WLED/wled00/FX.cpp

/*
  WS2812FX.cpp contains all effect methods
  Harm Aldick - 2016
  www.aldick.org
  LICENSE
  The MIT License (MIT)
  Copyright (c) 2016  Harm Aldick
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.

  Modified heavily for WLED
*/

#include "FX.h"

#define IBN 5100
#define PALETTE_SOLID_WRAP (paletteBlend == 1 || paletteBlend == 3)


/*
 * No blinking. Just plain old static light.
 */
uint16_t WS2812FX::mode_static(void) {
  fill(SEGCOLOR(0));
  return (SEGMENT.getOption(7)) ? FRAMETIME : 500; //update faster if in transition
}


/*
 * Blink/strobe function
 * Alternate between color1 and color2
 * if(strobe == true) then create a strobe effect
 * NOTE: Maybe re-rework without timer
 */
uint16_t WS2812FX::blink(uint32_t color1, uint32_t color2, bool strobe, bool do_palette) {
  uint16_t stateTime = SEGENV.aux1;
  uint32_t cycleTime = (255 - SEGMENT.speed)*20;
  uint32_t onTime = 0;
  uint32_t offTime = cycleTime;

  if (!strobe) {
    onTime = (cycleTime * SEGMENT.intensity) >> 8;
    offTime = cycleTime - onTime;
  }
  
  stateTime = ((SEGENV.aux0 & 1) == 0) ? onTime : offTime;
  stateTime += 20;
    
  if (now - SEGENV.step > stateTime)
  {
    SEGENV.aux0++;
    SEGENV.aux1 = stateTime;
    SEGENV.step = now;
  }

  uint32_t color = ((SEGENV.aux0 & 1) == 0) ? color1 : color2;
  if (color == color1 && do_palette)
  {
    for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
      setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 0));
    }
  } else fill(color);

  return FRAMETIME;
}


/*
 * Normal blinking. 50% on/off time.
 */
uint16_t WS2812FX::mode_blink(void) {
  return blink(SEGCOLOR(0), SEGCOLOR(1), false, true);
}


/*
 * Classic Blink effect. Cycling through the rainbow.
 */
uint16_t WS2812FX::mode_blink_rainbow(void) {
  return blink(color_wheel(SEGENV.call & 0xFF), SEGCOLOR(1), false, false);
}


/*
 * Classic Strobe effect.
 */
uint16_t WS2812FX::mode_strobe(void) {
  return blink(SEGCOLOR(0), SEGCOLOR(1), true, true);
}


/*
 * Classic Strobe effect. Cycling through the rainbow.
 */
uint16_t WS2812FX::mode_strobe_rainbow(void) {
  return blink(color_wheel(SEGENV.call & 0xFF), SEGCOLOR(1), true, false);
}


/*
 * Color wipe function
 * LEDs are turned on (color1) in sequence, then turned off (color2) in sequence.
 * if (bool rev == true) then LEDs are turned off in reverse order
 */
uint16_t WS2812FX::color_wipe(bool rev, bool useRandomColors) {
  uint32_t cycleTime = 750 + (255 - SEGMENT.speed)*150;
  uint32_t perc = now % cycleTime;
  uint16_t prog = (perc * 65535) / cycleTime;
  bool back = (prog > 32767);
  if (back) {
    prog -= 32767;
    if (SEGENV.step == 0) SEGENV.step = 1;
  } else {
    if (SEGENV.step == 2) SEGENV.step = 3; //trigger color change
  }

  if (useRandomColors) {
    if (SEGENV.call == 0) {
      SEGENV.aux0 = random8();
      SEGENV.step = 3;
    }
    if (SEGENV.step == 1) { //if flag set, change to new random color
      SEGENV.aux1 = get_random_wheel_index(SEGENV.aux0);
      SEGENV.step = 2;
    }
    if (SEGENV.step == 3) {
      SEGENV.aux0 = get_random_wheel_index(SEGENV.aux1);
      SEGENV.step = 0;
    }
  }

  uint16_t ledIndex = (prog * SEGLEN) >> 15;
  uint16_t rem = 0;
  rem = (prog * SEGLEN) * 2; //mod 0xFFFF
  rem /= (SEGMENT.intensity +1);
  if (rem > 255) rem = 255;

  uint32_t col1 = useRandomColors? color_wheel(SEGENV.aux1) : SEGCOLOR(1);
  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++)
  {
    uint16_t index = (rev && back)? SEGMENT.stop -1 -i +SEGMENT.start : i;
    uint32_t col0 = useRandomColors? color_wheel(SEGENV.aux0) : color_from_palette(index, true, PALETTE_SOLID_WRAP, 0);
    
    if (i - SEGMENT.start < ledIndex) 
    {
      setPixelColor(index, back? col1 : col0);
    } else
    {
      setPixelColor(index, back? col0 : col1);
      if (i - SEGMENT.start == ledIndex) setPixelColor(index, color_blend(back? col0 : col1, back? col1 : col0, rem));
    }
  } 
  return FRAMETIME;
}


/*
 * Lights all LEDs one after another.
 */
uint16_t WS2812FX::mode_color_wipe(void) {
  return color_wipe(false, false);
}

/*
 * Lights all LEDs one after another. Turns off opposite
 */
uint16_t WS2812FX::mode_color_sweep(void) {
  return color_wipe(true, false);
}


/*
 * Turns all LEDs after each other to a random color.
 * Then starts over with another color.
 */
uint16_t WS2812FX::mode_color_wipe_random(void) {
  return color_wipe(false, true);
}


/*
 * Random color introduced alternating from start and end of strip.
 */
uint16_t WS2812FX::mode_color_sweep_random(void) {
  return color_wipe(true, true);
}


/*
 * Lights all LEDs in one random color up. Then switches them
 * to the next random color.
 */
uint16_t WS2812FX::mode_random_color(void) {
  uint32_t cycleTime = 200 + (255 - SEGMENT.speed)*50;
  uint32_t it = now / cycleTime;
  uint32_t rem = now % cycleTime;
  uint16_t fadedur = (cycleTime * SEGMENT.intensity) >> 8;

  uint32_t fade = 255;
  if (fadedur) {
    fade = (rem * 255) / fadedur;
    if (fade > 255) fade = 255;
  }

  if (SEGENV.call == 0) {
    SEGENV.aux0 = random8();
    SEGENV.step = 2;
  }
  if (it != SEGENV.step) //new color
  {
    SEGENV.aux1 = SEGENV.aux0;
    SEGENV.aux0 = get_random_wheel_index(SEGENV.aux0); //aux0 will store our random color wheel index
    SEGENV.step = it;
  }

  fill(color_blend(color_wheel(SEGENV.aux1), color_wheel(SEGENV.aux0), fade));
  return FRAMETIME;
}


/*
 * Lights every LED in a random color. Changes all LED at the same time
// * to new random colors.
 */
uint16_t WS2812FX::mode_dynamic(void) {
  if (!SEGENV.allocateData(SEGLEN)) return mode_static(); //allocation failed
  
  if(SEGENV.call == 0) {
    for (uint16_t i = 0; i < SEGLEN; i++) SEGENV.data[i] = random8();
  }

  uint32_t cycleTime = 50 + (255 - SEGMENT.speed)*15;
  uint32_t it = now / cycleTime;
  if (it != SEGENV.step && SEGMENT.speed != 0) //new color
  {
    for (uint16_t i = 0; i < SEGLEN; i++) {
      if (random8() <= SEGMENT.intensity) SEGENV.data[i] = random8();
    }
    SEGENV.step = it;
  }
  
  for (uint16_t i = 0; i < SEGLEN; i++) {
    setPixelColor(SEGMENT.start + i, color_wheel(SEGENV.data[i]));
  }
  return FRAMETIME;
}


/*
 * Does the "standby-breathing" of well known i-Devices.
 */
uint16_t WS2812FX::mode_breath(void) {
  uint16_t var = 0;
  uint16_t counter = (now * ((SEGMENT.speed >> 3) +10));
  counter = (counter >> 2) + (counter >> 4); //0-16384 + 0-2048
  if (counter < 16384) {
    if (counter > 8192) counter = 8192 - (counter - 8192);
    var = sin16(counter) / 103; //close to parabolic in range 0-8192, max val. 23170
  }
  
  uint8_t lum = 30 + var;
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_blend(SEGCOLOR(1), color_from_palette(i, true, PALETTE_SOLID_WRAP, 0), lum));
  }

  return FRAMETIME;
}


/*
 * Fades the LEDs between two colors
 */
uint16_t WS2812FX::mode_fade(void) {
  uint16_t counter = (now * ((SEGMENT.speed >> 3) +10));
  uint8_t lum = triwave16(counter) >> 8;

