//---------------------------------------------------------------------------------------------------------
public Bitmap DrawSketch(float n, Vector2 from, Vector2 to)
{
//我日，边排列的顺序是右手的，而顶点排列顺序是左手的，操！
//LOS_RESULT ret = geo.LOS_Test(
// polys[254].edges[2].from.ToVector2(),
// polys[254].edges[1].from.ToVector2(),
// out wp);
LOS_RESULT ret = geo.LOS_Test(from, to, out wp);
Bitmap bmp = new Bitmap((int)maxx + 5, (int)maxy + 5, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
using (Graphics g = Graphics.FromImage(bmp))
{
Brush brush = new SolidBrush(Color.Black);
g.FillRectangle(brush, new Rectangle(0, 0, (int)maxx + 5, (int)maxy + 5));
brush.Dispose();
int H = (int)maxy + 1;
using (Pen pen = new Pen(Color.Red))
{
for (int i = 0; i < num_polys; i++)
{
DrawPolygonEdges(g, pen, i);
}
}
using (Pen pen = new Pen(Color.White))
{
for (int i = 0; i < num_polys; i++)
{
if (!polys[i].enterable)
{
DrawPolygonEdges(g, pen, i);
}
}
}
Font font = new Font("Tahoma", 8);
brush = new SolidBrush(Color.White);
string msg = string.Format("Points:{0} Edges:{1} Polygons:{2} xPolygons:{3}", num_points, num_edges, num_polys, num_xpolys);
g.DrawString(msg, font, brush, 2, 2);
font.Dispose();
brush.Dispose();
DrawRayPath(g); //把路径画出来！
//把测试多边形的AABB画出来！
//for (int i = 0; i < num_polys; i++) DrawAABB(g, i);
DrawAABB(g, 1);
}
return(bmp);
}
//调用该函数时，在大多数情况下，p0在target的内部、边或点上
LOS_RESULT StartLOS_P(Vector2 n0, Vector2 p0, Polygon target, int dstidx)
{
LOS_RESULT los = LOS_RESULT.FAILED;
if (target.idx == dstidx)
{
los = LOS_RESULT.CLEAR;
}
else //保证src与dst点不处于同一多边形
{
int i;
for (i = 0; i < target.num_edges; i++)
{
Edge edge = target.edges[i];
Vector2 from = edge.from.ToVector2() - p0;
Vector2 to = edge.to.ToVector2() - p0;
from.Normalize();
to.Normalize();
float ra = Vector2.Ccw(from, n0);
float rb = Vector2.Ccw(to, n0);
bool ta = FloatEqual(ra, 0); //V cross V = 零矢量
bool tb = FloatEqual(rb, 0);
/*
* //特殊情况1：穿出视线与多边形某边完全重合，计算精度导致
* if (ta && tb) //from/to/p0-n0三者共线
* {
* if (edge.neighbor_poly == dstidx || edge.belong_poly==dstidx )
* {
* los = LOS_RESULT.CLEAR;
* break;
* }
* else
* {
* Vector2 pos = new Vector2();
*
* float da = Vector2.Dot(from, n0);
* float db = Vector2.Dot(to, n0);
*
* if (FloatEqual(da, 1)) //from与n0同向
* pos = edge.from.ToVector2();
* else if (FloatEqual(db, 1)) //to与n0同向
* pos = edge.to.ToVector2();
* else
* Debug.Assert(false); //应该不可能
*
* w.Add(new WayPoint(pos, edge.belong_poly)); //最好取e.belong_poly，取e.neighbor_poly有可能==-1
* PrintDebugPosition(edge.belong_poly, pos);
*
* los = StartLOS_V(n0, pos, dstidx);
* break;
* }
* }
*
* //特殊情况2：穿出点正好是多边形的一个顶点
* //if (ta || tb) ：这句话导致死循环，它没有排除射入边的情况
* if ((ta && rb < 0) || (ra > 0 && tb)) //ta || tb 且保证边为穿出边
* {
* Vector2 pos = new Vector2();
* if (ta) pos = edge.from.ToVector2();
* if (tb) pos = edge.to.ToVector2();
*
* w.Add(new WayPoint(pos, edge.belong_poly)); //最好取e.belong_poly，取e.neighbor_poly有可能==-1
* PrintDebugPosition(edge.belong_poly, pos);
*
* los = StartLOS_V(n0, pos, dstidx);
* break;
* }
*/
//普通情况：穿出点在多边形的边上
if (ra > 0 && rb < 0) //找到穿出边，即from在n0左边，to在n0右边
{
//在确信射线与穿出边相交后，求其交点
Vector2 pos = CrossedRayLineSegIntersection(n0, p0, edge.from.ToVector2(), edge.to.ToVector2());
w.Add(new WayPoint(pos, edge.belong_poly));
PrintDebugPosition(edge.belong_poly, pos);
if (!edge.wall) //穿出边是可以穿透的么？
{
Polygon newtarget = polys[edge.neighbor_poly];
if (newtarget.idx == dstidx)
{
los = LOS_RESULT.CLEAR;
}
else
{
los = StartLOS_P(n0, pos, newtarget, dstidx); //ok
}
}
else
{
los = LOS_RESULT.BLOCKED;
}
break; //只有一根穿出边，找到了就over了
}
}
Debug.Assert(i != target.num_edges); //确信调用该函数时，p0始终在target的内部、边上或顶点上
}
return(los);
}
//---------------------------------------------------------------------------------------------------------
//from:起点；to:终点；waypoint:所有视线途经位点
public LOS_RESULT LOS_Test(Vector2 from, Vector2 to, out List <WayPoint> waypoint)
{
Belong_Status ret;
Debug.WriteLine("----------------------------------------------------");
////////////////////////////////////////////////////////////////////////////////////////
Polygon dstpoly;
Debug.Write("(目标) ");
ret = RelaxPostion(ref to, out dstpoly); //松弛目标点
if (ret != Belong_Status.Polygon || !dstpoly.enterable)
{
waypoint = null;
return(LOS_RESULT.FAILED); //目标点不合法
}
int dstidx = dstpoly.idx; //关键！目标点所处的多边形
////////////////////////////////////////////////////////////////////////////////////////
Polygon srcpoly;
Debug.Write("(源点) ");
ret = RelaxPostion(ref from, out srcpoly); //松弛源点
if (ret != Belong_Status.Polygon || !srcpoly.enterable)
{
waypoint = null;
return(LOS_RESULT.FAILED); //源点不合法
}
////////////////////////////////////////////////////////////////////////////////////////
w = new List <WayPoint>();
w.Add(new WayPoint(from, -1)); //这是对的！
PrintDebugPosition(-1, from);
////////////////////////////////////////////////////////////////////////////////////////
Vector2 n0 = to - from;
n0.Normalize();
////////////////////////////////////////////////////////////////////////////////////////
LOS_RESULT los = LOS_RESULT.FAILED;
if (!FloatEqual(n0.LengthSq(), 0)) //from/to两点不容许重合
{
Debug.Assert(ret == Belong_Status.Polygon);
los = StartLOS_P(n0, from, srcpoly, dstidx); //此刻from在srcpoly内部
}
if (los == LOS_RESULT.CLEAR)
{
w.Add(new WayPoint(to, dstidx));
PrintDebugPosition(dstidx, to);
}
Debug.WriteLine(string.Format("({0}) 共计 {1} 个位点", los.ToString(), w.Count));
Debug.WriteLine("----------------------------------------------------");
waypoint = w;
return(los);
}
