Class

• <DRM Linear Geometry>

Superclass

• <DRM Primitive Geometry>

Subclass

• <DRM Arc>
• <DRM Line>

Definition

An instance of this DRM class is a geometric linear representation.

The count field of a <DRM Linear Geometry> instance indicates how the <DRM Linear Geometry> instance is to be rendered. A count field value of zero for a given <DRM 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 <DRM 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 <DRM Light Rendering Properties> component are applicable to each light point as described in 4.15.3.6 Simulating lighting effects.
5. If a <DRM Rendering Properties> component is present, it is applicable to each light point as described in 4.15.3.4 Lighting effects.
6. No additional factors apply.

If count is greater than zero and L does not have a <DRM 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 <DRM Rendering Properties> component is present, it is applicable to each light point as described in 4.15.3.4 Lighting effects.
5. No additional factors apply.

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

Class diagram

Figure 6.160 — DRM_Linear_Geometry

Constraints

• Colour mapping constraints
• Constraints on components
• Continuous LOD constraints
• <DRM Linear Geometry> structure
• <DRM Presentation Domain> constraints
• <DRM Property> constraints
• Image mapping functions and texture coordinates
• Nested primitive geometry
• Non-cyclic aggregations
• Precedence of <DRM Property Set Index>
• Publishable object

Example(s)

• A <DRM Line> instance can be rendered as a single light point, as depicted in Figure 6.161.

  

  Figure 6.161 — <DRM Linear Geometry> light point example

• A <DRM Line> instance can be rendered as three line segments, as depicted in Figure 6.162.

  

  Figure 6.162 — <DRM Linear Geometry> line segment example