  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_blend(SEGCOLOR(1), color_from_palette(i, true, PALETTE_SOLID_WRAP, 0), lum));
  }

  return FRAMETIME;
}


/*
 * Scan mode parent function
 */
uint16_t WS2812FX::scan(bool dual)
{
  uint32_t cycleTime = 750 + (255 - SEGMENT.speed)*150;
  uint32_t perc = now % cycleTime;
  uint16_t prog = (perc * 65535) / cycleTime;
  uint16_t size = 1 + ((SEGMENT.intensity * SEGLEN) >>9);
  uint16_t ledIndex = (prog * ((SEGLEN *2) - size *2)) >> 16;

  fill(SEGCOLOR(1));

  int led_offset = ledIndex - (SEGLEN - size);
  led_offset = abs(led_offset);

  if (dual) {
    for (uint16_t j = led_offset; j < led_offset + size; j++) {
      uint16_t i2 = SEGMENT.stop -1 -j;
      setPixelColor(i2, color_from_palette(i2, true, PALETTE_SOLID_WRAP, (SEGCOLOR(2))? 2:0));
    }
  }

  for (uint16_t j = led_offset; j < led_offset + size; j++) {
    uint16_t i = SEGMENT.start + j;
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 0));
  }

  return FRAMETIME;
}


/*
 * Runs a single pixel back and forth.
 */
uint16_t WS2812FX::mode_scan(void) {
  return scan(false);
}


/*
 * Runs two pixel back and forth in opposite directions.
 */
uint16_t WS2812FX::mode_dual_scan(void) {
  return scan(true);
}


/*
 * Cycles all LEDs at once through a rainbow.
 */
uint16_t WS2812FX::mode_rainbow(void) {
  uint16_t counter = (now * ((SEGMENT.speed >> 3) +2)) & 0xFFFF;
  counter = counter >> 8;

  fill(color_wheel(counter));

  return FRAMETIME;
}


/*
 * Cycles a rainbow over the entire string of LEDs.
 */
uint16_t WS2812FX::mode_rainbow_cycle(void) {
  uint16_t counter = (now * ((SEGMENT.speed >> 3) +2)) & 0xFFFF;
  counter = counter >> 8;
  
  for(uint16_t i=0; i < SEGLEN; i++) {
    //intensity/29 = 0 (1/16) 1 (1/8) 2 (1/4) 3 (1/2) 4 (1) 5 (2) 6 (4) 7 (8) 8 (16)
    uint8_t index = (i * (16 << (SEGMENT.intensity /29)) / SEGLEN) + counter;
    setPixelColor(SEGMENT.start + i, color_wheel(index));
  }

  return FRAMETIME;
}


/*
 * theater chase function
 */
uint16_t WS2812FX::theater_chase(uint32_t color1, uint32_t color2, bool dopalette) {
  byte gap = 2 + ((255 - SEGMENT.intensity) >> 5);
  uint32_t cycleTime = 50 + (255 - SEGMENT.speed)*2;
  uint32_t it = now / cycleTime;
  if (it != SEGENV.step) //new color
  {
    SEGENV.aux0 = (SEGENV.aux0 +1) % gap;
    SEGENV.step = it;
  }
  
  for(uint16_t i=0; i < SEGLEN; i++) {
    if((i % gap) == SEGENV.aux0) {
      if (dopalette)
      {
        setPixelColor(SEGMENT.start + i, color_from_palette(SEGMENT.start + i, true, PALETTE_SOLID_WRAP, 0));
      } else {
        setPixelColor(SEGMENT.start + i, color1);
      }
    } else {
      setPixelColor(SEGMENT.start + i, color2);
    }
  }
  return FRAMETIME;
}


/*
 * Theatre-style crawling lights.
 * Inspired by the Adafruit examples.
 */
uint16_t WS2812FX::mode_theater_chase(void) {
  return theater_chase(SEGCOLOR(0), SEGCOLOR(1), true);
}


/*
 * Theatre-style crawling lights with rainbow effect.
 * Inspired by the Adafruit examples.
 */
uint16_t WS2812FX::mode_theater_chase_rainbow(void) {
  return theater_chase(color_wheel(SEGENV.step), SEGCOLOR(1), false);
}


/*
 * Running lights effect with smooth sine transition base.
 */
uint16_t WS2812FX::running_base(bool saw) {
  uint8_t x_scale = SEGMENT.intensity >> 2;
  uint32_t counter = (now * SEGMENT.speed) >> 9;

  for(uint16_t i=0; i < SEGLEN; i++) {
    uint8_t s = 0;
    uint8_t a = i*x_scale - counter;
    if (saw) {
      if (a < 16)
      {
        a = 192 + a*8;
      } else {
        a = map(a,16,255,64,192);
      }
    }
    s = sin8(a);
    setPixelColor(SEGMENT.start + i, color_blend(color_from_palette(SEGMENT.start + i, true, PALETTE_SOLID_WRAP, 0), SEGCOLOR(1), s));
  }
  return FRAMETIME;
}


/*
 * Running lights effect with smooth sine transition.
 */
uint16_t WS2812FX::mode_running_lights(void) {
  return running_base(false);
}


/*
 * Running lights effect with sawtooth transition.
 */
uint16_t WS2812FX::mode_saw(void) {
  return running_base(true);
}


/*
 * Blink several LEDs in random colors on, reset, repeat.
 * Inspired by www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/
 */
uint16_t WS2812FX::mode_twinkle(void) {
  fill(SEGCOLOR(1));

  uint32_t cycleTime = 20 + (255 - SEGMENT.speed)*5;
  uint32_t it = now / cycleTime;
  if (it != SEGENV.step)
  {
    uint16_t maxOn = map(SEGMENT.intensity, 0, 255, 1, SEGLEN); // make sure at least one LED is on
    if (SEGENV.aux0 >= maxOn)
    {
      SEGENV.aux0 = 0;
      SEGENV.aux1 = random16(); //new seed for our PRNG
    }
    SEGENV.aux0++;
    SEGENV.step = it;
  }
  
  uint16_t PRNG16 = SEGENV.aux1;

  for (uint16_t i = 0; i < SEGENV.aux0; i++)
  {
    PRNG16 = (uint16_t)(PRNG16 * 2053) + 13849; // next 'random' number
    uint32_t p = (uint32_t)SEGLEN * (uint32_t)PRNG16;
    uint16_t mapped = p >> 16;
    uint16_t j = SEGMENT.start + mapped;
    setPixelColor(j, color_from_palette(j, true, PALETTE_SOLID_WRAP, 0));
  }

  return FRAMETIME;
}


/*
 * Dissolve function
 */
uint16_t WS2812FX::dissolve(uint32_t color) {
  bool wa = (SEGCOLOR(1) != 0 && _brightness < 255); //workaround, can't compare getPixel to color if not full brightness
  
  for (uint16_t j = 0; j <= SEGLEN / 15; j++)
  {
    if (random8() <= SEGMENT.intensity) {
      for (uint8_t times = 0; times < 10; times++) //attempt to spawn a new pixel 5 times
      {
        uint16_t i = SEGMENT.start + random16(SEGLEN);
        if (SEGENV.aux0) { //dissolve to primary/palette
          if (getPixelColor(i) == SEGCOLOR(1) || wa) {
            if (color == SEGCOLOR(0))
            {
              setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 0));
            } else { setPixelColor(i, color); }     
            break; //only spawn 1 new pixel per frame per 50 LEDs
          }
        } else { //dissolve to secondary
          if (getPixelColor(i) != SEGCOLOR(1)) { setPixelColor(i, SEGCOLOR(1)); break; }
        }
      }
    }
  }

  if (SEGENV.call > (255 - SEGMENT.speed) + 15) 
  {
    SEGENV.aux0 = !SEGENV.aux0;
    SEGENV.call = 0;
  }
  
  return FRAMETIME;
}


/*
 * Blink several LEDs on and then off
 */
uint16_t WS2812FX::mode_dissolve(void) {
  return dissolve(SEGCOLOR(0));
}


