IDRISI Vector Format Feature Representation

In addition to the generic FME feature attributes that FME Workbench adds to all features (see About Feature Type Attributes), this format also adds format-specific attributes (Format Attributes).

IDRISI features consist of geometry and attributes.

The attribute names are defined in the Feature Type parameters, and there is a value for each attribute in each IDRISI feature. In addition, each IDRISI feature contains several special attributes to hold the type of the geometric entity and its display parameters.

All IDRISI features contain an idrisi_type attribute, which identifies the geometric type. Depending on the geometric type, the feature contains additional attributes specific to the geometric type. These are described below. All features contain an idrisi_id.

Points

idrisi_type: idrisi_point

IDRISI point features specify a coordinate in addition to its ID value. There are no attributes specific to this type.

Attribute Name

Contents

idrisi_type

The IDRISI geometric type of this entity.

Range:

idrisi_point

idrisi_line

idrisi_area

idrisi_text

Default: No default

idrisi_id

The ID value of the symbol. IDRISI IDs are used to link vector graphics with user-defined attributes.

Range: Any real > 0.

Default: 1 and increments by 1 for each additional feature

Lines

idrisi_type: idrisi_line

IDRISI line features specify linear features defined by an array of x and y coordinates. There are no attributes specific to only this type of element.

Regions

idrisi_type: idrisi_area

IDRISI area features specify area (polygonal) features. The areas that make up a single feature may or may not be disjoint, and may contain polygons that have holes. The first and last coordinates must be the same in order for it to be a region.

There are no attributes specific to this type of element.

Text

idrisi_type: idrisi_text

IDRISI text features are used to specify annotation information. Each text feature has a location defined by a single point geometry, and can have its text string, style, justification, and rotation angle set independently.

The following table lists the special FME attribute names used to control the IDRISI text settings.

Attribute Name

Contents

idrisi_text_string

This is the text string that is the label for the feature.

Range: 1 - 256 characters

Default: Empty string

idrisi_text_size

This the font size of the label for the feature.

Range: > 0

Default: 1/10th of the height of the map or 10

idrisi_style

The style code of the text string. This controls the color of the text string.

Range: Any integer > 0

Default: 1

idrisi_rotation

The rotation of the text, as measured in degrees counterclockwise from the horizontal.

Range: 0.0 - 360.0

Default: 0.0

idrisi_justification_x

The justification of the text in the X direction. Values approaching 1.00 shift the text to the left of the location point, and values the closer to 0.00 shift the text to the right.

Range:

0.00 - 1.00

0.00 Left margin

0.50 Centre

1.00 Right margin

Default: 0.00

idrisi_justification_y

The justification of the text in the Y direction. Values approaching 1.00 shift the text upward relative to the location point, and values the closer to 0.00 shift the text downward.

Range:

0.00 - 1.00

0.00 Bottom

0.50 Centre

1.00 Top

Default: 0.00