public void Intersect(AABB cuttingNodeBounds,
Plane[] cuttingNodePlanes,
Vector3 cuttingNodeTranslation,
Vector3 inputPolygonTranslation,
List<Polygon> inputPolygons,
List<Polygon> inside,
List<Polygon> aligned,
List<Polygon> revAligned,
List<Polygon> outside)
{
var categories = new PolygonSplitResult[cuttingNodePlanes.Length];
var translatedPlanes = new Plane[cuttingNodePlanes.Length];
var translation = Vector3.Subtract(cuttingNodeTranslation, inputPolygonTranslation);
// translate the planes we cut our polygons with so that they're located at the same
// relative distance from the polygons as the brushes are from each other.
for (int i = 0; i < cuttingNodePlanes.Length; i++)
translatedPlanes[i] = Plane.Translated(cuttingNodePlanes[i], translation);
var vertices = this.Vertices;
var edges = this.Edges;
var planes = this.Planes;
for (int i = inputPolygons.Count - 1; i >= 0; i--)
{
var inputPolygon = inputPolygons[i];
if (inputPolygon.FirstIndex == -1)
continue;
var bounds = inputPolygon.Bounds;
var finalResult = PolygonSplitResult.CompletelyInside;
// A quick check if the polygon lies outside the planes we're cutting our polygons with.
if (!AABB.IsOutside(cuttingNodeBounds, translation, bounds))
{
PolygonSplitResult intermediateResult;
Polygon outsidePolygon = null;
for (int otherIndex = 0; otherIndex < translatedPlanes.Length; otherIndex++)
{
var translatedCuttingPlane = translatedPlanes[otherIndex];
var side = cuttingNodePlanes[otherIndex].OnSide(bounds, translation.Negated());
if (side == PlaneSideResult.Outside)
{
finalResult = PolygonSplitResult.CompletelyOutside;
break; // nothing left to process, so we exit
} else
if (side == PlaneSideResult.Inside)
continue;
var polygon = inputPolygon;
intermediateResult = PolygonSplit(translatedCuttingPlane, inputPolygonTranslation, ref polygon, out outsidePolygon);
inputPolygon = polygon;
if (intermediateResult == PolygonSplitResult.CompletelyOutside)
{
finalResult = PolygonSplitResult.CompletelyOutside;
break; // nothing left to process, so we exit
} else
if (intermediateResult == PolygonSplitResult.Split)
{
if (outside != null)
outside.Add(outsidePolygon);
// Note: left over is still completely inside,
// or plane (opposite) aligned
} else
if (intermediateResult != PolygonSplitResult.CompletelyInside)
finalResult = intermediateResult;
}
} else
finalResult = PolygonSplitResult.CompletelyOutside;
switch (finalResult)
{
case PolygonSplitResult.CompletelyInside: inside .Add(inputPolygon); break;
case PolygonSplitResult.CompletelyOutside: outside.Add(inputPolygon); break;
// The polygon can only be visible if it's part of the last brush that shares it's surface area,
// otherwise we'd get overlapping polygons if two brushes overlap.
// When the (final) polygon is aligned with one of the cutting planes, we know it lies on the surface of
// the CSG node we're cutting the polygons with. We also know that this node is not the node this polygon belongs to
// because we've done that check earlier on. So we flag this polygon as being invisible.
case PolygonSplitResult.PlaneAligned: inputPolygon.Visible = false; aligned .Add(inputPolygon); break;
case PolygonSplitResult.PlaneOppositeAligned: inputPolygon.Visible = false; revAligned.Add(inputPolygon); break;
}
}
}
// Intersects a mesh with a brush (set of planes)
#region Intersect
public void Intersect(AABB cuttingNodeBounds,
Plane[] cuttingNodePlanes,
Vector3 cuttingNodeTranslation,
Vector3 inputPolygonTranslation,
List <Polygon> inputPolygons,
List <Polygon> inside,
List <Polygon> aligned,
List <Polygon> revAligned,
List <Polygon> outside)
{
var categories = new PolygonSplitResult[cuttingNodePlanes.Length];
var translatedPlanes = new Plane[cuttingNodePlanes.Length];
var translation = Vector3.Subtract(cuttingNodeTranslation, inputPolygonTranslation);
// translate the planes we cut our polygons with so that they're located at the same
// relative distance from the polygons as the brushes are from each other.
for (int i = 0; i < cuttingNodePlanes.Length; i++)
{
translatedPlanes[i] = Plane.Translated(cuttingNodePlanes[i], translation);
}
var vertices = this.Vertices;
var edges = this.Edges;
var planes = this.Planes;
for (int i = inputPolygons.Count - 1; i >= 0; i--)
{
var inputPolygon = inputPolygons[i];
if (inputPolygon.FirstIndex == -1)
{
continue;
}
var bounds = inputPolygon.Bounds;
var finalResult = PolygonSplitResult.CompletelyInside;
// A quick check if the polygon lies outside the planes we're cutting our polygons with.
if (!AABB.IsOutside(cuttingNodeBounds, translation, bounds))
{
PolygonSplitResult intermediateResult;
Polygon outsidePolygon = null;
for (int otherIndex = 0; otherIndex < translatedPlanes.Length; otherIndex++)
{
var translatedCuttingPlane = translatedPlanes[otherIndex];
var side = cuttingNodePlanes[otherIndex].OnSide(bounds, -translation);
if (side == PlaneSideResult.Outside)
{
finalResult = PolygonSplitResult.CompletelyOutside;
break; // nothing left to process, so we exit
}
else
if (side == PlaneSideResult.Inside)
{
continue;
}
var polygon = inputPolygon;
intermediateResult = PolygonSplit(translatedCuttingPlane, inputPolygonTranslation, ref polygon, out outsidePolygon);
inputPolygon = polygon;
if (intermediateResult == PolygonSplitResult.CompletelyOutside)
{
finalResult = PolygonSplitResult.CompletelyOutside;
break; // nothing left to process, so we exit
}
else
if (intermediateResult == PolygonSplitResult.Split)
{
if (outside != null)
{
outside.Add(outsidePolygon);
}
// Note: left over is still completely inside,
// or plane (opposite) aligned
}
else
if (intermediateResult != PolygonSplitResult.CompletelyInside)
{
finalResult = intermediateResult;
}
}
}
else
{
finalResult = PolygonSplitResult.CompletelyOutside;
}
switch (finalResult)
{
case PolygonSplitResult.CompletelyInside: inside.Add(inputPolygon); break;
case PolygonSplitResult.CompletelyOutside: outside.Add(inputPolygon); break;
// The polygon can only be visible if it's part of the last brush that shares it's surface area,
// otherwise we'd get overlapping polygons if two brushes overlap.
// When the (final) polygon is aligned with one of the cutting planes, we know it lies on the surface of
// the CSG node we're cutting the polygons with. We also know that this node is not the node this polygon belongs to
// because we've done that check earlier on. So we flag this polygon as being invisible.
case PolygonSplitResult.PlaneAligned: inputPolygon.Visible = false; aligned.Add(inputPolygon); break;
case PolygonSplitResult.PlaneOppositeAligned: inputPolygon.Visible = false; revAligned.Add(inputPolygon); break;
}
}
}