/*
 * Blink several LEDs on and then off in random colors
 */
uint16_t WS2812FX::mode_dissolve_random(void) {
  return dissolve(color_wheel(random8()));
}


/*
 * Blinks one LED at a time.
 * Inspired by www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/
 */
uint16_t WS2812FX::mode_sparkle(void) {
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 1));
  }
  uint32_t cycleTime = 10 + (255 - SEGMENT.speed)*2;
  uint32_t it = now / cycleTime;
  if (it != SEGENV.step)
  {
    SEGENV.aux0 = random16(SEGLEN); // aux0 stores the random led index
    SEGENV.step = it;
  }
  
  setPixelColor(SEGMENT.start + SEGENV.aux0, SEGCOLOR(0));
  return FRAMETIME;
}


/*
 * Lights all LEDs in the color. Flashes single white pixels randomly.
 * Inspired by www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/
 */
uint16_t WS2812FX::mode_flash_sparkle(void) {
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 0));
  }

  if(random8(5) == 0) {
    SEGENV.aux0 = random16(SEGLEN); // aux0 stores the random led index
    setPixelColor(SEGMENT.start + SEGENV.aux0, SEGCOLOR(1));
    return 20;
  } 
  return 20 + (uint16_t)(255-SEGMENT.speed);
}


/*
 * Like flash sparkle. With more flash.
 * Inspired by www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/
 */
uint16_t WS2812FX::mode_hyper_sparkle(void) {
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 0));
  }

  if(random8(5) < 2) {
    for(uint16_t i=0; i < max(1, SEGLEN/3); i++) {
      setPixelColor(SEGMENT.start + random16(SEGLEN), SEGCOLOR(1));
    }
    return 20;
  }
  return 20 + (uint16_t)(255-SEGMENT.speed);
}


/*
 * Strobe effect with different strobe count and pause, controlled by speed.
 */
uint16_t WS2812FX::mode_multi_strobe(void) {
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 1));
  }
  //blink(SEGCOLOR(0), SEGCOLOR(1), true, true);

  uint16_t delay = 50 + 20*(uint16_t)(255-SEGMENT.speed);
  uint16_t count = 2 * ((SEGMENT.speed / 10) + 1);
  if(SEGENV.step < count) {
    if((SEGENV.step & 1) == 0) {
      for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
        setPixelColor(i, SEGCOLOR(0));
      }
      delay = 20;
    } else {
      delay = 50;
    }
  }
  SEGENV.step = (SEGENV.step + 1) % (count + 1);
  return delay;
}

/*
 * Android loading circle
 */
uint16_t WS2812FX::mode_android(void) {
  if (SEGENV.call == 0)
  {
    SEGENV.step = SEGMENT.start;
  }
  
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 1));
  }

  if (SEGENV.aux1 > ((float)SEGMENT.intensity/255.0)*(float)SEGLEN)
  {
    SEGENV.aux0 = 1;
  } else
  {
    if (SEGENV.aux1 < 2) SEGENV.aux0 = 0;
  }

  uint16_t a = SEGENV.step;
  
  if (SEGENV.aux0 == 0)
  {
    if (SEGENV.call %3 == 1) {a++;}
    else {SEGENV.aux1++;}
  } else
  {
    a++;
    if (SEGENV.call %3 != 1) SEGENV.aux1--;
  }
  
  if (a >= SEGMENT.stop) a = SEGMENT.start;

  if (a + SEGENV.aux1 < SEGMENT.stop)
  {
    for(int i = a; i < a+SEGENV.aux1; i++) {
      setPixelColor(i, SEGCOLOR(0));
    }
  } else
  {
    for(int i = a; i < SEGMENT.stop; i++) {
      setPixelColor(i, SEGCOLOR(0));
    }
    for(int i = SEGMENT.start; i < SEGENV.aux1 - (SEGMENT.stop -a); i++) {
      setPixelColor(i, SEGCOLOR(0));
    }
  }
  SEGENV.step = a;

  return 3 + ((8 * (uint32_t)(255 - SEGMENT.speed)) / SEGLEN);
}

/*
 * color chase function.
 * color1 = background color
 * color2 and color3 = colors of two adjacent leds
 */
uint16_t WS2812FX::chase(uint32_t color1, uint32_t color2, uint32_t color3, bool dopalette) {
  uint16_t counter = now * (SEGMENT.speed >> 3) + 1;
  uint16_t a = counter * SEGLEN  >> 16;
  // Use intensity setting to vary chase up to 1/2 string length
  uint16_t b = (a + 1 + (SEGMENT.intensity * SEGLEN >> 10)) % SEGLEN;
  uint16_t c = (b + 1 + (SEGMENT.intensity * SEGLEN >> 10)) % SEGLEN;

  if (dopalette) color1 = color_from_palette(SEGMENT.start + a, true, PALETTE_SOLID_WRAP, 1);

  setPixelColor(SEGMENT.start + a, color1);
  setPixelColor(SEGMENT.start + b, color2);
  setPixelColor(SEGMENT.start + c, color3);

  return FRAMETIME;
}


/*
 * Bicolor chase, more primary color.
 */
uint16_t WS2812FX::mode_chase_color(void) {
  return chase(SEGCOLOR(1), SEGCOLOR(0), SEGCOLOR(0), true);
}


/*
 * Primary running followed by random color.
 */
uint16_t WS2812FX::mode_chase_random(void) {
  if(SEGENV.step == 0) {
    SEGENV.aux0 = get_random_wheel_index(SEGENV.aux0);
  }
  return chase(color_wheel(SEGENV.aux0), SEGCOLOR(0), SEGCOLOR(0), false);
}


/*
 * Primary running on rainbow.
 */
uint16_t WS2812FX::mode_chase_rainbow_white(void) {
  uint16_t n = SEGENV.step;
  uint16_t m = (SEGENV.step + 1) % SEGLEN;
  uint32_t color2 = color_wheel(((n * 256 / SEGLEN) + (SEGENV.call & 0xFF)) & 0xFF);
  uint32_t color3 = color_wheel(((m * 256 / SEGLEN) + (SEGENV.call & 0xFF)) & 0xFF);

  return chase(SEGCOLOR(0), color2, color3, false);
}


/*
 * Red - Amber - Green - Blue lights running
 */
uint16_t WS2812FX::mode_colorful(void) {
  uint32_t cols[]{0x00FF0000,0x00EEBB00,0x0000EE00,0x000077CC,0x00FF0000,0x00EEBB00,0x0000EE00};
  if (SEGMENT.intensity < 127) //pastel (easter) colors
  {
    cols[0] = 0x00FF8040;
    cols[1] = 0x00E5D241;
    cols[2] = 0x0077FF77;
    cols[3] = 0x0077F0F0;
    for (uint8_t i = 4; i < 7; i++) cols[i] = cols[i-4];
  }
  
  uint32_t cycleTime = 50 + (15 * (uint32_t)(255 - SEGMENT.speed));
  uint32_t it = now / cycleTime;
  if (it != SEGENV.step)
  {
    if (SEGMENT.speed > 0) SEGENV.aux0++;
    if (SEGENV.aux0 > 3) SEGENV.aux0 = 0;
    SEGENV.step = it;
  }
  
  uint16_t i = SEGMENT.start;
  for (i; i < SEGMENT.stop -3; i+=4)
  {
    setPixelColor(i, cols[SEGENV.aux0]);
    setPixelColor(i+1, cols[SEGENV.aux0+1]);
    setPixelColor(i+2, cols[SEGENV.aux0+2]);
    setPixelColor(i+3, cols[SEGENV.aux0+3]);
  }
  if(i < SEGMENT.stop)
  {
    setPixelColor(i, cols[SEGENV.aux0]);
    
    if(i+1 < SEGMENT.stop)
    {
      setPixelColor(i+1, cols[SEGENV.aux0+1]);
      
      if(i+2 < SEGMENT.stop)
      {
        setPixelColor(i+2, cols[SEGENV.aux0+2]);
      }
    }
  }
  
