three.js/src/geometries/ExtrudeGeometry.js

/**
 * @author zz85 / http://www.lab4games.net/zz85/blog
 *
 * Creates extruded geometry from a path shape.
 *
 * parameters = {
 *
 *  curveSegments: <int>, // number of points on the curves
 *  steps: <int>, // number of points for z-side extrusions / used for subdividing segments of extrude spline too
 *  amount: <int>, // Depth to extrude the shape
 *
 *  bevelEnabled: <bool>, // turn on bevel
 *  bevelThickness: <float>, // how deep into the original shape bevel goes
 *  bevelSize: <float>, // how far from shape outline is bevel
 *  bevelSegments: <int>, // number of bevel layers
 *
 *  extrudePath: <THREE.Curve> // curve to extrude shape along
 *  frames: <Object> // containing arrays of tangents, normals, binormals
 *
 *  UVGenerator: <Object> // object that provides UV generator functions
 *
 * }
 */

import { Geometry } from '../core/Geometry.js';
import { BufferGeometry } from '../core/BufferGeometry.js';
import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import { Vector2 } from '../math/Vector2.js';
import { Vector3 } from '../math/Vector3.js';
import { ShapeUtils } from '../extras/ShapeUtils.js';

// ExtrudeGeometry

function ExtrudeGeometry( shapes, options ) {

	Geometry.call( this );

	this.type = 'ExtrudeGeometry';

	this.parameters = {
		shapes: shapes,
		options: options
	};

	this.fromBufferGeometry( new ExtrudeBufferGeometry( shapes, options ) );
	this.mergeVertices();

}

ExtrudeGeometry.prototype = Object.create( Geometry.prototype );
ExtrudeGeometry.prototype.constructor = ExtrudeGeometry;

// ExtrudeBufferGeometry

function ExtrudeBufferGeometry( shapes, options ) {

	if ( typeof ( shapes ) === "undefined" ) {

		return;

	}

	BufferGeometry.call( this );

	this.type = 'ExtrudeBufferGeometry';

	shapes = Array.isArray( shapes ) ? shapes : [ shapes ];

	this.addShapeList( shapes, options );

	this.computeVertexNormals();

	// can't really use automatic vertex normals
	// as then front and back sides get smoothed too
	// should do separate smoothing just for sides

	//this.computeVertexNormals();

	//console.log( "took", ( Date.now() - startTime ) );

}

ExtrudeBufferGeometry.prototype = Object.create( BufferGeometry.prototype );
ExtrudeBufferGeometry.prototype.constructor = ExtrudeBufferGeometry;

ExtrudeBufferGeometry.prototype.getArrays = function () {

	var positionAttribute = this.getAttribute( "position" );
	var verticesArray = positionAttribute ? Array.prototype.slice.call( positionAttribute.array ) : [];

	var uvAttribute = this.getAttribute( "uv" );
	var uvArray = uvAttribute ? Array.prototype.slice.call( uvAttribute.array ) : [];

	var IndexAttribute = this.index;
	var indicesArray = IndexAttribute ? Array.prototype.slice.call( IndexAttribute.array ) : [];

	return {
		position: verticesArray,
		uv: uvArray,
		index: indicesArray
	};

};

ExtrudeBufferGeometry.prototype.addShapeList = function ( shapes, options ) {

	var sl = shapes.length;
	options.arrays = this.getArrays();

	for ( var s = 0; s < sl; s ++ ) {

		var shape = shapes[ s ];
		this.addShape( shape, options );

	}

	this.setIndex( options.arrays.index );
	this.addAttribute( 'position', new Float32BufferAttribute( options.arrays.position, 3 ) );
	this.addAttribute( 'uv', new Float32BufferAttribute( options.arrays.uv, 2 ) );

};

ExtrudeBufferGeometry.prototype.addShape = function ( shape, options ) {

	var arrays = options.arrays ? options.arrays : this.getArrays();
	var verticesArray = arrays.position;
	var indicesArray = arrays.index;
	var uvArray = arrays.uv;

	var placeholder = [];


	var amount = options.amount !== undefined ? options.amount : 100;

	var bevelThickness = options.bevelThickness !== undefined ? options.bevelThickness : 6; // 10
	var bevelSize = options.bevelSize !== undefined ? options.bevelSize : bevelThickness - 2; // 8
	var bevelSegments = options.bevelSegments !== undefined ? options.bevelSegments : 3;

	var bevelEnabled = options.bevelEnabled !== undefined ? options.bevelEnabled : true; // false

	var curveSegments = options.curveSegments !== undefined ? options.curveSegments : 12;

	var steps = options.steps !== undefined ? options.steps : 1;

	var extrudePath = options.extrudePath;
	var extrudePts, extrudeByPath = false;

