Command: lines

Syntax

{<entity> = } lines {
    <pcommand>
    ...
}

Description

Create a polyline graphic entity.

Parameters

• <entity>
  An entity or gstructure identifier. The lines entity will be given this name.

• <pcommand>
  A command line containing either:

1. a language command to be executed normally, which may or may not generate polyline vectors.

2. a series of point expressions separated by commas defining polyline vectors.

Switches

• -alph=<num>
  An alpha transparency factor between 0 and 1. A value 1 implies fully opaque, 0 means fully transparent (therefore invisible). The default is 1.

• -br=<num>
  A brightness factor between -1 and +1. A value 0 means normal, -1 means very dark (black), +1 means very bright (white). The default is 1.

• -col=<color>
  The color of the polyline vectors. If included, this will override any color defined in the linestyle (-ls). If omitted, the value no_change is used.

• -draw
  Display the entity graphics during creation. The default behavior is to suppress display until completion of the command, unless the command was typed from the keyboard.

• -fr=<num>
  Define a fragment number for the entity. If omitted the default fragment def_fragment is used.

• -g=<groups>
  The graphic groups of which the entity is to be a part.

• -ls=<linestyle | color>
  The linestyle of the polyline vectors. This can be a linestyle or a color. If omitted, the current modeling color (def_color) is used.

• -ra=<num>
  Define a rank for the entity. If omitted, the default rank def_rank is used.

• -th=<num>
  The thickness of the vectors. If included, this will override any thickness defined in the linestyle (-ls).

Notes

This command always creates a graphic entity. Duplicate consecutive points are ignored.

The symbology of polyline vectors may be changed by using relevant assignments within the command block, e.g. def_color = green.

During vector definition a vector phrase beginning with @ will indicate an invisible vector. A phrase beginning with $ will indicate a linestyled vector, using linestyle def_ls. If neither of these prefixes are present, then the linestyle given by the -ls switch is used.

Examples

Create an unnamed two-element polyline entity.

lines { gc, e:1000, n:1000 }

Create a named polyline entity (the vectors are defined interactively).

entity my_lines = lines -col=red {
    pseries; # Command
    r; # Point phrase "return to start"
}

Create an arguably useless stack of triangles.

numeric x = 1000
entity arches = lines {
    gc
    loop 8 { # Command
        e:x&u:x, e:x&d:x; # Point phrases
        @w:2x-100; # Invisible
        x -= 100; # Command.
    }
}

See Also