three.js/src/extras/helpers/PolarGridHelper.js

import { LineSegments } from '../../objects/LineSegments';
import { VertexColors } from '../../constants';
import { LineBasicMaterial } from '../../materials/LineBasicMaterial';
import { Float32BufferAttribute } from '../../core/BufferAttribute';
import { BufferGeometry } from '../../core/BufferGeometry';
import { Color } from '../../math/Color';

/**
 * @author mrdoob / http://mrdoob.com/
 * @author Mugen87 / http://github.com/Mugen87
 * @author Hectate / http://www.github.com/Hectate
 */

function PolarGridHelper( radius, radials, circles, divisions, color1, color2 ) {

    radius = radius || 10;
    radials = radials || 16;
    circles = circles || 8;
    divisions = divisions || 64;
    color1 = new Color( color1 !== undefined ? color1 : 0x444444 );
    color2 = new Color( color2 !== undefined ? color2 : 0x888888 );

    var vertices = [];
    var colors = [];

    var x, z;
    var v, i, j, r, color;

    // create the radials

    for ( i = 0; i <= radials; i++ ) {

        v = ( i / radials ) * ( Math.PI * 2 );

        x = Math.sin( v ) * radius;
        z = Math.cos( v ) * radius;

        vertices.push( 0, 0, 0 );
        vertices.push( x, 0, z );

        color = ( i & 1 ) ? color1 : color2;

        colors.push( color.r, color.g, color.b );
        colors.push( color.r, color.g, color.b );

    }

    // create the circles

    for ( i = 0; i <= circles; i++ ) {

        color = ( i & 1 ) ? color1 : color2;

        r = radius - ( radius / circles * i )

        for ( j = 0; j < divisions; j ++ ) {

            // first vertex

            v = ( j / divisions ) * ( Math.PI * 2 );

            x = Math.sin( v ) * r;
            z = Math.cos( v ) * r;

            vertices.push( x, 0, z );
            colors.push( color.r, color.g, color.b );

            // second vertex

            v = ( ( j + 1 ) / divisions ) * ( Math.PI * 2 );

            x = Math.sin( v ) * r;
            z = Math.cos( v ) * r;

            vertices.push( x, 0, z );
            colors.push( color.r, color.g, color.b );

        }

    }

    var geometry = new BufferGeometry();
    geometry.addAttribute( 'position', new Float32BufferAttribute( vertices, 3 ) );
    geometry.addAttribute( 'color', new Float32BufferAttribute( colors, 3 ) );

    var material = new LineBasicMaterial( { vertexColors: VertexColors } );

    LineSegments.call( this, geometry, material );

}

PolarGridHelper.prototype = Object.create( LineSegments.prototype );
PolarGridHelper.prototype.constructor = PolarGridHelper;

export { PolarGridHelper };