nkolban · nkolban · May 10, 2017 · May 10, 2017
diff --git a/cpp_utils/WS2812.cpp b/cpp_utils/WS2812.cpp
@@ -241,6 +241,73 @@ void WS2812::setPixel(uint16_t index, uint32_t pixel) {
 	this->pixels[index].blue  = (pixel & 0xff0000) >> 16;
 } // setPixel
 
+/**
+ * @brief Set the given pixel to the specified HSB color.
+ *
+ * The LEDs are not actually updated until a call to show().
+ *
+ * @param [in] index The pixel that is to have its color set.
+ * @param [in] hue The amount of hue in the pixel (0-360).
+ * @param [in] green The amount of saturation in the pixel (0-255).
+ * @param [in] blue The amount of brightnes in the pixel (0-255).
+ */
+void WS2812::setHSBPixel(uint16_t index, uint16_t hue, uint8_t saturation,	uint8_t brightnes) {
+    double sat_red;
+    double sat_green;
+    double sat_blue;
+    double ctmp_red;
+    double ctmp_green;
+    double ctmp_blue;
+    double new_red;
+    double new_green;
+    double new_blue;
+    double dSaturation=(double)saturation/255;
+    double dBrightnes=(double)brightnes/255;
+
+    assert(index < pixelCount);
+
+    if (hue < 120) {
+        sat_red = (120 - hue) / 60.0;
+        sat_green = hue / 60.0;
+        sat_blue = 0;
+    } else if (hue < 240) {
+        sat_red = 0;
+        sat_green = (240 - hue) / 60.0;
+        sat_blue = (hue - 120) / 60.0;
+    } else {
+        sat_red = (hue - 240) / 60.0;
+        sat_green = 0;
+        sat_blue = (360 - hue) / 60.0;
+    }
+
+    if (sat_red>1.0) {
+    	sat_red=1.0;
+    }
+    if (sat_green>1.0) {
+    	sat_green=1.0;
+    }
+    if (sat_blue>1.0) {
+    	sat_blue=1.0;
+    }
+
+    ctmp_red = 2 * dSaturation * sat_red + (1 - dSaturation);
+    ctmp_green = 2 * dSaturation * sat_green + (1 - dSaturation);
+    ctmp_blue = 2 * dSaturation * sat_blue + (1 - dSaturation);
+
+    if (dBrightnes < 0.5) {
+    	new_red = dBrightnes * ctmp_red;
+    	new_green = dBrightnes * ctmp_green;
+    	new_blue = dBrightnes * ctmp_blue;
+    } else {
+    	new_red = (1 - dBrightnes) * ctmp_red + 2 * dBrightnes - 1;
+    	new_green = (1 - dBrightnes) * ctmp_green + 2 * dBrightnes - 1;
+    	new_blue = (1 - dBrightnes) * ctmp_blue + 2 * dBrightnes - 1;
+    }
+
+    this->pixels[index].red   = (uint8_t)(new_red*255);
+    this->pixels[index].green = (uint8_t)(new_green*255);
+    this->pixels[index].blue  = (uint8_t)(new_blue*255);
+} // setHSBPixel
 
 /**
  * @brief Clear all the pixel colors.

diff --git a/cpp_utils/WS2812.h b/cpp_utils/WS2812.h
@@ -45,6 +45,7 @@ class WS2812 {
 	void setPixel(uint16_t index, uint8_t red, uint8_t green, uint8_t blue);
 	void setPixel(uint16_t index, pixel_t pixel);
 	void setPixel(uint16_t index, uint32_t pixel);
+	void setHSBPixel(uint16_t index, uint16_t hue, uint8_t saturation, uint8_t brightnes);
 	void clear();
 	virtual ~WS2812();
 private: