MeshLine as module

THREE.MeshLine.js

import * as THREE from "https://threejs.org/build/three.module.js";

function MeshLine() {

	this.positions = [];

	this.previous = [];
	this.next = [];
	this.side = [];
	this.width = [];
	this.indices_array = [];
	this.uvs = [];
	this.counters = [];
	this.geometry = new THREE.BufferGeometry();

	this.widthCallback = null;

}

MeshLine.prototype.setGeometry = function (g, c) {

	this.widthCallback = c;

	this.positions = [];
	this.counters = [];

	if (g instanceof THREE.Geometry) {
		for (var j = 0; j < g.vertices.length; j++) {
			var v = g.vertices[j];
			var c = j / g.vertices.length;
			this.positions.push(v.x, v.y, v.z);
			this.positions.push(v.x, v.y, v.z);
			this.counters.push(c);
			this.counters.push(c);
		}
	}

	if (g instanceof THREE.BufferGeometry) {
		// read attribute positions ?
	}

	if (g instanceof Float32Array || g instanceof Array) {
		for (var j = 0; j < g.length; j += 3) {
			var c = j / g.length;
			this.positions.push(g[j], g[j + 1], g[j + 2]);
			this.positions.push(g[j], g[j + 1], g[j + 2]);
			this.counters.push(c);
			this.counters.push(c);
		}
	}

	this.process();

}

MeshLine.prototype.compareV3 = function (a, b) {

	var aa = a * 6;
	var ab = b * 6;
	return (this.positions[aa] === this.positions[ab]) && (this.positions[aa + 1] === this.positions[ab + 1]) && (this.positions[aa + 2] === this.positions[ab + 2]);

}

MeshLine.prototype.copyV3 = function (a) {

	var aa = a * 6;
	return [this.positions[aa], this.positions[aa + 1], this.positions[aa + 2]];

}

MeshLine.prototype.process = function () {

	var l = this.positions.length / 6;

	this.previous = [];
	this.next = [];
	this.side = [];
	this.width = [];
	this.indices_array = [];
	this.uvs = [];

	for (var j = 0; j < l; j++) {
		this.side.push(1);
		this.side.push(-1);
	}

	var w;
	for (var j = 0; j < l; j++) {
		if (this.widthCallback) w = this.widthCallback(j / (l - 1));
		else w = 1;
		this.width.push(w);
		this.width.push(w);
	}

	for (var j = 0; j < l; j++) {
		this.uvs.push(j / (l - 1), 0);
		this.uvs.push(j / (l - 1), 1);
	}

	var v;

	if (this.compareV3(0, l - 1)) {
		v = this.copyV3(l - 2);
	} else {
		v = this.copyV3(0);
	}
	this.previous.push(v[0], v[1], v[2]);
	this.previous.push(v[0], v[1], v[2]);
	for (var j = 0; j < l - 1; j++) {
		v = this.copyV3(j);
		this.previous.push(v[0], v[1], v[2]);
		this.previous.push(v[0], v[1], v[2]);
	}

	for (var j = 1; j < l; j++) {
		v = this.copyV3(j);
		this.next.push(v[0], v[1], v[2]);
		this.next.push(v[0], v[1], v[2]);
	}

	if (this.compareV3(l - 1, 0)) {
		v = this.copyV3(1);
	} else {
		v = this.copyV3(l - 1);
	}
	this.next.push(v[0], v[1], v[2]);
	this.next.push(v[0], v[1], v[2]);

	for (var j = 0; j < l - 1; j++) {
		var n = j * 2;
		this.indices_array.push(n, n + 1, n + 2);
		this.indices_array.push(n + 2, n + 1, n + 3);
	}

