;
normal.z = dy * 0.0;
curNormal.copy( normal );
normal.x += prevNormal.x;
normal.y += prevNormal.y;
normal.z += prevNormal.z;
normal.normalize();
initNormals.push( normal.x, normal.y, normal.z );
prevNormal.copy( curNormal );
}
}
// generate vertices, uvs and normals
for ( let i = 0; i <= segments; i ++ ) {
const phi = phiStart + i * inverseSegments * phiLength;
const sin = Math.sin( phi );
const cos = Math.cos( phi );
for ( let j = 0; j <= ( points.length - 1 ); j ++ ) {
// vertex
vertex.x = points[ j ].x * sin;
vertex.y = points[ j ].y;
vertex.z = points[ j ].x * cos;
vertices.push( vertex.x, vertex.y, vertex.z );
// uv
uv.x = i / segments;
uv.y = j / ( points.length - 1 );
uvs.push( uv.x, uv.y );
// normal
const x = initNormals[ 3 * j + 0 ] * sin;
const y = initNormals[ 3 * j + 1 ];
const z = initNormals[ 3 * j + 0 ] * cos;
normals.push( x, y, z );
}
}
// indices
for ( let i = 0; i < segments; i ++ ) {
for ( let j = 0; j < ( points.length - 1 ); j ++ ) {
const base = j + i * points.length;
const a = base;
const b = base + points.length;
const c = base + points.length + 1;
const d = base + 1;
// faces
indices.push( a, b, d );
indices.push( c, d, b );
}
}
// build geometry
this.setIndex( indices );
this.setAttribute( 'position', new Float32BufferAttribute( vertices, 3 ) );
this.setAttribute( 'uv', new Float32BufferAttribute( uvs, 2 ) );
this.setAttribute( 'normal', new Float32BufferAttribute( normals, 3 ) );
}
copy( source ) {
super.copy( source );
this.parameters = Object.assign( {}, source.parameters );
return this;
}
static fromJSON( data ) {
return new LatheGeometry( data.points, data.segments, data.phiStart, data.phiLength );
}
}
export { LatheGeometry };