private Tuple <HermiteData, Edge[]> CubeInfo(Chunk c, Vector3I min, GridPoint XYZ, GridPoint XMaxYZ, GridPoint XYMaxZ, GridPoint XYZMax, GridPoint XMaxYMaxZ, GridPoint XMaxYZMax, GridPoint XYMaxZMax, GridPoint XMaxYMaxZMax)
{
HermiteData hermiteData = new HermiteData(new List <Vector3>(), new List <Vector3>());
// get edge table index
int cubeIndex = 0;
if (XYZ.Density < _minimumSolidDensity)
{
cubeIndex += 1;
}
if (XMaxYZ.Density < _minimumSolidDensity)
{
cubeIndex += 2;
}
if (XMaxYMaxZ.Density < _minimumSolidDensity)
{
cubeIndex += 4;
}
if (XYMaxZ.Density < _minimumSolidDensity)
{
cubeIndex += 8;
}
if (XYZMax.Density < _minimumSolidDensity)
{
cubeIndex += 16;
}
if (XMaxYZMax.Density < _minimumSolidDensity)
{
cubeIndex += 32;
}
if (XMaxYMaxZMax.Density < _minimumSolidDensity)
{
cubeIndex += 64;
}
if (XYMaxZMax.Density < _minimumSolidDensity)
{
cubeIndex += 128;
}
GridPoint[][][] lookupTable = new GridPoint[][][]
{
new GridPoint[][]
{
new GridPoint[]
{
XYZ,
XYZMax,
},
new GridPoint[]
{
XYMaxZ,
XYMaxZMax,
}
},
new GridPoint[][]
{
new GridPoint[]
{
XMaxYZ,
XMaxYZMax,
},
new GridPoint[]
{
XMaxYMaxZ,
XMaxYMaxZMax,
}
},
};
int edge = _edgeTable[cubeIndex];
List <Edge> xEdges = new List <Edge>();
// loop through all the edges
for (int i = 0; i < 12; i++)
{
// if this edge contains no intersection, skip it
if ((edge & (1 << i)) == 0)
{
continue;
}
int[] corner1Offset = _intersections[i][0];
int[] corner2Offset = _intersections[i][1];
Vector3I corner1 = min;
Vector3I corner2 = min;
corner1.X += corner1Offset[0];
corner1.Y += corner1Offset[1];
corner1.Z += corner1Offset[2];
corner2.X += corner2Offset[0];
corner2.Y += corner2Offset[1];
corner2.Z += corner2Offset[2];
GridPoint corner1Point = lookupTable[corner1Offset[0]][corner1Offset[1]][corner1Offset[2]];
GridPoint corner2Point = lookupTable[corner2Offset[0]][corner2Offset[1]][corner2Offset[2]];
Vector3I delta = (corner2 - corner1) * (corner1Point.Density < _minimumSolidDensity ? -1 : 1); // negate if corner1 is less than the isovalue because we assume corner2 at first.
Direction dir = GetDirectionFromDelta(delta);
xEdges.Add(new Edge(corner1, corner2, dir));
Vector3 intersectionPoint = DualContouring.InterpolateIntersectionPoint(_minimumSolidDensity, corner1.ToVector3(), corner2.ToVector3(),
corner1Point.Density,
corner2Point.Density);
Vector3I minCorner = Vector3I.Min(corner1, corner2);
GridPoint minPoint = (minCorner == corner1) ? corner1Point : corner2Point;
Vector3 naturalNormal = _densityGradientFunction.df(intersectionPoint.X, intersectionPoint.Y, intersectionPoint.Z);
Vector3F8 compressedNaturalNormal = new Vector3F8(naturalNormal);
Vector3 normal = compressedNaturalNormal.ToVector3();
//normal = naturalNormal;
switch (dir)
{
case Direction.XIncreasing:
case Direction.XDecreasing:
normal = minPoint.XPositiveNormal;
if (normal == Vector3.Zero)
{
GridPoint withNormal = new GridPoint(minPoint);
withNormal.XPositiveNormal = naturalNormal;
c.SetPoint(minCorner.X, minCorner.Y, minCorner.Z, withNormal, true);
}
break;
case Direction.YIncreasing:
case Direction.YDecreasing:
normal = minPoint.YPositiveNormal;
if (normal == Vector3.Zero)
{
GridPoint withNormal = new GridPoint(minPoint);
withNormal.YPositiveNormal = naturalNormal;
c.SetPoint(minCorner.X, minCorner.Y, minCorner.Z, withNormal, true);
}
break;
case Direction.ZIncreasing:
case Direction.ZDecreasing:
normal = minPoint.ZPositiveNormal;
if (normal == Vector3.Zero)
{
GridPoint withNormal = new GridPoint(minPoint);
withNormal.ZPositiveNormal = naturalNormal;
c.SetPoint(minCorner.X, minCorner.Y, minCorner.Z, withNormal, true);
}
break;
}
if (normal == Vector3.Zero)
{
normal = naturalNormal;
}
normal.Normalize();
hermiteData.Add(intersectionPoint, normal);
}
Tuple <HermiteData, Edge[]> ret = new Tuple <HermiteData, Edge[]>(hermiteData, xEdges.ToArray());
return(ret);
}
