fix(upscaling): fix FSR regression from 1.4.8

[Almoped]

Revert change from refactor. Tested on 1.4.8 and git-dev.

Fixes #2213

Summary by CodeRabbit

• Bug Fixes
  • Adjusted mipmap bias calculation for temporal upscaling: bias now matches the render vs. screen size ratio, with the additional -1.0 offset applied only when using DLSS. Improves visual consistency across non-TAA upscaling methods.

[coderabbitai]

Caution

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ℹ️ Recent review info

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Run ID: 20bcd4bb-3155-4688-882d-aef581ed863f

📥 Commits

Reviewing files that changed from the base of the PR and between 1e3fc89 and 28a8199.

📒 Files selected for processing (1)

• src/State.cpp

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📝 Walkthrough

Walkthrough

State::UpdateSharedData modifies MipBias in the temporal upscaling branch: it now computes MipBias = log2(renderSize.x / screenSize.x) for non-TAA methods and subtracts 1.0f only when the upscale method is DLSS.

Changes

MipBias Temporal Upscaling Adjustment

Layer / File(s)	Summary
MipBias calculation for temporal upscaling src/State.cpp	When temporal upscaling is enabled and the upscale method is not TAA, MipBias is computed from the render-to-screen ratio; the -1.0f offset now applies conditionally only for DLSS upscaling, replacing the previous unconditional offset.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Possibly related PRs

• community-shaders/skyrim-community-shaders#1523: Both PRs modify State::UpdateSharedData's data.MipBias logic for the temporal/upscale-not-TAA branch, including how and when the -1.0f offset is applied.
• community-shaders/skyrim-community-shaders#1521: Both PRs modify State::UpdateSharedData in the temporal/non-TAA upscaling path's MipBias calculation, including the render-size ratio computation and offset application logic.

Suggested reviewers

• alandtse
• doodlum
• jiayev

Poem

🐰 A tiny bias, shifted with care,
DLSS alone gets the extra flair,
Logs of sizes tell the tale,
Other methods follow the same trail,
Pixels stay sharp — a rabbit's cheer!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title directly and specifically identifies the main change: fixing an FSR (FidelityFX Super Resolution) regression introduced in version 1.4.8, which aligns with the pull request objectives and the code change that modifies MipBias calculation for non-TAA upscaling methods.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

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Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 OpenGrep (1.21.0)

OpenGrep fatal error (exit code 2): [00.12][ERROR]: Error: exception Unix_error: No such file or directory stat src/State.cpp
Raised by primitive operation at UTmp.replace_named_pipe_by_regular_file_if_needed in file "libs/commons/UTmp.ml", line 145, characters 8-27
Called from Scan_CLI.replace_target_roots_by_regular_files_where_needed.(fun) in file "src/osemgrep/cli_scan/Scan_CLI.ml", lines 1086-1087, characters 19-65
Called from List_.fast_map in file "libs/commons/List_.ml", line 81, characters 17-20
Called from Scan_CLI.repla

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