// 栅格/TIN图层等值线
public static GeomLayer Value2Contour(ValueLayer layer, IEnumerable <double> targetSplits, string postFix = "")
{
List <GeomPoint> points = null;
List <GeomArc> arcs = null;
// 执行搜索算法
switch (layer)
{
case GridLayer layer1:
Contour.GenContourGrid(layer1.data, targetSplits, out points, out arcs);
break;
case TINLayer layer1:
Contour.GenContourTIN(layer1.edgeSides, layer1.values, targetSplits, out points, out arcs);
break;
default:
return(null);
}
// 创建图层
var result = new GeomLayer(GeomType.Arc, layer.Name + "_等值线" + postFix)
{
points = points,
arcs = arcs
};
// 默认样式
result.colors["arc"] = ColorOps.Random();
result.SetPartVisible("point", false);
return(result);
}
// 等值线光滑
public static GeomLayer ContourSmooth(GeomLayer layer)
{
// 逐个平滑转换
List <double> values = new List <double>();
var raw_arcs = new List <TensionSpline>();
foreach (var arc in layer.arcs)
{
raw_arcs.Add(new TensionSpline(arc.points, 200)); // 使用低精度检查相交
values.Add(arc.value);
}
// 处理相交：整体增加张力
while (true)
{
var crossings = new HashSet <int>();
for (int i = 0; i < raw_arcs.Count; i++)
{
for (int j = i; j < raw_arcs.Count; j++)
{
if (raw_arcs[i].Crossing(raw_arcs[j]))
{
crossings.Add(i);
crossings.Add(j);
}
}
}
if (crossings.Count == 0)
{
break;
}
foreach (int i in crossings)
{
raw_arcs[i].IncreaseTension(3);
}
}
// 增加精度
foreach (var r in raw_arcs)
{
r.SetDetail(1200);
}
// 输出至图层
GeomLayer result = new GeomLayer(GeomType.Arc, layer.Name + "_平滑");
int idxPoint = 0, idxArc = 0;
for (int i = 0; i < values.Count; i++)
{
var currValue = values[i];
var newPoints = new List <GeomPoint>();
foreach (var v in raw_arcs[i].Smooth())
{
newPoints.Add(new GeomPoint(v.X, v.Y, ++idxPoint, currValue));
}
result.points.AddRange(newPoints);
result.arcs.Add(new GeomArc(newPoints, ++idxArc, currValue));
}
// 默认样式
result.colors["arc"] = Color.Red;
result.sizes["arc"] = 1;
result.SetPartVisible("point", false);
return(result);
}
