@antv/g2
Version:
the Grammar of Graphics in Javascript
203 lines • 6.89 kB
JavaScript
import { each, isEmpty, isNumber, isNumberEqual, max, min } from '@antv/util';
// 获取图形的包围盒
function getPointsBox(points) {
if (isEmpty(points)) {
return null;
}
var minX = points[0].x;
var maxX = points[0].x;
var minY = points[0].y;
var maxY = points[0].y;
each(points, function (point) {
minX = minX > point.x ? point.x : minX;
maxX = maxX < point.x ? point.x : maxX;
minY = minY > point.y ? point.y : minY;
maxY = maxY < point.y ? point.y : maxY;
});
return {
minX: minX,
maxX: maxX,
minY: minY,
maxY: maxY,
centerX: (minX + maxX) / 2,
centerY: (minY + maxY) / 2,
};
}
function uniqueValues(array) {
return Array.from(new Set(array)).length === 1;
}
function mid(array) {
return (min(array) + max(array)) / 2;
}
/**
* @ignore
* 根据弧度计算极坐标系下的坐标点
* @param centerX
* @param centerY
* @param radius
* @param angleInRadian
* @returns
*/
export function polarToCartesian(centerX, centerY, radius, angleInRadian) {
return {
x: centerX + radius * Math.cos(angleInRadian),
y: centerY + radius * Math.sin(angleInRadian),
};
}
/**
* @ignore
* 根据起始角度计算绘制扇形的 path
* @param centerX
* @param centerY
* @param radius
* @param startAngleInRadian
* @param endAngleInRadian
* @returns
*/
export function getSectorPath(centerX, centerY, radius, startAngleInRadian, endAngleInRadian, innerRadius) {
if (innerRadius === void 0) { innerRadius = 0; }
var start = polarToCartesian(centerX, centerY, radius, startAngleInRadian);
var end = polarToCartesian(centerX, centerY, radius, endAngleInRadian);
var innerStart = polarToCartesian(centerX, centerY, innerRadius, startAngleInRadian);
var innerEnd = polarToCartesian(centerX, centerY, innerRadius, endAngleInRadian);
if (endAngleInRadian - startAngleInRadian === Math.PI * 2) {
// 整个圆是分割成两个圆
var middlePoint = polarToCartesian(centerX, centerY, radius, startAngleInRadian + Math.PI);
var innerMiddlePoint = polarToCartesian(centerX, centerY, innerRadius, startAngleInRadian + Math.PI);
var circlePathCommands = [
['M', start.x, start.y],
['A', radius, radius, 0, 1, 1, middlePoint.x, middlePoint.y],
['A', radius, radius, 0, 1, 1, end.x, end.y],
['M', innerStart.x, innerStart.y],
];
if (innerRadius) {
circlePathCommands.push(['A', innerRadius, innerRadius, 0, 1, 0, innerMiddlePoint.x, innerMiddlePoint.y]);
circlePathCommands.push(['A', innerRadius, innerRadius, 0, 1, 0, innerEnd.x, innerEnd.y]);
}
circlePathCommands.push(['M', start.x, start.y]);
circlePathCommands.push(['Z']);
return circlePathCommands;
}
var arcSweep = endAngleInRadian - startAngleInRadian <= Math.PI ? 0 : 1;
var sectorPathCommands = [
['M', start.x, start.y],
['A', radius, radius, 0, arcSweep, 1, end.x, end.y],
['L', innerEnd.x, innerEnd.y],
];
if (innerRadius) {
sectorPathCommands.push(['A', innerRadius, innerRadius, 0, arcSweep, 0, innerStart.x, innerStart.y]);
}
sectorPathCommands.push(['L', start.x, start.y]);
sectorPathCommands.push(['Z']);
return sectorPathCommands;
}
/**
* @ignore
* Gets arc path
* @param centerX
* @param centerY
* @param radius
* @param startAngleInRadian
* @param endAngleInRadian
* @returns
*/
export function getArcPath(centerX, centerY, radius, startAngleInRadian, endAngleInRadian) {
var start = polarToCartesian(centerX, centerY, radius, startAngleInRadian);
var end = polarToCartesian(centerX, centerY, radius, endAngleInRadian);
if (isNumberEqual(endAngleInRadian - startAngleInRadian, Math.PI * 2)) {
var middlePoint = polarToCartesian(centerX, centerY, radius, startAngleInRadian + Math.PI);
return [
['M', start.x, start.y],
['A', radius, radius, 0, 1, 1, middlePoint.x, middlePoint.y],
['A', radius, radius, 0, 1, 1, start.x, start.y],
['A', radius, radius, 0, 1, 0, middlePoint.x, middlePoint.y],
['A', radius, radius, 0, 1, 0, start.x, start.y],
['Z'],
];
}
var arcSweep = endAngleInRadian - startAngleInRadian <= Math.PI ? 0 : 1;
return [
['M', start.x, start.y],
['A', radius, radius, 0, arcSweep, 1, end.x, end.y],
];
}
/**
* @ignore
* 从数据模型中的 points 换算角度
* @param shapeModel
* @param coordinate
* @returns
*/
export function getAngle(shapeModel, coordinate) {
var points = shapeModel.points;
var box = getPointsBox(points);
var endAngle;
var startAngle;
var coordStartAngle = coordinate.startAngle, coordEndAngle = coordinate.endAngle;
var diffAngle = coordEndAngle - coordStartAngle;
if (coordinate.isTransposed) {
endAngle = box.maxY * diffAngle;
startAngle = box.minY * diffAngle;
}
else {
endAngle = box.maxX * diffAngle;
startAngle = box.minX * diffAngle;
}
endAngle += coordStartAngle;
startAngle += coordStartAngle;
return {
startAngle: startAngle,
endAngle: endAngle,
};
}
/**
* @ignore
* 计算多边形重心: https://en.wikipedia.org/wiki/Centroid#Of_a_polygon
*/
export function getPolygonCentroid(xs, ys) {
if (isNumber(xs) && isNumber(ys)) {
// 普通色块图，xs 和 ys 是数值
return [xs, ys];
}
xs = xs;
ys = ys;
// 当这个 polygon 的点在一条线上的时候
// 也就是说 xs 里面的值都相同，比如：[1, 1, 1, 1]
// 或者说 ys 里面的值都相同，比如：[0, 0, 0, 0]
// 下面计算得到的 k = 0
// 导致返回的值是 [NaN, NaN]
// 所以这里做相应的处理
if (uniqueValues(xs) || uniqueValues(ys))
return [mid(xs), mid(ys)];
var i = -1;
var x = 0;
var y = 0;
var former;
var current = xs.length - 1;
var diff;
var k = 0;
while (++i < xs.length) {
former = current;
current = i;
k += diff = xs[former] * ys[current] - xs[current] * ys[former];
x += (xs[former] + xs[current]) * diff;
y += (ys[former] + ys[current]) * diff;
}
k *= 3;
return [x / k, y / k];
}
/**
* @ignore
* 获取需要替换的属性，如果原先图形元素存在，而新图形不存在，则设置 undefined
*/
export function getReplaceAttrs(sourceShape, targetShape) {
var originAttrs = sourceShape.attr();
var newAttrs = targetShape.attr();
each(originAttrs, function (v, k) {
if (newAttrs[k] === undefined) {
newAttrs[k] = undefined;
}
});
return newAttrs;
}
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