platform-building

Platform Building

Touch controls, VR input, and accessibility patterns for building systems.

Quick Start

import { TouchBuildController } from './scripts/touch-build-controller.js';
import { VRBuildingAdapter } from './scripts/vr-building-adapter.js';
import { AccessibilityConfig } from './scripts/accessibility-config.js';

// Mobile touch building
const touch = new TouchBuildController(canvas, {
  doubleTapToPlace: true,
  pinchToRotate: true,
  swipeToChangePiece: true
});

touch.onPlace = (position, rotation) => buildingSystem.place(position, rotation); touch.onRotate = (angle) => ghost.rotate(angle);

// VR building with hand tracking const vr = new VRBuildingAdapter(xrSession, { dominantHand: 'right', snapToGrid: true, comfortMode: true // Reduces motion sickness });

vr.onGrab = (piece) => selection.select(piece); vr.onRelease = (position) => buildingSystem.place(position);

// Accessibility configuration const a11y = new AccessibilityConfig({ colorblindMode: 'deuteranopia', // red-green highContrast: true, screenReaderHints: true });

// Apply to ghost preview ghost.setColors(a11y.getValidityColors());

## Reference

See `references/platform-considerations.md` for:
- Mobile gesture patterns (Fortnite Mobile, Minecraft PE)
- VR building research and comfort guidelines
- Colorblind palette recommendations
- Screen reader integration patterns
- Cross-platform input abstraction

## Scripts

| File | Lines | Purpose |
|------|-------|---------|
| `touch-build-controller.js` | ~450 | Mobile gestures: tap, drag, pinch, swipe |
| `vr-building-adapter.js` | ~400 | VR hand/controller input, comfort settings |
| `accessibility-config.js` | ~350 | Colorblind modes, contrast, screen reader |

## Platform Detection

```javascript
// Detect platform capabilities
const platform = {
  isMobile: /Android|iPhone|iPad|iPod/i.test(navigator.userAgent),
  isTouch: 'ontouchstart' in window,
  isVR: navigator.xr !== undefined,
  prefersReducedMotion: window.matchMedia('(prefers-reduced-motion: reduce)').matches,
  prefersHighContrast: window.matchMedia('(prefers-contrast: more)').matches
};

// Initialize appropriate controllers
if (platform.isVR && xrSession) {
  setupVRControls();
} else if (platform.isTouch) {
  setupTouchControls();
} else {
  setupMouseKeyboard();
}

Mobile Considerations

Fortnite Mobile demonstrates effective touch building with customizable HUD, auto-material selection, and gesture-based piece rotation. Key patterns include dedicated build mode toggle, large touch targets (minimum 44px), and visual feedback for all actions.

VR Considerations

VR building requires attention to comfort. Snap rotation reduces motion sickness, and arm-length building distances prevent fatigue. Hand tracking enables intuitive grab-and-place, while controller building benefits from laser-pointer selection for distant pieces.

Accessibility Patterns

Valheim uses blue/yellow instead of green/red for stability indicators, supporting deuteranopia (the most common colorblind condition). High contrast modes should use 7:1 ratio for critical indicators, and all visual feedback should have audio/haptic alternatives.