public List <List <Point2d <T> > > Geometry <T>(
uint?clipBuffer = null
, float?scale = null
)
{
// parameters passed to this method override parameters passed to the constructor
if (_clipBuffer.HasValue && !clipBuffer.HasValue)
{
clipBuffer = _clipBuffer;
}
if (_scale.HasValue && !scale.HasValue)
{
scale = _scale;
}
// TODO: how to cache 'finalGeom' without making whole class generic???
// and without using an object (boxing) ???
List <List <Point2d <T> > > finalGeom = _cachedGeometry as List <List <Point2d <T> > >;
if (null != finalGeom && scale == _previousScale)
{
return(finalGeom);
}
//decode commands and coordinates
List <List <Point2d <long> > > geom = DecodeGeometry.GetGeometry(
_layer.Extent
, GeometryType
, GeometryCommands
, scale.Value
);
if (clipBuffer.HasValue)
{
geom = UtilGeom.ClipGeometries(geom, GeometryType, (long)_layer.Extent, clipBuffer.Value, scale.Value);
}
//HACK: use 'Scale' to convert to <T> too
finalGeom = DecodeGeometry.Scale <T>(geom, scale.Value);
//set field needed for next iteration
_previousScale = scale;
_cachedGeometry = finalGeom;
return(finalGeom);
}
public List <List <Vector2 <T> > > Geometry <T>(
uint?clipBuffer = null
, float?scale = null
)
{
// parameters passed to this method override parameters passed to the constructor
if (_clipBuffer.HasValue && !clipBuffer.HasValue)
{
clipBuffer = _clipBuffer;
}
if (_scale.HasValue && !scale.HasValue)
{
scale = _scale;
}
// TODO: how to cache 'finalGeom' without making whole class generic???
// and without using an object (boxing) ???
var finalGeom = _cachedGeometry as List <List <Vector2 <T> > >;
if (null != finalGeom && scale == _previousScale)
{
return(finalGeom);
}
//decode commands and coordinates
List <List <Vector2 <long> > > geom = DecodeGeometry.GetGeometry(
Layer.Extent
, GeometryType
, GeometryCommands
, scale.Value
);
if (clipBuffer.HasValue)
{
// HACK !!!
// work around a 'feature' of clipper where the ring order gets mixed up
// with multipolygons containing holes
if (geom.Count < 2 || GeometryType != GeomType.POLYGON)
{
// work on points, lines and single part polygons as before
geom = UtilGeom.ClipGeometries(geom, GeometryType, (long)Layer.Extent, clipBuffer.Value,
scale.Value);
}
else
{
// process every ring of a polygon in a separate loop
var newGeom = new List <List <Vector2 <long> > >();
int geomCount = geom.Count;
for (int i = 0; i < geomCount; i++)
{
List <Vector2 <long> > part = geom[i];
var tmp = new List <List <Vector2 <long> > >();
// flip order of inner rings to look like outer rings
bool isInner = signedPolygonArea(part) >= 0;
if (isInner)
{
part.Reverse();
}
tmp.Add(part);
tmp = UtilGeom.ClipGeometries(tmp, GeometryType, (long)Layer.Extent, clipBuffer.Value,
scale.Value);
// ring was completely outside of clip border
if (0 == tmp.Count)
{
continue;
}
// one part might result in several geoms after clipping, eg 'u'-shape where the
// lower part is completely beyond the actual tile border but still within the buffer
foreach (List <Vector2 <long> > item in tmp)
{
// flip winding order of inner rings back
if (isInner)
{
item.Reverse();
}
newGeom.Add(item);
}
}
geom = newGeom;
}
}
//HACK: use 'Scale' to convert to <T> too
finalGeom = DecodeGeometry.Scale <T>(geom, scale.Value);
//set field needed for next iteration
_previousScale = scale;
_cachedGeometry = finalGeom;
return(finalGeom);
}
