Line

The line command draws individual straight-line segments stored as separate LINE entities in the DXF model. After each segment the command stays active and re-uses the endpoint as a new start point, so you can build connected paths one segment at a time. Unlike a Polyline, chained lines remain independent entities — each one can be trimmed, extended, or deleted without affecting its neighbours.

Drawing lines

1. Type line in the terminal or click the Line toolbar button.
2. Click the start point, or type X,Y and press Enter for an exact coordinate.
3. Click the end point — the segment is placed and the endpoint becomes the next start point. Coordinate entry works here too.
4. Keep clicking (or typing) to chain more segments.
5. Press Enter or Escape to stop.

  ●──────────●──────────●──────────●
 start     2nd click  3rd click   Enter to finish
            (auto-becomes next start)

Only need a single segment? Press Enter or Escape right after step 3.

Coordinate entry

Instead of clicking, type an exact position for the start or any subsequent point:

1. Type the X value (digits, ., or -).
2. Press , — the terminal shows [X], [Y{cursor}].
3. Type the Y value.
4. Press Enter to place the point.

Angle locking and exact length input

As you move the cursor after placing a point, the command watches for a 45° snap axis (0°, 45°, 90°, 135°, …). The angle locks when:

• the cursor is at least 5 × grip size from the anchor, and
• it is within 1 grip size of perpendicular distance from the nearest axis.

When locked the preview snaps to the axis and you can enter an exact length:

Key	Action
0–9, .	Append digit to the length value
-	Negative length — reverses direction along the axis (first character only)
Backspace	Delete the last typed character
Enter	Place the endpoint at the typed distance

The accumulated value is shown live in the terminal (e.g. click end point or enter length: 12.5). Click while locked and the click is projected onto the axis, so the endpoint always lies exactly on it.

Moving back close to the anchor point disengages the lock.

Keyboard reference

Key	Action
0–9, ., -	Start X coordinate entry, or distance when angle-locked
,	Lock X and move to Y entry
Backspace	Delete last typed character
Enter	Confirm typed coordinate or length, or finish the chain if nothing is typed
Escape	Finish the chain and exit

Grip editing — stretching endpoints

A selected line shows three grips:

Grip	Where	What it does
Start	First endpoint	Drag to reposition — the end stays fixed
Midpoint	Centre of the line	Activates Move for the whole line
End	Second endpoint	Drag to reposition — the start stays fixed

Stretching one endpoint never affects the other. This differs from Polyline grip editing, where moving a vertex reshapes the entire path.

Selecting lines

Method	Behaviour
Click	Selects the line if the click is within hit-test distance of the segment
Drag right (strict)	Line is selected only if both endpoints fall inside the box
Drag left (crossing)	Line is selected if any part of the segment crosses the box boundary

Supported edit commands

Lines are the only entity that Trim and Extend operate on. All standard transformation commands also apply:

Command	What happens to a line
Move	Translates both endpoints by the same displacement
Copy	Creates an identical line at a new position
Rotate	Rotates both endpoints around the chosen base point
Mirror	Reflects both endpoints across the mirror axis
Scale	Scales both endpoints uniformly from the base point
Offset	Creates a parallel line at a fixed perpendicular distance
Trim	Cuts the line at intersections — lines only
Extend	Stretches the nearest endpoint to reach a boundary — lines only
Delete	Removes the line from the drawing

Properties

When a line is selected the properties panel shows every field that the DXF LINE record carries:

General

Property	Default	Meaning
Color	256 (ByLayer)	ACI color index
Layer	0	Layer assignment
Linetype	ByLayer	Named linetype pattern
Linetype Scale	1	Scale factor on the linetype pattern
Thickness	0	Extrusion thickness

Geometry

Property	Meaning
Start X / Start Y	First endpoint coordinates
End X / End Y	Second endpoint coordinates

All fields are editable directly in the panel without re-running the command.

Line vs Polyline — when to use which

	Line	Polyline
Entity count	One LINE per segment	One LWPOLYLINE for the whole path
Trim / Extend	Yes — segment by segment	No
Closed shape	No	Yes (close flag)
Grip editing	Stretch individual endpoints	Move any vertex along the path
Best for	Construction lines, single segments, geometry you'll trim	Contours, outlines, shapes you keep whole

DXF — LINE entity

Lines are saved as LINE entities in the DXF file. Every property — start/end coordinates, color, layer, linetype, linetype scale, and thickness — round-trips without loss. When you open a DXF that contains LINE entities they become fully editable Line objects in the editor.

Lines drawn in the editor are also written as LINE entities on save, so they are readable by AutoCAD, LibreCAD, and any other DXF-compatible application.