animation-patterns

# Animation Patterns Correct API shapes and patterns for SwiftUI animations. Prevents the most common mistakes: mixed spring parameter generations, wrong PhaseAnimator/KeyframeAnimator closure signatures, and using matchedGeometryEffect where matchedTransitionSource is needed. ## When This Skill Activates Use this skill when the user: - Asks to add, fix, or review **animation** code - Mentions **spring**, **bounce**, or **snappy** animations - Wants **view transitions** (insertion/removal, hero, zoom) - Asks about **PhaseAnimator** or **KeyframeAnimator** - Wants **SF Symbol effects** (bounce, pulse, wiggle, breathe) - Mentions **matchedGeometryEffect** or **matchedTransitionSource** - Asks about **reduce motion** / animation accessibility - Wants to sequence or chain animations - Mentions **withAnimation**, **animation completions**, or **Transaction** - Wants **scroll-driven effects** (parallax, carousels, `scrollTransition`, `visualEffect`) - Mentions **MeshGradient**, **TextRenderer**, or **Metal shader effects** (`colorEffect`, `distortionEffect`, `layerEffect`) ## Decision Tree Choose the right reference file based on what the user needs: ``` What are you animating? │ ├─ A state change (opacity, position, color) │ └─ → core-animations.md │ ├─ withAnimation { } — explicit animation │ ├─ .animation(_:value:) — implicit animation │ └─ Spring configuration — .spring, .bouncy, .snappy, .smooth │ ├─ A multi-step / sequenced animation │ └─ → phase-keyframe-...