#include <Arduino.h>
#include <NeoPixelBus.h>

#define PIN D3
#define NUMPIXELS 3

NeoPixelBus<NeoGrbFeature, NeoEsp8266Uart1800KbpsMethod> strip(NUMPIXELS, PIN);

float hue[NUMPIXELS] = {0, 0, 0};
float sat[NUMPIXELS] = {0, 0, 0};
float bri[NUMPIXELS] = {0, 0, 0};

float hueSpeed[NUMPIXELS] = {1.0, 1.01, 1.025};
float satSpeed[NUMPIXELS] = {0.9, 0.95, 1.0};
float briSpeed[NUMPIXELS] = {0.95, 1.0, 1.05};

void setup() {
  strip.Begin();
  strip.Show();
}

void loop() {
  for(int i = 0; i < NUMPIXELS; i++) {
    hue[i] += hueSpeed[i];
    sat[i] += satSpeed[i];
    bri[i] += briSpeed[i];

    if(hue[i] >= 360) hue[i] = 0;
    if(sat[i] >= 360) sat[i] = 0;
    if(bri[i] >= 360) bri[i] = 0;

    float h = hue[i] / 360.0;
    float s = 0.5 + (sin(sat[i] * PI / 180.0) * 0.25);
    float b = 0.45 + (sin(bri[i] * PI / 180.0) * 0.25);

    HsbColor color(h, s, b);
    strip.SetPixelColor(i, color);
  }

  strip.Show();
  delay(20);
}