Feature/paint boolean ops by griffpatch · Pull Request #8917 · ScratchAddons/ScratchAddons

griffpatch · 2026-03-27T17:57:48Z

Note added by @DNin01

This pull request incorporates code generated by Claude Sonnet.

Changes

Adds a new Boolean shape operations addon to the vector costume editor.

A Shaping section is injected into the editor toolbar with two layout modes: inline (wide toolbar, five buttons sit directly in the bar) and collapsed (narrow toolbar, a single trigger button opens a hover dropdown panel).

Operations added:

Button	Shortcut	Behaviour
Unite	click	Merges all selected shapes into one, keeping the backmost shape's fill/stroke
Subtract	click	Cuts the upper shape(s) out of the backmost shape; Shift = Punch Through (cuts all other shapes); Alt = keep cutter
Intersect	click	Keeps only the overlapping region; Alt = Divide (splits all shapes into every distinct non-overlapping fragment, Illustrator-style)
Combine / Release	click	Combines selected paths into a CompoundPath with even-odd fill (punch-through holes), or releases a CompoundPath back into individual paths
Expand	click	Expands each shape by half its stroke width, converting the visual stroke to a filled outline
Open / Close Path	Reshape mode context bar	Opens a closed path at the selected anchor, duplicating the break-point so both endpoints overlap at the same position; closes an open path, merging endpoints if they are within 5 units

Additional details:

Text-to-path: selected text items are automatically converted to path outlines before any boolean operation, using a rasterise → threshold → marching-squares trace → Bézier curve-fit pipeline (we could add a hefty library to the dependencies to do this natively?)
Group awareness: Subtract, Intersect, and Punch Through descend recursively into paper.js Groups, preserving the original nesting structure
Style preservation: fill/stroke/strokeWidth are snapshotted before and restored after every operation (paper.js boolean ops silently lose styles)
Scratch open-circle fix: Scratch stores circles as open paths whose last point coincides with the first; a pre-processing step detects and closes these before boolean ops to avoid corrupt results
Dynamic enable/disable: the shaping section and mode-tools button are removed when the addon is disabled; button enabled states update live from the current paper.js selection

Reason for changes

The vector costume editor has no boolean shape tools. Creating complex shapes — cutouts, compound letters, logos, overlapping fills — requires tediously cutting paths by hand with the Reshape tool. Every professional illustration app (Illustrator Pathfinder, Inkscape Path menu, Figma boolean groups) provides these operations as first-class features. This addon brings the full set directly into the editor toolbar.

Tests

Tested in Chrome:

Unite, Subtract, Intersect on two plain paths
Subtract+Shift (Punch Through) on a stack of three shapes
Subtract+Alt / Intersect+Alt (keep cutter / Divide)
Combine and Release round-trip on a CompoundPath
Expand on paths with and without a stroke
Open/Close Path in Reshape mode, including handle preservation at the join and the 5-unit merge snap
Text-to-path conversion triggered via Unite and Subtract on PointText items
Group-aware Subtract where the target is a paper.js Group
All operations on Scratch circles (pseudo-open paths) — no corrupt output
Dynamic enable/disable via the addon toggle
Inline ↔ collapsed toolbar layout in response to toolbar width

…rver

Joeclinton1

Everything (almost) works! Amazing addon. I'm super impressed with the code inside and how this handles the edge cases.

Bugs:

Alt drag should duplicate an object and drag the duplicate only, but alt drag on a shape with a hole, duplicates and drags both parts.
if you click an object and then deselect it by clicking itself with shift (or sometimes ctrl) held down, the boolean operations will be grayed out the next time you click a shape. This doesn't always happen, but it is reproducible.

Ux change:
Personally the functionality of combine/release/expand is not clear without reading the PR description. In the addon description could you describe the different boolean features? Also maybe the tool tip could give some info.

…uble-drag

griffpatch · 2026-03-28T15:26:27Z

@Joeclinton1 Everything (almost) works! Amazing addon. I'm super impressed with the code inside and how this handles the edge cases.

Bugs:

Alt drag should duplicate an object and drag the duplicate only, but alt drag on a shape with a hole, duplicates and drags both parts.

This is actually a Scratch bug - If you import any SVG with a compound share, alt dragging it will show a similar issue - It's also present in Penguin Mod and other costume editors. However, I hate that bug too and I've found a solution so I've included a patch to Scratch's paint editor bug in this addon (can be turned off if wanted with a toggle)

if you click an object and then deselect it by clicking itself with shift (or sometimes ctrl) held down, the boolean operations will be grayed out the next time you click a shape. This doesn't always happen, but it is reproducible.

I've not been able to reproduce this one myself yet.

Ux change: Personally the functionality of combine/release/expand is not clear without reading the PR description. In the addon description could you describe the different boolean features? Also maybe the tool tip could give some info.

Agreed... I just didn't want to over-do it with lots of explanation text. I'll have a think

…ubtract default to punch-through

CubesterYT · 2026-03-28T17:19:51Z

That's not nice. Is it like you are using PenguinMod? or is it original?