  return FRAMETIME;
}


/*
 * Emulates a traffic light.
 */
uint16_t WS2812FX::mode_traffic_light(void) {
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++)
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 1));
  uint32_t mdelay = 500;
  for (int i = SEGMENT.start; i < SEGMENT.stop-2 ; i+=3)
  {
    switch (SEGENV.aux0)
    {
      case 0: setPixelColor(i, 0x00FF0000); mdelay = 150 + (100 * (uint32_t)(255 - SEGMENT.speed));break;
      case 1: setPixelColor(i, 0x00FF0000); mdelay = 150 + (20 * (uint32_t)(255 - SEGMENT.speed)); setPixelColor(i+1, 0x00EECC00); break;
      case 2: setPixelColor(i+2, 0x0000FF00); mdelay = 150 + (100 * (uint32_t)(255 - SEGMENT.speed));break;
      case 3: setPixelColor(i+1, 0x00EECC00); mdelay = 150 + (20 * (uint32_t)(255 - SEGMENT.speed));break;
    }
  }

  if (now - SEGENV.step > mdelay)
  {
    SEGENV.aux0++;
    if (SEGENV.aux0 > 3) SEGENV.aux0 = 0;
    SEGENV.step = now;
  }
  
  return FRAMETIME;
}


/*
 * Primary, secondary running on rainbow.
 */
uint16_t WS2812FX::mode_chase_rainbow(void) {
  uint8_t color_sep = 256 / SEGLEN;
  uint8_t color_index = SEGENV.call & 0xFF;
  uint32_t color = color_wheel(((SEGENV.step * color_sep) + color_index) & 0xFF);

  return chase(color, SEGCOLOR(0), SEGCOLOR(1), 0);
}


/*
 * Sec flashes running on prim.
 */
#define FLASH_COUNT 4
uint16_t WS2812FX::mode_chase_flash(void) {
  uint8_t flash_step = SEGENV.call % ((FLASH_COUNT * 2) + 1);

  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 0));
  }

  uint16_t delay = 10 + ((30 * (uint16_t)(255 - SEGMENT.speed)) / SEGLEN);
  if(flash_step < (FLASH_COUNT * 2)) {
    if(flash_step % 2 == 0) {
      uint16_t n = SEGENV.step;
      uint16_t m = (SEGENV.step + 1) % SEGLEN;
      setPixelColor(SEGMENT.start + n, SEGCOLOR(1));
      setPixelColor(SEGMENT.start + m, SEGCOLOR(1));
      delay = 20;
    } else {
      delay = 30;
    }
  } else {
    SEGENV.step = (SEGENV.step + 1) % SEGLEN;
  }
  return delay;
}


/*
 * Prim flashes running, followed by random color.
 */
uint16_t WS2812FX::mode_chase_flash_random(void) {
  uint8_t flash_step = SEGENV.call % ((FLASH_COUNT * 2) + 1);

  for(uint16_t i=0; i < SEGENV.step; i++) {
    setPixelColor(SEGMENT.start + i, color_wheel(SEGENV.aux0));
  }

  uint16_t delay = 1 + ((10 * (uint16_t)(255 - SEGMENT.speed)) / SEGLEN);
  if(flash_step < (FLASH_COUNT * 2)) {
    uint16_t n = SEGENV.step;
    uint16_t m = (SEGENV.step + 1) % SEGLEN;
    if(flash_step % 2 == 0) {
      setPixelColor(SEGMENT.start + n, SEGCOLOR(0));
      setPixelColor(SEGMENT.start + m, SEGCOLOR(0));
      delay = 20;
    } else {
      setPixelColor(SEGMENT.start + n, color_wheel(SEGENV.aux0));
      setPixelColor(SEGMENT.start + m, SEGCOLOR(1));
      delay = 30;
    }
  } else {
    SEGENV.step = (SEGENV.step + 1) % SEGLEN;

    if(SEGENV.step == 0) {
      SEGENV.aux0 = get_random_wheel_index(SEGENV.aux0);
    }
  }
  return delay;
}


/*
 * Alternating pixels running function.
 */
uint16_t WS2812FX::running(uint32_t color1, uint32_t color2) {
  uint8_t pxw = 1 + (SEGMENT.intensity >> 5);
  uint32_t cycleTime = 35 + (255 - SEGMENT.speed);
  uint32_t it = now / cycleTime;
  if (SEGMENT.speed == 0) it = 0;

  for(uint16_t i=0; i < SEGLEN; i++) {
    if((i + SEGENV.aux0) % (pxw*2) < pxw) {
      if (color1 == SEGCOLOR(0))
      {
        setPixelColor(SEGMENT.stop -i -1, color_from_palette(SEGMENT.stop -i -1, true, PALETTE_SOLID_WRAP, 0));
      } else
      {
        setPixelColor(SEGMENT.stop -i -1, color1);
      }
    } else {
      setPixelColor(SEGMENT.stop -i -1, color2);
    }
  }

  if (it != SEGENV.step )
  {
    SEGENV.aux0 = (SEGENV.aux0 +1) % (pxw*2);
    SEGENV.step = it;
  }
  return FRAMETIME;
}

/*
 * Alternating color/sec pixels running.
 */
uint16_t WS2812FX::mode_running_color(void) {
  return running(SEGCOLOR(0), SEGCOLOR(1));
}


/*
 * Alternating red/blue pixels running.
 */
uint16_t WS2812FX::mode_running_red_blue(void) {
  return running(RED, BLUE);
}


/*
 * Alternating red/green pixels running.
 */
uint16_t WS2812FX::mode_merry_christmas(void) {
  return running(RED, GREEN);
}


/*
 * Alternating orange/purple pixels running.
 */
uint16_t WS2812FX::mode_halloween(void) {
  return running(PURPLE, ORANGE);
}


/*
 * Random colored pixels running.
 */
uint16_t WS2812FX::mode_running_random(void) {
  uint32_t cycleTime = 25 + (3 * (uint32_t)(255 - SEGMENT.speed));
  uint32_t it = now / cycleTime;
  if (SEGENV.aux1 == it) return FRAMETIME;

  for(uint16_t i=SEGLEN-1; i > 0; i--) {
    setPixelColor(SEGMENT.start + i, getPixelColor(SEGMENT.start + i - 1));
  }

  if(SEGENV.step == 0) {
    SEGENV.aux0 = get_random_wheel_index(SEGENV.aux0);
    setPixelColor(SEGMENT.start, color_wheel(SEGENV.aux0));
  }

  SEGENV.step++;
  if (SEGENV.step > ((255-SEGMENT.intensity) >> 4))
  {
    SEGENV.step = 0;
  }

  SEGENV.aux1 = it;
  return FRAMETIME;
}


/*
 * K.I.T.T.
 */
uint16_t WS2812FX::mode_larson_scanner(void){
  return larson_scanner(false);
}

uint16_t WS2812FX::larson_scanner(bool dual) {
  uint16_t counter = now * ((SEGMENT.speed >> 2) +8);
  uint16_t index = counter * SEGLEN  >> 16;

  fade_out(SEGMENT.intensity);

  if (SEGENV.step > index && SEGENV.step - index > SEGLEN/2) {
    SEGENV.aux0 = !SEGENV.aux0;
  }
  
  for (uint16_t i = SEGENV.step; i < index; i++) {
    uint16_t j = (SEGENV.aux0)?i:SEGLEN-1-i;
    setPixelColor(SEGMENT.start + j, color_from_palette(j, true, PALETTE_SOLID_WRAP, 0));
  }
  if (dual) {
    uint32_t c;
    if (SEGCOLOR(2) != 0) {
      c = SEGCOLOR(2);
    } else {
      c = color_from_palette(index, true, PALETTE_SOLID_WRAP, 0);
    }

    for (uint16_t i = SEGENV.step; i < index; i++) {
      uint16_t j = (SEGENV.aux0)?SEGLEN-1-i:i;
      setPixelColor(SEGMENT.start + j, c);
    }
  }

