src/coord/axisTickLabelBuilder.ts - echarts - Git at Google

 /*
 * 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.
 */

 import * as zrUtil from 'zrender/src/core/util';
 import * as textContain from 'zrender/src/contain/text';
 import {makeInner} from '../util/model';
 import {
     makeLabelFormatter,
     getOptionCategoryInterval,
     shouldShowAllLabels
 } from './axisHelper';
 import Axis from './Axis';
 import Model from '../model/Model';
 import { AxisBaseOption } from './axisCommonTypes';
 import OrdinalScale from '../scale/Ordinal';
 import { AxisBaseModel } from './AxisBaseModel';
 import type Axis2D from './cartesian/Axis2D';

 type CacheKey = string | number;

 type InnerTickLabelCache<T> = {
     key: CacheKey
     value: T
 }[];

 interface InnerLabelCachedVal {
     labels: MakeLabelsResultObj[]
     labelCategoryInterval?: number
 }
 interface InnerTickCachedVal {
     ticks: number[]
     tickCategoryInterval?: number
 }

 type InnerStore = {
     labels: InnerTickLabelCache<InnerLabelCachedVal>
     ticks: InnerTickLabelCache<InnerTickCachedVal>
     autoInterval: number
     lastAutoInterval: number
     lastTickCount: number
     axisExtent0: number
     axisExtent1: number
 };

 const inner = makeInner<InnerStore, any>();

 export function createAxisLabels(axis: Axis): {
     labels: {
         level?: number,
         formattedLabel: string,
         rawLabel: string,
         tickValue: number
     }[],
     labelCategoryInterval?: number
 } {
     // Only ordinal scale support tick interval
     return axis.type === 'category'
         ? makeCategoryLabels(axis)
         : makeRealNumberLabels(axis);
 }

 /**
  * @param {module:echats/coord/Axis} axis
  * @param {module:echarts/model/Model} tickModel For example, can be axisTick, splitLine, splitArea.
  * @return {Object} {
  *     ticks: Array.<number>
  *     tickCategoryInterval: number
  * }
  */
 export function createAxisTicks(axis: Axis, tickModel: AxisBaseModel): {
     ticks: number[],
     tickCategoryInterval?: number
 } {
     // Only ordinal scale support tick interval
     return axis.type === 'category'
         ? makeCategoryTicks(axis, tickModel)
         : {ticks: zrUtil.map(axis.scale.getTicks(), tick => tick.value) };
 }

 function makeCategoryLabels(axis: Axis) {
     const labelModel = axis.getLabelModel();
     const result = makeCategoryLabelsActually(axis, labelModel);

     return (!labelModel.get('show') || axis.scale.isBlank())
         ? {labels: [], labelCategoryInterval: result.labelCategoryInterval}
         : result;
 }

 function makeCategoryLabelsActually(axis: Axis, labelModel: Model<AxisBaseOption['axisLabel']>) {
     const labelsCache = getListCache(axis, 'labels');
     const optionLabelInterval = getOptionCategoryInterval(labelModel);
     const result = listCacheGet(labelsCache, optionLabelInterval as CacheKey);

     if (result) {
         return result;
     }

     let labels;
     let numericLabelInterval;

     if (zrUtil.isFunction(optionLabelInterval)) {
         labels = makeLabelsByCustomizedCategoryInterval(axis, optionLabelInterval);
     }
     else {
         numericLabelInterval = optionLabelInterval === 'auto'
             ? makeAutoCategoryInterval(axis) : optionLabelInterval;
         labels = makeLabelsByNumericCategoryInterval(axis, numericLabelInterval);
     }

     // Cache to avoid calling interval function repeatedly.
     return listCacheSet(labelsCache, optionLabelInterval as CacheKey, {
         labels: labels, labelCategoryInterval: numericLabelInterval
     });
 }

 function makeCategoryTicks(axis: Axis, tickModel: AxisBaseModel) {
     const ticksCache = getListCache(axis, 'ticks');
     const optionTickInterval = getOptionCategoryInterval(tickModel);
     const result = listCacheGet(ticksCache, optionTickInterval as CacheKey);

     if (result) {
         return result;
     }

     let ticks: number[];
     let tickCategoryInterval;

