/// <summary>
/// Gets all <see cref="Face"/> objects referenced by this <see cref="Model"/>, recursively.
/// </summary>
/// <param name="bsp">This <see cref="BSP"/>.</param>
/// <param name="model">The <see cref="Model"/> to get all <see cref="Face"/> objects from. Depending on <see cref="BSP.version"/> this may need to traverse through <see cref="BSP.leaves"/>.</param>
/// <returns>A <see cref="List{T}"/><<see cref="Face"/>> containing all <see cref="Face"/> objects descended from <paramref name="model"/>.</returns>
public static List <Face> GetFacesInModel(this BSP bsp, Model model)
{
List <Face> result = null;
if (model.FirstFaceIndex >= 0)
{
if (result == null)
{
result = new List <Face>();
}
for (int i = 0; i < model.NumFaces; i++)
{
result.Add(bsp.faces[model.FirstFaceIndex + i]);
}
}
else
{
bool[] faceUsed = new bool[bsp.faces.Count];
List <Leaf> leaves = bsp.GetLeavesInModel(model);
foreach (Leaf leaf in leaves)
{
if (leaf.FirstMarkFaceIndex >= 0)
{
if (result == null)
{
result = new List <Face>();
}
for (int i = 0; i < leaf.NumMarkFaceIndices; i++)
{
int currentFace = (int)bsp.markSurfaces[leaf.FirstMarkFaceIndex + i];
if (!faceUsed[currentFace])
{
faceUsed[currentFace] = true;
result.Add(bsp.faces[currentFace]);
}
}
}
}
}
return(result);
}
