/// <summary>
/// Returns the indexes of shapes that fall within the specified polygon.
/// </summary>
/// <returns>False if an error occurs, true otherwise.</returns>
public static bool SelectLinesWithPolygon(ref MapWinGIS.Shapefile inputSF, ref MapWinGIS.Shape polygon, ref System.Collections.ArrayList results)
{
int numLines = inputSF.NumShapes;
results = new System.Collections.ArrayList();
// Boundary intersection test variables
double xMin1, xMax1, yMin1, yMax1, zMin1, zMax1, xMin2, xMax2, yMin2, yMax2, zMin2, zMax2;
// Get the masking polygon's boundaries only once:
polygon.Extents.GetBounds(out xMin2, out yMin2, out zMin2, out xMax2, out yMax2, out zMax2);
MapWinGIS.Shape currLine;
MapWinGIS.Point currPt;
for (int i = 0; i <= numLines - 1; i++)
{
currLine = inputSF.get_Shape(i);
currLine.Extents.GetBounds(out xMin1, out yMin1, out zMin1, out xMax1, out yMax1, out zMax1);
// Are the boundaries intersecting?
if (!(xMin1 > xMax2 || xMax1 < xMin2 || yMin1 > yMax2 || yMax1 < yMin2))
{
//lines are nasty, just because the boundaries intersect it
//doesn't mean the line enters the polygon
//do a quick point check before doing a more thorough investigation
int numPoints = currLine.numPoints;
bool ptInside = false;
for (int j = 0; j <= numPoints - 1; j++)
{
currPt = currLine.get_Point(j);
if (polygon.PointInThisPoly(currPt))
{
ptInside = true;
break;
}
}
if (ptInside)
{
results.Add(i);
}//end of ptInside check
else
{
// Avoid using a temp file to test each individual file;
// instead, just see if the line crosses the polygon
if (LineCrossesPoly(ref currLine, ref polygon))
{
//part of the line lies within the polygon, add to result file
results.Add(i);
} //end of successful cross
} //end of else no points were found inside polygon
} //end of checking bounds
} //end of looping through lines
return(results.Count > 0);
}
/// <summary>
/// Exports the shapes from the inputSF which fall within the given polygon, saving to the resultSF provided.
/// </summary>
/// <returns>False if an error occurs, true otherwise.</returns>
public static bool SelectLinesWithPolygon(ref MapWinGIS.Shapefile inputSF, ref MapWinGIS.Shape polygon, ref MapWinGIS.Shapefile resultSF, bool SkipMWShapeID)
{
int numLines = inputSF.NumShapes;
int shpIndex = 0;
// Boundary intersection test variables
double xMin1, xMax1, yMin1, yMax1, zMin1, zMax1, xMin2, xMax2, yMin2, yMax2, zMin2, zMax2;
// Get the masking polygon's boundaries only once:
polygon.Extents.GetBounds(out xMin2, out yMin2, out zMin2, out xMax2, out yMax2, out zMax2);
if (Globals.CopyFields(ref inputSF, ref resultSF) == false)
{
return(false);
}
MapWinGIS.Shape currLine;
MapWinGIS.Point currPt;
for (int i = 0; i <= numLines - 1; i++)
{
currLine = inputSF.get_Shape(i);
currLine.Extents.GetBounds(out xMin1, out yMin1, out zMin1, out xMax1, out yMax1, out zMax1);
// Are the boundaries intersecting?
if (!(xMin1 > xMax2 || xMax1 < xMin2 || yMin1 > yMax2 || yMax1 < yMin2))
{
//lines are nasty, just because the boundaries intersect it
//doesn't mean the line enters the polygon
//do a quick point check before doing a more thorough investigation
int numPoints = currLine.numPoints;
bool ptInside = false;
for (int j = 0; j <= numPoints - 1; j++)
{
currPt = currLine.get_Point(j);
if (polygon.PointInThisPoly(currPt))
{
ptInside = true;
break;
}
}
if (ptInside)
{
//we know part of the line is inside the polygon so add line to result file
shpIndex = resultSF.NumShapes;
if (resultSF.EditInsertShape(currLine, ref shpIndex) == false)
{
gErrorMsg = "Problem inserting shape into result file: " + resultSF.get_ErrorMsg(resultSF.LastErrorCode);
Debug.WriteLine(gErrorMsg);
Error.SetErrorMsg(gErrorMsg);
return(false);
}
//add the table values
int numFields = resultSF.NumFields;
for (int j = 0; j <= numFields - 1; j++)
{
if (resultSF.EditCellValue(j, shpIndex, inputSF.get_CellValue(j, i)) == false)
{
gErrorMsg = "Problem inserting value into DBF table: " + resultSF.get_ErrorMsg(resultSF.LastErrorCode);
Debug.WriteLine(gErrorMsg);
Error.SetErrorMsg(gErrorMsg);
return(false);
}
} //end of looping through table
} //end of ptInside check
else
{
// Avoid using a temp file to test each individual file;
// instead, just see if the line crosses the polygon
if (LineCrossesPoly(ref currLine, ref polygon))
{
//part of the line lies within the polygon, add to result file
shpIndex = resultSF.NumShapes;
if (resultSF.EditInsertShape(currLine, ref shpIndex) == false)
{
gErrorMsg = "Problem inserting shape into result file: " + resultSF.get_ErrorMsg(resultSF.LastErrorCode);
Debug.WriteLine(gErrorMsg);
Error.SetErrorMsg(gErrorMsg);
return(false);
}
//add the table values
int numFields = resultSF.NumFields;
for (int j = 0; j <= numFields - 1; j++)
{
if (resultSF.EditCellValue(j, shpIndex, inputSF.get_CellValue(j, i)) == false)
{
gErrorMsg = "Problem inserting value into DBF table: " + resultSF.get_ErrorMsg(resultSF.LastErrorCode);
Debug.WriteLine(gErrorMsg);
Error.SetErrorMsg(gErrorMsg);
return(false);
}
} //end of looping through table
} //end of successful cross
} //end of else no points were found inside polygon
} //end of checking bounds
} //end of looping through lines
if (resultSF.NumShapes > 0)
{
if (resultSF.NumFields == 0 || !SkipMWShapeID)
{
//add the ID field and values
if (Globals.DoInsertIDs(ref resultSF) == false)
{
return(false);
}
}
return(true);
}
else
{
return(false);
}
}