Determines if a percentage polygon overlap has occurred between an input polygon and polygon objects in a spatial file and, if so, returns the polygon and the percentage overlap with the input polygon.
Syntax
05 GDL-FIND-POLYGON-OVERLAP-PCT.
10 GDL-FPOP-HANDLE PIC S9(09) BINARY.
10 GDL-FPOP-POLYGON PIC S9(09) BINARY.
10 GDL-FPOP-OUTPUT-SHAPE PIC S9(09) BINARY.
10 GDL-FPOP-OVERLAP COMP-2.
*
CALL "GDLFPOP"
USING GDL-FIND-POLYGON-OVERLAP-PCT, GDL-RETURN-CODE.Arguments
GDL-FPOP-HANDLE
The gdlFileHandle returned by GDLOSF (GDL-OSF- SPATIAL-HANDLE). Input.
GDL-FPOP-POLYGON
The polygon with which to determine overlap (GDL-GES- SURFACE). Input.
GDL-FPOP-OUTPUT-SHAPE
A pointer to the overlapping polygon. Output.
GDL-FPOP-OVERLAP
The percentage of overlap. Output.
Return Values
| GDL-OK | Success |
| GDL-ERROR | Unknown internal error occurred or GDL-FPOP-HANDLE was not properly opened by GDLOSF |
| GDL-NOT-FOUND | No overlapping object is found |
| GDL-WRONG-TYPE | GDL-FPOP-POLYGON is not a polygon |
Prerequisites
GDLOSF
Alternates
GDLFPO - For better performance when percent overlap is not needed.
Notes
Following instances of this procedure, you should call GDLSF with the output polygon ( GDL-FPOP-OUTPUT-SHAPE) when you are finished using the output polygon to release system resources.
The percentage overlap determines the confidence rating.
The following diagram illustrates a polygon and the percentage overlap with an input polygon:
