echarts labelGuideHelper 源码
echarts labelGuideHelper 代码
文件路径：/src/label/labelGuideHelper.ts
/*
* 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 {
Point,
Path,
Polyline
} from '../util/graphic';
import PathProxy from 'zrender/src/core/PathProxy';
import { RectLike } from 'zrender/src/core/BoundingRect';
import { normalizeRadian } from 'zrender/src/contain/util';
import { cubicProjectPoint, quadraticProjectPoint } from 'zrender/src/core/curve';
import Element from 'zrender/src/Element';
import { defaults, retrieve2 } from 'zrender/src/core/util';
import { LabelLineOption, DisplayState, StatesOptionMixin } from '../util/types';
import Model from '../model/Model';
import { invert } from 'zrender/src/core/matrix';
import * as vector from 'zrender/src/core/vector';
import { DISPLAY_STATES, SPECIAL_STATES } from '../util/states';
const PI2 = Math.PI * 2;
const CMD = PathProxy.CMD;
const DEFAULT_SEARCH_SPACE = ['top', 'right', 'bottom', 'left'] as const;
type CandidatePosition = typeof DEFAULT_SEARCH_SPACE[number];
function getCandidateAnchor(
pos: CandidatePosition,
distance: number,
rect: RectLike,
outPt: Point,
outDir: Point
) {
const width = rect.width;
const height = rect.height;
switch (pos) {
case 'top':
outPt.set(
rect.x + width / 2,
rect.y - distance
);
outDir.set(0, -1);
break;
case 'bottom':
outPt.set(
rect.x + width / 2,
rect.y + height + distance
);
outDir.set(0, 1);
break;
case 'left':
outPt.set(
rect.x - distance,
rect.y + height / 2
);
outDir.set(-1, 0);
break;
case 'right':
outPt.set(
rect.x + width + distance,
rect.y + height / 2
);
outDir.set(1, 0);
break;
}
}
function projectPointToArc(
cx: number, cy: number, r: number, startAngle: number, endAngle: number, anticlockwise: boolean,
x: number, y: number, out: number[]
): number {
x -= cx;
y -= cy;
const d = Math.sqrt(x * x + y * y);
x /= d;
y /= d;
// Intersect point.
const ox = x * r + cx;
const oy = y * r + cy;
if (Math.abs(startAngle - endAngle) % PI2 < 1e-4) {
// Is a circle
out[0] = ox;
out[1] = oy;
return d - r;
}
if (anticlockwise) {
const tmp = startAngle;
startAngle = normalizeRadian(endAngle);
endAngle = normalizeRadian(tmp);
}
else {
startAngle = normalizeRadian(startAngle);
endAngle = normalizeRadian(endAngle);
}
if (startAngle > endAngle) {
endAngle += PI2;
}
let angle = Math.atan2(y, x);
if (angle < 0) {
angle += PI2;
}
if ((angle >= startAngle && angle <= endAngle)
|| (angle + PI2 >= startAngle && angle + PI2 <= endAngle)) {
// Project point is on the arc.
