Custom animation timing in iOS Swift - Build, Publish & Deploy

Build & Publish - Custom animation timing

Performance Impact of Custom Animation Timing

Custom animation timing controls how fast or slow animations run on screen. Smooth animations need to update frames at about 60 times per second (60fps). If your timing is too complex or uses heavy calculations, it can slow down the frame rate and make the app feel laggy.

Animations also use CPU and GPU resources. Poorly optimized timing can increase battery use and memory load, especially if many animations run at once.

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How to Optimize Custom Animation Timing for 60fps

Use built-in timing functions like CAMediaTimingFunction or UIViewPropertyAnimator with standard easing curves to keep animations smooth.

Avoid complex calculations inside animation blocks. Pre-calculate values if possible.

Limit the number of simultaneous animations. Use CADisplayLink carefully to sync updates with screen refresh.

Test animations on real devices to ensure they run smoothly without dropping frames.

Impact on App Bundle Size and Startup Time

Custom animation timing code itself is small and does not significantly increase app size.

However, if you include many custom animation assets or large timing libraries, bundle size can grow.

Startup time is usually unaffected unless animations start immediately on launch. In that case, delay animations until after the main UI loads.

iOS vs Android Differences for Custom Animation Timing

On iOS, animations use Core Animation and timing functions like CAMediaTimingFunction. You can customize timing curves easily with UIViewPropertyAnimator.

Android uses Animator classes and TimeInterpolator for timing. The concepts are similar but APIs differ.

iOS devices often have ProMotion displays with 120Hz refresh, so timing can be finer. Android devices vary more in refresh rates.

Relevant Store Review Guidelines and Requirements

• Ensure animations do not cause app crashes or freezes (Apple App Store guideline 2.1).
• Animations should not interfere with accessibility features like VoiceOver (Apple HIG).
• Do not use excessive CPU or battery during animations to avoid rejection.
• Respect user settings for reduced motion to improve accessibility.

Self-Check: Your app takes 5 seconds to load this screen. What's likely wrong?

It is likely your custom animation timing is causing heavy calculations or blocking the main thread during startup. You might be starting complex animations too early or running too many animations at once.

Try simplifying timing functions, delaying animations until after the UI loads, and profiling CPU usage during startup.

Key Result

Custom animation timing affects smoothness and battery use. Use built-in timing functions and avoid heavy calculations to keep animations running at 60fps. iOS uses Core Animation timing APIs, and you must respect accessibility and store guidelines for smooth, user-friendly animations.