private static Tuple <double, Point[]> GetPercentCovered(Point[] polygon, Rect rect)
{
// Figure out the intersected polygon
Point[] intersection = Math2D.GetIntersection_Polygon_Polygon(
polygon,
new Point[] { rect.TopLeft, rect.TopRight, rect.BottomRight, rect.BottomLeft });
if (intersection == null || intersection.Length == 0)
{
return(null);
}
// Calculate the area of the polygon
double areaPolygon = Math2D.GetAreaPolygon(intersection);
double areaRect = rect.Width * rect.Height;
if (areaPolygon > areaRect)
{
if (areaPolygon > areaRect * 1.01)
{
throw new ApplicationException(string.Format("Area of intersected polygon is larger than the rectangle that clipped it: polygon={0}, rectangle={1}", areaPolygon.ToString(), areaRect.ToString()));
}
areaPolygon = areaRect;
}
return(Tuple.Create(areaPolygon / areaRect, intersection));
}
private static Point[] ResizeConvexPolygon(Point[] polygon, double newArea)
{
Point center = Math2D.GetCenter(polygon);
// Create a delagate that returns the area of the polygon based on the percent size
Func <double, double> getOutput = new Func <double, double>(o =>
{
Point[] polyPoints = GetPolygon(center, polygon, o);
return(Math2D.GetAreaPolygon(polyPoints));
});
// Find a percent that returns the desired area
double percent = Math1D.GetInputForDesiredOutput_PosInput_PosCorrelation(newArea, newArea * .01, getOutput);
// Return the sized polygon
return(GetPolygon(center, polygon, percent));
}
private static double[] AnalyzeVoronoiCellSizes(VoronoiResult2D voronoi, ISOMInput[][] imagesByNode)
{
// Calculate area, density of each node
var sizes = Enumerable.Range(0, voronoi.ControlPoints.Length).
Select(o =>
{
double area = Math2D.GetAreaPolygon(voronoi.GetPolygon(o, 1)); // there are no rays
double imageCount = imagesByNode[o].Length.ToDouble();
return(new
{
ImagesCount = imageCount,
Area = area,
Density = imageCount / area,
});
}).
ToArray();
// Don't let any node have an area smaller than this
double minArea = sizes.Min(o => o.Area) * .2;
// Find the node with the largest density. This is the density to use when drawing all cells
var largestDensity = sizes.
OrderByDescending(o => o.Density).
First();
return(sizes.Select(o =>
{
// Figure out how much area it would take using the highest density
double area = o.ImagesCount / largestDensity.Density;
if (area < minArea)
{
area = minArea;
}
return area;
}).
ToArray());
}
private static OverlayResult[] IntersectTiles(Point[] polygon, Tuple <Rect, int, int>[] tiles)
{
List <OverlayResult> retVal = new List <OverlayResult>();
#region Get polygon AABB
double minX = double.MaxValue;
double minY = double.MaxValue;
double maxX = double.MinValue;
double maxY = double.MinValue;
for (int cntr = 0; cntr < polygon.Length; cntr++)
{
if (polygon[cntr].X < minX)
{
minX = polygon[cntr].X;
}
if (polygon[cntr].X > maxX)
{
maxX = polygon[cntr].X;
}
if (polygon[cntr].Y < minY)
{
minY = polygon[cntr].Y;
}
if (polygon[cntr].Y > maxY)
{
maxY = polygon[cntr].Y;
}
}
#endregion
foreach (var tile in tiles)
{
// AABB check
if (tile.Item1.Left > maxX)
{
continue; // polygon is left of the rectangle
}
else if (tile.Item1.Right < minX)
{
continue; // polygon is right of the rectangle
}
else if (tile.Item1.Top > maxY)
{
continue; // polygon is above rectangle
}
else if (tile.Item1.Bottom < minY)
{
continue; // polygon is below rectangle
}
// See if the polygon is completely inside the rectangle
if (minX >= tile.Item1.Left && maxX <= tile.Item1.Right && minY >= tile.Item1.Top && maxY <= tile.Item1.Bottom)
{
double areaPoly = Math2D.GetAreaPolygon(polygon);
double areaRect = tile.Item1.Width * tile.Item1.Height;
if (areaPoly > areaRect)
{
throw new ApplicationException(string.Format("Area of contained polygon is larger than the rectangle that contains it: polygon={0}, rectangle={1}", areaPoly.ToString(), areaRect.ToString()));
}
retVal.Add(new OverlayResult(tile.Item2, tile.Item3, areaPoly / areaRect));
continue;
}
// Intersect polygon with rect
var percent = GetPercentCovered(polygon, tile.Item1);
if (percent != null)
{
retVal.Add(new OverlayResult(tile.Item2, tile.Item3, percent.Item1));
}
}
return(retVal.ToArray());
}