	if (!this.attributes) {
		this.attributes = {
			position: new THREE.BufferAttribute(new Float32Array(this.positions), 3),
			previous: new THREE.BufferAttribute(new Float32Array(this.previous), 3),
			next: new THREE.BufferAttribute(new Float32Array(this.next), 3),
			side: new THREE.BufferAttribute(new Float32Array(this.side), 1),
			width: new THREE.BufferAttribute(new Float32Array(this.width), 1),
			uv: new THREE.BufferAttribute(new Float32Array(this.uvs), 2),
			index: new THREE.BufferAttribute(new Uint16Array(this.indices_array), 1),
			counters: new THREE.BufferAttribute(new Float32Array(this.counters), 1)
		}
	} else {
		this.attributes.position.copyArray(new Float32Array(this.positions));
		this.attributes.position.needsUpdate = true;
		this.attributes.previous.copyArray(new Float32Array(this.previous));
		this.attributes.previous.needsUpdate = true;
		this.attributes.next.copyArray(new Float32Array(this.next));
		this.attributes.next.needsUpdate = true;
		this.attributes.side.copyArray(new Float32Array(this.side));
		this.attributes.side.needsUpdate = true;
		this.attributes.width.copyArray(new Float32Array(this.width));
		this.attributes.width.needsUpdate = true;
		this.attributes.uv.copyArray(new Float32Array(this.uvs));
		this.attributes.uv.needsUpdate = true;
		this.attributes.index.copyArray(new Uint16Array(this.indices_array));
		this.attributes.index.needsUpdate = true;
	}

	this.geometry.addAttribute('position', this.attributes.position);
	this.geometry.addAttribute('previous', this.attributes.previous);
	this.geometry.addAttribute('next', this.attributes.next);
	this.geometry.addAttribute('side', this.attributes.side);
	this.geometry.addAttribute('width', this.attributes.width);
	this.geometry.addAttribute('uv', this.attributes.uv);
	this.geometry.addAttribute('counters', this.attributes.counters);

	this.geometry.setIndex(this.attributes.index);

}

function memcpy(src, srcOffset, dst, dstOffset, length) {
	var i

	src = src.subarray || src.slice ? src : src.buffer
	dst = dst.subarray || dst.slice ? dst : dst.buffer

	src = srcOffset ? src.subarray ?
		src.subarray(srcOffset, length && srcOffset + length) :
		src.slice(srcOffset, length && srcOffset + length) : src

	if (dst.set) {
		dst.set(src, dstOffset)
	} else {
		for (i = 0; i < src.length; i++) {
			dst[i + dstOffset] = src[i]
		}
	}

	return dst
}

/**
 * Fast method to advance the line by one position.  The oldest position is removed.
 * @param position
 */
MeshLine.prototype.advance = function (position) {

	var positions = this.attributes.position.array;
	var previous = this.attributes.previous.array;
	var next = this.attributes.next.array;
	var l = positions.length;

	// PREVIOUS
	memcpy(positions, 0, previous, 0, l);

	// POSITIONS
	memcpy(positions, 6, positions, 0, l - 6);

	positions[l - 6] = position.x;
	positions[l - 5] = position.y;
	positions[l - 4] = position.z;
	positions[l - 3] = position.x;
	positions[l - 2] = position.y;
	positions[l - 1] = position.z;

	// NEXT
	memcpy(positions, 6, next, 0, l - 6);

	next[l - 6] = position.x;
	next[l - 5] = position.y;
	next[l - 4] = position.z;
	next[l - 3] = position.x;
	next[l - 2] = position.y;
	next[l - 1] = position.z;

	this.attributes.position.needsUpdate = true;
	this.attributes.previous.needsUpdate = true;
	this.attributes.next.needsUpdate = true;

