forgot to commit everything...

user/Fader.h

@@ -0,0 +1,68 @@
+#ifndef FADER_H
+#define FADER_H
+
+#include "ESP8266lib/ext/led/WS2812B.h"
+
+/** fade between two colors */
+class FadeBetween {
+
+	Color c1;
+	Color c2;
+	int pos;
+	int speed;
+	int dir;
+
+public:
+
+	/** ctor */
+	FadeBetween() {
+        restart();
+	}
+
+	void setColor1(Color c1) {
+		this->c1 = c1;
+	}
+
+	void setColor2(Color c2) {
+		this->c2 = c2;
+	}
+
+    void restart()  {
+        pos = 0;
+        speed = 128;
+        dir = 0;
+    }
+
+	void update() {
+
+		if (dir == 0) {
+			++pos;
+			if (pos == speed) {dir = 1;}
+		} else {
+			--pos;
+			if (pos == 0) {dir = 0;}
+		}
+
+	}
+
+	Color getCurrent() const {
+		const int fac0 = pos;
+		const int fac1 = speed - fac0;
+		Color c;
+        c.r = clamp( (c1.r * fac0 + c2.r * fac1) / speed );
+        c.g = clamp( (c1.g * fac0 + c2.g * fac1) / speed );
+        c.b = clamp( (c1.b * fac0 + c2.b * fac1) / speed );
+		return c;
+	}
+
+private:
+
+    static inline uint8_t clamp(int val) {
+        if (val > 255) {return 255;}
+        if (val < 0) {return 0;}
+        return val;
+    }
+
+};
+
+#endif // FADER_H