Added 'rainbow' boot sequence

Moved color transform to utils lib

include/utils/ColorTransform.h

@@ -0,0 +1,50 @@
+#pragma once
+
+// STL includes
+#include <cstdint>
+
+/// Transform for a single color byte value
+///
+/// Transforms are applied in the following order:
+/// 1) a threshold is applied. All values below threshold will be set to zero
+/// 2) gamma color correction is applied
+/// 3) the output value is scaled from the [0:1] to [blacklevel:whitelevel]
+/// 4) finally, in case of a weird choice of parameters, the output is clamped between [0:1]
+///
+/// All configuration values are doubles and assume the color value to be between 0 and 1
+class ColorTransform
+{
+public:
+	ColorTransform();
+	ColorTransform(double threshold, double gamma, double blacklevel, double whitelevel);
+	~ColorTransform();
+
+	double getThreshold() const;
+	void setThreshold(double threshold);
+
+	double getGamma() const;
+	void setGamma(double gamma);
+
+	double getBlacklevel() const;
+	void setBlacklevel(double blacklevel);
+
+	double getWhitelevel() const;
+	void setWhitelevel(double whitelevel);
+
+	/// get the transformed value for the given byte value
+	uint8_t transform(uint8_t input) const
+	{
+		return _mapping[input];
+	}
+
+private:
+	void initializeMapping();
+
+private:
+	double _threshold;
+	double _gamma;
+	double _blacklevel;
+	double _whitelevel;
+
+	uint8_t _mapping[256];
+};

include/utils/HsvTransform.h

@@ -0,0 +1,30 @@
+#pragma once
+
+// STL includes
+#include <cstdint>
+
+class HsvTransform
+{
+public:
+	HsvTransform();
+	HsvTransform(double saturationGain, double valueGain);
+	~HsvTransform();
+
+	void setSaturationGain(double saturationGain);
+	double getSaturationGain() const;
+
+	void setValueGain(double valueGain);
+	double getValueGain() const;
+
+	void transform(uint8_t & red, uint8_t & green, uint8_t & blue) const;
+
+	/// integer version of the conversion are faster, but a little less accurate
+	/// all values are unsigned 8 bit values and scaled between 0 and 255 except
+	/// for the hue which is a 16 bit number and scaled between 0 and 360
+	static void rgb2hsv(uint8_t red, uint8_t green, uint8_t blue, uint16_t & hue, uint8_t & saturation, uint8_t & value);
+	static void hsv2rgb(uint16_t hue, uint8_t saturation, uint8_t value, uint8_t & red, uint8_t & green, uint8_t & blue);
+
+private:
+	double _saturationGain;
+	double _valueGain;
+};