我在d3v4中创建了力布局。标记添加了链接以表示方向，如给定的Jfiddle https://jsfiddle.net/rjyk72ea/所示 要求是箭头应该接触到节点但是当链接在node.how的对角线方向时，Arrows隐藏在节点下面（部分或完全）以解决此问题？
var mark = diagramLayout.append("svg:defs").selectAll("marker")//
.data(["end"]) // Different link/path types can be defined here
.enter().append("svg:marker") // This section adds in the arrows
.attr("id", String)
.attr("viewBox", "0 -5 10 10")
.attr("refX", markerRefx)
.attr("refY", 0)
.attr("markerWidth", 5)
.attr("markerHeight", 5)
.attr("orient", "auto")
.attr("stroke", "#000")
.attr("fill", "#000")
.append("svg:path")
.attr("d", "M0,-5L10,0L0,5")
.style("stroke-width", "0.3px")
}
答案 0 :(得分：4)
圆角正方形存在问题。您有两种选择：将它们视为圈子并执行as I did in this question。或者将它们视为矩形（正方形）并找到与正方形的交点。既然，我已经给出了圈子的先前答案，那么我们来谈谈方形（矩形）/线交叉。
现在，我不会详细了解矩形/直线交叉点背后的数学细节（谷歌搜索了大量资源），所以让我们从函数开始来自this great answer（它应该得到更多的赞成）并将其应用于你的问题。
首先，我更改您的链接代码以使用svg path而不是line。在我看来，更干净，更容易。使用我上面链接的功能，然后变得如此简单：
function ticked(e) {
link.attr("d", function(d) {
var inter = pointOnRect(d.source.x, d.source.y,
d.target.x - 20, d.target.y - 20,
d.target.x + 20, d.target.y + 20);
return "M" + d.source.x + "," + d.source.y + "L" + inter.x + "," + inter.y;
});
....
这是完整运行的代码：
<!DOCTYPE html>
<html>
<head>
<script data-require="d3@4.0.0" data-semver="4.0.0" src="https://d3js.org/d3.v4.min.js"></script>
<style>
.node {
stroke: #fff;
stroke-width: 1.5px;
}
.link {
stroke: #000;
stroke-opacity: .6;
}
</style>
</head>
<body>
<div id="mainScreen" style="height:100%;width:100%;position:absolute;">
<svg id="diagramLayout" style="height:100%;width:100%;position:absolute;"></svg>
</div>
<script>
var width = 500;
var height = 500;
var nodeWidth = 40;
var nodeHeight = 40;
var circleRadius = 5;
var diagramLayout;
var graphData = {
"nodes": [{
"uid": "Term20",
"name": "Term20",
"image": "images/Term.png"
}, {
"uid": "glossforArrow",
"name": "glossforArrow",
"image": "images/Glossary.png"
}, {
"uid": "Term43",
"name": "Term43",
"image": "images/Term.png"
}, {
"uid": "Term1",
"name": "Term43",
"image": "images/Term.png"
}, {
"uid": "Term2",
"name": "Term43",
"image": "images/Term.png"
}],
"links": [{
"source": "glossforArrow",
"target": "Term20",
"direction": "output",
"label": "Owned Terms"
}, {
"source": "glossforArrow",
"target": "Term43",
"direction": "output",
"label": "Owned Terms"
}, {
"source": "glossforArrow",
"target": "Term1",
"direction": "output",
"label": "Owned Terms"
}, {
"source": "glossforArrow",
"target": "Term2",
"direction": "output",
"label": "Owned Terms"
}]
};
forceInitialize(graphData)
function forceInitialize(graphData) {
diagramLayout = d3.select("#diagramLayout")
.attr("id", "diagramLayout") //set id
.attr("width", width) //set width
.attr("height", height) //set height
.append("g")
.attr("transform", "translate(" + 20 + "," + 20 + ")")
markerRefx = 35;
simulation = d3.forceSimulation();
alphaMulti = 1;
simulation.force("link", d3.forceLink().id(function(d) {
return d.uid;
}).distance(70).strength(0))
.force("charge", d3.forceManyBody().distanceMin(20).distanceMax(50))
.force("centre", d3.forceCenter(width / 2, height / 2))
.force("x", d3.forceX(2))
.force("y", d3.forceY(10))
.force("collide", d3.forceCollide().radius(function(d) {
return 80;
}).iterations(2))
simulation.on('end', function() {
simulation.force("link", d3.forceLink().id(function(d) {
return d.uid;
}).distance(30).strength(0.0).iterations(10))
.force("x", d3.forceX().strength(0))
.force("y", d3.forceX().strength(0))
});
force(graphData);
}
//Force Layout
function force(graphData) {
var linkEnter = diagramLayout.selectAll(".links");
linkEnter = linkEnter.data(graphData.links)
.enter().append("g")
.attr("class", "links")
var link = linkEnter.append("path")
.attr("stroke-width", function(d) {
return Math.sqrt(2);
})
.attr("stroke-opacity", "0.3")
.attr("stroke", "#000")
graphData.links.forEach(function(d) {
if (d.direction == "input") {
var mark = diagramLayout.append("svg:defs").selectAll("marker") //
.data(["start"]) // Different link/path types can be defined here
.enter().append("svg:marker") // This section adds in the arrows
.attr("id", String)
.attr("viewBox", "0 -5 10 10")
.attr("refX", 0)
.attr("refY", 0)
.attr("markerWidth", 5)
.attr("markerHeight", 5)
.attr("orient", "auto")
.attr("stroke", "#000")
.attr("fill", "#000")
.append("svg:path")
.attr("d", "M0,-5L10,0L0,5")
.style("stroke-width", "0.3px")
.attr("transform", "rotate(180,5, 0)");
} else if (d.direction == "output") {
