@antv/path-util
Version:
A common util collection for antv projects
118 lines • 4.47 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var gl_matrix_1 = require("gl-matrix");
function smoothBezier(points, smooth, isLoop, constraint) {
var cps = [];
var hasConstraint = !!constraint;
var prevPoint;
var nextPoint;
var min;
var max;
var nextCp0;
var cp1;
var cp0;
if (hasConstraint) {
min = constraint[0], max = constraint[1];
for (var i = 0, l = points.length; i < l; i += 1) {
var point = points[i];
min = gl_matrix_1.vec2.min([0, 0], min, point);
max = gl_matrix_1.vec2.max([0, 0], max, point);
}
}
for (var i = 0, len = points.length; i < len; i += 1) {
var point = points[i];
if (i === 0 && !isLoop) {
cp0 = point;
}
else if (i === len - 1 && !isLoop) {
cp1 = point;
cps.push(cp0);
cps.push(cp1);
}
else {
var prevIdx = [i ? i - 1 : len - 1, i - 1][isLoop ? 0 : 1];
prevPoint = points[prevIdx];
nextPoint = points[isLoop ? (i + 1) % len : i + 1];
var v = [0, 0];
v = gl_matrix_1.vec2.sub(v, nextPoint, prevPoint);
v = gl_matrix_1.vec2.scale(v, v, smooth);
var d0 = gl_matrix_1.vec2.distance(point, prevPoint);
var d1 = gl_matrix_1.vec2.distance(point, nextPoint);
var sum = d0 + d1;
if (sum !== 0) {
d0 /= sum;
d1 /= sum;
}
var v1 = gl_matrix_1.vec2.scale([0, 0], v, -d0);
var v2 = gl_matrix_1.vec2.scale([0, 0], v, d1);
cp1 = gl_matrix_1.vec2.add([0, 0], point, v1);
nextCp0 = gl_matrix_1.vec2.add([0, 0], point, v2);
// 下一个控制点必须在这个点和下一个点之间
nextCp0 = gl_matrix_1.vec2.min([0, 0], nextCp0, gl_matrix_1.vec2.max([0, 0], nextPoint, point));
nextCp0 = gl_matrix_1.vec2.max([0, 0], nextCp0, gl_matrix_1.vec2.min([0, 0], nextPoint, point));
// 重新计算 cp1 的值
v1 = gl_matrix_1.vec2.sub([0, 0], nextCp0, point);
v1 = gl_matrix_1.vec2.scale([0, 0], v1, -d0 / d1);
cp1 = gl_matrix_1.vec2.add([0, 0], point, v1);
// 上一个控制点必须要在上一个点和这一个点之间
cp1 = gl_matrix_1.vec2.min([0, 0], cp1, gl_matrix_1.vec2.max([0, 0], prevPoint, point));
cp1 = gl_matrix_1.vec2.max([0, 0], cp1, gl_matrix_1.vec2.min([0, 0], prevPoint, point));
// 重新计算 nextCp0 的值
v2 = gl_matrix_1.vec2.sub([0, 0], point, cp1);
v2 = gl_matrix_1.vec2.scale([0, 0], v2, d1 / d0);
nextCp0 = gl_matrix_1.vec2.add([0, 0], point, v2);
if (hasConstraint) {
cp1 = gl_matrix_1.vec2.max([0, 0], cp1, min);
cp1 = gl_matrix_1.vec2.min([0, 0], cp1, max);
nextCp0 = gl_matrix_1.vec2.max([0, 0], nextCp0, min);
nextCp0 = gl_matrix_1.vec2.min([0, 0], nextCp0, max);
}
cps.push(cp0);
cps.push(cp1);
cp0 = nextCp0;
}
}
if (isLoop) {
cps.push(cps.shift());
}
return cps;
}
/**
* create bezier spline from catmull rom spline
* @param {Array} crp Catmull Rom Points
* @param {boolean} z Spline is loop
* @param {Array} constraint Constraint
*/
function catmullRom2Bezier(crp, z, constraint) {
if (z === void 0) { z = false; }
if (constraint === void 0) { constraint = [
[0, 0],
[1, 1],
]; }
var isLoop = !!z;
var pointList = [];
for (var i = 0, l = crp.length; i < l; i += 2) {
pointList.push([crp[i], crp[i + 1]]);
}
var controlPointList = smoothBezier(pointList, 0.4, isLoop, constraint);
var len = pointList.length;
var d1 = [];
var cp1;
var cp2;
var p;
for (var i = 0; i < len - 1; i += 1) {
cp1 = controlPointList[i * 2];
cp2 = controlPointList[i * 2 + 1];
p = pointList[i + 1];
d1.push(['C', cp1[0], cp1[1], cp2[0], cp2[1], p[0], p[1]]);
}
if (isLoop) {
cp1 = controlPointList[len];
cp2 = controlPointList[len + 1];
p = pointList[0];
d1.push(['C', cp1[0], cp1[1], cp2[0], cp2[1], p[0], p[1]]);
}
return d1;
}
exports.default = catmullRom2Bezier;
//# sourceMappingURL=catmull-rom-2-bezier.js.map