};

function MeshLineMaterial(parameters) {

	var vertexShaderSource = [
		'precision highp float;',
		'',
		'attribute vec3 position;',
		'attribute vec3 previous;',
		'attribute vec3 next;',
		'attribute float side;',
		'attribute float width;',
		'attribute vec2 uv;',
		'attribute float counters;',
		'',
		'uniform mat4 projectionMatrix;',
		'uniform mat4 modelViewMatrix;',
		'uniform vec2 resolution;',
		'uniform float lineWidth;',
		'uniform vec3 color;',
		'uniform float opacity;',
		'uniform float near;',
		'uniform float far;',
		'uniform float sizeAttenuation;',
		'',
		'varying vec2 vUV;',
		'varying vec4 vColor;',
		'varying float vCounters;',
		'',
		'vec2 fix( vec4 i, float aspect ) {',
		'',
		'    vec2 res = i.xy / i.w;',
		'    res.x *= aspect;',
		'	 vCounters = counters;',
		'    return res;',
		'',
		'}',
		'',
		'void main() {',
		'',
		'    float aspect = resolution.x / resolution.y;',
		'	 float pixelWidthRatio = 1. / (resolution.x * projectionMatrix[0][0]);',
		'',
		'    vColor = vec4( color, opacity );',
		'    vUV = uv;',
		'',
		'    mat4 m = projectionMatrix * modelViewMatrix;',
		'    vec4 finalPosition = m * vec4( position, 1.0 );',
		'    vec4 prevPos = m * vec4( previous, 1.0 );',
		'    vec4 nextPos = m * vec4( next, 1.0 );',
		'',
		'    vec2 currentP = fix( finalPosition, aspect );',
		'    vec2 prevP = fix( prevPos, aspect );',
		'    vec2 nextP = fix( nextPos, aspect );',
		'',
		'	 float pixelWidth = finalPosition.w * pixelWidthRatio;',
		'    float w = 1.8 * pixelWidth * lineWidth * width;',
		'',
		'    if( sizeAttenuation == 1. ) {',
		'        w = 1.8 * lineWidth * width;',
		'    }',
		'',
		'    vec2 dir;',
		'    if( nextP == currentP ) dir = normalize( currentP - prevP );',
		'    else if( prevP == currentP ) dir = normalize( nextP - currentP );',
		'    else {',
		'        vec2 dir1 = normalize( currentP - prevP );',
		'        vec2 dir2 = normalize( nextP - currentP );',
		'        dir = normalize( dir1 + dir2 );',
		'',
		'        vec2 perp = vec2( -dir1.y, dir1.x );',
		'        vec2 miter = vec2( -dir.y, dir.x );',
		'        //w = clamp( w / dot( miter, perp ), 0., 4. * lineWidth * width );',
		'',
		'    }',
		'',
		'    //vec2 normal = ( cross( vec3( dir, 0. ), vec3( 0., 0., 1. ) ) ).xy;',
		'    vec2 normal = vec2( -dir.y, dir.x );',
		'    normal.x /= aspect;',
		'    normal *= .5 * w;',
		'',
		'    vec4 offset = vec4( normal * side, 0.0, 1.0 );',
		'    finalPosition.xy += offset.xy;',
		'',
		'    gl_Position = finalPosition;',
		'',
		'}'];

	var fragmentShaderSource = [
		'#extension GL_OES_standard_derivatives : enable',
		'precision mediump float;',
		'',
		'uniform sampler2D map;',
		'uniform sampler2D alphaMap;',
		'uniform float useMap;',
		'uniform float useAlphaMap;',
		'uniform float useDash;',
		'uniform vec2 dashArray;',
		'uniform float visibility;',
		'uniform float alphaTest;',
		'uniform vec2 repeat;',
		'',
		'varying vec2 vUV;',
		'varying vec4 vColor;',
		'varying float vCounters;',
		'',
		'void main() {',
		'',
		'    vec4 c = vColor;',
		'    if( useMap == 1. ) c *= texture2D( map, vUV * repeat );',
		'    if( useAlphaMap == 1. ) c.a *= texture2D( alphaMap, vUV * repeat ).a;',
		'	 if( c.a < alphaTest ) discard;',
		'	 if( useDash == 1. ){',
		'	 	 ',
		'	 }',
		'    gl_FragColor = c;',
		'	 gl_FragColor.a *= step(vCounters,visibility);',
		'}'];