out[0] = ox;
out[1] = oy;
return d - r;
}
const x1 = r * Math.cos(startAngle) + cx;
const y1 = r * Math.sin(startAngle) + cy;
const x2 = r * Math.cos(endAngle) + cx;
const y2 = r * Math.sin(endAngle) + cy;
const d1 = (x1 - x) * (x1 - x) + (y1 - y) * (y1 - y);
const d2 = (x2 - x) * (x2 - x) + (y2 - y) * (y2 - y);
if (d1 < d2) {
out[0] = x1;
out[1] = y1;
return Math.sqrt(d1);
}
else {
out[0] = x2;
out[1] = y2;
return Math.sqrt(d2);
}
}
function projectPointToLine(
x1: number, y1: number, x2: number, y2: number, x: number, y: number, out: number[], limitToEnds: boolean
) {
const dx = x - x1;
const dy = y - y1;
let dx1 = x2 - x1;
let dy1 = y2 - y1;
const lineLen = Math.sqrt(dx1 * dx1 + dy1 * dy1);
dx1 /= lineLen;
dy1 /= lineLen;
// dot product
const projectedLen = dx * dx1 + dy * dy1;
let t = projectedLen / lineLen;
if (limitToEnds) {
t = Math.min(Math.max(t, 0), 1);
}
t *= lineLen;
const ox = out[0] = x1 + t * dx1;
const oy = out[1] = y1 + t * dy1;
return Math.sqrt((ox - x) * (ox - x) + (oy - y) * (oy - y));
}
function projectPointToRect(
x1: number, y1: number, width: number, height: number, x: number, y: number, out: number[]
): number {
if (width < 0) {
x1 = x1 + width;
width = -width;
}
if (height < 0) {
y1 = y1 + height;
height = -height;
}
const x2 = x1 + width;
const y2 = y1 + height;
const ox = out[0] = Math.min(Math.max(x, x1), x2);
const oy = out[1] = Math.min(Math.max(y, y1), y2);
return Math.sqrt((ox - x) * (ox - x) + (oy - y) * (oy - y));
}
const tmpPt: number[] = [];
function nearestPointOnRect(pt: Point, rect: RectLike, out: Point) {
const dist = projectPointToRect(
rect.x, rect.y, rect.width, rect.height,
pt.x, pt.y, tmpPt
);
out.set(tmpPt[0], tmpPt[1]);
return dist;
}
/**
* Calculate min distance corresponding point.
* This method won't evaluate if point is in the path.
*/
function nearestPointOnPath(pt: Point, path: PathProxy, out: Point) {
let xi = 0;
let yi = 0;
let x0 = 0;
let y0 = 0;
let x1;
let y1;
let minDist = Infinity;
const data = path.data;
const x = pt.x;
const y = pt.y;
for (let i = 0; i < data.length;) {
const cmd = data[i++];
if (i === 1) {
xi = data[i];
yi = data[i + 1];
x0 = xi;
y0 = yi;
}
let d = minDist;
switch (cmd) {
case CMD.M:
// moveTo 命令重新创建一个新的 subpath, 并且更新新的起点
// 在 closePath 的时候使用
x0 = data[i++];
y0 = data[i++];
xi = x0;
yi = y0;
break;
case CMD.L:
d = projectPointToLine(xi, yi, data[i], data[i + 1], x, y, tmpPt, true);
xi = data[i++];
yi = data[i++];
break;
case CMD.C:
d = cubicProjectPoint(
xi, yi,
data[i++], data[i++], data[i++], data[i++], data[i], data[i + 1],
x, y, tmpPt
);
xi = data[i++];
yi = data[i++];
break;
case CMD.Q:
d = quadraticProjectPoint(
xi, yi,
data[i++], data[i++], data[i], data[i + 1],
x, y, tmpPt
);
xi = data[i++];
yi = data[i++];
break;
case CMD.A:
// TODO Arc 判断的开销比较大
const cx = data[i++];
const cy = data[i++];
const rx = data[i++];
const ry = data[i++];
const theta = data[i++];
const dTheta = data[i++];
// TODO Arc 旋转
i += 1;
const anticlockwise = !!(1 - data[i++]);
x1 = Math.cos(theta) * rx + cx;
y1 = Math.sin(theta) * ry + cy;
// 不是直接使用 arc 命令
if (i <= 1) {
// 第一个命令起点还未定义
x0 = x1;
y0 = y1;
}
// zr 使用scale来模拟椭圆, 这里也对x做一定的缩放
const _x = (x - cx) * ry / rx + cx;
d = projectPointToArc(
cx, cy, ry, theta, theta + dTheta, anticlockwise,
_x, y, tmpPt
);
xi = Math.cos(theta + dTheta) * rx + cx;
yi = Math.sin(theta + dTheta) * ry + cy;
break;
case CMD.R:
x0 = xi = data[i++];
y0 = yi = data[i++];
const width = data[i++];
const height = data[i++];
d = projectPointToRect(x0, y0, width, height, x, y, tmpPt);
break;
case CMD.Z:
d = projectPointToLine(xi, yi, x0, y0, x, y, tmpPt, true);
xi = x0;
yi = y0;
break;
}
if (d < minDist) {
minDist = d;
out.set(tmpPt[0], tmpPt[1]);
}
}
return minDist;
}
// Temporal varible for intermediate usage.