  SEGENV.step = index;
  return FRAMETIME;
}


/*
 * Firing comets from one end.
 */
uint16_t WS2812FX::mode_comet(void) {
  uint16_t counter = now * (SEGMENT.speed >>3) +1;
  uint16_t index = counter * SEGLEN >> 16;

  fade_out(SEGMENT.intensity);

  setPixelColor(SEGMENT.start + index, color_from_palette(index, true, PALETTE_SOLID_WRAP, 0));

  return FRAMETIME;
}


/*
 * Fireworks function.
 */
uint16_t WS2812FX::mode_fireworks() {
  fade_out(0);
  if (SEGENV.call == 0) {
    SEGENV.aux0 = UINT16_MAX;
    SEGENV.aux1 = UINT16_MAX;
  }
  bool valid1 = (SEGENV.aux0  < SEGMENT.stop && SEGENV.aux0  >= SEGMENT.start);
  bool valid2 = (SEGENV.aux1 < SEGMENT.stop && SEGENV.aux1 >= SEGMENT.start);
  uint32_t sv1 = 0, sv2 = 0;
  if (valid1) sv1 = getPixelColor(SEGENV.aux0);
  if (valid2) sv2 = getPixelColor(SEGENV.aux1);
  blur(255-SEGMENT.speed);
  if (valid1) setPixelColor(SEGENV.aux0 , sv1);
  if (valid2) setPixelColor(SEGENV.aux1, sv2);

  for(uint16_t i=0; i<max(1, SEGLEN/20); i++) {
    if(random8(129 - (SEGMENT.intensity >> 1)) == 0) {
      uint16_t index = SEGMENT.start + random(SEGLEN);
      setPixelColor(index, color_from_palette(random8(), false, false, 0));
      SEGENV.aux1 = SEGENV.aux0;
      SEGENV.aux0 = index;
    }
  }
  return FRAMETIME;
}


//Twinkling LEDs running. Inspired by https://github.com/kitesurfer1404/WS2812FX/blob/master/src/custom/Rain.h
uint16_t WS2812FX::mode_rain()
{
  SEGENV.step += FRAMETIME;
  if (SEGENV.step > SPEED_FORMULA_L) {
    SEGENV.step = 0;
    //shift all leds right
    uint32_t ctemp = getPixelColor(SEGMENT.stop -1);
    for(uint16_t i=SEGMENT.stop -1; i>SEGMENT.start; i--) {
      setPixelColor(i, getPixelColor(i-1));
    }
    setPixelColor(SEGMENT.start, ctemp);
    SEGENV.aux0++;
    SEGENV.aux1++;
    if (SEGENV.aux0 == 0) SEGENV.aux0 = UINT16_MAX;
    if (SEGENV.aux1 == 0) SEGENV.aux0 = UINT16_MAX;
    if (SEGENV.aux0 == SEGMENT.stop) SEGENV.aux0 = SEGMENT.start;
    if (SEGENV.aux1 == SEGMENT.stop) SEGENV.aux1 = SEGMENT.start;
  }
  return mode_fireworks();
}


/*
 * Fire flicker function
 */
uint16_t WS2812FX::mode_fire_flicker(void) {
  uint32_t cycleTime = 40 + (255 - SEGMENT.speed);
  uint32_t it = now / cycleTime;
  if (SEGENV.step == it) return FRAMETIME;
  
  byte w = (SEGCOLOR(0) >> 24) & 0xFF;
  byte r = (SEGCOLOR(0) >> 16) & 0xFF;
  byte g = (SEGCOLOR(0) >>  8) & 0xFF;
  byte b = (SEGCOLOR(0)        & 0xFF);
  byte lum = (SEGMENT.palette == 0) ? max(w, max(r, max(g, b))) : 255;
  lum /= (((256-SEGMENT.intensity)/16)+1);
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    byte flicker = random8(lum);
    if (SEGMENT.palette == 0) {
      setPixelColor(i, max(r - flicker, 0), max(g - flicker, 0), max(b - flicker, 0), max(w - flicker, 0));
    } else {
      setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 0, 255 - flicker));
    }
  }

  SEGENV.step = it;
  return FRAMETIME;
}


/*
 * Gradient run base function
 */
uint16_t WS2812FX::gradient_base(bool loading) {
  uint16_t counter = now * (SEGMENT.speed >> 3) + 1;
  SEGENV.step = counter * SEGLEN >> 16;
  if (SEGMENT.speed == 0) SEGENV.step = SEGMENT.start + (SEGLEN >> 1);
  if (SEGENV.call == 0) SEGENV.step = 0;
  float per,val; //0.0 = sec 1.0 = pri
  float brd = SEGMENT.intensity;
  if (!loading) brd = SEGMENT.intensity/2;
  if (brd <1.0) brd = 1.0;
  int pp = SEGENV.step;
  int p1 = pp-SEGLEN;
  int p2 = pp+SEGLEN;

  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++)
  {
    if (loading)
    {
      val = abs(((i>pp) ? p2:pp) -i);
    } else {
      val = min(abs(pp-i),min(abs(p1-i),abs(p2-i)));
    }
    per = val/brd;
    if (per >1.0) per = 1.0;
    setPixelColor(i, color_blend(SEGCOLOR(0), color_from_palette(i, true, PALETTE_SOLID_WRAP, 1), per*255));
  }

  return FRAMETIME;
}


/*
 * Gradient run
 */
uint16_t WS2812FX::mode_gradient(void) {
  return gradient_base(false);
}


/*
 * Gradient run with hard transition
 */
uint16_t WS2812FX::mode_loading(void) {
  return gradient_base(true);
}


//American Police Light with all LEDs Red and Blue 
uint16_t WS2812FX::police_base(uint32_t color1, uint32_t color2)
{
  uint16_t counter = now * ((SEGMENT.speed >> 3) +1);
  uint16_t idexR = (counter * SEGLEN) >> 16;
  if (idexR >= SEGLEN) idexR = 0;

  uint16_t topindex = SEGLEN >> 1;
  uint16_t idexB = idexR + topindex;

  if (idexR > topindex) idexB -= SEGLEN;
  if (idexB >= SEGLEN) idexB = 0; //otherwise overflow on odd number of LEDs

  setPixelColor(SEGMENT.start + idexR, color1);
  setPixelColor(SEGMENT.start + idexB, color2);

  return FRAMETIME;
}


//American Police Light with all LEDs Red and Blue 
uint16_t WS2812FX::mode_police_all()
{
  return police_base(RED, BLUE);
}


//Police Lights Red and Blue 
uint16_t WS2812FX::mode_police()
{
  fill(SEGCOLOR(1));

  return police_base(RED, BLUE);
}


//Police All with custom colors
uint16_t WS2812FX::mode_two_areas()
{
  return police_base(SEGCOLOR(0), SEGCOLOR(1));
}


//Police Lights with custom colors 
uint16_t WS2812FX::mode_two_dots()
{
  fill(SEGCOLOR(2));
  uint32_t color2 = (SEGCOLOR(1) == SEGCOLOR(2)) ? SEGCOLOR(0) : SEGCOLOR(1);

  return police_base(SEGCOLOR(0), color2);
}


/*
 * Tricolor chase function
 */
uint16_t WS2812FX::tricolor_chase(uint32_t color1, uint32_t color2) {
  uint32_t cycleTime = 50 + (255 - SEGMENT.speed)*2;
  uint32_t it = now / cycleTime;
  uint8_t width = (1 + SEGMENT.intensity/32) * 3; //value of 1-8 for each colour
  uint8_t index = it % width;
  
  for(uint16_t i=0; i < SEGLEN; i++, index++) {
    if(index > width-1) index = 0;

    uint32_t color = color1;
    if(index > width*2/3-1) color = color_from_palette(i, true, PALETTE_SOLID_WRAP, 1);
    else if(index > width/3-1) color = color2;

    setPixelColor(SEGMENT.stop - i -1, color);
  }

  return FRAMETIME;
}


/*
 * Alternating white/red/black pixels running. PLACEHOLDER
 */
uint16_t WS2812FX::mode_circus_combustus(void) {
  return tricolor_chase(RED, WHITE);
}


/*
 * Tricolor chase mode
 */
uint16_t WS2812FX::mode_tricolor_chase(void) {
  return tricolor_chase(SEGCOLOR(2), SEGCOLOR(0));
}


