Command: lineclip

Syntax

{<entity> = } lineclip <elist>

or

{<entity> = } lineclip <elist> {
    <pcommand>
    ...
}

Description

Clip one or more polyline graphic entities using a 2-D polygon mask.

Parameters

• <entity>
  An entity or gstructure identifier. The resulting lines entities will be given this name. This can be an entity array for multiple entity assignment.

• <elist>
  A group/entity list defining the polyline entities to be clipped. Only lines and vector entities are considered.

• <pcommand>
  When included, this is a command line containing either:

  A language command to be executed normally, which may or may not generate polygon vertices.

  A series of point expressions separated by commas defining polygon vertices.

  The resulting polygon provides the mask for the clip operation.

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 newly created lines entities. If included, this will override any color defined in the linestyle (-ls). If omitted, the value no_change is used.

• -dif
  Defines the clip operation to be difference, i.e. the result will be the parts of the polylines which do not clash with the mask.

• -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 entities are to be members. If this is an assignment of a compound child entity, the -g switch is ignored and the child assumes the group membership of its compound parent

• -int
  Defines the clip operation to be intersection. The result will be the parts of the polylines which clash with the mask. This is the default clip operation if -dif is not specified.

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

• -mask=<elist>
  A group/entity list providing the mask polygon(s) for the clip operation. When the mask is defined like this, the language block (containing <pcommands>) should be omitted.

• -mul=<elist>
  Without this switch present each input polyline entity will have an equivalent output polyline entity created (unless it is clipped out completely) with each set of contiguous clipped out lines replaced by a line break (an edge with an null linestyle).
  With this switch present, all input polyline entities will be clipped and converted to output polyline entities without line breaks.

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

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

• -tol=<num>
  A closeness tolerance for edge and vertex matching. If omitted, the default is 1.

Notes

This command creates one or more graphic entities of type lines. Even when the source entities are of type vector, the output will still be of type lines.

The clip operation should be considered as: <result> = <elist> <op> <mask>

All lines created by a lineclip command form the contents of the group these.

The system numeric found records the number of polyline entities created by the lineclip command.

Examples

Clip a polyline.

lines {gc, e:100, n:100, w:100, r }
lineclip this { (50,50), e:100, n:100, w:100, r }

See Also