public static PickRay operator *(Matrix4 trans, PickRay ray)
{
PickRay result = new PickRay();
result.Origin = (trans * new Vector4(ray.Origin, 1)).DivW.XYZ;
result.Direction = (trans * new Vector4(ray.Direction, 0)).XYZ;
return(result);
}
public Vector3?Pick(PickRay ray)
{
Vector3?closestPoint = null;
float closestDist = 0;
if (_primitiveTopology == PrimitiveTopology.TriangleList)
{
for (int i = 0; i < (IsIndexed ? _indices.Length : _vertices.Length); i += 3)
{
Vector3 p0;
Vector3 p1;
Vector3 p2;
if (IsIndexed)
{
p0 = _vertices[_indices[i + 0]].Position;
p1 = _vertices[_indices[i + 1]].Position;
p2 = _vertices[_indices[i + 2]].Position;
}
else
{
p0 = _vertices[i + 0].Position;
p1 = _vertices[i + 1].Position;
p2 = _vertices[i + 2].Position;
}
Vector3?point = RayTriIntersect(ray.Origin, ray.Direction, p0, p1, p2);
if (point != null)
{
float dist = (ray.Origin - point.Value).Length;
if (closestPoint == null || dist < closestDist)
{
closestPoint = point;
closestDist = dist;
}
}
}
}
else if (_primitiveTopology == PrimitiveTopology.LineList)
{
for (int i = 0; i < (IsIndexed ? _indices.Length : _vertices.Length); i += 2)
{
Vector3 p0;
Vector3 p1;
if (IsIndexed)
{
p0 = _vertices[_indices[i + 0]].Position;
p1 = _vertices[_indices[i + 1]].Position;
}
else
{
p0 = _vertices[i + 0].Position;
p1 = _vertices[i + 1].Position;
}
Vector3?point = RayLineIntersect(ray.Origin, ray.Direction, p0, p1);
if (point != null)
{
float dist = (ray.Origin - point.Value).Length;
if (closestPoint == null || dist < closestDist)
{
closestPoint = point;
closestDist = dist;
}
}
}
}
else
{
// not implemented
}
return(closestPoint);
}