const pt0 = new Point();
const pt1 = new Point();
const pt2 = new Point();
const dir = new Point();
const dir2 = new Point();
/**
* Calculate a proper guide line based on the label position and graphic element definition
* @param label
* @param labelRect
* @param target
* @param targetRect
*/
export function updateLabelLinePoints(
target: Element,
labelLineModel: Model<LabelLineOption>
) {
if (!target) {
return;
}
const labelLine = target.getTextGuideLine();
const label = target.getTextContent();
// Needs to create text guide in each charts.
if (!(label && labelLine)) {
return;
}
const labelGuideConfig = target.textGuideLineConfig || {};
const points = [[0, 0], [0, 0], [0, 0]];
const searchSpace = labelGuideConfig.candidates || DEFAULT_SEARCH_SPACE;
const labelRect = label.getBoundingRect().clone();
labelRect.applyTransform(label.getComputedTransform());
let minDist = Infinity;
const anchorPoint = labelGuideConfig.anchor;
const targetTransform = target.getComputedTransform();
const targetInversedTransform = targetTransform && invert([], targetTransform);
const len = labelLineModel.get('length2') || 0;
if (anchorPoint) {
pt2.copy(anchorPoint);
}
for (let i = 0; i < searchSpace.length; i++) {
const candidate = searchSpace[i];
getCandidateAnchor(candidate, 0, labelRect, pt0, dir);
Point.scaleAndAdd(pt1, pt0, dir, len);
// Transform to target coord space.
pt1.transform(targetInversedTransform);
// Note: getBoundingRect will ensure the `path` being created.
const boundingRect = target.getBoundingRect();
const dist = anchorPoint ? anchorPoint.distance(pt1)
: (target instanceof Path
? nearestPointOnPath(pt1, target.path, pt2)
: nearestPointOnRect(pt1, boundingRect, pt2));
// TODO pt2 is in the path
if (dist < minDist) {
minDist = dist;
// Transform back to global space.
pt1.transform(targetTransform);
pt2.transform(targetTransform);
pt2.toArray(points[0]);
pt1.toArray(points[1]);
pt0.toArray(points[2]);
}
}
limitTurnAngle(points, labelLineModel.get('minTurnAngle'));
labelLine.setShape({ points });
}
// Temporal variable for the limitTurnAngle function
const tmpArr: number[] = [];
const tmpProjPoint = new Point();
/**
* Reduce the line segment attached to the label to limit the turn angle between two segments.
* @param linePoints
* @param minTurnAngle Radian of minimum turn angle. 0 - 180
*/
export function limitTurnAngle(linePoints: number[][], minTurnAngle: number) {
if (!(minTurnAngle <= 180 && minTurnAngle > 0)) {
return;
}
minTurnAngle = minTurnAngle / 180 * Math.PI;
// The line points can be
// /pt1----pt2 (label)
// /
// pt0/
pt0.fromArray(linePoints[0]);
pt1.fromArray(linePoints[1]);
pt2.fromArray(linePoints[2]);
Point.sub(dir, pt0, pt1);
Point.sub(dir2, pt2, pt1);
const len1 = dir.len();
const len2 = dir2.len();
if (len1 < 1e-3 || len2 < 1e-3) {
return;
}
dir.scale(1 / len1);
dir2.scale(1 / len2);
const angleCos = dir.dot(dir2);
const minTurnAngleCos = Math.cos(minTurnAngle);
if (minTurnAngleCos < angleCos) { // Smaller than minTurnAngle
// Calculate project point of pt0 on pt1-pt2
const d = projectPointToLine(pt1.x, pt1.y, pt2.x, pt2.y, pt0.x, pt0.y, tmpArr, false);
tmpProjPoint.fromArray(tmpArr);
// Calculate new projected length with limited minTurnAngle and get the new connect point
tmpProjPoint.scaleAndAdd(dir2, d / Math.tan(Math.PI - minTurnAngle));
// Limit the new calculated connect point between pt1 and pt2.