     // Optimize for the case that large category data and no label displayed,
     // we should not return all ticks.
     if (!tickModel.get('show') || axis.scale.isBlank()) {
         ticks = [];
     }

     if (zrUtil.isFunction(optionTickInterval)) {
         ticks = makeLabelsByCustomizedCategoryInterval(axis, optionTickInterval, true);
     }
     // Always use label interval by default despite label show. Consider this
     // scenario, Use multiple grid with the xAxis sync, and only one xAxis shows
     // labels. `splitLine` and `axisTick` should be consistent in this case.
     else if (optionTickInterval === 'auto') {
         const labelsResult = makeCategoryLabelsActually(axis, axis.getLabelModel());
         tickCategoryInterval = labelsResult.labelCategoryInterval;
         ticks = zrUtil.map(labelsResult.labels, function (labelItem) {
             return labelItem.tickValue;
         });
     }
     else {
         tickCategoryInterval = optionTickInterval;
         ticks = makeLabelsByNumericCategoryInterval(axis, tickCategoryInterval, true);
     }

     // Cache to avoid calling interval function repeatedly.
     return listCacheSet(ticksCache, optionTickInterval as CacheKey, {
         ticks: ticks, tickCategoryInterval: tickCategoryInterval
     });
 }

 function makeRealNumberLabels(axis: Axis) {
     const ticks = axis.scale.getTicks();
     const labelFormatter = makeLabelFormatter(axis);
     return {
         labels: zrUtil.map(ticks, function (tick, idx) {
             return {
                 level: tick.level,
                 formattedLabel: labelFormatter(tick, idx),
                 rawLabel: axis.scale.getLabel(tick),
                 tickValue: tick.value
             };
         })
     };
 }

 // Large category data calculation is performance sensitive, and ticks and label
 // probably will be fetched multiple times. So we cache the result.
 // axis is created each time during a ec process, so we do not need to clear cache.
 function getListCache(axis: Axis, prop: 'ticks'): InnerStore['ticks'];
 function getListCache(axis: Axis, prop: 'labels'): InnerStore['labels'];
 function getListCache(axis: Axis, prop: 'ticks' | 'labels') {
     // Because key can be a function, and cache size always is small, we use array cache.
     return inner(axis)[prop] || (inner(axis)[prop] = []);
 }

 function listCacheGet<T>(cache: InnerTickLabelCache<T>, key: CacheKey): T {
     for (let i = 0; i < cache.length; i++) {
         if (cache[i].key === key) {
             return cache[i].value;
         }
     }
 }

 function listCacheSet<T>(cache: InnerTickLabelCache<T>, key: CacheKey, value: T): T {
     cache.push({key: key, value: value});
     return value;
 }

 function makeAutoCategoryInterval(axis: Axis) {
     const result = inner(axis).autoInterval;
     return result != null
         ? result
         : (inner(axis).autoInterval = axis.calculateCategoryInterval());
 }

 /**
  * Calculate interval for category axis ticks and labels.
  * To get precise result, at least one of `getRotate` and `isHorizontal`
  * should be implemented in axis.
  */
 export function calculateCategoryInterval(axis: Axis) {
     const params = fetchAutoCategoryIntervalCalculationParams(axis);
     const labelFormatter = makeLabelFormatter(axis);
     const rotation = (params.axisRotate - params.labelRotate) / 180 * Math.PI;

     const ordinalScale = axis.scale as OrdinalScale;
     const ordinalExtent = ordinalScale.getExtent();
     // Providing this method is for optimization:
     // avoid generating a long array by `getTicks`
     // in large category data case.
     const tickCount = ordinalScale.count();

