SVG路径元素,例如:
<path id="path1"
d="M 160 180 C 60 140 230 20 200 170 C 290 120 270 300 200 240 C 160 390 50 240 233 196"
stroke="#009900" stroke-width="4" fill="none"/>
它有4个svg片段(人眼中有3个曲线段):
M 160 180
C 60 140 230 20 200 170
C 290 120 270 300 200 240
C 160 390 50 240 233 196
点击路径后,我得到鼠标位置的x
和y
,然后如何检测点击了哪个曲线段?
function isInWhichSegment(pathElement,x,y){
//var segs = pathElement.pathSegList; //all segments
//
//return the index of which segment is clicked
//
}
答案 0 :(得分:1)
您可以使用 SVGPathElements 的几种方法。不是很直接,但你可以得到路径的总长度,然后用 getPointAtLength 检查坐标的每个长度,并将其与点击的坐标进行比较。一旦你确定点击是在哪个长度,你得到那个长度为 getPathSegAtLength 的段。比如那样:
var pathElement = document.getElementById('path1')
var len = pathElement.getTotalLength();
pathElement.onclick = function(e) {
console.log('The index of the clicked segment is', isInWhichSegment(pathElement, e.offsetX, e.offsetY))
}
function isInWhichSegment(pathElement, x, y) {
var seg;
// You get get the coordinates at the length of the path, so you
// check at all length point to see if it matches
// the coordinates of the click
for (var i = 0; i < len; i++) {
var pt = pathElement.getPointAtLength(i);
// you need to take into account the stroke width, hence the +- 2
if ((pt.x < (x + 2) && pt.x > (x - 2)) && (pt.y > (y - 2) && pt.y < (y + 2))) {
seg = pathElement.getPathSegAtLength(i);
break;
}
}
return seg;
}
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<svg>
<path id="path1" d="M10 80 C 40 10, 65 10, 95 80 S 150 150, 180 80" stroke="#009900" stroke-width="4" fill="none" />
</svg>
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