/*
 * ICU mode
 */
uint16_t WS2812FX::mode_icu(void) {
  uint16_t dest = SEGENV.step & 0xFFFF;

  fill(SEGCOLOR(1));

  byte pindex = map(dest, 0, SEGLEN/2, 0, 255);
  uint32_t col = color_from_palette(pindex, false, false, 0);

  setPixelColor(SEGMENT.start + dest, col);
  setPixelColor(SEGMENT.start + dest + SEGLEN/2, col);

  if(SEGENV.aux0 == dest) { // pause between eye movements
    if(random8(6) == 0) { // blink once in a while
      setPixelColor(SEGMENT.start + dest, SEGCOLOR(1));
      setPixelColor(SEGMENT.start + dest + SEGLEN/2, SEGCOLOR(1));
      return 200;
    }
    SEGENV.aux0 = random16(SEGLEN/2);
    return 1000 + random16(2000);
  }

  if(SEGENV.aux0 > SEGENV.step) {
    SEGENV.step++;
    dest++;
  } else if (SEGENV.aux0 < SEGENV.step) {
    SEGENV.step--;
    dest--;
  }

  setPixelColor(SEGMENT.start + dest, col);
  setPixelColor(SEGMENT.start + dest + SEGLEN/2, col);

  return SPEED_FORMULA_L;
}


/*
 * Custom mode by Aircoookie. Color Wipe, but with 3 colors
 */
uint16_t WS2812FX::mode_tricolor_wipe(void)
{
  uint32_t cycleTime = 1000 + (255 - SEGMENT.speed)*200;
  uint32_t perc = now % cycleTime;
  uint16_t prog = (perc * 65535) / cycleTime;
  uint16_t ledIndex = (prog * SEGLEN * 3) >> 16;
  uint16_t ledOffset = ledIndex;

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++)
  {
    setPixelColor(i, color_from_palette(i, true, PALETTE_SOLID_WRAP, 2));
  }
  
  if(ledIndex < SEGLEN) { //wipe from 0 to 1
    for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++)
    {
      setPixelColor(i, (i - SEGMENT.start > ledOffset)? SEGCOLOR(0) : SEGCOLOR(1));
    }
  } else if (ledIndex < SEGLEN*2) { //wipe from 1 to 2
    ledOffset = ledIndex - SEGLEN;
    for (uint16_t i = SEGMENT.start +ledOffset +1; i < SEGMENT.stop; i++)
    {
      setPixelColor(i, SEGCOLOR(1));
    }
  } else //wipe from 2 to 0
  {
    ledOffset = ledIndex - SEGLEN*2;
    for (uint16_t i = SEGMENT.start; i <= SEGMENT.start +ledOffset; i++)
    {
      setPixelColor(i, SEGCOLOR(0));
    }
  }

  return FRAMETIME;
}


/*
 * Fades between 3 colors
 * Custom mode by Keith Lord: https://github.com/kitesurfer1404/WS2812FX/blob/master/src/custom/TriFade.h
 * Modified by Aircoookie
 */
uint16_t WS2812FX::mode_tricolor_fade(void)
{
  uint16_t counter = now * ((SEGMENT.speed >> 3) +1);
  uint32_t prog = (counter * 768) >> 16;

  uint32_t color1 = 0, color2 = 0;
  byte stage = 0;

  if(prog < 256) {
    color1 = SEGCOLOR(0);
    color2 = SEGCOLOR(1);
    stage = 0;
  } else if(prog < 512) {
    color1 = SEGCOLOR(1);
    color2 = SEGCOLOR(2);
    stage = 1;
  } else {
    color1 = SEGCOLOR(2);
    color2 = SEGCOLOR(0);
    stage = 2;
  }

  byte stp = prog; // % 256
  uint32_t color = 0;
  for(uint16_t i=SEGMENT.start; i < SEGMENT.stop; i++) {
    if (stage == 2) {
      color = color_blend(color_from_palette(i, true, PALETTE_SOLID_WRAP, 2), color2, stp);
    } else if (stage == 1) {
      color = color_blend(color1, color_from_palette(i, true, PALETTE_SOLID_WRAP, 2), stp);
    } else {
      color = color_blend(color1, color2, stp);
    }
    setPixelColor(i, color);
  }

  return FRAMETIME;
}


/*
 * Creates random comets
 * Custom mode by Keith Lord: https://github.com/kitesurfer1404/WS2812FX/blob/master/src/custom/MultiComet.h
 */
uint16_t WS2812FX::mode_multi_comet(void)
{
  uint32_t cycleTime = 20 + (2 * (uint32_t)(255 - SEGMENT.speed));
  uint32_t it = now / cycleTime;
  if (SEGENV.step == it) return FRAMETIME;

  fade_out(SEGMENT.intensity);

  static uint16_t comets[] = {UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX};

  for(uint8_t i=0; i < 8; i++) {
    if(comets[i] < SEGLEN) {
      uint16_t index = SEGMENT.start + comets[i];
      if (SEGCOLOR(2) != 0)
      {
        setPixelColor(index, i % 2 ? color_from_palette(index, true, PALETTE_SOLID_WRAP, 0) : SEGCOLOR(2));
      } else
      {
        setPixelColor(index, color_from_palette(index, true, PALETTE_SOLID_WRAP, 0));
      }
      comets[i]++;
    } else {
      if(!random(SEGLEN)) {
        comets[i] = 0;
      }
    }
  }

  SEGENV.step = it;
  return FRAMETIME;
}


/*
 * Creates two Larson scanners moving in opposite directions
 * Custom mode by Keith Lord: https://github.com/kitesurfer1404/WS2812FX/blob/master/src/custom/DualLarson.h
 */
uint16_t WS2812FX::mode_dual_larson_scanner(void){
  return larson_scanner(true);
}


/*
 * Running random pixels
 * Custom mode by Keith Lord: https://github.com/kitesurfer1404/WS2812FX/blob/master/src/custom/RandomChase.h
 */
uint16_t WS2812FX::mode_random_chase(void)
{
  uint32_t cycleTime = 25 + (3 * (uint32_t)(255 - SEGMENT.speed));
  uint32_t it = now / cycleTime;
  if (SEGENV.step == it) return FRAMETIME;

  for(uint16_t i=SEGMENT.stop -1; i>SEGMENT.start; i--) {
    setPixelColor(i, getPixelColor(i-1));
  }
  uint32_t color = getPixelColor(SEGMENT.start);
  if (SEGLEN > 1) color = getPixelColor(SEGMENT.start + 1);
  uint8_t r = random8(6) != 0 ? (color >> 16 & 0xFF) : random8();
  uint8_t g = random8(6) != 0 ? (color >> 8  & 0xFF) : random8();
  uint8_t b = random8(6) != 0 ? (color       & 0xFF) : random8();
  setPixelColor(SEGMENT.start, r, g, b);

  SEGENV.step = it;
  return FRAMETIME;
}


typedef struct Oscillator {
  int16_t pos;
  int8_t  size;
  int8_t  dir;
  int8_t  speed;
} oscillator;

/*
/  Oscillating bars of color, updated with standard framerate
*/
uint16_t WS2812FX::mode_oscillate(void)
{
  uint8_t numOscillators = 3;
  uint16_t dataSize = sizeof(oscillator) * numOscillators;

  if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed
  
  Oscillator* oscillators = reinterpret_cast<Oscillator*>(SEGENV.data);

  if (SEGENV.call == 0)
  {
    oscillators[0] = {SEGLEN/4,   SEGLEN/8,  1, 1};
    oscillators[1] = {SEGLEN/4*3, SEGLEN/8,  1, 2};
    oscillators[2] = {SEGLEN/4*2, SEGLEN/8, -1, 1};
  }

  uint32_t cycleTime = 20 + (2 * (uint32_t)(255 - SEGMENT.speed));
  uint32_t it = now / cycleTime;

  for(uint8_t i=0; i < numOscillators; i++) {
    // if the counter has increased, move the oscillator by the random step
    if (it != SEGENV.step) oscillators[i].pos += oscillators[i].dir * oscillators[i].speed;
    oscillators[i].size = SEGLEN/(3+SEGMENT.intensity/8);
    if((oscillators[i].dir == -1) && (oscillators[i].pos <= 0)) {
      oscillators[i].pos = 0;
      oscillators[i].dir = 1;
      // make bigger steps for faster speeds
      oscillators[i].speed = SEGMENT.speed > 100 ? random8(2, 4):random8(1, 3);
    }
    if((oscillators[i].dir == 1) && (oscillators[i].pos >= (SEGLEN - 1))) {
      oscillators[i].pos = SEGLEN - 1;
      oscillators[i].dir = -1;
      oscillators[i].speed = SEGMENT.speed > 100 ? random8(2, 4):random8(1, 3);
    }
  }

  for(uint16_t i=0; i < SEGLEN; i++) {
    uint32_t color = BLACK;
    for(uint8_t j=0; j < numOscillators; j++) {
      if(i >= oscillators[j].pos - oscillators[j].size && i <= oscillators[j].pos + oscillators[j].size) {
        color = (color == BLACK) ? SEGMENT.colors[j] : color_blend(color, SEGMENT.colors[j], 128);
      }
    }
    setPixelColor(SEGMENT.start + i, color);
  }
 
