/// <summary>
/// http://alienryderflex.com/polygon_fill/
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="polygon"></param>
/// <param name="fillVolume"></param>
/// <param name="dimX"></param>
/// <param name="dimY"></param>
/// <param name="dimZ"></param>
/// <param name="sliceZ"></param>
/// <param name="fillValue"></param>
/// <returns></returns>
private static VoxelCounts FillPolygonAndCount(
PointF[] polygon,
ushort[] fillVolume,
ushort fillValue,
Volume2D <byte> countVolume,
byte foregroundId)
{
var bounds = GetBoundingBox(polygon);
const float epsilon = 0.01f;
var length = polygon.Length;
var nodeIntersections = new IntersectionXPoint[length * 2];
var nodeX = new float[length];
var polygonX = new float[length];
var polygonY = new float[length];
for (var index = 0; index < length; index++)
{
var point = polygon[index];
polygonX[index] = point.X;
polygonY[index] = point.Y;
}
var voxelCounts = new VoxelCounts();
// Loop through the rows of the image.
for (int y = 0; y < countVolume.DimY; y++)
{
float yPlusEpsilon = y + epsilon;
float yMinusEpsilon = y - epsilon;
if ((yPlusEpsilon < bounds.Top && yMinusEpsilon < bounds.Top) ||
(yPlusEpsilon > bounds.Bottom && yMinusEpsilon > bounds.Bottom))
{
continue;
}
// Build a list of nodes, sorted
int nodesBoth = FindIntersections(polygonX, polygonY, nodeIntersections, y, yPlusEpsilon, yMinusEpsilon);
// Merge
int nodes = MergeIntersections(nodeIntersections, nodeX, nodesBoth);
// Fill the pixels between node pairs.
voxelCounts += FillNodePairsAndCount(
fillVolume,
fillValue,
epsilon,
nodeX,
y,
nodes,
countVolume,
foregroundId);
}
return(voxelCounts);
}
/// <summary>
/// http://alienryderflex.com/polygon_fill/
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="polygon"></param>
/// <param name="result"></param>
/// <param name="dimX"></param>
/// <param name="dimY"></param>
/// <param name="dimZ"></param>
/// <param name="sliceZ"></param>
/// <param name="value"></param>
/// <returns></returns>
public static int Fill <T>(
PointF[] polygon,
T[] result,
int dimX,
int dimY,
int dimZ,
int sliceZ,
T value)
{
if (polygon == null)
{
throw new ArgumentNullException(nameof(polygon), "The polygon is null");
}
if (result == null)
{
throw new ArgumentNullException(nameof(result), "The result array is null");
}
if (polygon.Length == 0)
{
throw new ArgumentOutOfRangeException(nameof(polygon), "The polygon does not contain any points.");
}
if (dimX < 0 || dimY < 0 || dimZ < 0)
{
throw new ArgumentOutOfRangeException(nameof(polygon), "The polygon dimension lengths cannot be less than 0.");
}
if (sliceZ < 0 || (dimZ == 0 && sliceZ != 0) || (dimZ > 0 && sliceZ > dimZ - 1))
{
throw new ArgumentOutOfRangeException(nameof(polygon), "The Z slice must be within the Z dimensions.");
}
var dimXy = dimX * dimY;
if (result.Length != (dimZ == 0 ? dimXy : dimXy *dimZ))
{
throw new ArgumentException("The result array does not have the correct size. The size must equal dimX * dimY * dimZ.", nameof(result));
}
var bounds = GetBoundingBox(polygon);
const float epsilon = 0.01f;
var zOffset = sliceZ * dimX * dimY;
var length = polygon.Length;
var nodeIntersections = new IntersectionXPoint[length * 2];
int total = 0;
var nodeX = new float[length];
var polygonX = new float[length];
var polygonY = new float[length];
for (var index = 0; index < length; index++)
{
var point = polygon[index];
polygonX[index] = point.X;
polygonY[index] = point.Y;
}
// Loop through the rows of the image.
for (int y = 0; y < dimY; y++)
{
float yPlusEpsilon = y + epsilon;
float yMinusEpsilon = y - epsilon;
if ((yPlusEpsilon < bounds.Top && yMinusEpsilon < bounds.Top) ||
(yPlusEpsilon > bounds.Bottom && yMinusEpsilon > bounds.Bottom))
{
continue;
}
// Build a list of nodes, sorted
int nodesBoth = FindIntersections(polygonX, polygonY, nodeIntersections, y, yPlusEpsilon, yMinusEpsilon);
// Merge
int nodes = MergeIntersections(nodeIntersections, nodeX, nodesBoth);
// Fill the pixels between node pairs.
total = FillNodePairs(result, dimX, value, epsilon, zOffset, nodeX, total, y, nodes);
}
return(total);
}
