chart/crosshairPlot.js

import * as d3 from "d3";
import dataTransform from "../dataTransform";
import component from "../component";

/**
 * Reusable 3D Crosshair Plot (Experimental) Chart
 *
 * @module
 *
 * @example
 * let chartHolder = d3.select("#chartholder");
 *
 * let myData = [...];
 *
 * let myChart = d3.x3d.chart.crosshairPlot();
 *
 * chartHolder.datum(myData).call(myChart);
 */
export default function() {

	let x3d;
	let scene;

	/* Default Properties */
	let width = 500;
	let height = 500;
	let dimensions = { x: 40, y: 40, z: 40 };
	let classed = "d3X3dCrosshairPlot";
	let debug = false;

	/* Scales */
	let xScale;
	let yScale;
	let zScale;

	/* Components */
	const viewpoint = component.viewpoint();
	const axis = component.axisThreePlane();
	const crosshair = component.crosshair();

	/**
	 * Initialise Data and Scales
	 *
	 * @private
	 * @param {Array} data - Chart data.
	 */
	const init = function(data) {
		const { coordinatesMax } = dataTransform(data).summary();
		const { x: maxX, y: maxY, z: maxZ } = coordinatesMax;
		const { x: dimensionX, y: dimensionY, z: dimensionZ } = dimensions;

		xScale = d3.scaleLinear()
			.domain([0, maxX])
			.range([0, dimensionX]);

		yScale = d3.scaleLinear()
			.domain([0, maxY])
			.range([0, dimensionY]);

		zScale = d3.scaleLinear()
			.domain([0, maxZ])
			.range([0, dimensionZ]);
	};

	/**
	 * Create X3D base and scene
	 *
	 * @param selection
	 * @param layers
	 */
	function createBase(selection, layers) {
		// Create x3d element (if it does not exist already)
		if (!x3d) {
			x3d = selection.append("X3D");
			scene = x3d.append("Scene");

			x3d.attr("width", width + "px")
				.attr("height", height + "px")
				.attr("showLog", debug ? "true" : "false")
				.attr("showStat", debug ? "true" : "false")
				.attr("useGeoCache", false);

			// Disable gamma correction
			scene.append("Environment")
				.attr("gammaCorrectionDefault", "none");

			// Add a white background
			scene.append("Background")
				.attr("groundColor", "1 1 1")
				.attr("skyColor", "1 1 1");
		}

		// Add layer groups
		scene.classed(classed, true)
			.selectAll("Group")
			.data(layers)
			.enter()
			.append("Group")
			.attr("class", (d) => d);
	}

	/**
	 * Constructor
	 *
	 * @constructor
	 * @alias crosshairPlot
	 * @param {d3.selection} selection - The chart holder D3 selection.
	 */
	const my = function(selection) {
		const layers = ["axis", "crosshairs"];
		createBase(selection, layers);

		selection.each((data) => {
			init(data);

			// Add Viewpoint
			viewpoint.centerOfRotation([dimensions.x / 2, dimensions.y / 2, dimensions.z / 2]);

			scene.call(viewpoint);

			// Add Axis
			axis.xScale(xScale)
				.yScale(yScale)
				.zScale(zScale)
				.dimensions(dimensions);

			scene.select(".axis")
				.call(axis);

			// Add Crosshair
			crosshair.xScale(xScale)
				.yScale(yScale)
				.zScale(zScale);

			let crosshairs = scene.select(".crosshairs")
				.datum(data)
				.selectAll(".crosshair")
				.data((d) => d.values);

			crosshairs.enter()
				.append("group")
				.classed("crosshair", true)
				.merge(crosshairs)
				.transition()
				.each(function() {
					d3.select(this).call(crosshair);
				});
		});
	};

	/**
	 * Width Getter / Setter
	 *
	 * @param {number} _v - X3D canvas width in px.
	 * @returns {*}
	 */
	my.width = function(_v) {
		if (!arguments.length) return width;
		width = _v;
		return this;
	};

	/**
	 * Height Getter / Setter
	 *
	 * @param {number} _v - X3D canvas height in px.
	 * @returns {*}
	 */
	my.height = function(_v) {
		if (!arguments.length) return height;
		height = _v;
		return this;
	};

	/**
	 * Dimensions Getter / Setter
	 *
	 * @param {{x: number, y: number, z: number}} _v - 3D object dimensions.
	 * @returns {*}
	 */
	my.dimensions = function(_v) {
		if (!arguments.length) return dimensions;
		dimensions = _v;
		return this;
	};

	/**
	 * X Scale Getter / Setter
	 *
	 * @param {d3.scale} _v - D3 scale.
	 * @returns {*}
	 */
	my.xScale = function(_v) {
		if (!arguments.length) return xScale;
		xScale = _v;
		return my;
	};

	/**
	 * Y Scale Getter / Setter
	 *
	 * @param {d3.scale} _v - D3 scale.
	 * @returns {*}
	 */
	my.yScale = function(_v) {
		if (!arguments.length) return yScale;
		yScale = _v;
		return my;
	};

	/**
	 * Z Scale Getter / Setter
	 *
	 * @param {d3.scale} _v - D3 scale.
	 * @returns {*}
	 */
	my.zScale = function(_v) {
		if (!arguments.length) return zScale;
		zScale = _v;
		return my;
	};

	/**
	 * Debug Getter / Setter
	 *
	 * @param {boolean} _v - Show debug log and stats. True/False.
	 * @returns {*}
	 */
	my.debug = function(_v) {
		if (!arguments.length) return debug;
		debug = _v;
		return my;
	};

	return my;
}