	// Use default WorldUVGenerator if no UV generators are specified.
	var uvgen = options.UVGenerator !== undefined ? options.UVGenerator : ExtrudeGeometry.WorldUVGenerator;

	var splineTube, binormal, normal, position2;
	if ( extrudePath ) {

		extrudePts = extrudePath.getSpacedPoints( steps );

		extrudeByPath = true;
		bevelEnabled = false; // bevels not supported for path extrusion

		// SETUP TNB variables

		// TODO1 - have a .isClosed in spline?

		splineTube = options.frames !== undefined ? options.frames : extrudePath.computeFrenetFrames( steps, false );

		// console.log(splineTube, 'splineTube', splineTube.normals.length, 'steps', steps, 'extrudePts', extrudePts.length);

		binormal = new Vector3();
		normal = new Vector3();
		position2 = new Vector3();

	}

	// Safeguards if bevels are not enabled

	if ( ! bevelEnabled ) {

		bevelSegments = 0;
		bevelThickness = 0;
		bevelSize = 0;

	}

	// Variables initialization

	var ahole, h, hl; // looping of holes
	var scope = this;

	var shapePoints = shape.extractPoints( curveSegments );

	var vertices = shapePoints.shape;
	var holes = shapePoints.holes;

	var reverse = ! ShapeUtils.isClockWise( vertices );

	if ( reverse ) {

		vertices = vertices.reverse();

		// Maybe we should also check if holes are in the opposite direction, just to be safe ...

		for ( h = 0, hl = holes.length; h < hl; h ++ ) {

			ahole = holes[ h ];

			if ( ShapeUtils.isClockWise( ahole ) ) {

				holes[ h ] = ahole.reverse();

			}

		}

	}


	var faces = ShapeUtils.triangulateShape( vertices, holes );

	/* Vertices */

	var contour = vertices; // vertices has all points but contour has only points of circumference

	for ( h = 0, hl = holes.length; h < hl; h ++ ) {

		ahole = holes[ h ];

		vertices = vertices.concat( ahole );

	}


	function scalePt2( pt, vec, size ) {

		if ( ! vec ) console.error( "THREE.ExtrudeGeometry: vec does not exist" );

		return vec.clone().multiplyScalar( size ).add( pt );

	}

	var b, bs, t, z,
		vert, vlen = vertices.length,
		face, flen = faces.length;


	// Find directions for point movement


	function getBevelVec( inPt, inPrev, inNext ) {

		// computes for inPt the corresponding point inPt' on a new contour
		//   shifted by 1 unit (length of normalized vector) to the left
		// if we walk along contour clockwise, this new contour is outside the old one
		//
		// inPt' is the intersection of the two lines parallel to the two
		//  adjacent edges of inPt at a distance of 1 unit on the left side.

		var v_trans_x, v_trans_y, shrink_by; // resulting translation vector for inPt

		// good reading for geometry algorithms (here: line-line intersection)
		// http://geomalgorithms.com/a05-_intersect-1.html

		var v_prev_x = inPt.x - inPrev.x,
			v_prev_y = inPt.y - inPrev.y;
		var v_next_x = inNext.x - inPt.x,
			v_next_y = inNext.y - inPt.y;

		var v_prev_lensq = ( v_prev_x * v_prev_x + v_prev_y * v_prev_y );

		// check for collinear edges
		var collinear0 = ( v_prev_x * v_next_y - v_prev_y * v_next_x );

		if ( Math.abs( collinear0 ) > Number.EPSILON ) {

			// not collinear

			// length of vectors for normalizing

			var v_prev_len = Math.sqrt( v_prev_lensq );
			var v_next_len = Math.sqrt( v_next_x * v_next_x + v_next_y * v_next_y );

			// shift adjacent points by unit vectors to the left

			var ptPrevShift_x = ( inPrev.x - v_prev_y / v_prev_len );
			var ptPrevShift_y = ( inPrev.y + v_prev_x / v_prev_len );

			var ptNextShift_x = ( inNext.x - v_next_y / v_next_len );
			var ptNextShift_y = ( inNext.y + v_next_x / v_next_len );

