/// <summary>
/// 计算链接上结点速度
/// </summary>
public void forceLink()
{
alpha = Math.Round(alpha, 15);
for (int k = 0; k < iterations; k++)
{
for (int i = 0; i < Links.Count; i++)
{
ForceLink link = Links[i];
ForceNode source = link.source, target = link.target;
double x, y, l;
//计算下一步的节点速度
x = target.x + target.vx - source.x - source.vx;
if (x == 0) //此处有疑问
{
x = jiggle();
}
y = target.y + target.vy - source.y - source.vy;
if (y == 0)
{
y = jiggle();
}
l = Math.Sqrt(x * x + y * y);
l = (l - distancesLink[i]) / l * alpha * strengthsLink[i];
x *= l;
y *= l;
double b = bias[i];
target.vx -= x * b;
target.vy -= y * b;
b = 1 - b;
source.vx += x * b;
source.vy += y * b;
}
}
}
/// <summary>
/// 返回与距离位置<x，y> 给定搜索半径最接近的节点
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="radius">半径</param>
/// <returns></returns>
ForceNode find(double x, double y, double radius)
{
ForceNode closest = null;
if (radius == null)
{
radius = double.MaxValue;
}
else
{
radius *= radius;
}
for (int i = 0; i < Nodes.Count; i++)
{
var node = Nodes[i];
double dx = x - node.x;
double dy = y - node.y;
double d2 = dx * dx + dy * dy;
if (d2 < radius)
{
closest = node;
radius = d2;
}
}
if (closest != null)
{
return(closest);
}
else
{
return(null);
}
}
/// <summary>
/// 析构函数
/// </summary>
/// <param name="filePath">Json文件地址</param>
/// <param name="cWidth">绘图宽度</param>
/// <param name="cHeight">绘图高度</param>
public D3force(string filePath, double cWidth, double cHeight)
{
this.cWidth = cWidth;
this.cHeight = cHeight;
StreamReader sr = new StreamReader(filePath);
string str = sr.ReadToEnd();
sr.Close();
JObject json = JObject.Parse(str);
JArray jnodes = (JArray)json["nodes"];
int i = 0;
foreach (var x in jnodes)
{
ForceNode node = new ForceNode
{
group = Convert.ToInt32(x["group"]),
id = x["id"].ToString(),
index = i,
};
Nodes.Add(node);
i++;
}
JArray jlinks = (JArray)json["links"];
int j = 0;
foreach (var x in jlinks)
{
ForceLink link = new ForceLink
{
index = j,
value = Convert.ToInt32(x["value"]),
};
string source = x["source"].ToString();
ForceNode sn = Nodes.Find(s => s.id == source);
if (sn != null)
{
link.source = sn;
}
string target = x["target"].ToString();
ForceNode tn = Nodes.Find(s => s.id == target);
if (tn != null)
{
link.target = tn;
}
Links.Add(link);
j++;
}
//初始化结点
initializeNodes();
initializeForceLink();
initializeManyBody();
}
bool IsEqual(ForceNode source, ForceNode target)
{
if (source.group == target.group && source.id == target.id && source.index == target.index &&
source.vx == target.vx && source.vy == target.vy && source.x == target.x && source.y == target.y)
{
return(true);
}
else
{
return(false);
}
}
public override void VisitForce(ForceNode node)
{
Visit(node.Selections);
}
/// <summary>
/// 获取节点
/// </summary>
/// <param name="node"></param>
/// <returns></returns>
public int index(ForceNode node)
{
return(node.index);
}
/// <summary>
/// 添加节点
/// </summary>
/// <param name="x">节点x坐标</param>
/// <param name="y">节点y坐标</param>
/// <param name="d">节点数据</param>
void add(double x, double y, ForceNode d)
{
if (x == null || y == null)
{
return;
}
var node = this._root;
QuadtreeNode parent = node;
var leaf = new QuadtreeNode
{
IsLeaf = true,
data = d
};
double x0 = this._x0, x1 = this._x1, y0 = this._y0, y1 = this._y1;
double xm; //四叉树当前区块x轴中点
double ym; //四叉树当前区块y轴中点
double xp = .0; //数据结点x坐标
double yp = .0; //数据结点y坐标
int right;
int bottom;
int i = 0; //新结点在四叉树子节点列表中的位置
int j = 0; //旧结点在四叉树子节点列表中的位置
//如果根节点为空，初始化根节点为叶结点
if (node.children == null && node.data == null)
{
this._root = leaf;
return;
}
//找出新叶结点应在坐标，为其赋值
while (node.children != null) //当未查找至叶子节点时，不断计算
{
//判断叶新节点位于四叉树哪一个区块
xm = (x0 + x1) / 2;
if (x >= xm)
{
x0 = xm;
right = 1;
}
else
{
x1 = xm;
right = 0;
}
ym = (y0 + y1) / 2;
if (y >= ym)
{
y0 = ym;
bottom = 1;
}
else
{
y1 = ym;
bottom = 0;
}
i = bottom << 1 | right; //新结点在子节点中的排序
//当前坐标节点为空时，添加叶结点
parent = node;
node = node.children[i];
if (node == null)
{
parent.children[i] = leaf;
return;
}
}
if (node != null && node.data != null)
{
xp = node.data.x;
yp = node.data.y;
}
//判断新结点是否与已存在的节点的坐标完全一致
if (x == xp && y == yp)
{
if (parent.children != null || parent.data != null)
{
if (parent.children == null)
{
parent.children = new QuadtreeNode[4];
}
parent.children[i] = leaf;
}
else
{
this._root = leaf;
}
return;
}
//切割叶结点，直到新旧节点并存
var rootNode = parent;
if (rootNode.data == null)
{
int dfe = 0;
}
do
{
if (parent.children != null)
{
parent.children[i] = new QuadtreeNode();
parent = parent.children[i];
parent.children = new QuadtreeNode[4];
}
else
{
this._root.children = new QuadtreeNode[4];
//parent = this._root;
}
//判断叶新节点位于四叉树哪一个区块
xm = (x0 + x1) / 2;
if (x >= xm)
{
x0 = xm;
right = 1;
}
else
{
x1 = xm;
right = 0;
}
ym = (y0 + y1) / 2;
if (y >= ym)
{
y0 = ym;
bottom = 1;
}
else
{
y1 = ym;
bottom = 0;
}
i = bottom << 1 | right; //新结点在子节点中的排序
bool isOldY = yp >= ym;
bool isOldX = xp >= xm;
if (isOldY)
{
if (isOldX)
{
j = 1 << 1 | 1;
}
else
{
j = 1 << 1 | 0;
}
}
else
if (isOldX)
{
j = 0 << 1 | 1;
}
else
{
j = 0 << 1 | 0;
}
} while (i == j);
//清除原有数据，并赋新值
var oldNode = new QuadtreeNode
{
data = node.data,
IsLeaf = true
};
rootNode.data = null;
rootNode.IsLeaf = false;
parent.children[j] = oldNode;
parent.children[i] = leaf;
}