⚡ Optimize Canvas Dot Rotation Rendering

[jsem-nerad]

💡 What: The rendering logic inside _drawDot for stretched dots (when dotStretch is active) has been optimized. We replaced the expensive canvas state matrix modifications (this.ctx.save(), this.ctx.translate(), this.ctx.rotate(), this.ctx.restore()) by mapping rotation and translation natively into the this.ctx.ellipse() method.

🎯 Why: Modifying and restoring the global canvas transformation matrix for every single dot every frame is a known performance bottleneck, particularly for systems with high numbers of dots being stretched and rendered. Eliminating these 4 state calls per stretched dot vastly reduces overhead.

📊 Measured Improvement: We created a benchmark script using node-canvas rendering 10,000 stretched dots over 50 frames to heavily stress this exact code path.

• Average Baseline (Canvas): ~7020ms
• Average Optimized (Canvas): ~6224ms
• Improvement: ~11.3% reduction in execution time for the canvas rendering stress test.

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PR created automatically by Jules for task 9083841866824880453 started by @jsem-nerad

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[Copilot]

Pull request overview

This pull request optimizes DotWave’s stretched-dot rendering path by avoiding per-dot canvas transform state changes and instead using the native rotation parameter of CanvasRenderingContext2D.ellipse(), reducing per-frame overhead when many dots are stretched.

Changes:

• Replaced save()/translate()/rotate()/restore() usage in _drawDot with ctx.ellipse(x, y, radiusX, radiusY, rotation, ...) for stretched dots.
• Regenerated src/dotwave.min.js to reflect the source change.
• Added node_modules/ to .gitignore.

Reviewed changes

Copilot reviewed 1 out of 3 changed files in this pull request and generated no comments.

File	Description
src/dotwave.js	Uses ellipse(..., dot.currentAngle, ...) to draw rotated stretched dots without changing the global canvas transform state.
src/dotwave.min.js	Updated minified distribution build to include the optimized rendering logic.
.gitignore	Ignores node_modules/ to avoid committing dependencies.

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