laser-util-api 0.2.0

A simple Python API for the Laser Utility project

Python API for Laser Utility

This is a public Python API for the Laser Utility program.

When running, Laser Utility hosts a local JSON-RPC over TCP server bound to a local port on the loopback address. This API provides a series of constructs which allow you to work with the internal state of the software with a native feel in Python. Internally, the various API objects are maintaining state in order to provide the appearance of a shared application domain, while instead transforming actions into discrete JSON-RPC calls.

Installation

Install the laser-util-api package from PyPi. For example, using pip:

pip install laser-util-api

General Connection and Client Settings

To connect to the API, the Laser Utility program must be running. In the lower left corner of the software, the RPC server port will be displayed next to a green circle. The default port is 5000, but concurrent open windows will take the next available port in ascending order.

If no arguments are supplied, the client will default to port 5000 and length units of millimeters.

from laser_util_api import ApiClient

client = ApiClient()

Alternatively, port and units can be specified.

from laser_util_api import ApiClient, Units

client = ApiClient(port=5001, units=Units.INCHES)

Project-Level Functions

Project level functions allow things like saving, loading, and creating new projects, and finding the project name and path.

Saving a project:

from laser_util_api import ApiClient
from pathlib import Path

save_dir = Path("D:\\temp\\laser")

client = ApiClient()

# This will add the correct extension if the path does not end with it already
client.project.save_as(save_dir / "test")

Loading a project. Be warned, the API will not check to see if you want to discard unsaved changes before throwing away the current session.

save_dir = Path("D:\\temp\\laser")
client = ApiClient()

client.project.open(save_dir / "test.lsrwk")

Creating a new project. Be warned, the API will not check to see if you want to discard unsaved changes before throwing away the current session.

client = ApiClient()

client.project.new()

We can also check the name and the path of the currently open project.

client = ApiClient()

print(client.project.path())
print(client.project.name())

Work Settings Functions

Work settings functions control things like the selected material, the kerf, and fonts. They are accessed through the work_settings category of the client.

Materials

The options in the material library can be retrieved and examined.

from laser_util_api import ApiClient, Units

client = ApiClient(units=Units.INCHES)

options = client.work_settings.material_options()
for mat in options:
    print(mat)
    print(f" {mat.category}, {mat.material}, {mat.thickness:0.3f}, {mat.kerf:0.3f}")

The active material can be retrieved.

from laser_util_api import ApiClient, Units

client = ApiClient(units=Units.INCHES)
active = client.work_settings.active_material()
print(active)

Finally, any material option object can be set as active.

from laser_util_api import ApiClient, Units

client = ApiClient(units=Units.INCHES)

options = client.work_settings.material_options()

# Just set the last one active, as an example.
options[-1].set_active()

Kerf

The kerf is the width of the cut made by the laser. Boundaries are offset by half of the kerf width before they're cut. The kerf is a property of the active material option, but it can be overridden in the software to make small adjustments. A larger kerf makes a larger part, while a smaller kerf makes a smaller part.

The kerf can be read directly, and will come through in the client's units.

client = ApiClient(units=Units.INCHES)

print(client.work_settings.kerf)

The kerf override can be read and set as if it were a property of client.work_settings.

client = ApiClient(units=Units.INCHES)

print(client.work_settings.kerf_override)

client.work_settings.kerf_override = True

The kerf can only be set if it is overridden. Setting the kerf is straightforward, but will throw an exception if the kerf override is not active.

client = ApiClient(units=Units.INCHES)

# This will throw an exception if the kerf override is not on
client.work_settings.kerf = 0.1

Fonts

In the work settings there is a library of fonts used for etching. Each font has an integer ID number, a font family, and a font size. Fonts are referenced by their ID when creating a text etch element, allowing all text with that font ID to be adjusted at once. Fonts can be examined, modified, added, and removed through the API.