     if (ordinalExtent[1] - ordinalExtent[0] < 1) {
         return 0;
     }

     let step = 1;
     // Simple optimization. Empirical value: tick count should less than 40.
     if (tickCount > 40) {
         step = Math.max(1, Math.floor(tickCount / 40));
     }
     let tickValue = ordinalExtent[0];
     const unitSpan = axis.dataToCoord(tickValue + 1) - axis.dataToCoord(tickValue);
     const unitW = Math.abs(unitSpan * Math.cos(rotation));
     const unitH = Math.abs(unitSpan * Math.sin(rotation));

     let maxW = 0;
     let maxH = 0;

     // Caution: Performance sensitive for large category data.
     // Consider dataZoom, we should make appropriate step to avoid O(n) loop.
     for (; tickValue <= ordinalExtent[1]; tickValue += step) {
         let width = 0;
         let height = 0;

         // Not precise, do not consider align and vertical align
         // and each distance from axis line yet.
         const rect = textContain.getBoundingRect(
             labelFormatter({ value: tickValue }), params.font, 'center', 'top'
         );
         // Magic number
         width = rect.width * 1.3;
         height = rect.height * 1.3;

         // Min size, void long loop.
         maxW = Math.max(maxW, width, 7);
         maxH = Math.max(maxH, height, 7);
     }

     let dw = maxW / unitW;
     let dh = maxH / unitH;
     // 0/0 is NaN, 1/0 is Infinity.
     isNaN(dw) && (dw = Infinity);
     isNaN(dh) && (dh = Infinity);
     let interval = Math.max(0, Math.floor(Math.min(dw, dh)));

     const cache = inner(axis.model);
     const axisExtent = axis.getExtent();
     const lastAutoInterval = cache.lastAutoInterval;
     const lastTickCount = cache.lastTickCount;

     // Use cache to keep interval stable while moving zoom window,
     // otherwise the calculated interval might jitter when the zoom
     // window size is close to the interval-changing size.
     // For example, if all of the axis labels are `a, b, c, d, e, f, g`.
     // The jitter will cause that sometimes the displayed labels are
     // `a, d, g` (interval: 2) sometimes `a, c, e`(interval: 1).
     if (lastAutoInterval != null
         && lastTickCount != null
         && Math.abs(lastAutoInterval - interval) <= 1
         && Math.abs(lastTickCount - tickCount) <= 1
         // Always choose the bigger one, otherwise the critical
         // point is not the same when zooming in or zooming out.
         && lastAutoInterval > interval
         // If the axis change is caused by chart resize, the cache should not
         // be used. Otherwise some hidden labels might not be shown again.
         && cache.axisExtent0 === axisExtent[0]
         && cache.axisExtent1 === axisExtent[1]
     ) {
         interval = lastAutoInterval;
     }
     // Only update cache if cache not used, otherwise the
     // changing of interval is too insensitive.
     else {
         cache.lastTickCount = tickCount;
         cache.lastAutoInterval = interval;
         cache.axisExtent0 = axisExtent[0];
         cache.axisExtent1 = axisExtent[1];
     }

     return interval;
 }

 function fetchAutoCategoryIntervalCalculationParams(axis: Axis) {
     const labelModel = axis.getLabelModel();
     return {
         axisRotate: axis.getRotate
             ? axis.getRotate()
             : ((axis as Axis2D).isHorizontal && !(axis as Axis2D).isHorizontal())
             ? 90
             : 0,
         labelRotate: labelModel.get('rotate') || 0,
         font: labelModel.getFont()
     };
 }

 interface MakeLabelsResultObj {
     formattedLabel: string
     rawLabel: string
     tickValue: number
 }

 function makeLabelsByNumericCategoryInterval(axis: Axis, categoryInterval: number): MakeLabelsResultObj[];
 /* eslint-disable-next-line */
 function makeLabelsByNumericCategoryInterval(axis: Axis, categoryInterval: number, onlyTick: false): MakeLabelsResultObj[];
 function makeLabelsByNumericCategoryInterval(axis: Axis, categoryInterval: number, onlyTick: true): number[];
 function makeLabelsByNumericCategoryInterval(axis: Axis, categoryInterval: number, onlyTick?: boolean) {
     const labelFormatter = makeLabelFormatter(axis);
     const ordinalScale = axis.scale as OrdinalScale;
     const ordinalExtent = ordinalScale.getExtent();
     const labelModel = axis.getLabelModel();
     const result: (MakeLabelsResultObj | number)[] = [];

