public void CopyFrom(GISExtent extent)
{
GISVertex _bottomleft = new GISVertex(extent.MinX, extent.MinY);
GISVertex _upright = new GISVertex(extent.MaxX, extent.MaxY);
SetValue(_bottomleft, _upright);
}
public Point ToScreenPoint(GISVertex onevertex)
{
double ScreenX = MapWindowSize.Width / 2 - (CurrentMapExtent.MapCenter.x - onevertex.x) / ScaleX;
double ScreenY = MapWindowSize.Height / 2 - (onevertex.y - CurrentMapExtent.MapCenter.y) / ScaleY;
return(new Point((int)ScreenX, (int)ScreenY));
}
public GISExtent RectToExtent(Rectangle rect)
{
GISVertex bottomleft = ToMapVertex(new Point(rect.X, rect.Y + rect.Height));
GISVertex upright = ToMapVertex(new Point(rect.X + rect.Width, rect.Y));
return(new GISExtent(bottomleft, upright));
}
private static double CrossProduct(GISVertex A, GISVertex B, GISVertex C)
{
GISVertex AB = new GISVertex(B.x - A.x, B.y - A.y);
GISVertex AC = new GISVertex(C.x - A.x, C.y - A.y);
return(AB.x * AC.y - AB.y * AC.x);
}
private static double Distance(GISVertex A, GISVertex B)
{
double d1 = A.x - B.x;
double d2 = A.y - B.y;
return(Math.Sqrt(d1 * d1 + d2 * d2));
}
private static double DotProduct(GISVertex A, GISVertex B, GISVertex C)
{
GISVertex AB = new GISVertex(B.x - A.x, B.y - C.y);
GISVertex BC = new GISVertex(C.x - B.x, C.y - B.y);
return(AB.x * BC.x + AB.y * BC.y);
}
public bool WithInDistance(GISVertex vertex, double dist)
{
return(((vertex.x + dist) > MinX) &&
((vertex.y + dist) > MinY) &&
((vertex.x - dist) < MaxX) &&
((vertex.y - dist) < MaxY));
}
public void draw(Graphics graphics, GISView view, GISVertex location, int index)
{
Point screenpoint = view.ToScreenPoint(location);
graphics.DrawString(values[index].ToString(),
new Font("宋体", 20),
new SolidBrush(Color.Green),
new PointF(screenpoint.X, screenpoint.Y));
}
public double Distance(GISVertex vertex)
{
double distance = Double.MaxValue;
for (int i = 0; i < Vertexes.Count - 1; i++)
{
distance = Math.Min(GISVertex.PointToSegment(Vertexes[i], Vertexes[i + 1], vertex), distance);
}
return(distance);
}
public void draw(Graphics graphics, GISView view)
{
GISVertex v1 = view.ToMapVertex(new Point(0, view.MapWindowSize.Height - 1));
GISVertex v2 = view.ToMapVertex(new Point(view.MapWindowSize.Width - 1, 0));
GISExtent displayextent = new GISExtent(v1, v2);
for (int i = 0; i < layers.Count; i++)
{
layers[i].draw(graphics, view, displayextent);
}
}
static List <GISFeature> ReadFeatures(BinaryReader br, SHAPETYPE ShapeType, List <GISField> Fields, int FeatureCount)
{
List <GISFeature> Features = new List <GISFeature>();
for (int featureindex = 0; featureindex < FeatureCount; featureindex++)
{
GISFeature feature = new GISFeature(null, null);
if (ShapeType == SHAPETYPE.POINT)
{
GISVertex _location = ReadVertex(br);
feature.spatialpart = new GISPoint(_location);
}
else if (ShapeType == SHAPETYPE.LINE)
{
List <GISVertex> vs = new List <GISVertex>();
int vcount = br.ReadInt32();
for (int vc = 0; vc < vcount; vc++)
{
vs.Add(ReadVertex(br));
}
feature.spatialpart = new GISLine(vs);
}
else if (ShapeType == SHAPETYPE.POLYGON)
{
List <GISVertex> vs = new List <GISVertex>();
int vcount = br.ReadInt32();
for (int vc = 0; vc < vcount; vc++)
{
vs.Add(ReadVertex(br));
}
feature.spatialpart = new GISPolygon(vs);
}
GISAttribute ga = new GISAttribute();
for (int fieldindex = 0; fieldindex < Fields.Count; fieldindex++)
{
GISField field = Fields[fieldindex];
if (field.datatype == typeof(int))
{
ga.AddValue(br.ReadInt32());
}
else if (field.datatype == typeof(double))
{
ga.AddValue(br.ReadDouble());
}
else if (field.datatype == typeof(string))
{
ga.AddValue(ReadString(br));
}
}
feature.attributepart = ga;
Features.Add(feature);
}
return(Features);
}
public void SetValue(GISVertex _bottomleft, GISVertex _upright)
