Fix flip/mirror bugs: preserve on morph, keep pin text upright, flip non-rotatable ports

[darktorres]

Flip/mirror correctness for circuit elements — plus the vector-rendering (including ICs and truth tables), font, and SVG-asset work that grew out of fixing the baked-in pin labels. Organised as a focused, self-verifying commit sequence.

1. Rename rotatable → rotatesGraphic (no behaviour change)

The .rotatable / isRotatable() name was misleading: a rotatable = false element still rotates and flips — it just keeps its icon upright and repositions its ports instead of transforming the graphic. Renamed the constraint/metadata field and the getter to rotatesGraphic so the name matches what it controls. Pure mechanical rename across the metadata, getter, every call site (incl. the MCP handler) and the affected element tests.

2. Preserve flip / audio / volume / delay when morphing

MorphCommand::transferConnections() copied only a subset of element properties, so morphing a flipped element silently un-flipped it — and the audio file, volume and clock delay were dropped too. Flip is now carried over unconditionally (a base property of every element); audio/volume/delay are copied guarded by the existing hasAudio()/hasVolume()/hasDelay() checks, and the state round-trips through undo.

3. Flip & rotate fixed-graphic inputs/outputs by repositioning their ports (+ reconcile MCP)

Flipping a non-rotatable input/output — pushbutton, switch, LED, VCC/GND, clock, buzzer, 7/14/16-seg display — was a no-op: FlipCommand::redo() mirrored only elements that rotate their graphic. Flip now mirrors the ports to the opposite side while keeping the graphic upright, exactly how rotation already repositions them. A new GraphicElement::applyPortOrientation() applies the combined rotation + flip to each port (involutive; reproduces the previous rotation exactly when not flipped), and the old gate is removed. A pushbutton's output port moves to the left edge on horizontal flip; a display's pin columns swap; wires follow. The graphic is never mirrored, so a 7-seg display never renders reversed.

This also reconciles the MCP with the GUI: the context menu rotates these elements fine, but the rotate_element handler rejected them and setElementProperties ignored the request. Those guards are dropped so the MCP repositions ports exactly as the GUI does; the stale negative-case test is fixed.

4. Keep baked-in SVG pin text upright when flipping and rotating

Latches/flip-flops bake their pin letters (D, E, Q, S, R…) into the SVG as <text>, so the item flip (scale(-1)) and rotation rendered them backwards/sideways. When flipped or rotated, the displayed pixmap is derived from a variant rendered out of the same SVG with each <text> counter-oriented (Rotate(-angle) after the flip) about its own centre: the body moves to the mirrored/rotated side but the letters stay upright. No asset edits; unflipped/unrotated/text-free elements are byte-identical. Two robustness measures are folded in — the correction is gated on rotatesGraphic() (a non-rotatable element's text is never corrected) and the variant cache key canonicalizes the angle to [0,360) so equivalent rotations share one entry.

5. Crisp vector element rendering

Element SVGs were rasterized once into a fixed ~64×64 QPixmap and scaled by the view, blurring when zoomed in. GraphicElement::paint() now renders the SVG as vectors via QSvgRenderer (one parsed renderer per element, rebuilt only on appearance/flip/rotate change; Qt's existing DeviceCoordinateCache re-renders per zoom level), so every SVG element stays sharp at any magnification. Raster (PNG/JPG) appearances fall back to drawPixmap; pin labels stay upright via the same <text> counter-orientation as §4.

6. Inverted outputs as real glyphs + Noto Sans bundled on every platform

The inverted-output overlines (Q̄/P̄/C̄) were hand-drawn <path> bars that desynced from their letter under rotation; replaced with a single combining-overline glyph (U+0305) that rides with the letter through the counter-orientation. Noto Sans — the maintained successor of Droid Sans, which the SVGs already named but was never shipped — is bundled and registered in Application's constructor, and now ships on every platform: Fonts.qrc was previously compiled only into the WASM build, so on desktop the glyph silently fell back to a system font. Resources are split: desktop Fonts.qrc = NotoSans-Regular; WASM-only ScriptFonts.qrc = the large CJK/script fonts.

7. Re-center memory SVG pin labels

Removed dead Inkscape "Glow" <defs> filter blocks and leftover empty <text> placeholders from the memory-element SVGs, and re-centered each pin letter on its column (Noto Sans advances; baselines normalized to y=23/52) across the D/SR latches and D/SR/JK/T flip-flops in both Dark and Light themes. The clock triangle and overline glyphs are unchanged.

