Javascript 将SVG路径转换为相对命令
给定SVG路径元素,如何将所有路径命令转换为相对坐标?例如,转换此路径(包括每个命令,绝对和相对,交错):Javascript 将SVG路径转换为相对命令,javascript,svg,Javascript,Svg,给定SVG路径元素,如何将所有路径命令转换为相对坐标?例如,转换此路径(包括每个命令,绝对和相对,交错): 进入此等效路径: <path d="m3,7 l10,0 m-10 10 l10,0 v10 h10 v10 h10 c0,6 5,10 10,10 c0,5 5,10 10,10 s10,10 10,10 s-10,10 10,10 q-23,-27 0,-20 q20,-5 0,-10
进入此等效路径:
<path d="m3,7 l10,0 m-10 10 l10,0 v10 h10 v10 h10
c0,6 5,10 10,10 c0,5 5,10 10,10
s10,10 10,10 s-10,10 10,10
q-23,-27 0,-20 q20,-5 0,-10
t-3,-7 t0-15
a5,5 45 1 0 -30,-5 a5,5 20 0 1 -10,-10
z"/>
这个问题的动机是。我调整了这个转换相对函数:
function convertToRelative(path) {
function set(type) {
var args = [].slice.call(arguments, 1)
, rcmd = 'createSVGPathSeg'+ type +'Rel'
, rseg = path[rcmd].apply(path, args);
segs.replaceItem(rseg, i);
}
var dx, dy, x0, y0, x1, y1, x2, y2, segs = path.pathSegList;
for (var x = 0, y = 0, i = 0, len = segs.numberOfItems; i < len; i++) {
var seg = segs.getItem(i)
, c = seg.pathSegTypeAsLetter;
if (/[MLHVCSQTAZz]/.test(c)) {
if ('x1' in seg) x1 = seg.x1 - x;
if ('x2' in seg) x2 = seg.x2 - x;
if ('y1' in seg) y1 = seg.y1 - y;
if ('y2' in seg) y2 = seg.y2 - y;
if ('x' in seg) dx = -x + (x = seg.x);
if ('y' in seg) dy = -y + (y = seg.y);
switch (c) {
case 'M': set('Moveto',dx,dy); break;
case 'L': set('Lineto',dx,dy); break;
case 'H': set('LinetoHorizontal',dx); break;
case 'V': set('LinetoVertical',dy); break;
case 'C': set('CurvetoCubic',dx,dy,x1,y1,x2,y2); break;
case 'S': set('CurvetoCubicSmooth',dx,dy,x2,y2); break;
case 'Q': set('CurvetoQuadratic',dx,dy,x1,y1); break;
case 'T': set('CurvetoQuadraticSmooth',dx,dy); break;
case 'A': set('Arc',dx,dy,seg.r1,seg.r2,seg.angle,
seg.largeArcFlag,seg.sweepFlag); break;
case 'Z': case 'z': x = x0; y = y0; break;
}
}
else {
if ('x' in seg) x += seg.x;
if ('y' in seg) y += seg.y;
}
// store the start of a subpath
if (c == 'M' || c == 'm') {
x0 = x;
y0 = y;
}
}
path.setAttribute('d', path.getAttribute('d').replace(/Z/g, 'z'));
}
我还制作了一个小的phantomjs shell实用程序,它以这种方式转换svg中的所有路径(为了更好地衡量,在相同的要点中有一个对应的路径)。Snap.svg具有Snap.path.toRelative()
pathSegList
现在已经被弃用了:由于在Chrome(和其他浏览器)中上述API弃用后,这个答案不再正确,我将切换到Snap hack,或者它的兄弟Rafael中的类似解决方案:值得注意的是:至少这里链接的Snap.SVG版本()不会保留输入的坐标精度,但所有坐标的精度都将舍入到3位小数。
function convertToRelative(path) {
function set(type) {
var args = [].slice.call(arguments, 1)
, rcmd = 'createSVGPathSeg'+ type +'Rel'
, rseg = path[rcmd].apply(path, args);
segs.replaceItem(rseg, i);
}
var dx, dy, x0, y0, x1, y1, x2, y2, segs = path.pathSegList;
for (var x = 0, y = 0, i = 0, len = segs.numberOfItems; i < len; i++) {
var seg = segs.getItem(i)
, c = seg.pathSegTypeAsLetter;
if (/[MLHVCSQTAZz]/.test(c)) {
if ('x1' in seg) x1 = seg.x1 - x;
if ('x2' in seg) x2 = seg.x2 - x;
if ('y1' in seg) y1 = seg.y1 - y;
if ('y2' in seg) y2 = seg.y2 - y;
if ('x' in seg) dx = -x + (x = seg.x);
if ('y' in seg) dy = -y + (y = seg.y);
switch (c) {
case 'M': set('Moveto',dx,dy); break;
case 'L': set('Lineto',dx,dy); break;
case 'H': set('LinetoHorizontal',dx); break;
case 'V': set('LinetoVertical',dy); break;
case 'C': set('CurvetoCubic',dx,dy,x1,y1,x2,y2); break;
case 'S': set('CurvetoCubicSmooth',dx,dy,x2,y2); break;
case 'Q': set('CurvetoQuadratic',dx,dy,x1,y1); break;
case 'T': set('CurvetoQuadraticSmooth',dx,dy); break;
case 'A': set('Arc',dx,dy,seg.r1,seg.r2,seg.angle,
seg.largeArcFlag,seg.sweepFlag); break;
case 'Z': case 'z': x = x0; y = y0; break;
}
}
else {
if ('x' in seg) x += seg.x;
if ('y' in seg) y += seg.y;
}
// store the start of a subpath
if (c == 'M' || c == 'm') {
x0 = x;
y0 = y;
}
}
path.setAttribute('d', path.getAttribute('d').replace(/Z/g, 'z'));
}
var path = document.querySelector('path');
convertToRelative(path);
console.log(path.getAttribute('d'));
// m 3 7 l 10 0 m -10 10 l 10 0 v 10 h 10 v 10 h 10 c 0 6 5 10 10 10 c 0 5 5 10 10 10 s 10 10 10 10 s -10 10 10 10 q -23 -27 0 -20 q 20 -5 0 -10 t -3 -7 t 0 -15 a 5 5 45 1 0 -30 -5 a 5 5 20 0 1 -10 -10 z
var rel = Snap.path.toRelative(abspathstring);