public virtual IShape GetBuffered(double distance, SpatialContext ctx)
{
if (ctx.IsGeo)
{
//first check pole touching, triggering a world-wrap rect
if (maxY + distance >= 90)
{
return(ctx.MakeRectangle(-180, 180, Math.Max(-90, minY - distance), 90));
}
else if (minY - distance <= -90)
{
return(ctx.MakeRectangle(-180, 180, -90, Math.Min(90, maxY + distance)));
}
else
{
//doesn't touch pole
double latDistance = distance;
double closestToPoleY = (maxY - minY > 0) ? maxY : minY;
double lonDistance = DistanceUtils.CalcBoxByDistFromPt_deltaLonDEG(
closestToPoleY, minX, distance); //lat,lon order
//could still wrap the world though...
if (lonDistance * 2 + Width >= 360)
{
return(ctx.MakeRectangle(-180, 180, minY - latDistance, maxY + latDistance));
}
return(ctx.MakeRectangle(
DistanceUtils.NormLonDEG(minX - lonDistance),
DistanceUtils.NormLonDEG(maxX + lonDistance),
minY - latDistance, maxY + latDistance));
}
}
else
{
IRectangle worldBounds = ctx.WorldBounds;
double newMinX = Math.Max(worldBounds.MinX, minX - distance);
double newMaxX = Math.Min(worldBounds.MaxX, maxX + distance);
double newMinY = Math.Max(worldBounds.MinY, minY - distance);
double newMaxY = Math.Min(worldBounds.MaxY, maxY + distance);
return(ctx.MakeRectangle(newMinX, newMaxX, newMinY, newMaxY));
}
}
