Saturation & Brightness/Value Gain using Oklab color space (#1477)

* Imported Oklab reference implementation

* Add Okhsv conversions

* Fixed formatting error

* Add saturation and value gain to schemas

* Add english translation for saturation, value gain

* Created OkhsvTransform

* Make OkhsvTransform configurable

* Apply OkhvsTransform

* Clamped values during transform

* Precalculate isIdentity in OkhsvTransform

* Skip OkhsvTransform if it is the identity function

* Added changelog message

* Allow for full desaturation

* Imported recommended changes by LordGrey

* Fixed typo in constant

* Fixed anti-pattern in ok_color.h

* Correct indentions

* Correct remote-control

* Limited maximum gain settings to practical range

* Renane valueGain to brightnessGain for clarity and understanding

Co-authored-by: LordGrey <lordgrey.emmel@gmail.com>

include/utils/OkhsvTransform.h

@@ -0,0 +1,63 @@
+#ifndef OKHSVTRANSFORM_H
+#define OKHSVTRANSFORM_H
+
+#include <cstdint>
+
+///
+/// Color transformation to adjust the saturation and value of Okhsv colors
+///
+class OkhsvTransform
+{
+public:
+	///
+	/// Default constructor
+	///
+	OkhsvTransform();
+
+	///
+	/// Constructor
+	///
+	/// @param saturationGain gain factor to apply to saturation
+	/// @param brightnessGain gain factor to apply to value/brightness
+	///
+	OkhsvTransform(double saturationGain, double brightnessGain);
+
+	/// @return The current saturation gain value
+	double getSaturationGain() const;
+
+	/// @param saturationGain new saturation gain
+	void setSaturationGain(double saturationGain);
+
+	/// @return The current brightness gain value
+	double getBrightnessGain() const;
+
+	/// @param brightnessGain new value/brightness gain
+	void setBrightnessGain(double brightnessGain);
+
+	/// @return true if the current gain settings result in an identity transformation
+	bool isIdentity() const;
+
+	///
+	/// Apply the transform the the given RGB values.
+	///
+	/// @param red The red color component
+	/// @param green The green color component
+	/// @param blue The blue color component
+	///
+	/// @note The values are updated in place.
+	///
+	void transform(uint8_t & red, uint8_t & green, uint8_t & blue) const;
+
+private:
+	/// Sets _isIdentity to true if both gain values are at their neutral setting
+	void updateIsIdentity();
+
+	/// Gain settings
+	double _saturationGain;
+	double _brightnessGain;
+
+	/// Is true if the gain settings result in an identity transformation
+	bool _isIdentity;
+};
+
+#endif // OKHSVTRANSFORM_H