Getting a list of the active font options is done as follows:

client = ApiClient()

fonts = client.work_settings.fonts()
for font in fonts:
    print(font)

Each font item allows the family and size to be edited. The family is set as a string of the family name, if the family name does not exist on the system setting it will throw an exception.

client = ApiClient()

font = client.work_settings.fonts()[0]
font.size = 16
font.family = "Courier New"

The list of valid font family names on the system can be retrieved as shown:

client = ApiClient()

for name in client.work_settings.get_system_font_families():
    print(name)

A new font can be created using the create_font method, and then edited the same way as any other font.

client = ApiClient()

font = client.work_settings.create_font()
font.size = 20

A font can be located by its ID. If the ID does not exist, an exception will be thrown.

client = ApiClient()

font = client.work_settings.find_font(2)

A font can be deleted if it is not the last font left.

client = ApiClient()

font = client.work_settings.find_font(2)
font.delete()

Project Tree Functions

The project tree is the bar on the left side of the Laser Utility GUI which shows the different entities in the project. A subset of these entities can be interacted with through the Python API using the tree category of the client.

Project tree items which can be interacted with are the ones based on the common workspace entity format. Most project items which have a name, an origin, visibility, for-construction, etc, can be worked with through the API.

Listing and Finding Project Tree Items

You can iterate directly through the .tree category.

client = ApiClient()

for item in client.tree:
    print(item)

You can also index into the client tree. Using an integer will return the item by position, specifying a UUID or a string that converts into a UUID will directly search the tree using an API call. Finally, if given a string that can't be converted into a UUID, the client will check every project item to see if it's ID starts with the specified text.

client = ApiClient()

# Get the first item in the tree
item = client.tree[0]

# Get the item with the specified ID
item = client.tree["384b9cdd-14bb-4099-82ed-3df3a16015c5"]
item = client.tree[UUID("384b9cdd-14bb-4099-82ed-3df3a16015c5")]

# Search for the item with an ID starting with the following text
item = client.tree["384b9"]

Finally, project items can be retrieved based on tags.

client = ApiClient()

# Get a list of project items that have the given tag.
items = client.tree.with_tag("my tag")

Editing Tags

Tags are a feature to help Python scripts label and track project items. They do not currently appear in the UI.

Tags can be added or removed from items using the following methods:

client = ApiClient()

# Get the first item in the tree, just for demonstration purposes
item = client.tree[0]

# Add a tag
item.add_tag("TEST")
print(item.tags)

# Remove the tag
item.remove_tag("TEST")
print(item.tags)

Editing Basic Properties

Special project tree items have additional properties, but most items have at least the following.

Setting the name, visibility, drag lock, and construction states of an item.

client = ApiClient()
item = client.tree[0]

# Retrieve and set the name
print(item.name)
item.name = "Name Changed from API"

# Retrieve and set the visibility
print(item.visible)
item.visible = False

# Retrieve and set the drag lock
print(item.drag_locked)
item.drag_locked = True

# Retrieve and set the for-construction (suppression) property
print(item.for_construction)
item.for_construction = True

The origin X-Y-R can also be set. The rotation is always in radians.

import math
from laser_util_api import ApiClient, Xyr

client = ApiClient()
item = client.tree[0]

# Change the value of its origin position
item.origin = Xyr(100, 200, math.pi / 2)

The origin parent can be set to another project item, or set back to None to reference the workspace origin.

import math
from laser_util_api import ApiClient, Xyr

client = ApiClient()
item = client.tree[0]       # Grab the first item in the tree
parent = client.tree[-1]    # Grab the last item in the tree

# Set the parent of the origin to the last item in the list 
item.origin_parent = parent

# Set the origin parent back to the workspace origin
item.origin_parent = None

Deleting

Items can be deleted through acquiring their handle and using the .delete() method.

client = ApiClient()
item = client.tree[0]

item.delete()

The Scratch Workspaces

There are two scratch workspaces where you can create boundary loops and bodies. These workspaces are created when the client connects to the application and are disposed when the client disconnects. Things created in the scratch workspaces are unique to the client and not preserved between sessions.

Items in the scratch workspace can be used to create project items.

