// Adafruit_NeoPixel simple sketch
 
#include <Adafruit_NeoPixel.h>
#define LED_PIN     14
#define NUM_LEDS    300
#define BRIGHTNESS  100
Adafruit_NeoPixel pixels(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);
 
#define DELAYVAL 100 // Time (in milliseconds) to pause between pixels
#define LAMBDA 100
 
int loops = 0; //ループの回数を数える
 
void setup() {
  pixels.begin(); // INITIALIZE NeoPixel strip object (REQUIRED)
  pixels.setBrightness(BRIGHTNESS);
  Serial.begin(115200);
 
  pixels.clear(); // Set all pixel colors to 'off'
}
 
int sinwave(int rgb, int _loops) {
  float n;
  n = (sin(2 * 3.14 * (float(_loops) / LAMBDA + float(rgb) / 3)) + 1) * 127.5;
  n = pow((n/255),3)*255; //gamma transform
  n = constrain(n, 3, 255);
  return n;
}
 
void loop() {
  //pixels.clear(); // Set all pixel colors to 'off'
  for (int i = 0; i < NUM_LEDS; i++) { // For each pixel...
    pixels.setPixelColor(i, pixels.Color(sinwave(0, loops),
                                         sinwave(1, loops),
                                         sinwave(2, loops)));
//    pixels.setPixelColor(i, pixels.Color(sinwave(0, loops),0,0));
 
//    Serial.println(i);
//    Serial.println(loops);
//    Serial.println(sinwave(0,loops));
//    Serial.println(sinwave(1,loops));
//    Serial.println();
  }
  pixels.show();
  //  delay(DELAYVAL); // Pause before next pass through loop
  loops = ++loops % LAMBDA;
}