			// scaling factor for v_prev to intersection point

			var sf = ( ( ptNextShift_x - ptPrevShift_x ) * v_next_y -
					( ptNextShift_y - ptPrevShift_y ) * v_next_x ) /
				( v_prev_x * v_next_y - v_prev_y * v_next_x );

			// vector from inPt to intersection point

			v_trans_x = ( ptPrevShift_x + v_prev_x * sf - inPt.x );
			v_trans_y = ( ptPrevShift_y + v_prev_y * sf - inPt.y );

			// Don't normalize!, otherwise sharp corners become ugly
			//  but prevent crazy spikes
			var v_trans_lensq = ( v_trans_x * v_trans_x + v_trans_y * v_trans_y );
			if ( v_trans_lensq <= 2 ) {

				return new Vector2( v_trans_x, v_trans_y );

			} else {

				shrink_by = Math.sqrt( v_trans_lensq / 2 );

			}

		} else {

			// handle special case of collinear edges

			var direction_eq = false; // assumes: opposite
			if ( v_prev_x > Number.EPSILON ) {

				if ( v_next_x > Number.EPSILON ) {

					direction_eq = true;

				}

			} else {

				if ( v_prev_x < - Number.EPSILON ) {

					if ( v_next_x < - Number.EPSILON ) {

						direction_eq = true;

					}

				} else {

					if ( Math.sign( v_prev_y ) === Math.sign( v_next_y ) ) {

						direction_eq = true;

					}

				}

			}

			if ( direction_eq ) {

				// console.log("Warning: lines are a straight sequence");
				v_trans_x = - v_prev_y;
				v_trans_y = v_prev_x;
				shrink_by = Math.sqrt( v_prev_lensq );

			} else {

				// console.log("Warning: lines are a straight spike");
				v_trans_x = v_prev_x;
				v_trans_y = v_prev_y;
				shrink_by = Math.sqrt( v_prev_lensq / 2 );

			}

		}

		return new Vector2( v_trans_x / shrink_by, v_trans_y / shrink_by );

	}


	var contourMovements = [];

	for ( var i = 0, il = contour.length, j = il - 1, k = i + 1; i < il; i ++, j ++, k ++ ) {

		if ( j === il ) j = 0;
		if ( k === il ) k = 0;

		//  (j)---(i)---(k)
		// console.log('i,j,k', i, j , k)

		contourMovements[ i ] = getBevelVec( contour[ i ], contour[ j ], contour[ k ] );

	}

	var holesMovements = [],
		oneHoleMovements, verticesMovements = contourMovements.concat();

	for ( h = 0, hl = holes.length; h < hl; h ++ ) {

		ahole = holes[ h ];

		oneHoleMovements = [];

		for ( i = 0, il = ahole.length, j = il - 1, k = i + 1; i < il; i ++, j ++, k ++ ) {

			if ( j === il ) j = 0;
			if ( k === il ) k = 0;

			//  (j)---(i)---(k)
			oneHoleMovements[ i ] = getBevelVec( ahole[ i ], ahole[ j ], ahole[ k ] );

		}

		holesMovements.push( oneHoleMovements );
		verticesMovements = verticesMovements.concat( oneHoleMovements );

	}


	// Loop bevelSegments, 1 for the front, 1 for the back

	for ( b = 0; b < bevelSegments; b ++ ) {

		//for ( b = bevelSegments; b > 0; b -- ) {

		t = b / bevelSegments;
		z = bevelThickness * Math.cos( t * Math.PI / 2 );
		bs = bevelSize * Math.sin( t * Math.PI / 2 );

		// contract shape

		for ( i = 0, il = contour.length; i < il; i ++ ) {

			vert = scalePt2( contour[ i ], contourMovements[ i ], bs );

			v( vert.x, vert.y, - z );

		}

		// expand holes

		for ( h = 0, hl = holes.length; h < hl; h ++ ) {

			ahole = holes[ h ];
			oneHoleMovements = holesMovements[ h ];

			for ( i = 0, il = ahole.length; i < il; i ++ ) {

				vert = scalePt2( ahole[ i ], oneHoleMovements[ i ], bs );

				v( vert.x, vert.y, - z );

			}

		}

	}

	bs = bevelSize;

	// Back facing vertices

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

		vert = bevelEnabled ? scalePt2( vertices[ i ], verticesMovements[ i ], bs ) : vertices[ i ];

		if ( ! extrudeByPath ) {

			v( vert.x, vert.y, 0 );

