70 lines
1.8 KiB
Plaintext
70 lines
1.8 KiB
Plaintext
"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.default = pathIterator;
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/**
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* @file 遍历路径的路径集合，包括segment和 bezier curve
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* @author mengke01(kekee000@gmail.com)
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*/
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/**
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* 遍历路径的路径集合
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*
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* @param {Array} contour 坐标点集
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* @param {Function} callBack 回调函数，参数集合：command, p0, p1, p2, i
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* p0, p1, p2 直线或者贝塞尔曲线参数
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* i 当前遍历的点
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* 其中command = L 或者 Q，表示直线或者贝塞尔曲线
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*/
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function pathIterator(contour, callBack) {
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var curPoint;
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var prevPoint;
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var nextPoint;
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var cursorPoint; // cursorPoint 为当前单个绘制命令的起点
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for (var i = 0, l = contour.length; i < l; i++) {
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curPoint = contour[i];
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prevPoint = i === 0 ? contour[l - 1] : contour[i - 1];
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nextPoint = i === l - 1 ? contour[0] : contour[i + 1];
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// 起始坐标
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if (i === 0) {
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if (curPoint.onCurve) {
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cursorPoint = curPoint;
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} else if (prevPoint.onCurve) {
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cursorPoint = prevPoint;
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} else {
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cursorPoint = {
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x: (prevPoint.x + curPoint.x) / 2,
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y: (prevPoint.y + curPoint.y) / 2
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};
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}
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}
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// 直线
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if (curPoint.onCurve && nextPoint.onCurve) {
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if (false === callBack('L', curPoint, nextPoint, 0, i)) {
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break;
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}
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cursorPoint = nextPoint;
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} else if (!curPoint.onCurve) {
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if (nextPoint.onCurve) {
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if (false === callBack('Q', cursorPoint, curPoint, nextPoint, i)) {
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break;
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}
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cursorPoint = nextPoint;
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} else {
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var last = {
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x: (curPoint.x + nextPoint.x) / 2,
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y: (curPoint.y + nextPoint.y) / 2
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};
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if (false === callBack('Q', cursorPoint, curPoint, last, i)) {
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break;
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}
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cursorPoint = last;
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}
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}
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}
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} |