var mark = diagramLayout.append("svg:defs").selectAll("marker") //
.data(["end"]) // Different link/path types can be defined here
.enter().append("svg:marker") // This section adds in the arrows
.attr("id", String)
.attr("viewBox", "0 -5 10 10")
.attr("refX", 9)
.attr("refY", 0)
.attr("markerWidth", 5)
.attr("markerHeight", 5)
.attr("orient", "auto")
.attr("stroke", "#000")
.attr("fill", "#000")
.append("svg:path")
.attr("d", "M0,-5L10,0L0,5")
.style("stroke-width", "0.3px")
}
});
link.attr("marker-end", function(d) {
if (d.direction === "input")
return "";
else
return "url(#end)";
})
link.attr("marker-start", function(d) {
if (d.direction === "input")
return "url(#start)";
else
return "";
})
var node = diagramLayout.selectAll(".node");
node = node.data(graphData.nodes, function(d) {
return d.uid;
});
var nodeEnter = node.enter().append("g")
.attr("class", "node")
.attr("height", nodeHeight)
.attr("width", nodeWidth)
var nodeIcon = nodeEnter.append("rect")
.attr("class", "rect")
.attr("x", -20)
.attr("y", -20)
.attr("rx", 10)
.attr("width", 40)
.attr("height", 40)
.attr("stroke-width", function(d) {
return Math.sqrt(2);
})
.attr("stroke-opacity", "0.3")
.attr("stroke", "#000")
.attr("fill", "steelblue")
nodeIcon.call(d3.drag()
.on("start", dragstarted)
.on("drag", dragged)
.on("end", dragended));
simulation
.nodes(graphData.nodes)
.on("tick", ticked);
setTimeout(function tick() {
simulation.tick();
if (simulation.alpha() >= .005);
setTimeout(tick, 0);
}, 0);
simulation.force("link")
.links(graphData.links);
simulation.restart();
function ticked(e) {
link.attr("d", function(d) {
var inter = pointOnRect(d.source.x, d.source.y,
d.target.x - 20, d.target.y - 20,
d.target.x + 20, d.target.y + 20);
return "M" + d.source.x + "," + d.source.y + "L" + inter.x + "," + inter.y;
})
nodeEnter.attr("transform", function(d) {
d.fixed = true;
return "translate(" + d.x + "," + d.y + ")";
});
}
function dragstarted(d) {
if (!d3.event.active) simulation.alphaTarget(0.3).restart();
d.fx = d.x;
d.fy = d.y;
}
function dragged(d) {
d.fx = d3.event.x;
d.fy = d3.event.y;
}
function dragended(d) {
d3.select(this).classed("fixed", d.fixed = false);
d3.selectAll(".node").fixed = true;
}
/**
* Finds the intersection point between
* * the rectangle
* with parallel sides to the x and y axes
* * the half-line pointing towards (x,y)
* originating from the middle of the rectangle
*
* Note: the function works given min[XY] <= max[XY],
* even though minY may not be the "top" of the rectangle
* because the coordinate system is flipped.
*
* @param (x,y):Number point to build the line segment from
* @param minX:Number the "left" side of the rectangle
* @param minY:Number the "top" side of the rectangle
* @param maxX:Number the "right" side of the rectangle
* @param maxY:Number the "bottom" side of the rectangle
* @param check:boolean (optional) whether to treat point inside the rect as error
* @return an object with x and y members for the intersection
* @throws if check == true and (x,y) is inside the rectangle
* @author TWiStErRob
* @see <a href="https://stackoverflow.com/a/31254199/253468">source</a>
* @see <a href="https://stackoverflow.com/a/18292964/253468">based on</a>
*/
function pointOnRect(x, y, minX, minY, maxX, maxY, check) {
//assert minX <= maxX;
//assert minY <= maxY;
if (check && (minX <= x && x <= maxX) && (minY <= y && y <= maxY))
throw "Point " + [x, y] + "cannot be inside " + "the rectangle: " + [minX, minY] + " - " + [maxX, maxY] + ".";
var midX = (minX + maxX) / 2;
var midY = (minY + maxY) / 2;
// if (midX - x == 0) -> m == ±Inf -> minYx/maxYx == x (because value / ±Inf = ±0)
var m = (midY - y) / (midX - x);
if (x <= midX) { // check "left" side
var minXy = m * (minX - x) + y;
if (minY <= minXy && minXy <= maxY)
return {
x: minX,
y: minXy
};
}
if (x >= midX) { // check "right" side
var maxXy = m * (maxX - x) + y;
if (minY <= maxXy && maxXy <= maxY)
return {
x: maxX,
y: maxXy
};
}
if (y <= midY) { // check "top" side
var minYx = (minY - y) / m + x;
if (minX <= minYx && minYx <= maxX)
return {
x: minYx,
y: minY
};
}
if (y >= midY) { // check "bottom" side
var maxYx = (maxY - y) / m + x;
if (minX <= maxYx && maxYx <= maxX)
return {
x: maxYx,
y: maxY
};
}
// Should never happen :) If it does, please tell me!
throw "Cannot find intersection for " + [x, y] + " inside rectangle " + [minX, minY] + " - " + [maxX, maxY] + ".";
}
}
</script>
</body>
</html>