		} else {

			// v( vert.x, vert.y + extrudePts[ 0 ].y, extrudePts[ 0 ].x );

			normal.copy( splineTube.normals[ 0 ] ).multiplyScalar( vert.x );
			binormal.copy( splineTube.binormals[ 0 ] ).multiplyScalar( vert.y );

			position2.copy( extrudePts[ 0 ] ).add( normal ).add( binormal );

			v( position2.x, position2.y, position2.z );

		}

	}

	// Add stepped vertices...
	// Including front facing vertices

	var s;

	for ( s = 1; s <= steps; s ++ ) {

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

			vert = bevelEnabled ? scalePt2( vertices[ i ], verticesMovements[ i ], bs ) : vertices[ i ];

			if ( ! extrudeByPath ) {

				v( vert.x, vert.y, amount / steps * s );

			} else {

				// v( vert.x, vert.y + extrudePts[ s - 1 ].y, extrudePts[ s - 1 ].x );

				normal.copy( splineTube.normals[ s ] ).multiplyScalar( vert.x );
				binormal.copy( splineTube.binormals[ s ] ).multiplyScalar( vert.y );

				position2.copy( extrudePts[ s ] ).add( normal ).add( binormal );

				v( position2.x, position2.y, position2.z );

			}

		}

	}


	// Add bevel segments planes

	//for ( b = 1; b <= bevelSegments; b ++ ) {
	for ( b = bevelSegments - 1; b >= 0; b -- ) {

		t = b / bevelSegments;
		z = bevelThickness * Math.cos( t * Math.PI / 2 );
		bs = bevelSize * Math.sin( t * Math.PI / 2 );

		// contract shape

		for ( i = 0, il = contour.length; i < il; i ++ ) {

			vert = scalePt2( contour[ i ], contourMovements[ i ], bs );
			v( vert.x, vert.y, amount + z );

		}

		// expand holes

		for ( h = 0, hl = holes.length; h < hl; h ++ ) {

			ahole = holes[ h ];
			oneHoleMovements = holesMovements[ h ];

			for ( i = 0, il = ahole.length; i < il; i ++ ) {

				vert = scalePt2( ahole[ i ], oneHoleMovements[ i ], bs );

				if ( ! extrudeByPath ) {

					v( vert.x, vert.y, amount + z );

				} else {

					v( vert.x, vert.y + extrudePts[ steps - 1 ].y, extrudePts[ steps - 1 ].x + z );

				}

			}

		}

	}

	/* Faces */

	// Top and bottom faces

	buildLidFaces();

	// Sides faces

	buildSideFaces();


	/////  Internal functions

	function buildLidFaces() {

		var start = verticesArray.length / 3;

		if ( bevelEnabled ) {

			var layer = 0; // steps + 1
			var offset = vlen * layer;

			// Bottom faces

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

				face = faces[ i ];
				f3( face[ 2 ] + offset, face[ 1 ] + offset, face[ 0 ] + offset );

			}

			layer = steps + bevelSegments * 2;
			offset = vlen * layer;

			// Top faces

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

				face = faces[ i ];
				f3( face[ 0 ] + offset, face[ 1 ] + offset, face[ 2 ] + offset );

			}

		} else {

			// Bottom faces

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

				face = faces[ i ];
				f3( face[ 2 ], face[ 1 ], face[ 0 ] );

			}

			// Top faces

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

				face = faces[ i ];
				f3( face[ 0 ] + vlen * steps, face[ 1 ] + vlen * steps, face[ 2 ] + vlen * steps );

			}

		}

		scope.addGroup( start, verticesArray.length / 3 - start, options.material !== undefined ? options.material : 0 );

	}

	// Create faces for the z-sides of the shape

	function buildSideFaces() {

		var start = verticesArray.length / 3;
		var layeroffset = 0;
		sidewalls( contour, layeroffset );
		layeroffset += contour.length;

		for ( h = 0, hl = holes.length; h < hl; h ++ ) {

			ahole = holes[ h ];
			sidewalls( ahole, layeroffset );

			//, true
			layeroffset += ahole.length;

		}


		scope.addGroup( start, verticesArray.length / 3 - start, options.extrudeMaterial !== undefined ? options.extrudeMaterial : 1 );


	}

	function sidewalls( contour, layeroffset ) {

		var j, k;
		i = contour.length;

		while ( -- i >= 0 ) {

			j = i;
			k = i - 1;
			if ( k < 0 ) k = contour.length - 1;

