// Forum: https://forum.arduino.cc/t/can-you-use-the-strip-fill-command-to-fill-from-the-opposite-direction/1189165/
// This Wokwi project: https://wokwi.com/projects/381398312933908481

#include <Adafruit_NeoPixel.h>

#define LED_PIN 6
#define LED_PIN2 5
#define NUM_PIXELS 18

Adafruit_NeoPixel strip(NUM_PIXELS, LED_PIN, NEO_GRB + NEO_KHZ800);
Adafruit_NeoPixel strip_b(NUM_PIXELS, LED_PIN2, NEO_GRB + NEO_KHZ800);

void setup() {
  // These lines are specifically to support the Adafruit Trinket 5V 16 MHz.
  // Any other board, you can remove this part (but no harm leaving it):
#if defined(__AVR_ATtiny85__) && (F_CPU == 16000000)
  clock_prescale_set(clock_div_1);
#endif
  // END of Trinket-specific code.

  strip.begin();           // INITIALIZE NeoPixel strip object (REQUIRED)
  strip.show();            // Turn OFF all pixels ASAP
  strip_b.begin();           // INITIALIZE NeoPixel strip object (REQUIRED)
  strip_b.show();
}

int pos = 0, dir = 1; // Position, direction of "eye"

// loop() function -- runs repeatedly as long as board is on ---------------

void loop() {
  // Fill along the length of the strip in various colors...
  uint32_t softred = strip.Color(255,   0,   55);
  strip.show();
  uint32_t softred_b = strip_b.Color(255,   0,   55);
  strip_b.show();
  //strip.fill(softred, 0, 18);
  uint32_t softblue = strip.Color(55,   10,   255);
  strip.show();
  uint32_t darkred = strip.Color(18,   0,   0);
  strip.show();
  uint32_t mediumred = strip.Color(128,   0,   0);
  strip.show();
  uint32_t softblue_b = strip_b.Color(55,   10,   255);
  strip_b.show();
  int j;

  // Draw 5 pixels centered on pos.  setPixelColor() will clip any
  // pixels off the ends of the strip, we don't need to watch for that.
  //strip.setPixelColor(pos - 2, darkred); // Dark red
  //strip.setPixelColor(pos - 1, mediumred); // Medium red
  strip.setPixelColor(pos +2, softred);
  strip.setPixelColor(pos +1, softred); // Center pixel is brightest
  strip.setPixelColor(pos , softred);
  strip.setPixelColor(pos -1, 0);
  strip.setPixelColor(pos -2, 0);
  strip.setPixelColor(pos -3, softred);
  strip.setPixelColor(pos -4, softred); // Center pixel is brightest
  strip.setPixelColor(pos -5, softred);
  strip.setPixelColor(pos -6, 0);
  strip.setPixelColor(pos -7, 0);
  strip.setPixelColor(pos -8, softred);
  strip.setPixelColor(pos -9, softred); // Center pixel is brightest
  strip.setPixelColor(pos -10, softred);
  strip.setPixelColor(pos -11, 0);
  strip.setPixelColor(pos -12, 0);
  strip.setPixelColor(pos -13, softred);
  strip.setPixelColor(pos -14, softred); // Center pixel is brightest
  strip.setPixelColor(pos -15, softred);
  strip.setPixelColor(pos -16, 0);
  strip.setPixelColor(pos -17, 0);
  strip.setPixelColor(pos -18, softred);
  strip.setPixelColor(pos -19, softred); // Center pixel is brightest
  strip.setPixelColor(pos -20, softred);
  strip.setPixelColor(pos -21, 0);
  strip.setPixelColor(pos -22, 0);
  strip.setPixelColor(pos -23, softred);
  strip.setPixelColor(pos -24, softred); // Center pixel is brightest
  strip.setPixelColor(pos -25, softred);
  strip.setPixelColor(pos -26, 0);
  strip.setPixelColor(pos -27, 0);
  
 
  //strip.setPixelColor(pos + 1, mediumred); // Medium red
  //strip.setPixelColor(pos + 2, darkred); // Dark red

  strip.show();
  delay(100);

  // Rather than being sneaky and erasing just the tail pixel,
  // it's easier to erase it all and draw a new one next time.
//strip.fill(softred, 0, 18);
    for(j=-2; j<= 4; j++) strip.setPixelColor(pos+j, 0);{
      // Bounce off ends of strip
      pos += dir;
      if(pos < 0) {
      pos = 1;
      //dir = -dir;
      } else if(pos >= strip.numPixels()+26) {
      pos = 1;
      }
}
}

    //for(int a=0; a<10; a++) {
      //strip.setPixelColor(1, softred);
      //strip.setPixelColor(8, softblue);
      //strip_b.setPixelColor(12, softblue);
      //delay(200);
      //strip.clear();}
  //strip.fill(softblue, 0, 18);
  //colorWipe(strip.Color(255,   0,   55), 50); // Red
  //colorWipe(strip.Color(55,   10, 255), 50); // Blue
// Some functions of our own for creating animated effects -----------------

// Fill strip pixels one after another with a color. Strip is NOT cleared
// first; anything there will be covered pixel by pixel. Pass in color
// (as a single 'packed' 32-bit value, which you can get by calling
// strip.Color(red, green, blue) as shown in the loop() function above),
// and a delay time (in milliseconds) between pixels.
void colorWipe(uint32_t color, int wait) {
  for(int i=0; i<strip.numPixels(); i++) { // For each pixel in strip...
    strip.setPixelColor(i, color);         //  Set pixel's color (in RAM)
    strip.show();                          //  Update strip to match
    delay(wait);                           //  Pause for a moment
  }
}

void theaterChase(uint32_t color, int wait) {
  for(int a=0; a<10; a++) {  // Repeat 10 times...
    for(int b=0; b<3; b++) { //  'b' counts from 0 to 2...
      strip.clear();         //   Set all pixels in RAM to 0 (off)
      // 'c' counts up from 'b' to end of strip in steps of 3...
      for(int c=b; c<strip.numPixels(); c += 3) {
        strip.setPixelColor(c, color); // Set pixel 'c' to value 'color'
      }
      strip.show(); // Update strip with new contents
      delay(wait);  // Pause for a moment
    }
  }
}