	function check(v, d) {
		if (v === undefined) return d;
		return v;
	}

	THREE.Material.call(this);

	parameters = parameters || {};

	this.lineWidth = check(parameters.lineWidth, 1);
	this.map = check(parameters.map, null);
	this.useMap = check(parameters.useMap, 0);
	this.alphaMap = check(parameters.alphaMap, null);
	this.useAlphaMap = check(parameters.useAlphaMap, 0);
	this.color = check(parameters.color, new THREE.Color(0xffffff));
	this.opacity = check(parameters.opacity, 1);
	this.resolution = check(parameters.resolution, new THREE.Vector2(1, 1));
	this.sizeAttenuation = check(parameters.sizeAttenuation, 1);
	this.near = check(parameters.near, 1);
	this.far = check(parameters.far, 1);
	this.dashArray = check(parameters.dashArray, []);
	this.useDash = (this.dashArray !== []) ? 1 : 0;
	this.visibility = check(parameters.visibility, 1);
	this.alphaTest = check(parameters.alphaTest, 0);
	this.repeat = check(parameters.repeat, new THREE.Vector2(1, 1));

	var material = new THREE.RawShaderMaterial({
		uniforms: {
			lineWidth: { type: 'f', value: this.lineWidth },
			map: { type: 't', value: this.map },
			useMap: { type: 'f', value: this.useMap },
			alphaMap: { type: 't', value: this.alphaMap },
			useAlphaMap: { type: 'f', value: this.useAlphaMap },
			color: { type: 'c', value: this.color },
			opacity: { type: 'f', value: this.opacity },
			resolution: { type: 'v2', value: this.resolution },
			sizeAttenuation: { type: 'f', value: this.sizeAttenuation },
			near: { type: 'f', value: this.near },
			far: { type: 'f', value: this.far },
			dashArray: { type: 'v2', value: new THREE.Vector2(this.dashArray[0], this.dashArray[1]) },
			useDash: { type: 'f', value: this.useDash },
			visibility: { type: 'f', value: this.visibility },
			alphaTest: { type: 'f', value: this.alphaTest },
			repeat: { type: 'v2', value: this.repeat }
		},
		vertexShader: vertexShaderSource.join('\r\n'),
		fragmentShader: fragmentShaderSource.join('\r\n')
	});

	delete parameters.lineWidth;
	delete parameters.map;
	delete parameters.useMap;
	delete parameters.alphaMap;
	delete parameters.useAlphaMap;
	delete parameters.color;
	delete parameters.opacity;
	delete parameters.resolution;
	delete parameters.sizeAttenuation;
	delete parameters.near;
	delete parameters.far;
	delete parameters.dashArray;
	delete parameters.visibility;
	delete parameters.alphaTest;
	delete parameters.repeat;

	material.type = 'MeshLineMaterial';

	material.setValues(parameters);

	return material;

};

MeshLineMaterial.prototype = Object.create(THREE.Material.prototype);
MeshLineMaterial.prototype.constructor = MeshLineMaterial;

MeshLineMaterial.prototype.copy = function (source) {

	THREE.Material.prototype.copy.call(this, source);

	this.lineWidth = source.lineWidth;
	this.map = source.map;
	this.useMap = source.useMap;
	this.alphaMap = source.alphaMap;
	this.useAlphaMap = source.useAlphaMap;
	this.color.copy(source.color);
	this.opacity = source.opacity;
	this.resolution.copy(source.resolution);
	this.sizeAttenuation = source.sizeAttenuation;
	this.near = source.near;
	this.far = source.far;
	this.dashArray.copy(source.dashArray);
	this.useDash = source.useDash;
	this.visibility = source.visibility;
	this.alphaTest = source.alphaTest;
	this.repeat.copy(source.repeat);

	return this;

};

export { MeshLine, MeshLineMaterial };