Loops

There are several ways of creating boundary loops in the scratch workspace. Each will return a LoopHandle object, which will allow further modifications to the loop.

from laser_util_api import ApiClient, Vector

client = ApiClient()

# Create a rectangle whose top-left corner is at x=1, y=2, with width=3 and height=4
rect = client.scratch.loops.rectangle(Vector(1, 2), 3, 4)

# Create a rounded rectangle of the same parameters, but with corner radius 0.25
rnd_rect = client.scratch.loops.rounded_rectangle(Vector(1, 2), 3, 4, 0.25)

# Create a circle at x=1, y=2, with radius=3
circle = client.scratch.loops.circle(Vector(1, 2), 3)

# Reverse the circle direction, turning it into a negative boundary
circle.reverse()

# Create an empty loop, then use the cursor to insert a pill shape.  Each element added to the boundary (segment or
# arc) has the *start* point defined, and will run until it hits the start point of the *next* element.  For arcs, the
# circle center must be equidistant from the arc start point and the start point of the next element.
pill = client.scratch.loops.create()
pill.insert_seg_abs(Vector(0, 0))
pill.insert_arc_abs(Vector(1, 0), Vector(1, 1), False)
pill.insert_seg_abs(Vector(1, 2))
pill.insert_arc_abs(Vector(0, 2), Vector(0, 1), False)

Bodies

A body can be created from an initial boundary loop (must be positive), and then modified through shape operations performed with more boundary loops.

To create a basic boundary loop, first let's use a circle.

from laser_util_api import ApiClient, Vector

client = ApiClient()

# Create a circle boundary at 0, 0 with radius 1
circle = client.scratch.loops.circle(Vector(0, 0), 1)

# Now create a body from the circle.
body = client.scratch.bodies.create(circle)

# Now create a rectangular cut to take out of it.
cut0 = client.scratch.loops.rectangle(Vector(0, -0.5), 2, 1)
cut0.reverse()
body.operate(cut0)

# Now create a positive protrusion to add to the top
pos0 = client.scratch.loops.circle(Vector(0, 1), 0.375)
body.operate(pos0)

Creating Project Items

For now, body and etch project items can be created through the API. Both are accessible through the create category of the client.

Body Project Item

Creating an actual project item from a body can be done using either a loop or a body. Both will be immutable after creation, but will persist after the client program ends.

client = ApiClient(units=Units.INCHES)

# Create a circle boundary at 0, 0 with radius 1
circle = client.scratch.loops.circle(Vector(0, 0), 1)

# Create a circle body project item from the circle loop.
circle_body = client.create.body(circle)
circle_body.name = "Body Item from Boundary Loop"

# Now we'll create a body with a cut from the circle and use it to create a more complex body project item
body = client.scratch.bodies.create(circle)
cut0 = client.scratch.loops.rectangle(Vector(0, -0.5), 2, 1)
cut0.reverse()
body.operate(cut0)

complex_body = client.create.body(body)
complex_body.name = "Body Item from Body"

Creating and Editing an Etch Project Item

Etch project items can have text and lines. The following is an example of creating graduated scale marks.

from laser_util_api import import ApiClient, Vector, Units, HAlign, VAlign

client = ApiClient(units=Units.INCHES)

# Create the etch entity
etch = client.create.etch()
etch.name = "Example Etch Markings"

# From a corner at 1, 2 inches, we'll put marks every 1/2 inch
corner = Vector(1, 2)

for i in range(5):
    mark = corner + Vector(0.5, 0) * i

    # Create a vertical line starting at the mark point, 0.25 in tall, with a width of 0.01 inches
    etch.add_line(mark, mark + Vector(0, 0.25), 0.01)

    # Create a text item horizontally centered at the mark, up 0.25 inches. See the
    # function documentation for details
    etch.add_text(mark - Vector(0, 0.25), 0, f"{i + 1}", 1, VAlign.CENTER, HAlign.CENTER)

Adding a large amount of items to an etch feature can involve a lot of back and forth traffic and waiting while the user interface updates. Transactions consisting of many batched etch entities can be created using the with syntax. The transaction object (t in the example below) has the same features as the etch object in the example above, except that it is caching the operations instead of performing them. When the context manager ends as the program exits the scope of the with block, a single large transaction will be performed creating all the cached elements at once.

from laser_util_api import import ApiClient, Vector

client = ApiClient(units=Units.INCHES)

# Create the etch entity
etch = client.create.etch()
etch.name = "Example Etch Markings"

# We're going to create a grid pattern of hatch marks, spaced every inch.
with etch.transaction() as t:
    for i in range(10):
        for j in range(10):
            x = i + 0.5
            y = j + 0.5
            t.add_line(Vector(x - 0.125, y), Vector(x + 0.125, y), 0.02)
            t.add_line(Vector(x, y - 0.125), Vector(x, y + 0.125), 0.02)