Lines

igds_type: igds_line

Features with their igds_type set to igds_line are stored in and read from IGDS files in one of three ways, depending on the number of coordinates they have.

Number of
Coordinates

IGDS Element
Type

Description

2

3

If the feature contained exactly two points, then an IGDS type 3 element is used to store the data if IGDS_CREATE_LINE_ELEMENTS was yes; otherwise, a type 4 element will be created.

In V7: Between 3 and 101

In V8: Between 3 and 5000

4

If the coordinates can fit in a single element, then an IGDS type 4 element is used to store the line.

In V7: Greater than 101

In V8: Greater than 5000

12, 4

If the coordinates cannot fit into a single element, then they are grouped together into a complex line string element (type 12). This consists of a single type 12 element, followed by as many type 4 elements as required to hold all the coordinate data. The type 4 elements have their complex bit turned on. Furthermore, such a complex line string element will be split into multiple complex line string elements if the size of the data exceeds the maximum size that the header can address, which is approximately 65K words.

There are no attributes specific to this type of element.