     // TODO: axisType: ordinalTime, pick the tick from each month/day/year/...

     const step = Math.max((categoryInterval || 0) + 1, 1);
     let startTick = ordinalExtent[0];
     const tickCount = ordinalScale.count();

     // Calculate start tick based on zero if possible to keep label consistent
     // while zooming and moving while interval > 0. Otherwise the selection
     // of displayable ticks and symbols probably keep changing.
     // 3 is empirical value.
     if (startTick !== 0 && step > 1 && tickCount / step > 2) {
         startTick = Math.round(Math.ceil(startTick / step) * step);
     }

     // (1) Only add min max label here but leave overlap checking
     // to render stage, which also ensure the returned list
     // suitable for splitLine and splitArea rendering.
     // (2) Scales except category always contain min max label so
     // do not need to perform this process.
     const showAllLabel = shouldShowAllLabels(axis);
     const includeMinLabel = labelModel.get('showMinLabel') || showAllLabel;
     const includeMaxLabel = labelModel.get('showMaxLabel') || showAllLabel;

     if (includeMinLabel && startTick !== ordinalExtent[0]) {
         addItem(ordinalExtent[0]);
     }

     // Optimize: avoid generating large array by `ordinalScale.getTicks()`.
     let tickValue = startTick;
     for (; tickValue <= ordinalExtent[1]; tickValue += step) {
         addItem(tickValue);
     }

     if (includeMaxLabel && tickValue - step !== ordinalExtent[1]) {
         addItem(ordinalExtent[1]);
     }

     function addItem(tickValue: number) {
         const tickObj = { value: tickValue };
         result.push(onlyTick
             ? tickValue
             : {
                 formattedLabel: labelFormatter(tickObj),
                 rawLabel: ordinalScale.getLabel(tickObj),
                 tickValue: tickValue
             }
         );
     }

     return result;
 }

 type CategoryIntervalCb = (tickVal: number, rawLabel: string) => boolean;

 // When interval is function, the result `false` means ignore the tick.
 // It is time consuming for large category data.
 /* eslint-disable-next-line */
 function makeLabelsByCustomizedCategoryInterval(axis: Axis, categoryInterval: CategoryIntervalCb): MakeLabelsResultObj[];
 /* eslint-disable-next-line */
 function makeLabelsByCustomizedCategoryInterval(axis: Axis, categoryInterval: CategoryIntervalCb, onlyTick: false): MakeLabelsResultObj[];
 /* eslint-disable-next-line */
 function makeLabelsByCustomizedCategoryInterval(axis: Axis, categoryInterval: CategoryIntervalCb, onlyTick: true): number[];
 function makeLabelsByCustomizedCategoryInterval(axis: Axis, categoryInterval: CategoryIntervalCb, onlyTick?: boolean) {
     const ordinalScale = axis.scale;
     const labelFormatter = makeLabelFormatter(axis);
     const result: (MakeLabelsResultObj | number)[] = [];

     zrUtil.each(ordinalScale.getTicks(), function (tick) {
         const rawLabel = ordinalScale.getLabel(tick);
         const tickValue = tick.value;
         if (categoryInterval(tick.value, rawLabel)) {
             result.push(
                 onlyTick
                 ? tickValue
                 : {
                     formattedLabel: labelFormatter(tick),
                     rawLabel: rawLabel,
                     tickValue: tickValue
                 }
             );
         }
     });

