dev-patterns-ui-animations

name	dev-patterns-ui-animations
description	Game UI and HUD animation patterns with Framer Motion. Use when animating HUD elements.
category	patterns

Game UI Animations

"Smooth, responsive UI animations provide critical game feel feedback."

When to Use

Use when:

• Creating HUD elements (kill feed, score updates, notifications)
• Adding entry/exit animations for UI panels
• Implementing smooth value transitions (timer countdown, health bars)

Quick Start

import { motion, AnimatePresence } from 'motion/react';

// Kill feed entry animation
function KillFeedEntry({ kill, onExit }) {
  return (
    <AnimatePresence>
      <motion.div
        initial={{ x: 100, opacity: 0 }}
        animate={{ x: 0, opacity: 1 }}
        exit={{ x: -100, opacity: 0 }}
        transition={{ duration: 0.3, ease: 'easeOut' }}
        onAnimationComplete={onExit}
      >
        {kill.killer} splatted {kill.victim}
      </motion.div>
    </AnimatePresence>
  );
}

Decision Framework

Need	Use
Simple entry/exit animations	CSS transitions with Tailwind classes
Complex choreography	Motion (Framer Motion) variants
Continuous value updates	CSS transforms with requestAnimationFrame
3D UI attached to camera	R3F Html component + CSS animations
High-frequency updates	Transform only (no layout triggers)

CSS-Only Animations (Fastest)

function KillFeedItem({ killer, victim }) {
  return (
    <div className="kill-feed-item animate-slide-in">
      <span className="killer-name">{killer}</span>
      <span className="skull-icon">💀</span>
      <span className="victim-name">{victim}</span>
    </div>
  );
}

/* CSS */
@keyframes slideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@keyframes fadeOut {
  from { opacity: 1; }
  to { opacity: 0; }
}

.kill-feed-item {
  animation: slideIn 0.3s ease-out;
  will-change: transform, opacity;
}

Framer Motion for Complex UI

function KillFeed({ kills }) {
  return (
    <div className="kill-feed">
      <AnimatePresence mode="popLayout">
        {kills.map((kill) => (
          <motion.div
            key={kill.id}
            layout
            initial={{ x: 100, opacity: 0, scale: 0.8 }}
            animate={{ x: 0, opacity: 1, scale: 1 }}
            exit={{ x: -100, opacity: 0, scale: 0.8 }}
            transition={{
              type: 'spring',
              stiffness: 300,
              damping: 25
            }}
            className="kill-entry"
          >
            <span className="killer">{kill.killer}</span>
            <span>⚔️</span>
            <span className="victim">{kill.victim}</span>
          </motion.div>
        ))}
      </AnimatePresence>
    </div>
  );
}

Timer Animation

function MatchTimer({ duration, remaining }) {
  const progress = remaining / duration;

  return (
    <div className="match-timer">
      <motion.div
        className="timer-bar"
        style={{
          scaleX: progress,
          transformOrigin: 'left'
        }}
        transition={{ ease: 'linear', duration: 1 }}
      />
      <span className="timer-text">
        {Math.floor(remaining / 60)}:{(remaining % 60).toString().padStart(2, '0')}
      </span>
    </div>
  );
}

Health/Ink Bar with Color Transition

function InkTankIndicator({ current, max }) {
  const percentage = (current / max) * 100;

  // Color transitions from blue (full) to red (low)
  const color = percentage > 50
    ? '#3b82f6' // blue
    : percentage > 25
    ? '#f59e0b' // orange
    : '#ef4444'; // red

  return (
    <div className="ink-tank">
      <motion.div
        className="ink-level"
        style={{ backgroundColor: color }}
        animate={{ width: `${percentage}%` }}
        transition={{ type: 'spring', stiffness: 200, damping: 20 }}
      />
      <span className="ink-text">{Math.floor(current)} / {max}</span>
    </div>
  );
}

Common Mistakes

❌ Wrong	✅ Right
Animating layout properties (width, height)	Use transform: scaleX/scaleX
Not using will-change	Add for GPU acceleration
Overusing spring animations	Use for UI, not game logic
Animating during high FPS	Consider throttling

Reference

• mobile-haptics.md - Haptic feedback