Proposal: Windows Should Expose Optional Compositor‑Level APIs for Better Window Animations
I’d like to suggest a set of optional compositor APIs that would allow developers to create smoother, more modern window animations and effects on Windows. Tools like WindowFX already try to do this, but they’re forced to rely on old Win32 hooks and workarounds because Windows doesn’t expose enough of the Desktop Window Manager (DWM).
This proposal wouldn’t change anything for existing apps — it would simply give developers more power if they choose to use it.
Why this matters
Right now, Windows doesn’t provide:
- GPU‑accelerated window transforms (scale, rotate, skew, etc.)
- Proper animation hooks for window open/close/minimize
- Access to a window’s compositor surface
- Modern event subscriptions for window lifecycle events
Because of this, any advanced animation tool has to fake effects using overlays, delayed visibility, and message hooks. It works, but it’s fragile and inconsistent.
Other platforms (like macOS with Core Animation) already expose this kind of functionality, which is why their window animations look smoother and more unified.
What Windows could add (all optional)
1. Window Transform API
Allow GPU‑level transforms such as:
- scale
- rotation
- perspective
- opacity
- motion blur
- shader effects
This would let developers animate windows smoothly without hacks.
2. Window Lifecycle Hooks
Expose events like:
- OnWindowWillShow
- OnWindowWillHide
- OnWindowWillMinimize
- OnWindowWillRestore
This would make animations consistent and flicker‑free.
3. Access to Window’s GPU Surface
Even read‑only access would enable:
- elastic zooms
- blur‑while‑moving
- physics‑based effects
- real‑time transitions
This could be sandboxed for security.
4. Modern Event Subscription System
Instead of relying on SetWindowsHookEx, provide a safe, high‑level API for window events. This would reduce conflicts and improve stability.
5. Optional Drag Animation APIs
Expose compositor‑level drag interpolation so developers can create smooth, physics‑based drag effects.
Why optional APIs are the right approach
- No impact on legacy apps
- No forced behavior changes
- Developers opt in only if they want to
- Keeps Windows stable and compatible
- Allows gradual adoption
Closing thoughts
Windows already has a powerful compositor — it just doesn’t expose much of it. Optional APIs would unlock a new generation of UI tools and let developers create richer, smoother, more modern window experiences without relying on workarounds.
I’d love to see Microsoft consider this for future versions of Windows.