     return result;
 }
	/*
	* 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.
	*/

	import * as zrUtil from 'zrender/src/core/util';
	import * as textContain from 'zrender/src/contain/text';
	import {makeInner} from '../util/model';
	import {
	makeLabelFormatter,
	getOptionCategoryInterval,
	shouldShowAllLabels
	} from './axisHelper';
	import Axis from './Axis';
	import Model from '../model/Model';
	import { AxisBaseOption } from './axisCommonTypes';
	import OrdinalScale from '../scale/Ordinal';
	import { AxisBaseModel } from './AxisBaseModel';
	import type Axis2D from './cartesian/Axis2D';

	type CacheKey = string \| number;

	type InnerTickLabelCache<T> = {
	key: CacheKey
	value: T
	}[];

	interface InnerLabelCachedVal {
	labels: MakeLabelsResultObj[]
	labelCategoryInterval?: number
	}
	interface InnerTickCachedVal {
	ticks: number[]
	tickCategoryInterval?: number
	}

	type InnerStore = {
	labels: InnerTickLabelCache<InnerLabelCachedVal>
	ticks: InnerTickLabelCache<InnerTickCachedVal>
	autoInterval: number
	lastAutoInterval: number
	lastTickCount: number
	axisExtent0: number
	axisExtent1: number
	};

	const inner = makeInner<InnerStore, any>();

	export function createAxisLabels(axis: Axis): {
	labels: {
	level?: number,
	formattedLabel: string,
	rawLabel: string,
	tickValue: number
	}[],
	labelCategoryInterval?: number
	} {
	// Only ordinal scale support tick interval
	return axis.type === 'category'
	? makeCategoryLabels(axis)
	: makeRealNumberLabels(axis);
	}

	/**
	* @param {module:echats/coord/Axis} axis
	* @param {module:echarts/model/Model} tickModel For example, can be axisTick, splitLine, splitArea.
	* @return {Object} {
	* ticks: Array.<number>
	* tickCategoryInterval: number
	* }
	*/
	export function createAxisTicks(axis: Axis, tickModel: AxisBaseModel): {
	ticks: number[],
	tickCategoryInterval?: number
	} {
	// Only ordinal scale support tick interval
	return axis.type === 'category'
	? makeCategoryTicks(axis, tickModel)
	: {ticks: zrUtil.map(axis.scale.getTicks(), tick => tick.value) };
	}

	function makeCategoryLabels(axis: Axis) {
	const labelModel = axis.getLabelModel();
	const result = makeCategoryLabelsActually(axis, labelModel);

	return (!labelModel.get('show') \|\| axis.scale.isBlank())
	? {labels: [], labelCategoryInterval: result.labelCategoryInterval}
	: result;
	}

	function makeCategoryLabelsActually(axis: Axis, labelModel: Model<AxisBaseOption['axisLabel']>) {
	const labelsCache = getListCache(axis, 'labels');
	const optionLabelInterval = getOptionCategoryInterval(labelModel);
	const result = listCacheGet(labelsCache, optionLabelInterval as CacheKey);

	if (result) {
	return result;
	}

	let labels;
	let numericLabelInterval;

	if (zrUtil.isFunction(optionLabelInterval)) {
	labels = makeLabelsByCustomizedCategoryInterval(axis, optionLabelInterval);
	}
	else {
	numericLabelInterval = optionLabelInterval === 'auto'
	? makeAutoCategoryInterval(axis) : optionLabelInterval;
	labels = makeLabelsByNumericCategoryInterval(axis, numericLabelInterval);
	}

	// Cache to avoid calling interval function repeatedly.
	return listCacheSet(labelsCache, optionLabelInterval as CacheKey, {
	labels: labels, labelCategoryInterval: numericLabelInterval
	});
	}

	function makeCategoryTicks(axis: Axis, tickModel: AxisBaseModel) {
	const ticksCache = getListCache(axis, 'ticks');
	const optionTickInterval = getOptionCategoryInterval(tickModel);
	const result = listCacheGet(ticksCache, optionTickInterval as CacheKey);

	if (result) {
	return result;
	}

	let ticks: number[];
	let tickCategoryInterval;

