//========================================================================================================
public void Test(FPoint p0, Vector2 n0)
{
int y_idx = (int)(p0.y / 64);
int x_idx = (int)(p0.x / 64);
if (y_idx >= 0 && y_idx < topo.num_Y_grids && x_idx >= 0 && x_idx < topo.num_X_grids)
{
Grid g = topo.grids[y_idx, x_idx];
for (int i = 0; i < g.num_polys; i++)
{
Polygon p = g.polygons[i];
foreach (Border b in p.borders)
{
if (p0.Equals(b.from))
{
//shit，原来是个顶点
return;
}
Vector2 d = GetV2FromBorder(b);
Vector2 test = GetV2(p0) - GetV2(b.from);
//decimal t1 = (decimal)test.X / (decimal)d.X;
//decimal t2 = (decimal)test.Y / (decimal)d.Y;
//以下全错！
long dx = (long)(test.X * 10000) / (long)(d.X * 10000);
long dy = (long)(test.Y * 10000) / (long)(d.Y * 10000);
double ddx = ((double)dx) / 10000;
if (dx == dy && ddx > 0 && ddx < 1) //b.from、p0、b.to三点共线
{
//判断Vector2.Ccw(b,n0)的符号，belong/neighbor得到polygon
Vector2 vb = GetV2FromBorder(b);
int poly_idx;
if (Vector2.Ccw(vb, n0) > 0)
{
poly_idx = b.belong_poly;
}
else
{
poly_idx = b.neighbor_poly;
}
return;
}
}
//if (g.polygons[i].IsWithin(test_p))
// g.poly_idxs[i];
}
}
}
//========================================================================================================
public void LOS_Engine(FPoint from, FPoint to)
{
int srcp = topo.SelectPolygon(from.x, from.y);
int dstp = topo.SelectPolygon(to.x, to.y);
if (srcp == -1 || dstp == -1)
{
return;
}
if (!topo.polys[srcp].enterable || !topo.polys[dstp].enterable)
{
return;
}
lfp.Add(from);
if (srcp == dstp)
{
lfp.Add(to);
return;
}
Vector2 n0 = GetV2(from, to);
n0.Normalize();
TestBorderCall(from, n0, topo.polys[srcp]);
do
{
switch (ret.result)
{
case RESULT.TEST_BORDER:
TestVertexPolygon(ret.p0, ret.n0, ret.poly);
break;
case RESULT.TEST_VERTEX:
TestPureVertex(ret.p0, ret.n0);
break;
}
//以下是检测LOS是否可终止
Polygon dst = topo.polys[dstp];
switch (ret.result)
{
case RESULT.TEST_BORDER:
if (ret.poly == dst)
{
lfp.Add(to);
return;
}
break;
case RESULT.TEST_VERTEX:
FPoint fp = lfp[lfp.Count - 1];
foreach (Border b in dst.borders)
{
if (fp.Equals(b.from))
{
lfp.Add(to);
return;
}
}
break;
}
} while (ret.result != RESULT.TEST_END);
}