/// <summary>
/// Gets outline corners of a box as seen from given position (in clockwise order).
/// Returns null if position is inside the box.
/// </summary>
public static V3d[] GetOutlineCornersCW(this Box3d box, V3d fromPosition)
{
var cs = box.ComputeCorners();
return(GetOutlineCornerIndicesCW(box, fromPosition).Map(i => cs[i]));
}
/// <summary>
/// Gets outline corner indices of a box as seen from given position (in clockwise order).
/// Returns null if position is inside the box.
/// </summary>
public static int[] GetOutlineCornerIndicesCW(this Box3d box, V3d fromPosition)
{
var cs = box.ComputeCorners();
if (fromPosition.X < box.Min.X)
{ //-X
if (fromPosition.Y < box.Min.Y)
{ //-Y
if (fromPosition.Z < box.Min.Z)
{ // -X -Y -Z
return(new[] { 1, 3, 2, 6, 4, 5 });
}
else if (fromPosition.Z > box.Max.Z)
{ // -X -Y +Z
return(new[] { 0, 2, 6, 7, 5, 1 });
}
else
{ // -X -Y Z
return(new[] { 1, 2, 6, 5 });
}
}
else if (fromPosition.Y > box.Max.Y)
{ // +Y
if (fromPosition.Z < box.Min.Z)
{ // -X +Y -Z
return(new[] { 0, 1, 3, 7, 6, 4 });
}
else if (fromPosition.Z > box.Max.Z)
{ // -X +Y +Z
return(new[] { 0, 2, 3, 7, 5, 4 });
}
else
{ // -X +Y Z
return(new[] { 0, 3, 7, 4 });
}
}
else
{ // Y
if (fromPosition.Z < box.Min.Z)
{ // -X Y -Z
return(new[] { 1, 3, 6, 4 });
}
else if (fromPosition.Z > box.Max.Z)
{ // -X Y +Z
return(new[] { 0, 2, 7, 5 });
}
else
{ // -X Y Z
return(new[] { 0, 2, 6, 4 });
}
}
}
else if (fromPosition.X > box.Max.X)
{ // +X
if (fromPosition.Y < box.Min.Y)
{ //-Y
if (fromPosition.Z < box.Min.Z)
{ // +X -Y -Z
return(new[] { 0, 4, 5, 7, 3, 2 });
}
else if (fromPosition.Z > box.Max.Z)
{ // +X -Y +Z
return(new[] { 0, 4, 6, 7, 3, 1 });
}
else
{ // +X -Y Z
return(new[] { 0, 4, 7, 3 });
}
}
else if (fromPosition.Y > box.Max.Y)
{ // +Y
if (fromPosition.Z < box.Min.Z)
{ // +X +Y -Z
return(new[] { 0, 1, 5, 7, 6, 2 });
}
else if (fromPosition.Z > box.Max.Z)
{ // +X +Y +Z
return(new[] { 1, 5, 4, 6, 2, 3 });
}
else
{ // +X +Y Z
return(new[] { 1, 5, 6, 2 });
}
}
else
{ // Y
if (fromPosition.Z < box.Min.Z)
{ // +X Y -Z
return(new[] { 0, 5, 7, 2 });
}
else if (fromPosition.Z > box.Max.Z)
{ // +X Y +Z
return(new[] { 1, 4, 6, 3 });
}
else
{ // +X Y Z
return(new[] { 1, 5, 7, 3 });
}
}
}
else
{ // X
if (fromPosition.Y < box.Min.Y)
{ //-Y
if (fromPosition.Z < box.Min.Z)
{ // X -Y -Z
return(new[] { 2, 4, 5, 3 });
}
else if (fromPosition.Z > box.Max.Z)
{ // X -Y +Z
return(new[] { 0, 6, 7, 1 });
}
else
{ // X -Y Z
return(new[] { 0, 4, 5, 1 });
}
}
else if (fromPosition.Y > box.Max.Y)
{ // +Y
if (fromPosition.Z < box.Min.Z)
{ // X +Y -Z
return(new[] { 0, 1, 7, 6 });
}
else if (fromPosition.Z > box.Max.Z)
{ // X +Y +Z
return(new[] { 2, 3, 5, 4 });
}
else
{ // X +Y Z
return(new[] { 2, 3, 7, 6 });
}
}
else
{ // Y
if (fromPosition.Z < box.Min.Z)
{ // X Y -Z
return(new[] { 0, 1, 3, 2 });
}
else if (fromPosition.Z > box.Max.Z)
{ // X Y +Z
return(new[] { 4, 6, 7, 5 });
}
else
{ // X Y Z
return(null);
}
}
}
}