	// Optimize for the case that large category data and no label displayed,
	// we should not return all ticks.
	if (!tickModel.get('show') \|\| axis.scale.isBlank()) {
	ticks = [];
	}

	if (zrUtil.isFunction(optionTickInterval)) {
	ticks = makeLabelsByCustomizedCategoryInterval(axis, optionTickInterval, true);
	}
	// Always use label interval by default despite label show. Consider this
	// scenario, Use multiple grid with the xAxis sync, and only one xAxis shows
	// labels. `splitLine` and `axisTick` should be consistent in this case.
	else if (optionTickInterval === 'auto') {
	const labelsResult = makeCategoryLabelsActually(axis, axis.getLabelModel());
	tickCategoryInterval = labelsResult.labelCategoryInterval;
	ticks = zrUtil.map(labelsResult.labels, function (labelItem) {
	return labelItem.tickValue;
	});
	}
	else {
	tickCategoryInterval = optionTickInterval;
	ticks = makeLabelsByNumericCategoryInterval(axis, tickCategoryInterval, true);
	}

	// Cache to avoid calling interval function repeatedly.
	return listCacheSet(ticksCache, optionTickInterval as CacheKey, {
	ticks: ticks, tickCategoryInterval: tickCategoryInterval
	});
	}

	function makeRealNumberLabels(axis: Axis) {
	const ticks = axis.scale.getTicks();
	const labelFormatter = makeLabelFormatter(axis);
	return {
	labels: zrUtil.map(ticks, function (tick, idx) {
	return {
	level: tick.level,
	formattedLabel: labelFormatter(tick, idx),
	rawLabel: axis.scale.getLabel(tick),
	tickValue: tick.value
	};
	})
	};
	}

	// Large category data calculation is performance sensitive, and ticks and label
	// probably will be fetched multiple times. So we cache the result.
	// axis is created each time during a ec process, so we do not need to clear cache.
	function getListCache(axis: Axis, prop: 'ticks'): InnerStore['ticks'];
	function getListCache(axis: Axis, prop: 'labels'): InnerStore['labels'];
	function getListCache(axis: Axis, prop: 'ticks' \| 'labels') {
	// Because key can be a function, and cache size always is small, we use array cache.
	return inner(axis)[prop] \|\| (inner(axis)[prop] = []);
	}

	function listCacheGet<T>(cache: InnerTickLabelCache<T>, key: CacheKey): T {
	for (let i = 0; i < cache.length; i++) {
	if (cache[i].key === key) {
	return cache[i].value;
	}
	}
	}

	function listCacheSet<T>(cache: InnerTickLabelCache<T>, key: CacheKey, value: T): T {
	cache.push({key: key, value: value});
	return value;
	}

	function makeAutoCategoryInterval(axis: Axis) {
	const result = inner(axis).autoInterval;
	return result != null
	? result
	: (inner(axis).autoInterval = axis.calculateCategoryInterval());
	}

	/**
	* Calculate interval for category axis ticks and labels.
	* To get precise result, at least one of `getRotate` and `isHorizontal`
	* should be implemented in axis.
	*/
	export function calculateCategoryInterval(axis: Axis) {
	const params = fetchAutoCategoryIntervalCalculationParams(axis);
	const labelFormatter = makeLabelFormatter(axis);
	const rotation = (params.axisRotate - params.labelRotate) / 180 * Math.PI;

	const ordinalScale = axis.scale as OrdinalScale;
	const ordinalExtent = ordinalScale.getExtent();
	// Providing this method is for optimization:
	// avoid generating a long array by `getTicks`
	// in large category data case.
	const tickCount = ordinalScale.count();

	if (ordinalExtent[1] - ordinalExtent[0] < 1) {
	return 0;
	}

	let step = 1;
	// Simple optimization. Empirical value: tick count should less than 40.
	if (tickCount > 40) {
	step = Math.max(1, Math.floor(tickCount / 40));
	}
	let tickValue = ordinalExtent[0];
	const unitSpan = axis.dataToCoord(tickValue + 1) - axis.dataToCoord(tickValue);
	const unitW = Math.abs(unitSpan * Math.cos(rotation));
	const unitH = Math.abs(unitSpan * Math.sin(rotation));

	let maxW = 0;
	let maxH = 0;

