feat(upscaling): add downscale percentages

[alandtse]

Summary by CodeRabbit

• New Features

  • Preset labels now dynamically show scale percentages or “unavailable,” reflecting the selected upscaling method.
  • UI retains per-backend preset scales, enabling consistent preset display across methods.

• Bug Fixes

  • Prevented out-of-bounds reads when switching upscaling methods, improving UI stability.
  • Corrected near-100% scales to display as true 100%, avoiding unintended downscale interpretation.

• Performance

  • Faster, more responsive preset display by reusing previously obtained scale values, reducing unnecessary recomputation and UI flicker.

[coderabbitai]

Warning

Rate limit exceeded

@alandtse has exceeded the limit for the number of commits or files that can be reviewed per hour. Please wait 2 minutes and 18 seconds before requesting another review.

⌛ How to resolve this issue?

After the wait time has elapsed, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

We recommend that you space out your commits to avoid hitting the rate limit.

🚦 How do rate limits work?

CodeRabbit enforces hourly rate limits for each developer per organization.

Our paid plans have higher rate limits than the trial, open-source and free plans. In all cases, we re-allow further reviews after a brief timeout.

Please see our FAQ for further information.

📥 Commits

Reviewing files that changed from the base of the PR and between 68d8cd7 and b402b99.

📒 Files selected for processing (2)

• src/Features/Upscaling.cpp (6 hunks)
• src/Features/Upscaling.h (1 hunks)

Note

Other AI code review bot(s) detected

CodeRabbit has detected other AI code review bot(s) in this pull request and will avoid duplicating their findings in the review comments. This may lead to a less comprehensive review.

Walkthrough

Adds runtime caching of preset upscaling scales per backend and integrates it into ConfigureUpscaling and Upscale flows. Updates UI label handling to use cached scales and clamp indices. Introduces sentinel-based cache fields and internal helper to populate cache, plus minor type and structural adjustments.

Changes

Cohort / File(s)	Summary of Changes
Upscaling feature implementation src/Features/Upscaling.cpp	Added per-backend preset scale caching and UI scaffolding (fsr/xess/dlss scales). Implemented PopulateCachedPresetScales(...) and invoked it in ConfigureUpscaling and Upscale. Switched type of currentUpscaleMode to uint32_t. Clamped slider index for method label. Dynamic preset label shows scale % or “(unavailable)”.
Upscaling header/interface src/Features/Upscaling.h	Introduced kScaleUnavailable sentinel, cachedPresetScales array, and cachedPresetMethod. Declared private helper PopulateCachedPresetScales(UpscaleMethod) to fill cache via vendor SDKs; no exported API changes.

Sequence Diagram(s)

sequenceDiagram
    autonumber
    actor User as UI
    participant U as Upscaling
    participant F as FSR/XeSS/DLSS Backend

    User->>U: ConfigureUpscaling()
    rect rgb(235, 245, 255)
        note over U: Ensure cache aligns with selected method
        U->>U: PopulateCachedPresetScales(method)
        alt Backend available
            U->>F: Query preset scales
            F-->>U: Scale list (floats)
            U->>U: Normalize (~1.0 -> 1.0), store in cache
        else Unavailable/exception
            U->>U: Mark cache invalid (sentinel)
        end
    end
    U-->>User: Render UI with clamped method label and preset scale %

    User->>U: Upscale(frame)
    U->>U: Perform upscaling workflow
    U->>U: PopulateCachedPresetScales(current method)
    U-->>User: UI can display updated preset scale labels

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• fix(upscaling): more upscaling fixes #1498 — Also modifies Upscaling.cpp and related control flow (ConfigureUpscaling and Upscale paths), likely interacting with the new cache-population calls.

Poem

I cached some scales in a tidy heap,
So presets wake without a peep.
Clamp the knob, no bounds to break,
Labels sing the percent they take.
FSR, XeSS, DLSS—hurray!
A rabbit approves: hop, cache, display. 🐇✨

Pre-merge checks and finishing touches

❌ 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%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title "feat(upscaling): add downscale percentages" is concise, follows conventional-commit style, and directly describes the primary change of exposing preset downscale percentages in the upscaling UI (including cached per-backend preset scales and updated labels). The PR's summaries show added cachedPresetScales, per-backend scale arrays, and UI label changes that render scale percentages or "(unavailable)", which matches the title. Overall the title accurately captures the main intent and is clear for a teammate scanning history.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[github-actions]

Using provided base ref: bfafeff
Using base ref: bfafeff
Base commit date: 2025-09-22T00:39:30+01:00 (Monday, September 22, 2025 12:39 AM)
No actionable suggestions for changed features.

[Copilot]

Pull Request Overview

This PR enhances the upscaling feature's UI by adding downscale percentage display for different upscaling methods. The changes provide users with clearer information about the actual resolution scaling applied by each upscaling preset.