const t = pt2.x !== pt1.x
? (tmpProjPoint.x - pt1.x) / (pt2.x - pt1.x)
: (tmpProjPoint.y - pt1.y) / (pt2.y - pt1.y);
if (isNaN(t)) {
return;
}
if (t < 0) {
Point.copy(tmpProjPoint, pt1);
}
else if (t > 1) {
Point.copy(tmpProjPoint, pt2);
}
tmpProjPoint.toArray(linePoints[1]);
}
}
/**
* Limit the angle of line and the surface
* @param maxSurfaceAngle Radian of minimum turn angle. 0 - 180. 0 is same direction to normal. 180 is opposite
*/
export function limitSurfaceAngle(linePoints: vector.VectorArray[], surfaceNormal: Point, maxSurfaceAngle: number) {
if (!(maxSurfaceAngle <= 180 && maxSurfaceAngle > 0)) {
return;
}
maxSurfaceAngle = maxSurfaceAngle / 180 * Math.PI;
pt0.fromArray(linePoints[0]);
pt1.fromArray(linePoints[1]);
pt2.fromArray(linePoints[2]);
Point.sub(dir, pt1, pt0);
Point.sub(dir2, pt2, pt1);
const len1 = dir.len();
const len2 = dir2.len();
if (len1 < 1e-3 || len2 < 1e-3) {
return;
}
dir.scale(1 / len1);
dir2.scale(1 / len2);
const angleCos = dir.dot(surfaceNormal);
const maxSurfaceAngleCos = Math.cos(maxSurfaceAngle);
if (angleCos < maxSurfaceAngleCos) {
// Calculate project point of pt0 on pt1-pt2
const d = projectPointToLine(pt1.x, pt1.y, pt2.x, pt2.y, pt0.x, pt0.y, tmpArr, false);
tmpProjPoint.fromArray(tmpArr);
const HALF_PI = Math.PI / 2;
const angle2 = Math.acos(dir2.dot(surfaceNormal));
const newAngle = HALF_PI + angle2 - maxSurfaceAngle;
if (newAngle >= HALF_PI) {
// parallel
Point.copy(tmpProjPoint, pt2);
}
else {
// Calculate new projected length with limited minTurnAngle and get the new connect point
tmpProjPoint.scaleAndAdd(dir2, d / Math.tan(Math.PI / 2 - newAngle));
// Limit the new calculated connect point between pt1 and pt2.
const t = pt2.x !== pt1.x
? (tmpProjPoint.x - pt1.x) / (pt2.x - pt1.x)
: (tmpProjPoint.y - pt1.y) / (pt2.y - pt1.y);
if (isNaN(t)) {
return;
}
if (t < 0) {
Point.copy(tmpProjPoint, pt1);
}
else if (t > 1) {
Point.copy(tmpProjPoint, pt2);
}
}
tmpProjPoint.toArray(linePoints[1]);
}
}
type LabelLineModel = Model<LabelLineOption>;
function setLabelLineState(
labelLine: Polyline,
ignore: boolean,
stateName: string,
stateModel: Model
) {
const isNormal = stateName === 'normal';
const stateObj = isNormal ? labelLine : labelLine.ensureState(stateName);
// Make sure display.
