Universal 1x Grid Migration Strategy (Option A)

Background & Rationale

Currently, OpenHW Studio operates on a 1.5x scaled grid (15px pin spacing) relative to upstream Wokwi element definitions, which operate on a 1x native grid (10px pin spacing). While the 1.5x scale provides larger touch targets and clearer visual ergonomics in the browser UI, it introduces complexity when importing third-party Wokwi projects (diagram.json), requiring dynamic 1.5x coordinate and waypoint scaling during import to prevent component overlap.

To achieve complete architectural purity and 1:1 upstream ecosystem alignment in a future release (e.g., Phase 6), OpenHW Studio plans to migrate the entire emulator component registry to a universal 1x grid.

Architectural Roadmap

1. Registry Manifest Refactoring

Every component manifest in openhw-studio-emulator/src/components/* will be updated to native 1x dimensions:

• Bounding Boxes: Bounding dimensions (w, h) will be scaled down by 1.5x (e.g., Uno width from 311 to 207).
• Pin Coordinates: All pin x, y positions will be scaled down by 1.5x to match the standard 10px pin spacing grid.

2. Legacy Project Fallback (0.6667x Scale)

To ensure zero breakage of existing OpenHW Studio user projects, a reverse scaling fallback will be implemented inside projectUtils.js (normalizeImportedCircuitData):

function migrateLegacyOpenHWProject(circuitData) {
  const isLegacyScale = detectLegacyProject(circuitData);
  if (!isLegacyScale) return circuitData;

  const SCALE_FACTOR = 1 / 1.5; // 0.6667

  const migratedComponents = circuitData.components.map(comp => ({
    ...comp,
    x: Number(comp.x) * SCALE_FACTOR,
    y: Number(comp.y) * SCALE_FACTOR
  }));

  const migratedWires = circuitData.wires.map(wire => ({
    ...wire,
    waypoints: (wire.waypoints || []).map(wp => {
      if (Array.isArray(wp)) return [Number(wp[0]) * SCALE_FACTOR, Number(wp[1]) * SCALE_FACTOR];
      if (wp && typeof wp === 'object') return { ...wp, x: Number(wp.x) * SCALE_FACTOR, y: Number(wp.y) * SCALE_FACTOR };
      return wp;
    })
  }));

  return { components: migratedComponents, wires: migratedWires };
}

3. Benefits of Universal 1x Grid Parity

• Seamless Interoperability: Direct 1:1 compatibility with Wokwi diagram.json without any import-time mathematical scaling.
• Simplified Custom Components: Third-party developers creating custom SVG components can use standard Wokwi element viewBox dimensions directly.
• Unified Mental Model: Eliminates the cognitive overhead of maintaining two separate coordinate systems across frontend simulation and worker execution.