svg-tools/docs/TRANSFORM_MODEL.md

Transform model

SVG transform functions are parsed without changing order: matrix, translate, scale, rotate (with optional center), skewX and skewY. The inspector shows each selected/ancestor source transform, accumulated matrix, determinant/invertibility diagnostics and the candidate matrix.

A draft combines translate, origin, rotate, scale and skew. It affects only the iframe/overlay until Apply. The proposed source and rendering are shown before one revision-checked transaction; undo restores the exact pre-apply text.

Bake support

Element	Supported result
path	all segment points transformed; arcs retained for safe conformal cases or converted/disclosed when required
line	transformed endpoints, remains line
polyline, polygon	transformed point list, same element
rect	remains rect for axis-aligned safe cases; otherwise candidate path
circle	remains circle under conformal scale; otherwise explicit ellipse/path as required
ellipse	remains ellipse for safe axis-aligned cases; otherwise path

Numbers remain full precision internally and are serialized with stable bounded precision only at the explicit operation boundary. Invalid/non-finite geometry, negative radii and unsupported element types fail before patch creation.

Policies and limits

• Non-conformal transforms with a visible stroke produce a warning; stroke width/vector-effect is not silently rewritten.
• General arc conversion is disclosed in the preview.
• Shared gradients, patterns, markers, filters, masks and clips are indexed but not cloned or remapped during bake.
• Text transforms remain attributes; text-to-path is not implemented.
• Group flattening and partial multi-child baking are not implemented.
• Consolidation is available through an appended matrix candidate; a full editable transform-list UI/decomposition is future work.

Browser rendering, particularly text and filters, is the visual oracle; the unit suite checks matrix and geometry invariants but does not claim pixel-perfect equivalence for every renderer.