Determines if a binary polygon overlap has occurred between an input polygon and polygon objects in a spatial file and, if so, returns the polygon that is in overlap with the input polygon.
Syntax
05 GDL-FIND-POLYGON-OVERLAP.
10 GDL-FPO-HANDLE PIC S9(09) BINARY.
10 GDL-FPO-POLYGON PIC S9(09) BINARY.
10 GDL-FPO-OUTPUT-SHAPE PIC S9(09) BINARY.
*
CALL "GDLFPO"
USING GDL-FIND-POLYGON-OVERLAP, GDL-RETURN-CODE.Arguments
GDL-FPO-HANDLE
The gdlFileHandle returned by GDLOSF (GDL-OSF- SPATIAL-HANDLE). Input.
GDL-FPO-POLYGON
The polygon with which to determine overlap (GDL-GES- SURFACE). Input.
GDL-FPO-OUTPUT-SHAPE
A pointer to the overlapping polygon. Output.
Return Values
| GDL-OK | Success |
| GDL-ERROR | An internal error occurred |
| GDL-NOT-FOUND | No further returns are available |
| GDL-WRONG-TYP | GDL-FPOP-POLYGON is not a polygon |
Prerequisites
GDLOSF
Alternates
GDLFPOP - If percentage overlap is required.
Notes
Following instances of this procedure, you should call GDLSF with the output polygon (GDL-FPO-OUTPUT-SHAPE) when you are finished using the output polygon to release system resources.
The following diagram illustrates a polygon that is in overlap with an input polygon:
