Add 'lineshuffle' command

CHANGELOG.md

@@ -7,6 +7,7 @@ Release date: UNRELEASED
 ### New features and improvements
 
 * Added a `--orientation` option to the `pagerotate` command to conditionally rotate the page to a target orientation (thanks to @gatesphere) (#705)
+* Added a `lineshuffle` command to randomize the plotting order of lines in the current geometry (thanks to @gatesphere) (#715)
 
 ### Bug fixes
 

docs/conf.py

@@ -4,7 +4,6 @@
 
 import vpype as vp
 
-
 project = "vpype"
 # noinspection PyShadowingBuiltins
 copyright = "2020-2022, Antoine Beyeler"

docs/reference.rst

@@ -87,6 +87,10 @@ CLI reference
 .. click:: vpype_cli:linemerge
    :prog: linemerge
 
+.. _cmd_lineshuffle:
+.. click:: vpype_cli:lineshuffle
+   :prog: lineshuffle
+
 .. _cmd_linesimplify:
 .. click:: vpype_cli:linesimplify
    :prog: linesimplify

tests/test_commands.py

@@ -53,6 +53,7 @@ class Command:
     Command("skew 0 0"),
     Command("translate 0 0"),
     Command("crop 0 0 1 1"),
+    Command("lineshuffle"),
     Command("linesort"),
     Command("linesort --two-opt"),
     Command("random linesort"),  # make sure there is something sort

vpype_cli/operations.py

@@ -2,6 +2,7 @@
 
 import logging
 import math
+import random
 from typing import cast
 
 import click
@@ -25,6 +26,7 @@
     "filter_command",
     "layout",
     "linemerge",
+    "lineshuffle",
     "linesimplify",
     "linesort",
     "multipass",
@@ -328,6 +330,20 @@ def linesimplify(lines: vp.LineCollection, tolerance):
     return new_lines
 
 
+@cli.command(group="Operations")
+@layer_processor
+def lineshuffle(lines: vp.LineCollection) -> vp.LineCollection:
+    """Randomizes the line order within layer.
+
+    This command may be useful for testing purposes or spreading out the area in which the pen
+    is drawing over time, for example to let ink dry. It will almost always increase plotting
+    time, sometimes considerably.
+    """
+
+    random.shuffle(lines.lines)
+    return lines
+
+
 @cli.command(group="Operations")
 @click.option(
     "-t",