This PR is completely unrelated to PenguinMod, he stated he wasn't aware of the mod till now. This is a completely original implementation. Please stop bugging him.

pufferfish101007

This is very exciting. I've left some comments, primarily regarding code style. I think the standard is for class selectors to be written as [class*="class_class-name_"] with a trailing underscore but I didn't make a comment for every occurrence. I trust that the various algorithms work!

- Remove dead #PRE_BLUR and #DEBUG flags and their branches - Remove redundant bare block scopes - Add style.css for dropdown static styles (move from inline cssText) - Replace all setTimeout(updateButtonStates,50) with deferUpdateButtonStates() using double-rAF - Add comment explaining why the defer is needed - Remove '-- Private --' comment that was inaccurate - Add RDP comment explaining 1e-10 guard and fallback - Use class*= with trailing _ for CSS module selectors - Update mode-tools selectors to use trailing _

TSFBCE24RhythmHeaveners · 2026-03-29T08:09:36Z

I tested it and It felt like PenguinMod's.

pufferfish101007

Thanks for doing the menu collapsing - it really makes a difference for small screens. It is not cleared up when the addon is dynamically disabled but that doesn't affect normal reusability at all, and will probably be a very rare occurrence in the wild.

Overall looks good to me; as usual, my approval doesn't count towards the required number, but I'll give an approving review anyway.

pufferfish101007 · 2026-07-24T19:44:23Z

I have just noticed that @Samq64's concerns re. compact editor compatibility from #8917 (comment) haven't been addressed

Samq64 · 2026-07-24T20:00:15Z

Wihtout editor-compact: Shrinking then expanding the window causes the tools to disappear entirely until it becomes wide enough to display all of them without the overflow menu.

With editor-compact: While shrinking the tools appear both in the toolbar and in the overflow menu. Expanding works as expected.

griffpatch · 2026-07-25T11:44:24Z

Wihtout editor-compact: Shrinking then expanding the window causes the tools to disappear entirely until it becomes wide enough to display all of them without the overflow menu.

With editor-compact: While shrinking the tools appear both in the toolbar and in the overflow menu. Expanding works as expected.

I have separated off the toolbar integrating code from the main addon code which is a big code quality improvement. And have reworked that scripting to be more resilient. It should now collapse and expand robustly as well as react to enabling / disabling consistently.

Thanks for your bug reports!

Samq64 · 2026-07-25T11:50:50Z

I have not re-tested yet but one more minor thing from yesterday: with editor-compact could the overflow menu's padding be reduced to match the height of the tools?

griffpatch · 2026-07-25T12:19:05Z

I have not re-tested yet but one more minor thing from yesterday: with editor-compact could the overflow menu's padding be reduced to match the height of the tools?

This isn't an issue with this extension, but would require a change to the editor-compact addon I believe?
The clean fix belongs in editor-compact/userstyle.css: reduce vertical padding for [class*="fixed-tools_mod-menu-item_"]. That will compact Front/Back and our operations consistently.

mxmou

I have a few suggestions for the addon's presentation on the settings page.

griffpatch · 2026-07-31T13:47:03Z

Thanks, I have made the requested wording changes in 392da5b. The description and info text now use full sentences, the Expand text uses Scratch's outline wording and explains the fill edge, and there is a notice that the buttons may move into the More menu on smaller screens. I also brought the tooltips into line with the same wording. JSON and whitespace checks pass.

pufferfish101007 · 2026-08-03T15:08:55Z

Just noticed that the PR description mentions the "Open / Close Path" tool, which isn't mentioned in the addon description. Could some explanation of that be added too, preferably with a more scratch-friendly name?

…mpound button

griffpatch · 2026-08-03T16:31:43Z

I made a small change to have the correct bounding box drawn after a boolean operation

…name from Open/Close Path, add tooltips

griffpatch · 2026-08-03T16:37:19Z

Just noticed that the PR description mentions the "Open / Close Path" tool, which isn't mentioned in the addon description. Could some explanation of that be added too, preferably with a more scratch-friendly name?

Quite right - I've changed the label and added tooltips

…er separators

pufferfish101007 · 2026-08-03T18:28:25Z

So nearly there! Unfortunately it looks like d2f7547 sometimes overcompensates (by quite a lot!)

2026-08-03.19-26-10.mp4

(I checked and that commit is the culprit)

If I fully ungroup all of the subgroups by pressing the ungroup button again, the bug doesn't occur.

griffpatch · 2026-08-03T18:54:09Z

So nearly there! Unfortunately it looks like d2f7547 sometimes overcompensates (by quite a lot!)

2026-08-03.19-26-10.mp4
(I checked and that commit is the culprit)

If I fully ungroup all of the subgroups by pressing the ungroup button again, the bug doesn't occur.

