contour polygon. * * @param {Array} contour - An array of 2D points. * @return {number} The area. */ static area( contour ) { const n = contour.length; let a = 0.0; for ( let p = n - 1, q = 0; q < n; p = q ++ ) { a += contour[ p ].x * contour[ q ].y - contour[ q ].x * contour[ p ].y; } return a * 0.5; } /** * Returns `true` if the given contour uses a clockwise winding order. * * @param {Array} pts - An array of 2D points defining a polygon. * @return {boolean} Whether the given contour uses a clockwise winding order or not. */ static isClockWise( pts ) { return ShapeUtils.area( pts ) < 0; } /** * Triangulates the given shape definition. * * @param {Array} contour - An array of 2D points defining the contour. * @param {Array>} holes - An array that holds arrays of 2D points defining the holes. * @return {Array>} An array that holds for each face definition an array with three indices. */ static triangulateShape( contour, holes ) { const vertices = []; // flat array of vertices like [ x0,y0, x1,y1, x2,y2, ... ] const holeIndices = []; // array of hole indices const faces = []; // final array of vertex indices like [ [ a,b,d ], [ b,c,d ] ] removeDupEndPts( contour ); addContour( vertices, contour ); // let holeIndex = contour.length; holes.forEach( removeDupEndPts ); for ( let i = 0; i < holes.length; i ++ ) { holeIndices.push( holeIndex ); holeIndex += holes[ i ].length; addContour( vertices, holes[ i ] ); } // const triangles = Earcut.triangulate( vertices, holeIndices ); // for ( let i = 0; i < triangles.length; i += 3 ) { faces.push( triangles.slice( i, i + 3 ) ); } return faces; } } function removeDupEndPts( points ) { const l = points.length; if ( l > 2 && points[ l - 1 ].equals( points[ 0 ] ) ) { points.pop(); } } function addContour( vertices, contour ) { for ( let i = 0; i < contour.length; i ++ ) { vertices.push( contour[ i ].x ); vertices.push( contour[ i ].y ); } } /** * Creates extruded geometry from a path shape. * * ```js * const length = 12, width = 8; * * const shape = new THREE.Shape(); * shape.moveTo( 0,0 ); * shape.lineTo( 0, width ); * shape.lineTo( length, width ); * shape.lineTo( length, 0 ); * shape.lineTo( 0, 0 ); * * const geometry = new THREE.ExtrudeGeometry( shape ); * const material = new THREE.MeshBasicMaterial( { color: 0x00ff00 } ); * const mesh = new THREE.Mesh( geometry, material ) ; * scene.add( mesh ); * ``` * * @augments BufferGeometry * @demo scenes/geometry-browser.html#ExtrudeGeometry */ class ExtrudeGeometry extends BufferGeometry { /** * Constructs a new extrude geometry. * * @param {Shape|Array} [shapes] - A shape or an array of shapes. * @param {ExtrudeGeometry~Options} [options] - The extrude settings. */ constructor( shapes = new Shape( [ new Vector2( 0.5, 0.5 ), new Vector2( -0.5, 0.5 ), new Vector2( -0.5, -0.5 ), new Vector2( 0.5, -0.5 ) ] ), options = {} ) { super(); this.type = 'ExtrudeGeometry'; /** * Holds the constructor parameters that have been * used to generate the geometry. Any modification * after instantiation does not change the geometry. * * @type {Object} */ this.parameters = { shapes: shapes, options: options }; shapes = Array.isArray( shapes ) ? shapes : [ shapes ]; const scope = this; const verticesArray = []; const uvArray = []; for ( let i = 0, l = shapes.length; i < l; i ++ ) { const shape = shapes[ i ]; addShape( shape ); } // build geometry this.setAttribute( 'position', new Float32BufferAttribute( verticesArray, 3 ) ); this.setAttribute( 'uv', new Float32BufferAttribute( uvArray, 2 ) ); this.computeVertexNormals(); // functions function addShape( shape ) { const placeholder = []; // options const curveSegments = options.curveSegments !== undefined ? options.curveSegments : 12; const steps = options.steps !== undefined ? options.steps : 1; const depth = options.depth !== undefined ? options.depth : 1; let bevelEnabled = options.bevelEnabled !== undefined ? options.bevelEnabled : true; let bevelThickness = options.bevelThickness !== undefined ? options.bevelThickness : 0.2; let bevelSize = options.bevelSize !== undefined ? options.bevelSize : bevelThickness - 0.1; let bevelOffset = options.bevelOffset !== undefined ? options.bevelOffset : 0; let bevelSegments = options.bevelSegments !== undefined ? options.bevelSegments : 3; const extrudePath = options.extrudePath; const uvgen = options.UVGenerator !== undefined ? options.UVGenerator : WorldUVGenerator; // let extrudePts, extrudeByPath = false; let splineTube, binormal, normal, position2; if ( extrudePath ) { extrudePts = extrudePath.getSpacedPoints( steps ); extrudeByPath = true;