	// Caution: Performance sensitive for large category data.
	// Consider dataZoom, we should make appropriate step to avoid O(n) loop.
	for (; tickValue <= ordinalExtent[1]; tickValue += step) {
	let width = 0;
	let height = 0;

	// Not precise, do not consider align and vertical align
	// and each distance from axis line yet.
	const rect = textContain.getBoundingRect(
	labelFormatter({ value: tickValue }), params.font, 'center', 'top'
	);
	// Magic number
	width = rect.width * 1.3;
	height = rect.height * 1.3;

	// Min size, void long loop.
	maxW = Math.max(maxW, width, 7);
	maxH = Math.max(maxH, height, 7);
	}

	let dw = maxW / unitW;
	let dh = maxH / unitH;
	// 0/0 is NaN, 1/0 is Infinity.
	isNaN(dw) && (dw = Infinity);
	isNaN(dh) && (dh = Infinity);
	let interval = Math.max(0, Math.floor(Math.min(dw, dh)));

	const cache = inner(axis.model);
	const axisExtent = axis.getExtent();
	const lastAutoInterval = cache.lastAutoInterval;
	const lastTickCount = cache.lastTickCount;

	// Use cache to keep interval stable while moving zoom window,
	// otherwise the calculated interval might jitter when the zoom
	// window size is close to the interval-changing size.
	// For example, if all of the axis labels are `a, b, c, d, e, f, g`.
	// The jitter will cause that sometimes the displayed labels are
	// `a, d, g` (interval: 2) sometimes `a, c, e`(interval: 1).
	if (lastAutoInterval != null
	&& lastTickCount != null
	&& Math.abs(lastAutoInterval - interval) <= 1
	&& Math.abs(lastTickCount - tickCount) <= 1
	// Always choose the bigger one, otherwise the critical
	// point is not the same when zooming in or zooming out.
	&& lastAutoInterval > interval
	// If the axis change is caused by chart resize, the cache should not
	// be used. Otherwise some hidden labels might not be shown again.
	&& cache.axisExtent0 === axisExtent[0]
	&& cache.axisExtent1 === axisExtent[1]
	) {
	interval = lastAutoInterval;
	}
	// Only update cache if cache not used, otherwise the
	// changing of interval is too insensitive.
	else {
	cache.lastTickCount = tickCount;
	cache.lastAutoInterval = interval;
	cache.axisExtent0 = axisExtent[0];
	cache.axisExtent1 = axisExtent[1];
	}

	return interval;
	}

	function fetchAutoCategoryIntervalCalculationParams(axis: Axis) {
	const labelModel = axis.getLabelModel();
	return {
	axisRotate: axis.getRotate
	? axis.getRotate()
	: ((axis as Axis2D).isHorizontal && !(axis as Axis2D).isHorizontal())
	? 90
	: 0,
	labelRotate: labelModel.get('rotate') \|\| 0,
	font: labelModel.getFont()
	};
	}

	interface MakeLabelsResultObj {
	formattedLabel: string
	rawLabel: string
	tickValue: number
	}

	function makeLabelsByNumericCategoryInterval(axis: Axis, categoryInterval: number): MakeLabelsResultObj[];
	/* eslint-disable-next-line */
	function makeLabelsByNumericCategoryInterval(axis: Axis, categoryInterval: number, onlyTick: false): MakeLabelsResultObj[];
	function makeLabelsByNumericCategoryInterval(axis: Axis, categoryInterval: number, onlyTick: true): number[];
	function makeLabelsByNumericCategoryInterval(axis: Axis, categoryInterval: number, onlyTick?: boolean) {
	const labelFormatter = makeLabelFormatter(axis);
	const ordinalScale = axis.scale as OrdinalScale;
	const ordinalExtent = ordinalScale.getExtent();
	const labelModel = axis.getLabelModel();
	const result: (MakeLabelsResultObj \| number)[] = [];

