[prostohz]

PR description

Bulk selection and movement repeatedly alternate geometry reads with selection-outline writes. They also update the shared resize grips for elements whose grips are hidden. This makes commands on selections of hundreds of shapes expensive.

This change:

• Reads bounding boxes before updating selection outlines during bulk selection and movement.
• Updates the shared grips when shown or when their owning selector changes size, and reuses selectors without repeatedly scanning from the start of the pool.
• Accumulates 2D matrix products numerically before creating the result matrix, preserves the existing 3D fallback, and avoids unnecessary identity transforms and bounding-box reads.
• Skips rotation lookup for non-geometric attribute changes and reuses menu references and live toolbar collections.

Performance evidence

Exploratory Chromium benchmarks against c44f061d2f9a626d2771cc931298af5a45522d87 (the current master), using 500 rect/circle elements and 100 measurements per scenario. Five workers each run one scenario at a time. Values are medians in milliseconds:

Scenario	Before	After
Select	37.717	8.568
Move	49.867	16.435
Duplicate	89.878	33.733
Group	4.623	3.855
Ungroup	26.545	4.242
Align left	49.260	16.360
Fill	1.182	0.877
Delete	2.215	1.590
Undo move	222.915	75.510
Redo move	211.735	80.150

The timer covers the synchronous API call and its synchronous handlers, including layout forced during that call. Setup and result checks are outside the timer. Deferred work and subsequent paint are excluded; in particular, the fill result does not measure completion of the deferred fill operation. These are measurements on one machine with concurrent workers, and the patch was selected during a 20-iteration optimization experiment, rather than evaluated on an independent holdout run.

The source changes are the accepted cumulative patch from iteration-018. Raw samples and iteration history and the benchmark harness are available for inspection.

Validation

• npm run build passed.
• npm test passed: Standard lint, 617 unit tests, and 87 Playwright tests.
• Added four browser regression tests covering matrix composition (including 3D inputs), independent empty transforms, selector reuse, and grip positions after bulk movement, undo, and redo.

The repository's PR template refers to Cypress; these tests use its current Playwright suite. No user-facing API changes or new documentation are needed.

Summary by Sourcery

Optimize bulk selection and editing workflows while preserving selection geometry and transform behavior.

Bug Fixes:

• Keep selection grips, outlines, and matrix handling correct during bulk selection, movement, undo, redo, and empty-transform cases.

Enhancements:

• Reduce bulk selection, movement, transformation, history, and editor UI overhead by minimizing redundant geometry work, reusing selectors and DOM collections, and avoiding unnecessary calculations.

Tests:

• Add browser regression coverage for matrix composition, independent identity transforms, selector reuse, and grip positioning across bulk edits and history operations.

[sourcery-ai]

Reviewer's Guide

This PR improves bulk editing performance by batching geometry reads, minimizing selector and grip DOM updates, reusing selector instances efficiently, and optimizing matrix, history, and UI lookup paths while retaining 3D transform behavior and adding browser regressions for the highest-risk changes.

Sequence diagram for batched bulk selection geometry updates

sequenceDiagram
    participant Selection
    participant SelectorManager
    participant Selector
    participant DOM

    Selection->>Selection: getBBox(elem)
    Selection->>SelectorManager: requestSelector(elem, bbox)
    SelectorManager->>Selector: reset(elem, bbox)
    Selection->>Selector: showGrips(false)
    Selection->>Selector: resize(bbox)
    Selector->>DOM: update selector outline
    opt grips shown
        Selector->>Selector: updateGrips()
        Selector->>DOM: update shared grip positions
    end

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Sequence diagram for bulk movement and selector reuse

sequenceDiagram
    participant Move
    participant SelectorManager
    participant Selector
    participant DOM

    Move->>Move: apply movement transforms
    Move->>Move: utilsGetBBox(selected)
    Move->>SelectorManager: requestSelector(selected, bbox)
    SelectorManager->>Selector: reuse available selector
    SelectorManager->>Selector: resize(bbox)
    Selector->>DOM: update selector outline
    opt active grips
        Selector->>Selector: updateGrips()
        Selector->>DOM: update shared grips
    end

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Flow diagram for optimized matrix multiplication

flowchart LR
    A[Matrix arguments] --> B{Any matrix is2D false?}
    B -->|Yes| C[DOMMatrix.fromMatrix]
    C --> D[3D matrix multiplication]
    B -->|No| E[Accumulate a b c d e f numerically]
    E --> F[Create SVG matrix result]
    D --> G[normalizeNearZero]
    F --> G
    H[Empty transform list] --> I[Return identity transform]

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File-Level Changes

Change	Details	Files
Reduces geometry and DOM work during bulk selection, movement, and selector updates.	Precomputes bounding boxes before requesting or resizing selectors. Updates shared grips only when visible or when their owning selector changes size. Reuses selector instances via a tracked free-list position instead of rescanning the pool. Adds end-to-end coverage for bulk movement grip placement and selector reuse.	packages/svgcanvas/core/select.js packages/svgcanvas/core/selected-elem.js packages/svgcanvas/core/selection.js tests/e2e/bulk-selection-regressions.spec.js
Optimizes transform composition while preserving correct behavior for 3D matrices and empty transform lists.	Accumulates 2D matrix products numerically and creates the SVG matrix only once. Uses the DOMMatrix path when any input is 3D. Avoids creating or repeatedly resolving identity transforms for empty transform lists. Adds regression coverage for transform ordering, 3D inputs, and independent identity results.	packages/svgcanvas/core/math.js packages/svgcanvas/core/select.js tests/e2e/unit/svgcore-matrix-regressions.spec.js
Defers selected-element bounding-box reads until after transform setup where possible.	Skips the initial bounding-box read for common geometric element types. Reads the box after transform-related calculations and retains handling for elements without usable bounds.	packages/svgcanvas/core/recalculate.js
Avoids unnecessary history and UI lookup work for non-geometric updates.	Skips rotation lookup unless the changed attribute can affect the bounding-box center. Caches context-menu link references. Caches live toolbar element collections and simplifies single-child link handling.	packages/svgcanvas/core/undo.js src/editor/dialogs/cmenuDialog.js src/editor/panels/TopPanel.js

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[sourcery-ai]

Hey - I've reviewed your changes and they look great!

Sourcery assessment

Approved.

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