The SEDRIS Data Representation Model
APPENDIX A - Classes
Line

Class Name: Line

Superclass - <Linear Geometry>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies a sequence of connected line segments, each implicitly specified between the i, i+1 pair of <Vertex> components.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

This class appears on only one page of the DRM class diagram.

Example

  1. Consider a <Line> instance L representing a string of 30 evenly spaced lights along one side of a runway.

    To specify what L represents, it has a qualified <Classification Data> component C with tag = ECC_AERODROME_LIGHTING, where C has a <Property Value> component with:

    meaning = {SE_PROPCODTYP_ATTRIBUTE, {EAC_AERONAUTICAL_LIGHT_TYPE}}
    value = {EDCS_AVT_ENUMERATION, {EEC_AEROLGTTY_RUNWAY}}.

    L also has a <Light Rendering Properties> component with an appropriate <Flashing Light Behaviour> component. The field values of L are count = 30 and suppress_last = SE_FALSE, so that L is rendered as a string of 30 evenly spaced flashing lights.

FAQs

No FAQs supplied.

Constraints

Associated with (two-way) (inherited)

Composed of (two-way) (inherited)

Composed of (two-way)

Composed of (two-way metadata) (inherited)

Component of (two-way) (inherited)

Inherited Field Elements

SE_Short_Integer_Unsigned

count;

2

SE_Boolean

suppress_last;

3

Notes

Composed of Notes


Union_Of_Primitive_Geometry

A <Primitive Geometry> instance P has a <Union Of Primitive Geometry> component only when P can be decomposed into nested <Primitive Geometry> instances.

EXAMPLE  A <Polygon> instance can be decomposed into multiple <Polygon> instances representing subfaces.

Fields Notes

count

The count field of a <Linear Geometry> instance indicates how the <Linear Geometry> instance is to be rendered. A count field value of zero for a given <Linear Geometry> instance L indicates that L is to be rendered as one solid line segment, and the suppress_last field does not apply.

If count is greater than zero and L has a <Light Rendering Properties> component, the following applies:

  1. count is the number of evenly spaced light points to be rendered along L.
  2. The distance between light points is calculated by dividing the total length of L by count - 1.
  3. If count is one, a single light point is placed at the halfway point of L and the suppress_last field does not apply.
  4. The fields of the <Light Rendering Properties> component are applicable to each light point as described in 4.15.3.6 Simulating lighting effects of ISO/IEC 18023-1.
  5. If a <Rendering Properties> component is present, it is applicable to each light point as described in 4.15.3.4 Lighting effects of ISO/IEC 18023-1.
  6. No additional factors apply.

If count is greater than zero and L does not have a <Light Rendering Properties> component, the following applies:

  1. count is the number of evenly spaced line segments to be rendered along L.
  2. The length of a segment is calculated by dividing the total length of L by count.
  3. If count is one, a single solid line segment is used and the suppress_last field does not apply.
  4. If a <Rendering Properties> component is present, it is applicable to each light point as described in 4.15.3.4 Lighting effects of ISO/IEC 18023-1.
  5. No additional factors apply.

suppress_last

If count is greater than one, the suppress_last field specifies whether the last segment or point in the sequence is suppressed or rendered.

Prev: Light Source Control Link. Next: Lineage. Up:Index.

Last updated: June 24, 2007 Copyright © 2007 SEDRIS™