You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
108 lines
3.3 KiB
JavaScript
108 lines
3.3 KiB
JavaScript
const COMMAND = 0;
|
|
const NUMBER = 1;
|
|
const EOD = 2;
|
|
const PARAMS = { A: 7, a: 7, C: 6, c: 6, H: 1, h: 1, L: 2, l: 2, M: 2, m: 2, Q: 4, q: 4, S: 4, s: 4, T: 2, t: 2, V: 1, v: 1, Z: 0, z: 0 };
|
|
function tokenize(d) {
|
|
const tokens = new Array();
|
|
while (d !== '') {
|
|
if (d.match(/^([ \t\r\n,]+)/)) {
|
|
d = d.substr(RegExp.$1.length);
|
|
}
|
|
else if (d.match(/^([aAcChHlLmMqQsStTvVzZ])/)) {
|
|
tokens[tokens.length] = { type: COMMAND, text: RegExp.$1 };
|
|
d = d.substr(RegExp.$1.length);
|
|
}
|
|
else if (d.match(/^(([-+]?[0-9]+(\.[0-9]*)?|[-+]?\.[0-9]+)([eE][-+]?[0-9]+)?)/)) {
|
|
tokens[tokens.length] = { type: NUMBER, text: `${parseFloat(RegExp.$1)}` };
|
|
d = d.substr(RegExp.$1.length);
|
|
}
|
|
else {
|
|
return [];
|
|
}
|
|
}
|
|
tokens[tokens.length] = { type: EOD, text: '' };
|
|
return tokens;
|
|
}
|
|
function isType(token, type) {
|
|
return token.type === type;
|
|
}
|
|
export function parsePath(d) {
|
|
const segments = [];
|
|
const tokens = tokenize(d);
|
|
let mode = 'BOD';
|
|
let index = 0;
|
|
let token = tokens[index];
|
|
while (!isType(token, EOD)) {
|
|
let paramsCount = 0;
|
|
const params = [];
|
|
if (mode === 'BOD') {
|
|
if (token.text === 'M' || token.text === 'm') {
|
|
index++;
|
|
paramsCount = PARAMS[token.text];
|
|
mode = token.text;
|
|
}
|
|
else {
|
|
return parsePath('M0,0' + d);
|
|
}
|
|
}
|
|
else if (isType(token, NUMBER)) {
|
|
paramsCount = PARAMS[mode];
|
|
}
|
|
else {
|
|
index++;
|
|
paramsCount = PARAMS[token.text];
|
|
mode = token.text;
|
|
}
|
|
if ((index + paramsCount) < tokens.length) {
|
|
for (let i = index; i < index + paramsCount; i++) {
|
|
const numbeToken = tokens[i];
|
|
if (isType(numbeToken, NUMBER)) {
|
|
params[params.length] = +numbeToken.text;
|
|
}
|
|
else {
|
|
throw new Error('Param not a number: ' + mode + ',' + numbeToken.text);
|
|
}
|
|
}
|
|
if (typeof PARAMS[mode] === 'number') {
|
|
const segment = { key: mode, data: params };
|
|
segments.push(segment);
|
|
index += paramsCount;
|
|
token = tokens[index];
|
|
if (mode === 'M')
|
|
mode = 'L';
|
|
if (mode === 'm')
|
|
mode = 'l';
|
|
}
|
|
else {
|
|
throw new Error('Bad segment: ' + mode);
|
|
}
|
|
}
|
|
else {
|
|
throw new Error('Path data ended short');
|
|
}
|
|
}
|
|
return segments;
|
|
}
|
|
export function serialize(segments) {
|
|
const tokens = [];
|
|
for (const { key, data } of segments) {
|
|
tokens.push(key);
|
|
switch (key) {
|
|
case 'C':
|
|
case 'c':
|
|
tokens.push(data[0], `${data[1]},`, data[2], `${data[3]},`, data[4], data[5]);
|
|
break;
|
|
case 'S':
|
|
case 's':
|
|
case 'Q':
|
|
case 'q':
|
|
tokens.push(data[0], `${data[1]},`, data[2], data[3]);
|
|
break;
|
|
default:
|
|
tokens.push(...data);
|
|
break;
|
|
}
|
|
}
|
|
return tokens.join(' ');
|
|
}
|