8. Repo-wide SVG cruft scrub (render-identical)

Stripped Inkscape editor cruft from all 191 SVGs via a conservative SVGO allow-list (no geometry/path/style plugins): XML comments, <sodipodi:namedview>, <metadata>/RDF, every inkscape:/sodipodi: attribute (including inkscape:export-filename, which leaked the original author's local /home/… paths in 121 files), unreferenced <defs>, and unused ids/namespaces. Most files shrink dramatically (e.g. a counter segment 109 → 6 lines); ~−20k lines net. The dolphin's embedded PNG is kept as clean single-line base64 (SVGO 4 line-wraps and can corrupt whitespace inside base64 data URIs). svgo.config.mjs makes the cleanup reproducible and documents that hazard.

9. Vectorize dolphin_icon

Traced dolphin_icon.svg's 64×64 embedded PNG — the last embedded raster in the repo — into a single vector <path> (potrace, 96% IoU vs the original mask), replacing the <image>. The toolbar icon is now fully vector, crisp at any zoom, with no base64.

10. Locale flags render correctly in Qt (clip-paths baked to geometry)

Qt's QSvgRenderer does not support clip-path (confirmed against Qt's own docs — the lone gap; filter/feGaussianBlur, mask, pattern, symbol, marker are all parsed since 6.7). Three locale flags rendered correctly in browsers but wrong in-app. Each clip is baked into explicit QPainterPath-boolean geometry, dropping the clip-path attributes and <clipPath> defs while staying pixel-identical in spec-compliant renderers:

• brasil.svg — the white "Ordem e Progresso" band (clipped to the blue disc) overflowed the whole flag, and the letter G in "PROGRESSO" (an O-ring carved by a second clip) was malformed. Band = disc ∩ outer band-circle − inner band-circle (4 arcs); G = O-ring with the arm notch (~5 commands).
• english.svg — the red St Patrick saltire (full diagonals clipped to the counterchanged halves) drew as a symmetric red X. Baked as stroke(diagonals, 4) ∩ the 4 counterchange triangles.
• slovak.svg — the blue hills (clipped to the coat-of-arms shield) overflowed past the shield. Baked as hills ∩ shield (compact polygon; the shield path #s is kept in <defs> for its two <use> refs).

11. Crisp IC and TruthTable bodies

§5 missed ICs and truth tables: each composed its whole body into a fixed-resolution raster QPixmap (the DIP package rect, a rasterised mascot/table logo, the shadow and — for IC — the pin-1 notch) in generatePixmap() and blitted it in an overridden paint(), so the body blurred when zoomed. Both now draw the body directly on the painter every paint — the rounded-rects and the notch are vector primitives, and the logo renders through a shared lazily-built QSvgRenderer instead of a pre-rasterised pixmap. generatePixmap() keeps m_pixmap only as a transparent, correctly-sized placeholder (so pixmapCenter()/boundingRect() and the ports are unchanged), and the existing DeviceCoordinateCache caches the crisp result per zoom level.

12. Refresh translation source locations

Mechanical update_translations pass after the rework: only the <location line="N"> references across the 39 .ts files shift to track the new source line numbers (548 strings, 0 new or removed). No translatable text or translations change.

Tests & verification

• testMorphPreservesFlip / testMorphPreservesVolume — flip, and a non-default volume, survive morph + undo (Buzzer↔AudioBox).
• testFlipTextPixmapVariant / testRotateTextPixmapVariant / testFlipRotateTextPixmapVariant — a flipped / rotated / both latch gets a text-corrected variant distinct from base, rotate-only and flip-only; round-trips; no-op for a text-free gate.
• testFlipNonRotatablePorts / testRotateNonRotatablePorts / testFlipRotateNonRotatablePort — a pushbutton's (and Display7's) port mirrors/rotates to the opposite side while the item transform stays identity, and round-trips on undo.
• The SVG scrub is verified render-identical: a QSvgRenderer pixel-compare of all 191 SVGs (pristine vs cleaned) shows 0 differences at 256px. (The same compare caught — and this PR avoids — a base64 character SVGO had mangled in the dolphin's PNG.)
• Each baked flag is verified by rendering the asset through Qt's own QSvgRenderer (before: band/saltire/hills overflow or malformed; after: correct) and pixel-matching the baked geometry against the QPainterPath intersection ground truth (edge anti-aliasing only).
• IC/TruthTable crispness is GUI-confirmed (the body and logo stay sharp at high zoom instead of pixelating); the change is logic-preserving for the existing IC/TruthTable tests — sizing, ports and save/load are untouched.
• Full suite green locally: ctest --preset debug, 176/176.