	// TODO: axisType: ordinalTime, pick the tick from each month/day/year/...

	const step = Math.max((categoryInterval \|\| 0) + 1, 1);
	let startTick = ordinalExtent[0];
	const tickCount = ordinalScale.count();

	// Calculate start tick based on zero if possible to keep label consistent
	// while zooming and moving while interval > 0. Otherwise the selection
	// of displayable ticks and symbols probably keep changing.
	// 3 is empirical value.
	if (startTick !== 0 && step > 1 && tickCount / step > 2) {
	startTick = Math.round(Math.ceil(startTick / step) * step);
	}

	// (1) Only add min max label here but leave overlap checking
	// to render stage, which also ensure the returned list
	// suitable for splitLine and splitArea rendering.
	// (2) Scales except category always contain min max label so
	// do not need to perform this process.
	const showAllLabel = shouldShowAllLabels(axis);
	const includeMinLabel = labelModel.get('showMinLabel') \|\| showAllLabel;
	const includeMaxLabel = labelModel.get('showMaxLabel') \|\| showAllLabel;

	if (includeMinLabel && startTick !== ordinalExtent[0]) {
	addItem(ordinalExtent[0]);
	}

	// Optimize: avoid generating large array by `ordinalScale.getTicks()`.
	let tickValue = startTick;
	for (; tickValue <= ordinalExtent[1]; tickValue += step) {
	addItem(tickValue);
	}

	if (includeMaxLabel && tickValue - step !== ordinalExtent[1]) {
	addItem(ordinalExtent[1]);
	}

	function addItem(tickValue: number) {
	const tickObj = { value: tickValue };
	result.push(onlyTick
	? tickValue
	: {
	formattedLabel: labelFormatter(tickObj),
	rawLabel: ordinalScale.getLabel(tickObj),
	tickValue: tickValue
	}
	);
	}

	return result;
	}

	type CategoryIntervalCb = (tickVal: number, rawLabel: string) => boolean;

	// When interval is function, the result `false` means ignore the tick.
	// It is time consuming for large category data.
	/* eslint-disable-next-line */
	function makeLabelsByCustomizedCategoryInterval(axis: Axis, categoryInterval: CategoryIntervalCb): MakeLabelsResultObj[];
	/* eslint-disable-next-line */
	function makeLabelsByCustomizedCategoryInterval(axis: Axis, categoryInterval: CategoryIntervalCb, onlyTick: false): MakeLabelsResultObj[];
	/* eslint-disable-next-line */
	function makeLabelsByCustomizedCategoryInterval(axis: Axis, categoryInterval: CategoryIntervalCb, onlyTick: true): number[];
	function makeLabelsByCustomizedCategoryInterval(axis: Axis, categoryInterval: CategoryIntervalCb, onlyTick?: boolean) {
	const ordinalScale = axis.scale;
	const labelFormatter = makeLabelFormatter(axis);
	const result: (MakeLabelsResultObj \| number)[] = [];

	zrUtil.each(ordinalScale.getTicks(), function (tick) {
	const rawLabel = ordinalScale.getLabel(tick);
	const tickValue = tick.value;
	if (categoryInterval(tick.value, rawLabel)) {
	result.push(
	onlyTick
	? tickValue
	: {
	formattedLabel: labelFormatter(tick),
	rawLabel: rawLabel,
	tickValue: tickValue
	}
	);
	}
	});

	return result;
	}