Kelsidavis-WoWee/docs/AMD_FSR2_INTEGRATION.md

AMD FSR2 Integration Notes

This project currently has two FSR2 states:

• AMD FidelityFX SDK backend (preferred): enabled when SDK sources are present.
• Internal fallback backend: used when SDK is missing.

SDK Location

Drop AMD's official FSR2 repo at:

extern/FidelityFX-FSR2

Expected header for detection:

extern/FidelityFX-FSR2/src/ffx-fsr2-api/ffx_fsr2.h

Build Flags

• WOWEE_ENABLE_AMD_FSR2=ON (default): try to use AMD SDK if detected.
• WOWEE_HAS_AMD_FSR2 compile define:
  • 1 when SDK header is found.
  • 0 otherwise (fallback path).

Current Status

• CMake detects the SDK and defines WOWEE_HAS_AMD_FSR2.
• UI shows active FSR2 backend label in settings.
• Runtime logs clearly indicate whether AMD SDK is available.

Remaining Work (to finish official AMD path)

1. Add backend wrapper around FfxFsr2Context and Vulkan backend helpers.
2. Feed required inputs each frame:
   • Color, depth, motion vectors
   • Jitter offsets
   • Delta time and render/display resolution
   • Exposure / reactive mask as needed
3. Replace custom compute accumulation path with ffxFsr2ContextDispatch.
4. Keep current fallback path behind a runtime switch for safety.
5. Add a debug overlay:
   • Backend in use
   • Internal resolution
   • Jitter values
   • Motion vector validity stats
6. Validate with fixed camera + movement sweeps:
   • Static shimmer
   • Moving blur/ghosting
   • Fine geometry stability