Oh wow - you are great at finding gotchas! - This wasn't a bug in the latest commit, but it did reveal a bug that I hadn't tracked down previously but had seen... that when you combine shapes, sometimes it just didn't look right... It was combining shapes with nested groupings, the nested transformations were not being undone so some of the inner shapes got transported far away! hence the weird selection you saw! I've patched this and WOW does the combine look so much better now! Thanks for spotting that!

pufferfish101007 · 2026-08-03T19:08:16Z

Hopefully final things (all of which I'm happy to push):

versionAdded needs updated to 1.46.0
icons/exclude.svg is unused
some other addons that use the alt key specify that this is option on mac (see the first few results of https://github.com/search?q=repo%3AScratchAddons%2FScratchAddons+%22alt%22+language%3AJSON+path%3Aaddons%2F&type=code) - I think we should do the same here, in both the addon description and the tooltips, probably inline (...Hold Alt (Option on macOS)...)

griffpatch · 2026-08-03T19:15:44Z

Hopefully final things (all of which I'm happy to push):

versionAdded needs updated to 1.46.0

icons/exclude.svg is unused

some other addons that use the alt key specify that this is option on mac (see the first few results of https://github.com/search?q=repo%3AScratchAddons%2FScratchAddons+%22alt%22+language%3AJSON+path%3Aaddons%2F&type=code) - I think we should do the same here, in both the addon description and the tooltips, probably inline (...Hold Alt (Option on macOS)...)

Done

griffpatch added 2 commits March 27, 2026 17:48

Add paint-boolean-ops addon: boolean path operations for vector editor

bcf37b5

Fix no-useless-assignment lint error in text-to-path.js

7168ed1

griffpatch force-pushed the feature/paint-boolean-ops branch from b432be2 to 7168ed1 Compare March 27, 2026 18:41

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paint-boolean-ops: fix Open/Close button injection using MutationObse…

aec01e3

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griffpatch force-pushed the feature/paint-boolean-ops branch 2 times, most recently from 27c66df to aec01e3 Compare March 27, 2026 23:00

Joeclinton1 requested a review from CST1229 March 28, 2026 02:04

Joeclinton1 requested changes Mar 28, 2026

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paint-boolean-ops: format with Prettier 3.2.5 (matching CI)

ca8dabc

Samq64 added type: enhancement New feature for the project new addon Related to new addons to this extension. `scope: addon` should still be added. labels Mar 28, 2026

paint-boolean-ops: add hotfixes for stuck Alt key and CompoundPath do…

706398d

…uble-drag

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paint-boolean-ops: improve UX — better descriptions, tooltips, swap s…

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…ubtract default to punch-through

paint-boolean-ops: fix expand description

5fcb8a4

griffpatch force-pushed the feature/paint-boolean-ops branch from 1919d89 to 5fcb8a4 Compare March 28, 2026 17:25

griffpatch requested a review from Joeclinton1 March 28, 2026 17:27

pufferfish101007 requested changes Mar 28, 2026

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DNin01 added this to the v1.46.0 milestone Mar 28, 2026

griffpatch added 2 commits March 28, 2026 23:57

paint-boolean-ops: remove unnecessary parens in ternaries

0580989

griffpatch force-pushed the feature/paint-boolean-ops branch from 776e9ec to 453a110 Compare March 28, 2026 23:58

griffpatch requested a review from pufferfish101007 March 29, 2026 00:03

Format code

2b60917

pufferfish101007 approved these changes Jun 22, 2026

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pufferfish101007 linked an issue Jul 20, 2026 that may be closed by this pull request

Combine shapes in costume editor #8052

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fix(paint-boolean-ops): stabilize responsive toolbar

d3211de

Samq64 mentioned this pull request Jul 25, 2026

New addon: Shape operations in costume editor #8129

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mxmou reviewed Jul 29, 2026

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Comment thread addons/paint-boolean-ops/addon.json Outdated

Comment thread addons/paint-boolean-ops/addon.json Outdated

Comment thread addons/paint-boolean-ops/addon.json Outdated

Comment thread addons/paint-boolean-ops/addon.json

paint-boolean-ops: improve settings descriptions

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pufferfish101007 reviewed Aug 3, 2026

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Comment thread addons/paint-boolean-ops/userscript.js Outdated

griffpatch added 2 commits August 3, 2026 17:18

fix(paint-boolean-ops): remove stray dashed-border separator after Co…

781fd36

…mpound button

fix(paint-boolean-ops): refresh bounding-box handles after boolean ops

d2f7547

paint-boolean-ops: describe Open/Close Shape in addon description, re…

36211c9

…name from Open/Close Path, add tooltips

paint-boolean-ops: wrap shaping buttons in group divs for dashed-bord…

e62741b

…er separators

Fix combine with nested groups

121da20

Address final review feedback

67d5261

pufferfish101007 merged commit 2c43897 into ScratchAddons:master Aug 3, 2026
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pufferfish101007 mentioned this pull request Aug 3, 2026

editor-compact: paint editor "more" menu much larger than other buttons #9147

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griffpatch mentioned this pull request Aug 5, 2026

Preserve stroke styles after paint boolean operations #9149

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Tests

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