technical-constraints（技术限制）

Technical Constraints

Work within platform limitations while preserving animation intent.

Problem Indicators

• Animation doesn't work on target browsers
• Mobile devices can't handle animation
• Framework limitations block implementation
• File size constraints (Lottie, sprites)
• Email/constrained environment needs

Diagnosis by Principle

Straight Ahead vs Pose-to-Pose

Issue: Runtime calculations too expensive Fix: Pre-calculate animations. Use CSS keyframes (pose-to-pose) over JS frame-by-frame (straight ahead).

Solid Drawing

Issue: Complex shapes cause rendering issues Fix: Simplify geometry. Use CSS shapes over SVG paths. Reduce polygon counts in 3D.

Timing

Issue: Consistent timing across devices Fix: Use relative units. Test on slowest target device. Consider requestAnimationFrame for JS.

Secondary Action

Issue: Budget only allows essential animation Fix: Prioritize primary actions. Cut secondary animations first when constrained.

Staging

Issue: Limited screen real estate Fix: Animate in place. Use transforms that don't affect layout. Consider reduce-motion as default on constrained platforms.

Quick Fixes

1. Use CSS over JavaScript - Better browser optimization
2. Progressive enhancement - Core function works without animation
3. Feature detection - Check capability before animating
4. Fallback states - Static alternative for unsupported browsers
5. Lazy load animation libraries - Don't block initial render

Troubleshooting Checklist

• List target browsers/devices
• Check caniuse.com for feature support
• Test on oldest supported browser
• Measure animation impact on bundle size
• Verify fallback experience is acceptable
• Test with animation disabled
• Check framework animation capabilities
• Consider server-rendered alternatives (GIF, video)

Code Pattern

// Feature detection
const supportsAnimation =
  'animate' in Element.prototype &&
  CSS.supports('transform', 'translateZ(0)');

if (supportsAnimation) {
  element.animate(keyframes, options);
} else {
  element.classList.add('final-state');
}

// Progressive enhancement
@supports (animation: name) {
  .element {
    animation: fadeIn 200ms ease-out;
  }
}

Platform-Specific Tips

• Email: Use GIF or static images
• iOS Safari: Test -webkit- prefixes
• Older Android: Reduce animation complexity
• Low-end devices: Use prefers-reduced-motion as proxy