NVIDIA DLSS in place of the game's upscale (optional, RTX GPUs) - #850

…on top of NotRexed#850's DLSS frame code)

A second backend for NotRexed#850's replacement of OoT's gameplay upscale, ported
from the FSR 4.1 work on Lichii's OoT branch (madebyjordan/Lichii-Hyrule
oot-dev, 7f8ae5b337..c5f2fce17d). It takes the same colour, depth and
camera motion as DLSS; DLSS keeps priority when it is on.

- vk_fsr4.cpp: AMD's FSR API (FidelityFX SDK 2.4). Only the MIT headers
  are vendored (third_party/fidelityfx); AMD's signed loader and upscaler
  DLLs load at run time from RX_FSR4_DIR or beside hookshot.exe. The
  newest 4.x provider the loader lists is picked explicitly (RDNA 2 and 3
  run its INT8 model). LDR, non-linear colour, standard depth. One
  context per output size, render sizes up to it, so the Resolution row
  and the game's dynamic resolution need no new context.
- Jitter: the game draws without one, so the draws that test or write
  the scene's depth move by a Halton (2, 3) sub-pixel offset through the
  viewport, and FSR is told it. The offset is part of the state dyn_pack
  compares, or a frame whose draws match the last frame's would keep the
  old one. From Lichii: the phase moves on at the network's pass (where
  the game's frame ends), not at presents; it is on only while FSR drew
  the last network pass.
- AMD edge line (Lichii, RX 6700 XT): moved up or left, the AMD driver
  draws nothing into the scene's last column or row, a stale near-white
  value that became a flickering line in FSR's history. FSR's colour and
  the motion's depth repeat the column and row before them. Colour going
  into FSR is cleaned of NaN and Inf and clamped to [0, 1]; the output
  pass drops NaN and Inf for both upscalers.
- FSR history resets when FSR did not draw the last network pass or on
  a camera cut, not by present count.
- Menu: "AMD FSR 4.1" (Off/On, at once; ini key fsr4, RX_FSR4=0/1).
  Resolution sets what it upscales from (75% Quality, 50% Performance,
  100% anti-aliasing only). RX_FSR4_JITTER=0 turns the jitter off.
- What changes on native, compared with Lichii: no GPU-time divisor
  (Hookshot already scales the game's timer, so it keeps full quality),
  no hunt for the tonemap draw or depth reader (NotRexed#818 takes them where
  the draws are), no 4/3-only size check.
- tests/test_fsr_jitter.py: the jitter is compared and applied, moves on
  at the network's pass, and the edge repeat is in both passes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

… images given back

- The FSR context is made with FFX_UPSCALE_ENABLE_DYNAMIC_RESOLUTION: the
  render size changes under it with the Resolution row and the game's
  dynamic resolution.
- vk_fsr4.cpp is Windows only (AMD's signed runtime is), with stubs
  elsewhere: the Linux build has no LoadLibraryExA.
- AMD's dispatches count as work (note_work, vk_work.h), so full_barrier
  does not leave out the barrier after them as a repeat.
- dlss_image gives a replaced image back 120 presents later, as
  typed_upscale does with its histories, instead of keeping it: DLSS
  fixes the render size, but FSR can run with Resolution Auto.
- The dlss_*.comp headers regenerated at SPIR-V 1.6, as NotRexed#850 makes them.
- readme: FSR 4 claims limited to what was tested (RX 6700 XT, INT8).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…on top of NotRexed#850's DLSS frame code)

A second backend for NotRexed#850's replacement of OoT's gameplay upscale, ported
from the FSR 4.1 work on Lichii's OoT branch (madebyjordan/Lichii-Hyrule
oot-dev, 7f8ae5b337..c5f2fce17d). It takes the same colour, depth and
camera motion as DLSS; DLSS keeps priority when it is on.

- vk_fsr4.cpp: AMD's FSR API (FidelityFX SDK 2.4). Only the MIT headers
  are vendored (third_party/fidelityfx); AMD's signed loader and upscaler
  DLLs load at run time from RX_FSR4_DIR or beside hookshot.exe. The
  newest 4.x provider the loader lists is picked explicitly (RDNA 2 and 3
  run its INT8 model). LDR, non-linear colour, standard depth. One
  context per output size, render sizes up to it, so the Resolution row
  and the game's dynamic resolution need no new context.
- Jitter: the game draws without one, so the draws that test or write
  the scene's depth move by a Halton (2, 3) sub-pixel offset through the
  viewport, and FSR is told it. The offset is part of the state dyn_pack
  compares, or a frame whose draws match the last frame's would keep the
  old one. From Lichii: the phase moves on at the network's pass (where
  the game's frame ends), not at presents; it is on only while FSR drew
  the last network pass.
- AMD edge line (Lichii, RX 6700 XT): moved up or left, the AMD driver
  draws nothing into the scene's last column or row, a stale near-white
  value that became a flickering line in FSR's history. FSR's colour and
  the motion's depth repeat the column and row before them. Colour going
  into FSR is cleaned of NaN and Inf and clamped to [0, 1]; the output
  pass drops NaN and Inf for both upscalers.
- FSR history resets when FSR did not draw the last network pass or on
  a camera cut, not by present count.
- Menu: "AMD FSR 4.1" (Off/On, at once; ini key fsr4, RX_FSR4=0/1).
  Resolution sets what it upscales from (75% Quality, 50% Performance,
  100% anti-aliasing only). RX_FSR4_JITTER=0 turns the jitter off.
- What changes on native, compared with Lichii: no GPU-time divisor
  (Hookshot already scales the game's timer, so it keeps full quality),
  no hunt for the tonemap draw or depth reader (NotRexed#818 takes them where
  the draws are), no 4/3-only size check.
- tests/test_fsr_jitter.py: the jitter is compared and applied, moves on
  at the network's pass, and the edge repeat is in both passes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

… images given back

- The FSR context is made with FFX_UPSCALE_ENABLE_DYNAMIC_RESOLUTION: the
  render size changes under it with the Resolution row and the game's
  dynamic resolution.
- vk_fsr4.cpp is Windows only (AMD's signed runtime is), with stubs
  elsewhere: the Linux build has no LoadLibraryExA.
- AMD's dispatches count as work (note_work, vk_work.h), so full_barrier
  does not leave out the barrier after them as a repeat.
- dlss_image gives a replaced image back 120 presents later, as
  typed_upscale does with its histories, instead of keeping it: DLSS
  fixes the render size, but FSR can run with Resolution Auto.
- The dlss_*.comp headers regenerated at SPIR-V 1.6, as NotRexed#850 makes them.
- readme: FSR 4 claims limited to what was tested (RX 6700 XT, INT8).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>