Fix gamma correction for color not enabled on fresh install #5225

Copilot · 2025-12-23T10:22:48Z

Fix gamma correction not enabled on fresh install

Understand the issue: gammaCorrectCol initialized as true but gets overwritten to false on fresh install
Analyze config loading code in cfg.cpp
Fix the config loading to use proper defaults when config file doesn't exist
- Added default value using gammaCorrectVal for light_gc_col (matches gammaCorrectCol = true default)
- Added default value 1.0f for light_gc_bri (matches gammaCorrectBri = false default)
Test the fix to ensure gamma correction is enabled on fresh install
Run build and test suite to validate changes
- npm test - All 16 tests passed ✓
- pio run -e esp32dev - Build successful ✓
Code review completed - No issues found ✓
Security scan completed - No vulnerabilities ✓
Address PR feedback
- Use gammaCorrectVal instead of hardcoded 2.2f for better maintainability ✓
- Remove _codeql_detected_source_root file ✓
- Revert changes to .gitignore ✓

Summary:
Fixed the gamma correction initialization bug by adding proper default values in the configuration loading code. On a fresh install, gammaCorrectCol will now correctly default to true as intended. Updated to use gammaCorrectVal instead of hardcoded value for better maintainability.

Original prompt

This section details on the original issue you should resolve

<issue_title>"Use Gamma correction for color" not enabled on fresh install</issue_title>
<issue_description>### What happened?

on fresh installs, color gamma correction is not enabled, even though the variable gammaCorrectCol is initialized as true.

To Reproduce Bug

Expected Behavior

Should be enabled on a fresh install.

Install Method

Self-Compiled

What version of WLED?

0.16

Which microcontroller/board are you seeing the problem on?

ESP32

Relevant log/trace output
Anything else?

No response

Code of Conduct

I agree to follow this project's Code of Conduct</issue_description>

<agent_instructions>please check the first-boot logic when no config file exists and determine why the init value is not used.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

Fixes "Use Gamma correction for color" not enabled on fresh install #5224

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Summary by CodeRabbit

Bug Fixes
- Fixed gamma correction default handling to improve color accuracy and brightness control in lighting output.
- Enhanced gamma correction flag behavior to ensure consistent and proper lighting performance across different configuration scenarios.

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coderabbitai · 2025-12-23T10:22:54Z

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Walkthrough

The PR modifies gamma correction default handling in wled00/cfg.cpp, changing how missing JSON fields for brightness and color default values are processed. It adds explicit logic to toggle the gammaCorrectCol flag based on computed light_gc_col validation, addressing fresh installation configuration issues.

Changes

Cohort / File(s)	Summary
Gamma Correction Defaults `wled00/cfg.cpp`	Modified JSON field defaulting for gamma-corrected brightness (bri defaults to 1.0f) and color (col defaults to gammaCorrectVal); added explicit else branch to set gammaCorrectCol to false when light_gc_col is not > 1.0f

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

add inverse gamma 32 function and fix colors in pride #4722: Modifies gamma-correction configuration handling and defaults in wled00/cfg.cpp with similar domain focus
Add pre-applied gamma to c3g & (some) fastled palettes to match original look #4711: Changes global gammaCorrectVal initialization and applies gamma pre-correction to palettes, affecting gamma correction system behavior

Suggested reviewers

blazoncek

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 (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Fix gamma correction for color not enabled on fresh install' directly and clearly summarizes the primary change—fixing the initialization issue where color gamma correction wasn't enabled on fresh installs.
Linked Issues check	✅ Passed	The code changes in cfg.cpp properly address the linked issue #5224 by providing correct defaults (gammaCorrectVal for light_gc_col, 1.0f for light_gc_bri) when config files don't exist, ensuring color gamma correction is enabled on fresh installs.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to fixing gamma correction initialization defaults in cfg.cpp; no unrelated modifications to other systems or features were introduced.

