/// <summary>
/// For each solid in <see cref="carvers"/>, split intersecting solids in <see cref="carvees"/>
/// by that solid. A carvee may be carved multiple times by the carver set.
/// </summary>
/// <param name="document">The document that's being edited</param>
/// <param name="carvers">The list of objects to carve with</param>
/// <param name="carvees">The list of objects that will be carved</param>
/// <returns>An operation that will commit the changes.</returns>
private static Transaction CarveObjects(MapDocument document, IEnumerable <Solid> carvers, IEnumerable <Solid> carvees)
{
// Create a copy of the carvee list which will be modified as the carve happens
var carveSet = carvees.ToList();
// Create a carve data to track changes before they are committed
var data = new CarveData(carveSet);
foreach (var carver in carvers)
{
var added = new List <Solid>();
var removed = new List <Solid>();
// Carve all the candidates in the carve set
// Since we're carving with only one object at this point, we can do all the carve set in one go
// and do the add/remove operations at the end. This stops the carve result from potentially being re-carved somehow.
foreach (var carvee in carveSet)
{
var result = PerformCarve(document, carver, carvee, data);
if (result == null)
{
continue;
}
added.AddRange(result);
removed.Add(carvee);
}
// Update the carve set with the new changes
carveSet.RemoveAll(removed.Contains);
carveSet.AddRange(added);
}
// Return the result
return(data.Transaction);
}
/// <summary>
/// Carve one solid into another and output the results into the provided lists.
/// </summary>
/// <param name="document">The document that's being edited</param>
/// <param name="carver">The solid to carve with</param>
/// <param name="carvee">The solid to carve into</param>
/// <param name="data">The current carve data</param>
/// <returns>The list of added solids if the carve was successful, null otherwise</returns>
private static List <Solid> PerformCarve(MapDocument document, Solid carver, Solid carvee, CarveData data)
{
var split = false;
var solid = carvee; // this reference will change as the carve continues
var list = new List <Solid>();
foreach (var plane in carver.Faces.Select(x => x.Plane))
{
// Split solid by plane
Solid back, front;
try
{
if (!solid.Split(document.Map.NumberGenerator, plane, out back, out front))
{
// If the solid is completely in front of the plane, then the solids don't overlap
if (back == null && front != null)
{
return(null);
}
}
}
catch
{
// We're not too fussy about over-complicated carving, just get out if we've broken it.
break;
}
split = true;
if (front != null)
{
// Retain the front solid
if (solid.IsSelected)
{
front.IsSelected = true;
}
list.Add(front);
}
// If the back isn't valid, exit the carve as it cannot continue
if (back == null || !back.IsValid())
{
break;
}
// Use the back solid as the new clipping target
if (solid.IsSelected)
{
back.IsSelected = true;
}
solid = back;
}
if (!split)
{
return(null);
}
// Update the carve data
foreach (var s in list)
{
data.Attach(carvee, s);
}
data.Detatch(carvee);
return(list);
}
