protected void ScanTriangleLine(Plane plane, int y, float x1, float x2, Candidate candidate)
{
var startX = (int) Math.Ceiling(Math.Min(x1, x2));
var endX = (int) Math.Floor(Math.Max(x1, x2));
if (startX > endX) return;
var z0 = plane[startX, y];
var dz = plane.A;
for (var x = startX; x <= endX; x++)
{
if (PointStates[x, y] != PointState.Used)
{
var z = HeightMap[x, y];
var diff = Math.Abs(z - z0);
candidate.Consider(x, y, diff);
}
z0 += dz;
}
}
public void ScanTriangle(TrackedTriangle tri)
{
var zPlane = new Plane();
ComputePlane(zPlane, tri, HeightMap);
var vecArray = new[] {tri.Point1, tri.Point2, tri.Point3};
Array.Sort(vecArray, new Vector2TriangleComparer());
var x1 = vecArray[0].X;
var x2 = vecArray[0].X;
var dx1 = (vecArray[1].X - vecArray[0].X)/(vecArray[1].Y - vecArray[0].Y);
var dx2 = (vecArray[2].X - vecArray[0].X)/(vecArray[2].Y - vecArray[0].Y);
var startY = (int) vecArray[0].Y;
var endY = (int) vecArray[1].Y;
var candidate = new Candidate();
for(var y = startY; y < endY; y++)
{
ScanTriangleLine(zPlane, y, x1, x2, candidate);
x1 += dx1;
x2 += dx2;
}
dx1 = (vecArray[2].X - vecArray[1].X)/(vecArray[2].Y - vecArray[1].Y);
x1 = vecArray[1].X;
startY = (int) vecArray[1].Y;
endY = (int) vecArray[2].Y;
for (var y = startY; y < endY; y++)
{
ScanTriangleLine(zPlane, y, x1, x2, candidate);
x1 += dx1;
x2 += dx2;
}
if (candidate.Importance < 1e-4f)
{
if (tri.Token != Heap.NOT_IN_HEAP)
{
heap.Kill(tri.Token);
}
tri.SetCandidate(-69, -69, 0.0f);
return;
}
Debug.Assert(PointStates[candidate.X, candidate.Y] == PointState.Unused);
tri.SetCandidate(candidate.X, candidate.Y, candidate.Importance);
if (tri.Token == Heap.NOT_IN_HEAP)
{
heap.Insert(tri, candidate.Importance);
}
else
{
heap.Update(tri, candidate.Importance);
}
}
