public static void ExtrudeSection(
this IMeshBuilder meshBuilder,
IMeshSelection currentSelection,
int sectionStart,
int sectionEnd,
Func <int, Vector3, Vector3> extrudeTranslationFunc)
{
var sectionSelection = currentSelection.SelectRange(sectionStart, sectionEnd);
sectionSelection = meshBuilder.ExtrudeEdge(
sectionSelection,
extrudeTranslationFunc);
var origStart = currentSelection.GetAtVirtualIndex(sectionStart);
var origEnd = currentSelection.GetAtVirtualIndex(sectionEnd);
for (int i = 0; i < sectionSelection.Count; i++)
{
var currentSelectionIndex = (sectionStart + i).Wrap(currentSelection.Count - 1);
currentSelection[currentSelectionIndex] = sectionSelection[i];
}
// If the section selection covers the entire current selection, we don't need to
// insert any indices to maintain the link back to the current selection.
if (origStart == sectionEnd)
{
return;
}
if (sectionStart <= sectionEnd)
{
currentSelection.Insert(origEnd, sectionEnd + 1);
currentSelection.Insert(origStart, sectionStart);
}
else
{
currentSelection.Insert(origStart, sectionStart);
currentSelection.Insert(origEnd, sectionEnd + 1);
}
}
