PolygonZ
A PolygonZ consists of a number of rings. A ring is a closed, non-self-intersecting loop. A PolygonZ may contain multiple outer rings. The rings of a PolygonZ are referred to as its parts.
- Box
- The bounding box for the PolygonZ stored in the order Xmin, Ymin, Xmax, Ymax
- NumParts
- The number of rings in the PolygonZ
- NumPoints
- The total number of points for all rings
- Parts
- An array of length NumParts
Stores, for each ring, the index of its first point in the points array. Array indexes are numbered with respect to 0.
- Points
- An array of length NumPoints
The points for each ring in the PolygonZ are stored end to end. The points for ring 2 follow the points for ring 1, and so on. The parts array holds the array index of the starting point for each ring. There is no delimiter in the points array between rings.
- Z Range
- The minimum and maximum Z values for the PolygonZ stored in the order Zmin, Zmax
- Z Array
- An array of length NumPoints
The Z values for each ring in the PolygonZ are stored end to end. The Z values for ring 2 follow the Z values for ring 1, and so on. The parts array holds the array index of the starting Z value for each ring. There is no delimiter in the Z value array between rings.
- The rings are closed (the first and last vertex of a ring must be the same).
- The order of rings in the points array is not significant.
| Position | Field | Value | Type | Number | Byte order |
|---|---|---|---|---|---|
| Byte 0 | Shape Type | 19 | Integer | 1 | Little endian |
| Byte 4 | Box | Box | Double | 4 | Little endian |
| Byte 36 | NumParts | NumParts | Integer | 1 | Little endian |
| Byte 40 | NumPoints | NumPoints | Integer | 1 | Little endian |
| Byte 44 | Parts | Parts | Integer | NumParts | Little endian |
| Byte X | Points | Points | Point | NumPoints | Little endian |
| Byte Y | Zmin | Zmin | Double | 1 | Little endian |
| Byte Y+8 | Zmax | Zmax | Double | 1 | Little endian |
| Byte Y+16 | Z Array | Z Array | Double | NumPoints | Little endian |