			//console.log('b', i,j, i-1, k,vertices.length);

			var s = 0,
				sl = steps + bevelSegments * 2;

			for ( s = 0; s < sl; s ++ ) {

				var slen1 = vlen * s;
				var slen2 = vlen * ( s + 1 );

				var a = layeroffset + j + slen1,
					b = layeroffset + k + slen1,
					c = layeroffset + k + slen2,
					d = layeroffset + j + slen2;

				f4( a, b, c, d );

			}

		}

	}

	function v( x, y, z ) {

		placeholder.push( x );
		placeholder.push( y );
		placeholder.push( z );

	}


	function f3( a, b, c ) {

		addVertex( a );
		addVertex( b );
		addVertex( c );

		var nextIndex = verticesArray.length / 3;
		var uvs = uvgen.generateTopUV( scope, verticesArray, nextIndex - 3, nextIndex - 2, nextIndex - 1 );

		addUV( uvs[ 0 ] );
		addUV( uvs[ 1 ] );
		addUV( uvs[ 2 ] );

	}

	function f4( a, b, c, d ) {

		addVertex( a );
		addVertex( b );
		addVertex( d );

		addVertex( b );
		addVertex( c );
		addVertex( d );


		var nextIndex = verticesArray.length / 3;
		var uvs = uvgen.generateSideWallUV( scope, verticesArray, nextIndex - 6, nextIndex - 3, nextIndex - 2, nextIndex - 1 );

		addUV( uvs[ 0 ] );
		addUV( uvs[ 1 ] );
		addUV( uvs[ 3 ] );

		addUV( uvs[ 1 ] );
		addUV( uvs[ 2 ] );
		addUV( uvs[ 3 ] );

	}

	function addVertex( index ) {

		indicesArray.push( verticesArray.length / 3 );
		verticesArray.push( placeholder[ index * 3 + 0 ] );
		verticesArray.push( placeholder[ index * 3 + 1 ] );
		verticesArray.push( placeholder[ index * 3 + 2 ] );

	}


	function addUV( vector2 ) {

		uvArray.push( vector2.x );
		uvArray.push( vector2.y );

	}

	if ( ! options.arrays ) {

		this.setIndex( indicesArray );
		this.addAttribute( 'position', new Float32BufferAttribute( verticesArray, 3 ) );
		this.addAttribute( 'uv', new Float32BufferAttribute( options.arrays.uv, 2 ) );

	}

};

ExtrudeGeometry.WorldUVGenerator = {

	generateTopUV: function ( geometry, vertices, indexA, indexB, indexC ) {

		var a_x = vertices[ indexA * 3 ];
		var a_y = vertices[ indexA * 3 + 1 ];
		var b_x = vertices[ indexB * 3 ];
		var b_y = vertices[ indexB * 3 + 1 ];
		var c_x = vertices[ indexC * 3 ];
		var c_y = vertices[ indexC * 3 + 1 ];

		return [
			new Vector2( a_x, a_y ),
			new Vector2( b_x, b_y ),
			new Vector2( c_x, c_y )
		];

	},

	generateSideWallUV: function ( geometry, vertices, indexA, indexB, indexC, indexD ) {

		var a_x = vertices[ indexA * 3 ];
		var a_y = vertices[ indexA * 3 + 1 ];
		var a_z = vertices[ indexA * 3 + 2 ];
		var b_x = vertices[ indexB * 3 ];
		var b_y = vertices[ indexB * 3 + 1 ];
		var b_z = vertices[ indexB * 3 + 2 ];
		var c_x = vertices[ indexC * 3 ];
		var c_y = vertices[ indexC * 3 + 1 ];
		var c_z = vertices[ indexC * 3 + 2 ];
		var d_x = vertices[ indexD * 3 ];
		var d_y = vertices[ indexD * 3 + 1 ];
		var d_z = vertices[ indexD * 3 + 2 ];

		if ( Math.abs( a_y - b_y ) < 0.01 ) {

			return [
				new Vector2( a_x, 1 - a_z ),
				new Vector2( b_x, 1 - b_z ),
				new Vector2( c_x, 1 - c_z ),
				new Vector2( d_x, 1 - d_z )
			];

		} else {

			return [
				new Vector2( a_y, 1 - a_z ),
				new Vector2( b_y, 1 - b_z ),
				new Vector2( c_y, 1 - c_z ),
				new Vector2( d_y, 1 - d_z )
			];

		}

	}
};


export { ExtrudeGeometry, ExtrudeBufferGeometry };