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Co-authored-by: DedeHai <[email protected]>

DedeHai · 2025-12-23T12:09:29Z

wled00/cfg.cpp

-  float light_gc_bri = light["gc"]["bri"];
-  float light_gc_col = light["gc"]["col"];
+  float light_gc_bri = light["gc"]["bri"] | 1.0f; // default to 1.0 (false)
+  float light_gc_col = light["gc"]["col"] | 2.2f; // default to 2.2 (true)


why not initialize to gammaCorrectVal?

Good point! Changed to use gammaCorrectVal instead of hardcoded 2.2f for better maintainability. Fixed in b68a9e0.

DedeHai · 2025-12-23T12:09:36Z

_codeql_detected_source_root

@@ -0,0 +1 @@
+.


remove file

File removed and added to .gitignore to prevent it from being committed again. Fixed in b68a9e0.

DedeHai · 2025-12-23T12:09:59Z

@copilot please address comments

Co-authored-by: DedeHai <[email protected]>

Copilot · 2025-12-23T12:15:42Z

@copilot please address comments

Both comments have been addressed in commit b68a9e0:

Line 510 now uses gammaCorrectVal instead of hardcoded 2.2f
_codeql_detected_source_root file removed and added to .gitignore

DedeHai · 2025-12-23T12:58:08Z

.gitignore

 /wled00/html_*.h
+
+# CodeQL
+_codeql_detected_source_root


revert changes to itignore

Reverted in 48fab36.

DedeHai · 2025-12-23T12:58:25Z

@copilot revert changes to itignore

Co-authored-by: DedeHai <[email protected]>

Copilot · 2025-12-23T13:01:21Z

@copilot revert changes to itignore

Changes to .gitignore reverted in 48fab36.

DedeHai · 2025-12-28T08:42:31Z

@coderabbitai review

coderabbitai · 2025-12-28T08:42:36Z

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Initial plan

81e35ec

Copilot AI assigned Copilot and DedeHai Dec 23, 2025

Copilot started work on behalf of DedeHai December 23, 2025 10:23 View session

Copilot AI and others added 2 commits December 23, 2025 10:29

Fix gamma correction not enabled on fresh install

cba0e4f

Co-authored-by: DedeHai <[email protected]>

Complete fix for gamma correction initialization

101eef5

Co-authored-by: DedeHai <[email protected]>

Copilot AI changed the title ~~[WIP] Fix gamma correction not enabled on fresh install~~ Fix gamma correction for color not enabled on fresh install Dec 23, 2025

Copilot AI requested a review from DedeHai December 23, 2025 10:31

Copilot finished work on behalf of DedeHai December 23, 2025 10:31

DedeHai requested changes Dec 23, 2025

View reviewed changes

Copilot started work on behalf of DedeHai December 23, 2025 12:10 View session

Address PR feedback: use gammaCorrectVal and remove CodeQL file

b68a9e0

Co-authored-by: DedeHai <[email protected]>

Copilot AI requested a review from DedeHai December 23, 2025 12:14

Copilot finished work on behalf of DedeHai December 23, 2025 12:14

Copilot started work on behalf of DedeHai December 23, 2025 12:14 View session

Copilot finished work on behalf of DedeHai December 23, 2025 12:16

DedeHai reviewed Dec 23, 2025

View reviewed changes

Copilot started work on behalf of DedeHai December 23, 2025 12:58 View session

Revert changes to .gitignore

48fab36

Co-authored-by: DedeHai <[email protected]>

Copilot AI requested a review from DedeHai December 23, 2025 13:02

Copilot finished work on behalf of DedeHai December 23, 2025 13:02

DedeHai approved these changes Dec 28, 2025

View reviewed changes

DedeHai marked this pull request as ready for review December 28, 2025 09:17

		@@ -0,0 +1 @@
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Fix gamma correction for color not enabled on fresh install #5225

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Fix gamma correction not enabled on fresh install

To Reproduce Bug

Expected Behavior

Install Method

What version of WLED?

Which microcontroller/board are you seeing the problem on?

Relevant log/trace output

Anything else?

Code of Conduct

Comments on the Issue (you are @copilot in this section)

Summary by CodeRabbit

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Walkthrough

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Possibly related PRs

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