  SEGENV.step = it;
  return FRAMETIME;
}


uint16_t WS2812FX::mode_lightning(void)
{
  uint16_t ledstart = SEGMENT.start + random16(SEGLEN);               // Determine starting location of flash
  uint16_t ledlen = random16(SEGMENT.stop -1 -ledstart);                      // Determine length of flash (not to go beyond NUM_LEDS-1)
  uint8_t bri = 255/random8(1, 3);

  if (SEGENV.step == 0)
  {
    SEGENV.aux0 = random8(3, 3 + SEGMENT.intensity/20); //number of flashes
    bri = 52;
    SEGENV.aux1 = 1;
  }

  fill(SEGCOLOR(1));

  if (SEGENV.aux1) {
    for (int i = ledstart; i < ledstart + ledlen; i++)
    {
      if (SEGMENT.palette == 0)
      {
        setPixelColor(i,bri,bri,bri,bri);
      } else {
        setPixelColor(i,color_from_palette(i, true, PALETTE_SOLID_WRAP, 0, bri));
      }
    }
    SEGENV.aux1 = 0;
    SEGENV.step++;
    return random8(4, 10);                                    // each flash only lasts 4-10 milliseconds
  }

  SEGENV.aux1 = 1;
  if (SEGENV.step == 1) return (200);                       // longer delay until next flash after the leader

  if (SEGENV.step <= SEGENV.aux0) return (50 + random8(100));  // shorter delay between strokes

  SEGENV.step = 0;
  return (random8(255 - SEGMENT.speed) * 100);                            // delay between strikes
}


// Pride2015
// Animated, ever-changing rainbows.
// by Mark Kriegsman: https://gist.github.com/kriegsman/964de772d64c502760e5
uint16_t WS2812FX::mode_pride_2015(void)
{
  uint16_t duration = 10 + SEGMENT.speed;
  uint16_t sPseudotime = SEGENV.step;
  uint16_t sHue16 = SEGENV.aux0;

  uint8_t sat8 = beatsin88( 87, 220, 250);
  uint8_t brightdepth = beatsin88( 341, 96, 224);
  uint16_t brightnessthetainc16 = beatsin88( 203, (25 * 256), (40 * 256));
  uint8_t msmultiplier = beatsin88(147, 23, 60);

  uint16_t hue16 = sHue16;//gHue * 256;
  uint16_t hueinc16 = beatsin88(113, 1, 3000);

  sPseudotime += duration * msmultiplier;
  sHue16 += duration * beatsin88( 400, 5,9);
  uint16_t brightnesstheta16 = sPseudotime;
  CRGB fastled_col;

  for( uint16_t i = SEGMENT.start ; i < SEGMENT.stop; i++) {
    hue16 += hueinc16;
    uint8_t hue8 = hue16 >> 8;

    brightnesstheta16  += brightnessthetainc16;
    uint16_t b16 = sin16( brightnesstheta16  ) + 32768;

    uint16_t bri16 = (uint32_t)((uint32_t)b16 * (uint32_t)b16) / 65536;
    uint8_t bri8 = (uint32_t)(((uint32_t)bri16) * brightdepth) / 65536;
    bri8 += (255 - brightdepth);

    CRGB newcolor = CHSV( hue8, sat8, bri8);
    fastled_col = col_to_crgb(getPixelColor(i));

    nblend( fastled_col, newcolor, 64);
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }
  SEGENV.step = sPseudotime;
  SEGENV.aux0 = sHue16;
  return FRAMETIME;
}


//eight colored dots, weaving in and out of sync with each other
uint16_t WS2812FX::mode_juggle(void){
  fade_out(SEGMENT.intensity);
  CRGB fastled_col;
  byte dothue = 0;
  for ( byte i = 0; i < 8; i++) {
    uint16_t index = SEGMENT.start + beatsin88((128 + SEGMENT.speed)*(i + 7), 0, SEGLEN -1);
    fastled_col = col_to_crgb(getPixelColor(index));
    fastled_col |= (SEGMENT.palette==0)?CHSV(dothue, 220, 255):ColorFromPalette(currentPalette, dothue, 255);
    setPixelColor(index, fastled_col.red, fastled_col.green, fastled_col.blue);
    dothue += 32;
  }
  return FRAMETIME;
}


uint16_t WS2812FX::mode_palette()
{
  uint16_t counter = 0;
  if (SEGMENT.speed != 0) 
  {
    counter = (now * ((SEGMENT.speed >> 3) +1)) & 0xFFFF;
    counter = counter >> 8;
  }
  
  bool noWrap = (paletteBlend == 2 || (paletteBlend == 0 && SEGMENT.speed == 0));
  for (uint16_t i = 0; i < SEGLEN; i++)
  {
    uint8_t colorIndex = (i * 255 / SEGLEN) - counter;
    
    if (noWrap) colorIndex = map(colorIndex, 0, 255, 0, 240); //cut off blend at palette "end"
    
    setPixelColor(SEGMENT.start + i, color_from_palette(colorIndex, false, true, 255));
  }
  return FRAMETIME;
}


// WLED limitation: Analog Clock overlay will NOT work when Fire2012 is active
// Fire2012 by Mark Kriegsman, July 2012
// as part of "Five Elements" shown here: http://youtu.be/knWiGsmgycY
//// 
// This basic one-dimensional 'fire' simulation works roughly as follows:
// There's a underlying array of 'heat' cells, that model the temperature
// at each point along the line.  Every cycle through the simulation, 
// four steps are performed:
//  1) All cells cool down a little bit, losing heat to the air
//  2) The heat from each cell drifts 'up' and diffuses a little
//  3) Sometimes randomly new 'sparks' of heat are added at the bottom
//  4) The heat from each cell is rendered as a color into the leds array
//     The heat-to-color mapping uses a black-body radiation approximation.
//
// Temperature is in arbitrary units from 0 (cold black) to 255 (white hot).
//
// This simulation scales it self a bit depending on NUM_LEDS; it should look
// "OK" on anywhere from 20 to 100 LEDs without too much tweaking. 
//
// I recommend running this simulation at anywhere from 30-100 frames per second,
// meaning an interframe delay of about 10-35 milliseconds.
//
// Looks best on a high-density LED setup (60+ pixels/meter).
//
//
// There are two main parameters you can play with to control the look and
// feel of your fire: COOLING (used in step 1 above) (Speed = COOLING), and SPARKING (used
// in step 3 above) (Effect Intensity = Sparking).


uint16_t WS2812FX::mode_fire_2012()
{
  uint32_t it = now >> 5; //div 32

  if (!SEGENV.allocateData(SEGLEN)) return mode_static(); //allocation failed
  
  byte* heat = SEGENV.data;

  if (it != SEGENV.step)
  {
    // Step 1.  Cool down every cell a little
    for (uint16_t i = 0; i < SEGLEN; i++) {
      SEGENV.data[i] = qsub8(heat[i],  random8(0, (((20 + SEGMENT.speed /3) * 10) / SEGLEN) + 2));
    }
  
    // Step 2.  Heat from each cell drifts 'up' and diffuses a little
    for (uint16_t k= SEGLEN -1; k > 1; k--) {
      heat[k] = (heat[k - 1] + heat[k - 2] + heat[k - 2] ) / 3;
    }
    
    // Step 3.  Randomly ignite new 'sparks' of heat near the bottom
    if (random8() <= SEGMENT.intensity) {
      uint8_t y = random8(7);
      if (y < SEGLEN) heat[y] = qadd8(heat[y], random8(160,255));
    }
    SEGENV.step = it;
  }

