FSR EASU and FSR2 sharpen fragment shaders had a manual Y-flip to undo
the now-removed postprocess.vert flip. Strip those since the vertex
shader no longer flips, making all postprocess paths consistent.
Also flip the default mouse Y-axis to match user expectation (mouse
down = look up / flight-sim style) and make FSR1 disable MSAA on
enable, matching FSR2 behaviour (FSR provides its own spatial AA).
- Motion vectors: single unjittered reprojection matrix (80 bytes) instead of
two jittered matrices (160 bytes), eliminating numerical instability from
jitter amplification through large world coordinates
- Sharpen pass: fix Y-flip for correct UV sampling, double-buffer descriptor
sets to avoid race with in-flight command buffers
- MSAA: auto-disable when FSR2 enabled, grey out AA setting in UI
- Accumulation: variance-based neighborhood clamping in YCoCg space,
correct history layout transitions
- Frame index: wrap at 256 for stable Halton sequence
Full FSR 2.2 pipeline with depth-based motion vector reprojection,
temporal accumulation with YCoCg neighborhood clamping, and RCAS
contrast-adaptive sharpening.
Architecture (designed for FSR 3.x frame generation readiness):
- Camera: Halton(2,3) sub-pixel jitter with unjittered projection
stored separately for motion vector computation
- Motion vectors: compute shader reconstructs world position from
depth + inverse VP, reprojects with previous frame's VP
- Temporal accumulation: compute shader blends 5-10% current frame
with 90-95% clamped history, adaptive blend for disocclusion
- History: ping-pong R16G16B16A16 buffers at display resolution
- Sharpening: RCAS fragment pass with contrast-adaptive weights
Integration:
- FSR2 replaces both FSR1 and MSAA when enabled
- Scene renders to internal resolution framebuffer (no MSAA)
- Compute passes run between scene and swapchain render passes
- Camera cut detection resets history on teleport
- Quality presets shared with FSR1 (0.50-0.77 scale factors)
- UI: "Upscaling" combo with Off/FSR 1.0/FSR 2.2 options
