Polar.js

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

/**
 * @module echarts/coord/polar/Polar
 */

import RadiusAxis from './RadiusAxis';
import AngleAxis from './AngleAxis';

/**
 * @alias {module:echarts/coord/polar/Polar}
 * @constructor
 * @param {string} name
 */
var Polar = function (name) {

    /**
     * @type {string}
     */
    this.name = name || '';

    /**
     * x of polar center
     * @type {number}
     */
    this.cx = 0;

    /**
     * y of polar center
     * @type {number}
     */
    this.cy = 0;

    /**
     * @type {module:echarts/coord/polar/RadiusAxis}
     * @private
     */
    this._radiusAxis = new RadiusAxis();

    /**
     * @type {module:echarts/coord/polar/AngleAxis}
     * @private
     */
    this._angleAxis = new AngleAxis();

    this._radiusAxis.polar = this._angleAxis.polar = this;
};

Polar.prototype = {

    type: 'polar',

    axisPointerEnabled: true,

    constructor: Polar,

    /**
     * @param {Array.<string>}
     * @readOnly
     */
    dimensions: ['radius', 'angle'],

    /**
     * @type {module:echarts/coord/PolarModel}
     */
    model: null,

    /**
     * If contain coord
     * @param {Array.<number>} point
     * @return {boolean}
     */
    containPoint: function (point) {
        var coord = this.pointToCoord(point);
        return this._radiusAxis.contain(coord[0])
            && this._angleAxis.contain(coord[1]);
    },

    /**
     * If contain data
     * @param {Array.<number>} data
     * @return {boolean}
     */
    containData: function (data) {
        return this._radiusAxis.containData(data[0])
            && this._angleAxis.containData(data[1]);
    },

    /**
     * @param {string} dim
     * @return {module:echarts/coord/polar/AngleAxis|module:echarts/coord/polar/RadiusAxis}
     */
    getAxis: function (dim) {
        return this['_' + dim + 'Axis'];
    },

    /**
     * @return {Array.<module:echarts/coord/Axis>}
     */
    getAxes: function () {
        return [this._radiusAxis, this._angleAxis];
    },

    /**
     * Get axes by type of scale
     * @param {string} scaleType
     * @return {module:echarts/coord/polar/AngleAxis|module:echarts/coord/polar/RadiusAxis}
     */
    getAxesByScale: function (scaleType) {
        var axes = [];
        var angleAxis = this._angleAxis;
        var radiusAxis = this._radiusAxis;
        angleAxis.scale.type === scaleType && axes.push(angleAxis);
        radiusAxis.scale.type === scaleType && axes.push(radiusAxis);

        return axes;
    },

    /**
     * @return {module:echarts/coord/polar/AngleAxis}
     */
    getAngleAxis: function () {
        return this._angleAxis;
    },

    /**
     * @return {module:echarts/coord/polar/RadiusAxis}
     */
    getRadiusAxis: function () {
        return this._radiusAxis;
    },

    /**
     * @param {module:echarts/coord/polar/Axis}
     * @return {module:echarts/coord/polar/Axis}
     */
    getOtherAxis: function (axis) {
        var angleAxis = this._angleAxis;
        return axis === angleAxis ? this._radiusAxis : angleAxis;
    },

    /**
     * Base axis will be used on stacking.
     *
     * @return {module:echarts/coord/polar/Axis}
     */
    getBaseAxis: function () {
        return this.getAxesByScale('ordinal')[0]
            || this.getAxesByScale('time')[0]
            || this.getAngleAxis();
    },

    /**
     * @param {string} [dim] 'radius' or 'angle' or 'auto' or null/undefined
     * @return {Object} {baseAxes: [], otherAxes: []}
     */
    getTooltipAxes: function (dim) {
        var baseAxis = (dim != null && dim !== 'auto')
            ? this.getAxis(dim) : this.getBaseAxis();
        return {
            baseAxes: [baseAxis],
            otherAxes: [this.getOtherAxis(baseAxis)]
        };
    },

    /**
     * Convert a single data item to (x, y) point.
     * Parameter data is an array which the first element is radius and the second is angle
     * @param {Array.<number>} data
     * @param {boolean} [clamp=false]
     * @return {Array.<number>}
     */
    dataToPoint: function (data, clamp) {
        return this.coordToPoint([
            this._radiusAxis.dataToRadius(data[0], clamp),
            this._angleAxis.dataToAngle(data[1], clamp)
        ]);
    },

    /**
     * Convert a (x, y) point to data
     * @param {Array.<number>} point
     * @param {boolean} [clamp=false]
     * @return {Array.<number>}
     */
    pointToData: function (point, clamp) {
        var coord = this.pointToCoord(point);
        return [
            this._radiusAxis.radiusToData(coord[0], clamp),
            this._angleAxis.angleToData(coord[1], clamp)
        ];
    },

    /**
     * Convert a (x, y) point to (radius, angle) coord
     * @param {Array.<number>} point
     * @return {Array.<number>}
     */
    pointToCoord: function (point) {
        var dx = point[0] - this.cx;
        var dy = point[1] - this.cy;
        var angleAxis = this.getAngleAxis();
        var extent = angleAxis.getExtent();
        var minAngle = Math.min(extent[0], extent[1]);
        var maxAngle = Math.max(extent[0], extent[1]);
        // Fix fixed extent in polarCreator
        // FIXME
        angleAxis.inverse
            ? (minAngle = maxAngle - 360)
            : (maxAngle = minAngle + 360);

        var radius = Math.sqrt(dx * dx + dy * dy);
        dx /= radius;
        dy /= radius;

        var radian = Math.atan2(-dy, dx) / Math.PI * 180;

        // move to angleExtent
        var dir = radian < minAngle ? 1 : -1;
        while (radian < minAngle || radian > maxAngle) {
            radian += dir * 360;
        }

        return [radius, radian];
    },

    /**
     * Convert a (radius, angle) coord to (x, y) point
     * @param {Array.<number>} coord
     * @return {Array.<number>}
     */
    coordToPoint: function (coord) {
        var radius = coord[0];
        var radian = coord[1] / 180 * Math.PI;
        var x = Math.cos(radian) * radius + this.cx;
        // Inverse the y
        var y = -Math.sin(radian) * radius + this.cy;

        return [x, y];
    }

};

export default Polar;