public bool Intersects(ref Triangle t, CollisionContent cc)
{
return t.Intersects(cc, ref sphere);
}
void AppendGeometry(MeshContent mc, Matrix x, Gather g)
{
int ta = 2;
int tb = 1;
if (SwapWindingOrder)
{
ta = 1;
tb = 2;
}
int vBase = g.Vertices.Count;
bool first = (g.Bounds.Lo == Vector3.Zero && g.Bounds.Hi == Vector3.Zero);
foreach (Vector3 v in mc.Positions)
{
Vector3 vt = Vector3.Transform(v, x);
g.Vertices.Add(vt);
if (first)
{
first = false;
g.Bounds.Set(vt, vt);
}
g.Bounds.Include(vt);
}
foreach (GeometryContent gc in mc.Geometry)
{
for (int i = 0, n = gc.Indices.Count - 2; i < n; i += 3)
{
Triangle t = new Triangle();
t.VertexA = gc.Indices[i] + vBase;
t.VertexB = gc.Indices[i + ta] + vBase;
t.VertexC = gc.Indices[i + tb] + vBase;
t.Normal = Vector3.Cross(g.Vertices[t.VertexB] - g.Vertices[t.VertexA], g.Vertices[t.VertexC] - g.Vertices[t.VertexB]);
if (t.Normal.Y < 0)
{
++negYCount;
}
if (t.Normal.LengthSquared() > 1e-10f)
{
t.Normal.Normalize();
}
else
{
context.Logger.LogImportantMessage("Normal is surprisingly short: {0} for tri {1}",
t.Normal, i / 3);
// set some normal; I don't really care
if (t.Normal.X > 0)
t.Normal = Vector3.Right;
else if (t.Normal.X < 0)
t.Normal = Vector3.Left;
else if (t.Normal.Z > 0)
t.Normal = Vector3.Backward;
else if (t.Normal.Z < 0)
t.Normal = Vector3.Forward;
else if (t.Normal.Y < 0)
t.Normal = Vector3.Down;
else
t.Normal = Vector3.Up;
}
// Assume the center of the bounding sphere is the center of the longest edge.
// This is true for any triangle that is right-angled or blunt. The center will
float la = (g.Vertices[t.VertexB] - g.Vertices[t.VertexA]).Length();
float lb = (g.Vertices[t.VertexC] - g.Vertices[t.VertexB]).Length();
float lc = (g.Vertices[t.VertexA] - g.Vertices[t.VertexC]).Length();
Vector3 c;
if (la > lb)
if (la > lc)
c = (g.Vertices[t.VertexB] + g.Vertices[t.VertexA]) * 0.5f;
else
c = (g.Vertices[t.VertexA] + g.Vertices[t.VertexC]) * 0.5f;
else
if (lb > lc)
c = (g.Vertices[t.VertexC] + g.Vertices[t.VertexB]) * 0.5f;
else
c = (g.Vertices[t.VertexA] + g.Vertices[t.VertexC]) * 0.5f;
t.Distance = Vector3.Dot(t.Normal, c);
g.Triangles.Add(t);
float r = (g.Vertices[t.VertexA] - c).Length();
r = Math.Max(r, (g.Vertices[t.VertexB] - c).Length());
r = Math.Max(r, (g.Vertices[t.VertexC] - c).Length());
BoundingSphere bs = new BoundingSphere(c, r);
// The center is somewhere inside for a triangle that is sharp.
// Calculate an alternative center to get a better bounding sphere.
if (la < lb)
if (la < lc)
c = (g.Vertices[t.VertexC] * 2 + g.Vertices[t.VertexB] + g.Vertices[t.VertexA]) * 0.25f;
else
c = (g.Vertices[t.VertexB] * 2 + g.Vertices[t.VertexC] + g.Vertices[t.VertexA]) * 0.25f;
else
if (lb < lc)
c = (g.Vertices[t.VertexA] * 2 + g.Vertices[t.VertexB] + g.Vertices[t.VertexC]) * 0.25f;
else
c = (g.Vertices[t.VertexB] * 2 + g.Vertices[t.VertexC] + g.Vertices[t.VertexA]) * 0.25f;
r = (g.Vertices[t.VertexA] - c).Length();
r = Math.Max(r, (g.Vertices[t.VertexB] - c).Length());
r = Math.Max(r, (g.Vertices[t.VertexC] - c).Length());
if (r < bs.Radius)
{
bs.Center = c;
bs.Radius = r;
}
g.BoundingSpheres.Add(bs);
}
}
}
public bool Intersects(ref Triangle t, CollisionContent cc)
{
float dd = collRayD;
return t.Intersects(cc, ref collRay, ref dd);
}
