SmrtHub WinUI3 DPI Discipline (Authoritative Extract)

Status: Active Owner: Platform / UI Engineering

This page is the in-site copy of the authoritative README in README.Files/SmrtHub-WinUI3-DPI-Discipline.README.md.

Core Discipline

• Declare only x64 platform; no AnyCPU WinUI packaging builds.
• Use vector (SVG / Path) assets where possible; raster only when pixel-fitted.
• Enforce consistent scaling logic – never mix raw pixel sizes with effective DPI without explicit conversion.

Layout & Scaling Rules

1. Use DisplayInformation (or WinUI3 equivalent) to query scale; convert asset pixel dimensions using that factor.
2. Minimum interaction target: 32x32 effective pixels (after scale) for pointer-friendly controls.
3. Do not round intermediate layout calculations down; round to nearest to reduce cumulative drift.
4. Avoid fixed pixel sizes in styles; prefer resource tokens referencing scale-aware helpers.

Assets & DPI

• UI icons: keep a single SVG authoring source, but render as XAML geometry (PathIconSource) so icons tint cleanly across theme + state.
• Only produce raster fallbacks for shell/tray icons (multi-size .ico).
• Logo: supply SVG + a few tuned raster fallbacks (48, 128, 256) if clarity requires.

Testing Checklist

Check	Tooling
High-DPI text crisp	Manual at 150/200%
SVG icons sharp	Visual + pixel zoom
No double-scaling	Inspect transforms
Interaction targets >= 32px	UI inspection
No clipped layout at 125/175%	Resize test

(For full rationale and edge cases consult the root README copy.)