LazPaint scripts: what changed

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Title: LazPaint scripts

New		Line
1	+	[[LazPaint\|Go back]]
2	+
3	+	Scripts are accessible from the Script menu. There are in Python language and stored in the scripts folder of the application.
4	+
5	+	## Provided scripts
6	+
7	+	- Channels: separate the color channels to RGB or HSL.
8	+	- Layer effects: known layer effects like drop shadow, stroke or color overlay.
9	+	- Mask: function to create a mask layer
10	+	- Render: some example of using the tools from a script
11	+	- Version: show the version of Python
12	+
13	+	## How to make a script
14	+
15	+	A script is a text file with the extension .py that contains the code to run. The first line is a comment that contains the title of the script:
16	+
17	+	`# My script`
18	+
19	+	Or if you want it to be in a submenu:
20	+
21	+	`# My folder > My script`
22	+
23	+	You will need modules to communicate with Lazpaint from the script, so for example to show a message you would write:
24	+
25	+	`from lazpaint import dialog`
26	+
27	+	To use a function from the module:
28	+
29	+	`dialog.show_message("hello world")`
30	+
31	+	So here is our hello world program:
32	+
33	+	`# Tutorial > Hello world program`\
34	+	`from lazpaint import dialog`\
35	+	`dialog.show_message("hello world")`
36	+
37	+	## Run a script
38	+
39	+	### Run from a user folder
40	+
41	+	You can save your script in your documents and in LazPaint use Script \> Run script to browse the folders.
42	+
43	+	### Run from Script menu
44	+
45	+	Alternatively you can add you script to the menu of LazPaint. To do that, using administrator rights, copy the script file into the scripts folder of LazPaint:
46	+
47	+	- On Windows: C:\Program Files\LazPaint\scripts
48	+	- On Linux: /usr/share/lazpaint/scripts
49	+
50	+	Note that the first line must start with a \# and have no spacing before. You need to restart LazPaint to update the Script menu.
51	+
52	+	## Available modules
53	+
54	+	- colors: definitions of colors and color filters
55	+	- command: send raw commands and get version of LazPaint
56	+	- dialog: show messages and dialog boxes
57	+	- filters: apply filters (other than color filters)
58	+	- image: new, load, rotate...
59	+	- imagelist: use the imagelist window (get next image, add files)
60	+	- layer: configure layers, access pixels
61	+	- selection: act on the selection (in particular the blue selection)
62	+	- tools: use the tools by providing mouse positions and key strokes
63	+	- view: zoom and grid
64	+
65	+	## Grouping changes
66	+
67	+	Generally you would like the script to be undoable by clicking only once on Undo. To do that you need to group the changes. For example:
68	+
69	+	`from lazpaint import image, layer, colors`\
70	+	`image.do_begin() # start undo block`\
71	+	`layer.new() # first action: new layer`\
72	+	`layer.fill(colors.YELLOW) # second action: fill with yellow`\
73	+	`image.do_end() # end undo block`
74	+
75	+	## Interact with Pillow
76	+
77	+	If you want to modify the image using a module like [Pillow](https://python-pillow.org/), you can transfer the image to the module using a temporary file:
78	+
79	+	`from lazpaint import image, layer`\
80	+	`from PIL import Image`\
81	+	`temp_name = image.get_temporary_name()`\
82	+	`temp_name = layer.save_as(temp_name) # export to disk`\
83	+	`im = Image.open(temp_name) # load into Pillow`
84	+
85	+	Then you can transfer back the image to LazPaint:
86	+
87	+	`im.save(temp_name, "PNG") # export to disk`\
88	+	`layer.add_from_file(temp_name) # import from disk`
89	+
90	+	## Do an action on each layer
91	+
92	+	The module image contains the function iterate_layers which selects each layer one after another.
93	+
94	+	`from lazpaint import image, colors`\
95	+	`image.do_begin()`\
96	+	`for cur_layer_id in image.iterate_layers():`\
97	+	` colors.complementary()`\
98	+	`image.do_end()`
99	+
100	+	## Color values
101	+
102	+	Colors are stored in an instance of the class colors.RGBA. It has 4 fields: red, green, blue and alpha which are between 0 and 255. Those are in [sRGB](https://en.wikipedia.org/wiki/SRGB) colorspace.
103	+
104	+	The functions colors.to_linear and colors.to_std transforms a channel value from sRGB and from linear RGB. Linear values are floating point values between 0 and 1.
105	+
106	+	`from lazpaint import colors, dialog, tools`\
107	+	`dodger_blue = colors.RGB(30, 144, 255)`\
108	+	`half_transparent_black = colors.RGBA(0, 0, 0, 128)`\
109	+	`dialog.show_message(dodger_blue.blue) # displays 255`\
110	+	`tools.set_fore_color(dodger_blue) # select dodger blue as pen color`
111	+
112	+	---
113	+	From the Free Pascal wiki, page "LazPaint scripts", as it stood on 2020-04-16 after a change by Circular, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).

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