calc.js

/**
* Copyright 2012-2018, Plotly, Inc.
* All rights reserved.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/

'use strict';

var isNumeric = require('fast-isnumeric');

var Lib = require('../../lib');
var Axes = require('../../plots/cartesian/axes');
var BADNUM = require('../../constants/numerical').BADNUM;

var subTypes = require('./subtypes');
var calcColorscale = require('./colorscale_calc');
var arraysToCalcdata = require('./arrays_to_calcdata');
var calcSelection = require('./calc_selection');

function calc(gd, trace) {
    var xa = Axes.getFromId(gd, trace.xaxis || 'x');
    var ya = Axes.getFromId(gd, trace.yaxis || 'y');
    var x = xa.makeCalcdata(trace, 'x');
    var y = ya.makeCalcdata(trace, 'y');
    var serieslen = trace._length;
    var cd = new Array(serieslen);

    var ppad = calcMarkerSize(trace, serieslen);
    calcAxisExpansion(gd, trace, xa, ya, x, y, ppad);

    for(var i = 0; i < serieslen; i++) {
        cd[i] = (isNumeric(x[i]) && isNumeric(y[i])) ?
            {x: x[i], y: y[i]} :
            {x: BADNUM, y: BADNUM};

        if(trace.ids) {
            cd[i].id = String(trace.ids[i]);
        }
    }

    arraysToCalcdata(cd, trace);
    calcColorscale(trace);
    calcSelection(cd, trace);

    gd.firstscatter = false;
    return cd;
}

function calcAxisExpansion(gd, trace, xa, ya, x, y, ppad) {
    var serieslen = trace._length;

    // cancel minimum tick spacings (only applies to bars and boxes)
    xa._minDtick = 0;
    ya._minDtick = 0;

    // check whether bounds should be tight, padded, extended to zero...
    // most cases both should be padded on both ends, so start with that.
    var xOptions = {padded: true};
    var yOptions = {padded: true};

    if(ppad) {
        xOptions.ppad = yOptions.ppad = ppad;
    }

    // TODO: text size

    // include zero (tight) and extremes (padded) if fill to zero
    // (unless the shape is closed, then it's just filling the shape regardless)
    if(((trace.fill === 'tozerox') ||
            ((trace.fill === 'tonextx') && gd.firstscatter)) &&
            ((x[0] !== x[serieslen - 1]) || (y[0] !== y[serieslen - 1]))) {
        xOptions.tozero = true;
    }

    // if no error bars, markers or text, or fill to y=0 remove x padding
    else if(!trace.error_y.visible && (
            ['tonexty', 'tozeroy'].indexOf(trace.fill) !== -1 ||
            (!subTypes.hasMarkers(trace) && !subTypes.hasText(trace))
        )) {
        xOptions.padded = false;
        xOptions.ppad = 0;
    }

    // now check for y - rather different logic, though still mostly padded both ends
    // include zero (tight) and extremes (padded) if fill to zero
    // (unless the shape is closed, then it's just filling the shape regardless)
    if(((trace.fill === 'tozeroy') || ((trace.fill === 'tonexty') && gd.firstscatter)) &&
            ((x[0] !== x[serieslen - 1]) || (y[0] !== y[serieslen - 1]))) {
        yOptions.tozero = true;
    }

    // tight y: any x fill
    else if(['tonextx', 'tozerox'].indexOf(trace.fill) !== -1) {
        yOptions.padded = false;
    }

    Axes.expand(xa, x, xOptions);
    Axes.expand(ya, y, yOptions);
}

function calcMarkerSize(trace, serieslen) {
    if(!subTypes.hasMarkers(trace)) return;

    // Treat size like x or y arrays --- Run d2c
    // this needs to go before ppad computation
    var marker = trace.marker;
    var sizeref = 1.6 * (trace.marker.sizeref || 1);
    var markerTrans;

    if(trace.marker.sizemode === 'area') {
        markerTrans = function(v) {
            return Math.max(Math.sqrt((v || 0) / sizeref), 3);
        };
    } else {
        markerTrans = function(v) {
            return Math.max((v || 0) / sizeref, 3);
        };
    }

    if(Lib.isArrayOrTypedArray(marker.size)) {
        // I tried auto-type but category and dates dont make much sense.
        var ax = {type: 'linear'};
        Axes.setConvert(ax);

        var s = ax.makeCalcdata(trace.marker, 'size');

        var sizeOut = new Array(serieslen);
        for(var i = 0; i < serieslen; i++) {
            sizeOut[i] = markerTrans(s[i]);
        }
        return sizeOut;

    } else {
        return markerTrans(marker.size);
    }
}

module.exports = {
    calc: calc,
    calcMarkerSize: calcMarkerSize,
    calcAxisExpansion: calcAxisExpansion
};