• Adds caching mechanism for preset scale values from FSR, XeSS, and DLSS backends
• Updates UI to display percentage values alongside preset names (e.g., "Performance (75%)")
• Improves bounds checking and type safety in upscaling method selection

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

File	Description
src/Features/Upscaling.h	Adds cached preset scales storage and population method declaration
src/Features/Upscaling.cpp	Implements scale caching, UI percentage display, and improved bounds checking

[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (4)

src/Features/Upscaling.h (1)

218-227: Missing include for std::array (prevents ODR/implicit-include reliance).

This header uses std::array but doesn’t include . Add it here to avoid relying on transitive includes.

Apply outside-range addition:

// near other headers
#include <array>

src/Features/Upscaling.cpp (3)

187-193: Guard label index with availableModes, not vector size.

When DLSS is unavailable, availableModes=3 but upscaleModes has 5 entries; using size()-1 may format the DLSS label for one frame. Use availableModes for the label index.

Apply this diff:

-uint32_t modeLabelIndex = std::min(*currentUpscaleMode, static_cast<uint32_t>(upscaleModes.size() - 1));
+uint32_t modeLabelIndex = std::min(*currentUpscaleMode, availableModes);
 std::string currentLabel = upscaleModes[modeLabelIndex];

---

315-316: Avoid std::format in per-frame UI when not needed.

These strings contain no '%' and don’t need formatting. Passing the raw C-strings saves allocations every frame.

Apply this diff:

-ImGui::SliderInt("Frame Limit (Variable Refresh Rate)", (int*)&settings.frameLimitMode, 0, 1, std::format("{}", toggleModes[settings.frameLimitMode]).c_str());
+ImGui::SliderInt("Frame Limit (Variable Refresh Rate)", (int*)&settings.frameLimitMode, 0, 1, toggleModes[settings.frameLimitMode]);

-ImGui::SliderInt("Force Enable Frame Generation", (int*)&settings.frameGenerationForceEnable, 0, 1, std::format("{}", toggleModes[settings.frameGenerationForceEnable]).c_str());
+ImGui::SliderInt("Force Enable Frame Generation", (int*)&settings.frameGenerationForceEnable, 0, 1, toggleModes[settings.frameGenerationForceEnable]);

Also applies to: 321-322

---

722-785: Cache population is robust; consider clamping/validating SDK-returned scales.

Nice defensive try/catch and “near-1.0 → 1.0” normalization. Add finite/range checks to harden against SDK anomalies (NaN/inf or >1).

Apply this diff pattern inside each backend loop:

- float s = <SDK>.GetInputResolutionScale(..., q);
- if (s >= 0.99f) s = 1.0f;
- cachedPresetScales[q] = s;
+ float s = <SDK>.GetInputResolutionScale(..., q);
+ if (!std::isfinite(s) || s <= 0.0f) {
+   cachedPresetScales[q] = Upscaling::kScaleUnavailable;
+   continue;
+ }
+ if (s >= 0.99f) s = 1.0f;
+ cachedPresetScales[q] = std::min(s, 1.0f);

Note: requires .

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between bfafeff and 68d8cd7.

📒 Files selected for processing (2)

• src/Features/Upscaling.cpp (5 hunks)
• src/Features/Upscaling.h (1 hunks)

🧰 Additional context used

📓 Path-based instructions (2)

**/*.{cpp,cxx,cc,c,h,hpp,hxx,hlsl,hlsli,fx,fxh,py}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

Do not include TODO/FIXME placeholders; provide complete, working solutions

Files:

• src/Features/Upscaling.cpp
• src/Features/Upscaling.h

src/**/*.{cpp,cxx,cc,h,hpp,hxx}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

src/**/*.{cpp,cxx,cc,h,hpp,hxx}: Ensure SE/AE/VR runtime compatibility; use runtime detection patterns (e.g., REL::RelocateMember())
Include robust error handling and resource management with graceful degradation in the plugin code

Files:

• src/Features/Upscaling.cpp
• src/Features/Upscaling.h

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: Build plugin and addons

🔇 Additional comments (5)

src/Features/Upscaling.cpp (5)

221-237: Label builder is safe for ImGui’s printf-style fmt.

Using "%%" to render a literal '%' is correct here; no change needed.

---

257-259: Good: single SliderInt with dynamic label.

Consolidating preset selection into one slider with the computed label reduces duplicated UI and keeps state coherent.

---

864-866: Good: populate cache during ConfigureUpscaling.

Keeps UI in sync even before first Upscale pass completes.

---

1609-1610: Good: refresh cache post-upscale.

Ensures freshest values after backend selection/quality changes.

---

176-178: Pointer type mismatch — make pointer and Settings field the same fixed-width type

• src/Features/Upscaling.cpp:176-178 — uint32_t* currentUpscaleMode = &settings.upscaleMethod; I could not locate the Settings definition or any typedef for uint in the repo; confirm the declared type of settings.upscaleMethod. If it's uint (unsigned int), either make Settings::upscaleMethod uint32_t or change the pointer to uint*/unsigned int* so the pointed-to type matches exactly. Use fixed-width types (e.g., uint32_t) for values passed to shaders/constant buffers.

[github-actions]

✅ A pre-release build is available for this PR:
Download