stateObj.ignore = ignore;
// Set smooth
let smooth = stateModel.get('smooth');
if (smooth && smooth === true) {
smooth = 0.3;
}
stateObj.shape = stateObj.shape || {};
if (smooth > 0) {
(stateObj.shape as Polyline['shape']).smooth = smooth as number;
}
const styleObj = stateModel.getModel('lineStyle').getLineStyle();
isNormal ? labelLine.useStyle(styleObj) : stateObj.style = styleObj;
}
function buildLabelLinePath(path: CanvasRenderingContext2D, shape: Polyline['shape']) {
const smooth = shape.smooth as number;
const points = shape.points;
if (!points) {
return;
}
path.moveTo(points[0][0], points[0][1]);
if (smooth > 0 && points.length >= 3) {
const len1 = vector.dist(points[0], points[1]);
const len2 = vector.dist(points[1], points[2]);
if (!len1 || !len2) {
path.lineTo(points[1][0], points[1][1]);
path.lineTo(points[2][0], points[2][1]);
return;
}
const moveLen = Math.min(len1, len2) * smooth;
const midPoint0 = vector.lerp([], points[1], points[0], moveLen / len1);
const midPoint2 = vector.lerp([], points[1], points[2], moveLen / len2);
const midPoint1 = vector.lerp([], midPoint0, midPoint2, 0.5);
path.bezierCurveTo(midPoint0[0], midPoint0[1], midPoint0[0], midPoint0[1], midPoint1[0], midPoint1[1]);
path.bezierCurveTo(midPoint2[0], midPoint2[1], midPoint2[0], midPoint2[1], points[2][0], points[2][1]);
}
else {
for (let i = 1; i < points.length; i++) {
path.lineTo(points[i][0], points[i][1]);
}
}
}
/**
* Create a label line if necessary and set it's style.
*/
export function setLabelLineStyle(
targetEl: Element,
statesModels: Record<DisplayState, LabelLineModel>,
defaultStyle?: Polyline['style']
) {
let labelLine = targetEl.getTextGuideLine();
const label = targetEl.getTextContent();
if (!label) {
// Not show label line if there is no label.
if (labelLine) {
targetEl.removeTextGuideLine();
}
return;
}
const normalModel = statesModels.normal;
const showNormal = normalModel.get('show');
const labelIgnoreNormal = label.ignore;
for (let i = 0; i < DISPLAY_STATES.length; i++) {
const stateName = DISPLAY_STATES[i];
const stateModel = statesModels[stateName];
const isNormal = stateName === 'normal';
if (stateModel) {
const stateShow = stateModel.get('show');
const isLabelIgnored = isNormal
? labelIgnoreNormal
: retrieve2(label.states[stateName] && label.states[stateName].ignore, labelIgnoreNormal);
if (isLabelIgnored // Not show when label is not shown in this state.
|| !retrieve2(stateShow, showNormal) // Use normal state by default if not set.
) {
const stateObj = isNormal ? labelLine : (labelLine && labelLine.states[stateName]);
if (stateObj) {
stateObj.ignore = true;
}
continue;
}
// Create labelLine if not exists
if (!labelLine) {
labelLine = new Polyline();
targetEl.setTextGuideLine(labelLine);
// Reset state of normal because it's new created.
// NOTE: NORMAL should always been the first!
if (!isNormal && (labelIgnoreNormal || !showNormal)) {
setLabelLineState(labelLine, true, 'normal', statesModels.normal);
}
// Use same state proxy.
if (targetEl.stateProxy) {
labelLine.stateProxy = targetEl.stateProxy;
}
}
setLabelLineState(labelLine, false, stateName, stateModel);
}
}
if (labelLine) {
defaults(labelLine.style, defaultStyle);
// Not fill.
labelLine.style.fill = null;
const showAbove = normalModel.get('showAbove');
const labelLineConfig = (targetEl.textGuideLineConfig = targetEl.textGuideLineConfig || {});
labelLineConfig.showAbove = showAbove || false;
// Custom the buildPath.
labelLine.buildPath = buildLabelLinePath;
}
}
export function getLabelLineStatesModels<LabelName extends string = 'labelLine'>(
itemModel: Model<StatesOptionMixin<any, any> & Partial<Record<LabelName, any>>>,
labelLineName?: LabelName
): Record<DisplayState, LabelLineModel> {
labelLineName = (labelLineName || 'labelLine') as LabelName;
const statesModels = {
normal: itemModel.getModel(labelLineName) as LabelLineModel
} as Record<DisplayState, LabelLineModel>;
for (let i = 0; i < SPECIAL_STATES.length; i++) {
const stateName = SPECIAL_STATES[i];
statesModels[stateName] = itemModel.getModel([stateName, labelLineName]);
}
return statesModels;
}
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