{
upright = _upright;
bottomleft = _bottomleft;
MinX = bottomleft.getX();
MinY = bottomleft.getY();
MaxX = upright.getX();
MaxY = upright.getY();
Width = upright.getX() - bottomleft.getX();
Height = upright.getY() - bottomleft.getY();
MapCenter = new GISVertex((MinX + MaxX) / 2, (MinY + MaxY) / 2);
}
public GISFeature SelectPolygonByVertex(GISVertex vertex)
{
for (int i = 0; i < Features.Count; i++)
{
if (Features[i].spatialpart.extent.WithInDistance(vertex, 0) == false)
{
continue;
}
GISPolygon polygon = (GISPolygon)(Features[i].spatialpart);
if (polygon.Include(vertex))
{
return(Features[i]);
}
}
return(null);
}
public static double PointToSegment(GISVertex A, GISVertex B, GISVertex C)
{
double dot1 = DotProduct(A, B, C);
if (dot1 > 0)
{
return(Distance(B, C));
}
double dot2 = DotProduct(B, A, C);
if (dot2 > 0)
{
return(Distance(A, C));
}
double dist = CrossProduct(A, B, C) / Distance(A, B);
return(Math.Abs(dist));
}
public GISFeature SelectByClick(Point mousepoint, GISView view)
{
GISFeature feature = null;
GISVertex vertex = view.ToMapVertex(mousepoint);
double mindist = view.ToMapDistance(MINIMUMSCREENDISTANCE);
if (ShapeType == SHAPETYPE.POINT)
{
feature = SelectPointByVertex(vertex, mindist);
}
if (ShapeType == SHAPETYPE.LINE)
{
feature = SelectLineByVertex(vertex, mindist);
}
if (ShapeType == SHAPETYPE.POLYGON)
{
feature = SelectPolygonByVertex(vertex);
}
return(feature);
}
// 判断射线与线段的关系一相交返回1，不相交返回0，射线起点在线段上返回-1
public static int IntersactCount(GISVertex p1, GISVertex p2, GISVertex mp)
{
double minX = Math.Min(p1.x, p2.x);
double minY = Math.Min(p1.y, p2.y);
double maxX = Math.Max(p1.x, p2.x);
double maxY = Math.Max(p1.y, p2.y);
if (mp.x > maxX || mp.y > maxY || mp.y < minY)
{
return(0);
}
if (p1.y == p2.y)
{
if (mp.x > minX && mp.x < maxX)//水平线段，则点在线段上返回一1，否则返回0
{
return(-1);
}
else
{
return(0);
}
}
double X0 = p1.x + (mp.y - p1.y) * (p2.x - p1.x) / (p2.y - p1.y);
if (X0 < mp.x)//交点在射线起点左侧(射线与线段不相交)
{
return(0);
}
else if (X0 == mp.x)//交点与射线起点相同一点在线段上，返回一1
{
return(-1);
}
else if (mp.y == minY)//如果射线穿过线段下端点则不计数
{
return(0);
}
else
{
return(1);//交点在边的中间点或者上端点，计数
}
}
public GISFeature SelectLineByVertex(GISVertex vertex, double mindist)
{
Double distance = Double.MaxValue;
int id = -1;
for (int i = 0; i < Features.Count; i++)
{
if (Features[i].spatialpart.extent.WithInDistance(vertex, mindist) == false)
{
continue;
}
GISLine line = (GISLine)(Features[i].spatialpart);
double dist = line.Distance(vertex);
if (dist < distance)
{
distance = dist;
id = i;
}
}
return((distance < mindist) ? Features[id] : null);
}
public bool Include(GISVertex vertex)
{
int count = 0;
int sum = 0;
for (int i = 0; i < Vertexes.Count - 1; i++)
{
count = GISVertex.IntersactCount(Vertexes[i], Vertexes[i + 1], vertex);
if (count < 0)
{
return(true);
}
sum += count;
}
count = GISVertex.IntersactCount(Vertexes[Vertexes.Count - 1], Vertexes[0], vertex);
if (count < 0)
{
return(true);
}
sum += count;
return(sum % 2 != 0);
}
public double Distance(GISVertex anothervertex)
{
return(Math.Sqrt((x - anothervertex.x) * (x - anothervertex.x) + (y - anothervertex.y) * (y - anothervertex.y)));
}
static void WriteVertex(GISVertex v, BinaryWriter bw)
{
bw.Write(v.getX());
bw.Write(v.getY());
}
public GISExtent(GISVertex _bottomleft, GISVertex _upright)
{
SetValue(_bottomleft, _upright);
}
public double Distance(GISVertex anothervertex)
{
return(Location.Distance(anothervertex));
}
public GISPoint(GISVertex onevertex)
{
Location = onevertex;
centroid = onevertex;
extent = new GISExtent(onevertex, onevertex);
}
public void SetMapCenter(GISVertex v)
{
SetValue(new GISVertex(v.x - Width / 2, v.y - Height / 2),
new GISVertex(v.x + Width / 2, v.y + Height / 2));
}