  // Step 4.  Map from heat cells to LED colors
  for (uint16_t j = 0; j < SEGLEN; j++) {
    CRGB color = ColorFromPalette(currentPalette, min(heat[j],240), 255, LINEARBLEND);
    setPixelColor(SEGMENT.start + j, color.red, color.green, color.blue);
  }
  return FRAMETIME;
}


// ColorWavesWithPalettes by Mark Kriegsman: https://gist.github.com/kriegsman/8281905786e8b2632aeb
// This function draws color waves with an ever-changing,
// widely-varying set of parameters, using a color palette.
uint16_t WS2812FX::mode_colorwaves()
{
  uint16_t duration = 10 + SEGMENT.speed;
  uint16_t sPseudotime = SEGENV.step;
  uint16_t sHue16 = SEGENV.aux0;

  uint8_t brightdepth = beatsin88( 341, 96, 224);
  uint16_t brightnessthetainc16 = beatsin88( 203, (25 * 256), (40 * 256));
  uint8_t msmultiplier = beatsin88(147, 23, 60);

  uint16_t hue16 = sHue16;//gHue * 256;
  uint16_t hueinc16 = beatsin88(113, 300, 1500);

  sPseudotime += duration * msmultiplier;
  sHue16 += duration * beatsin88( 400, 5, 9);
  uint16_t brightnesstheta16 = sPseudotime;
  CRGB fastled_col;

  for ( uint16_t i = SEGMENT.start ; i < SEGMENT.stop; i++) {
    hue16 += hueinc16;
    uint8_t hue8 = hue16 >> 8;
    uint16_t h16_128 = hue16 >> 7;
    if ( h16_128 & 0x100) {
      hue8 = 255 - (h16_128 >> 1);
    } else {
      hue8 = h16_128 >> 1;
    }

    brightnesstheta16  += brightnessthetainc16;
    uint16_t b16 = sin16( brightnesstheta16  ) + 32768;

    uint16_t bri16 = (uint32_t)((uint32_t)b16 * (uint32_t)b16) / 65536;
    uint8_t bri8 = (uint32_t)(((uint32_t)bri16) * brightdepth) / 65536;
    bri8 += (255 - brightdepth);

    CRGB newcolor = ColorFromPalette(currentPalette, hue8, bri8);
    fastled_col = col_to_crgb(getPixelColor(i));

    nblend(fastled_col, newcolor, 128);
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }
  SEGENV.step = sPseudotime;
  SEGENV.aux0 = sHue16;
  return FRAMETIME;
}


// colored stripes pulsing at a defined Beats-Per-Minute (BPM)
uint16_t WS2812FX::mode_bpm()
{
  CRGB fastled_col;
  uint32_t stp = (now / 20) & 0xFF;
  uint8_t beat = beatsin8(SEGMENT.speed, 64, 255);
  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {
    fastled_col = ColorFromPalette(currentPalette, stp + (i * 2), beat - stp + (i * 10));
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }
  return FRAMETIME;
}


uint16_t WS2812FX::mode_fillnoise8()
{
  if (SEGENV.call == 0) SEGENV.step = random16(12345);
  CRGB fastled_col;
  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {
    uint8_t index = inoise8(i * SEGLEN, SEGENV.step + i * SEGLEN) % 255;
    fastled_col = ColorFromPalette(currentPalette, index, 255, LINEARBLEND);
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }
  SEGENV.step += beatsin8(SEGMENT.speed, 1, 6); //10,1,4

  return FRAMETIME;
}

uint16_t WS2812FX::mode_noise16_1()
{
  uint16_t scale = 320;                                      // the "zoom factor" for the noise
  CRGB fastled_col;
  SEGENV.step += (1 + SEGMENT.speed/16);

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {

    uint16_t shift_x = beatsin8(11);                           // the x position of the noise field swings @ 17 bpm
    uint16_t shift_y = SEGENV.step/42;             // the y position becomes slowly incremented


    uint16_t real_x = (i + shift_x) * scale;                  // the x position of the noise field swings @ 17 bpm
    uint16_t real_y = (i + shift_y) * scale;                  // the y position becomes slowly incremented
    uint32_t real_z = SEGENV.step;                          // the z position becomes quickly incremented

    uint8_t noise = inoise16(real_x, real_y, real_z) >> 8;   // get the noise data and scale it down

    uint8_t index = sin8(noise * 3);                         // map LED color based on noise data

    fastled_col = ColorFromPalette(currentPalette, index, 255, LINEARBLEND);   // With that value, look up the 8 bit colour palette value and assign it to the current LED.
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }

  return FRAMETIME;
}


uint16_t WS2812FX::mode_noise16_2()
{
  uint16_t scale = 1000;                                       // the "zoom factor" for the noise
  CRGB fastled_col;
  SEGENV.step += (1 + (SEGMENT.speed >> 1));

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {

    uint16_t shift_x = SEGENV.step >> 6;                         // x as a function of time
    uint16_t shift_y = SEGENV.step/42;

    uint32_t real_x = (i + shift_x) * scale;                  // calculate the coordinates within the noise field

    uint8_t noise = inoise16(real_x, 0, 4223) >> 8;    // get the noise data and scale it down

    uint8_t index = sin8(noise * 3);                          // map led color based on noise data

    fastled_col = ColorFromPalette(currentPalette, index, noise, LINEARBLEND);   // With that value, look up the 8 bit colour palette value and assign it to the current LED.
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }

  return FRAMETIME;
}


uint16_t WS2812FX::mode_noise16_3()
{
  uint16_t scale = 800;                                       // the "zoom factor" for the noise
  CRGB fastled_col;
  SEGENV.step += (1 + SEGMENT.speed);

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {

    uint16_t shift_x = 4223;                                  // no movement along x and y
    uint16_t shift_y = 1234;

    uint32_t real_x = (i + shift_x) * scale;                  // calculate the coordinates within the noise field
    uint32_t real_y = (i + shift_y) * scale;                  // based on the precalculated positions
    uint32_t real_z = SEGENV.step*8;  

    uint8_t noise = inoise16(real_x, real_y, real_z) >> 8;    // get the noise data and scale it down

    uint8_t index = sin8(noise * 3);                          // map led color based on noise data

    fastled_col = ColorFromPalette(currentPalette, index, noise, LINEARBLEND);   // With that value, look up the 8 bit colour palette value and assign it to the current LED.
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }

  return FRAMETIME;
}


//https://github.com/aykevl/ledstrip-spark/blob/master/ledstrip.ino
uint16_t WS2812FX::mode_noise16_4()
{
  CRGB fastled_col;
  uint32_t stp = (now * SEGMENT.speed) >> 7;
  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {
    int16_t index = inoise16(uint32_t(i - SEGMENT.start) << 12, stp);
    fastled_col = ColorFromPalette(currentPalette, index);
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }
  return FRAMETIME;
}


//based on https://gist.github.com/kriegsman/5408ecd397744ba0393e
uint16_t WS2812FX::mode_colortwinkle()
{
  uint16_t dataSize = (SEGLEN+7) >> 3; //1 bit per LED
  if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed
  
  CRGB fastled_col, prev;
  fract8 fadeUpAmount = 8 + (SEGMENT.speed/4), fadeDownAmount = 5 + (SEGMENT.speed/7);
  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {
    fastled_col = col_to_crgb(getPixelColor(i));
    prev = fastled_col;
    uint16_t index = (i - SEGMENT.start) >> 3;
    uint8_t  bitNum = (i - SEGMENT.start) & 0x07;
    bool fadeUp = bitRead(SEGENV.data[index], bitNum);
    
    if (fadeUp) {
      CRGB incrementalColor = fastled_col;
      incrementalColor.nscale8_video( fadeUpAmount);
      fastled_col += incrementalColor;

      if (fastled_col.red == 255 || fastled_col.green == 255 || fastled_col.blue == 255) {
        bitWrite(SEGENV.data[index], bitNum, false);
      }
      setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);

      if (col_to_crgb(getPixelColor(i)) == prev) //fix "stuck" pixels
      {
        fastled_col += fastled_col;
        setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
      }
    } else {
      fastled_col.nscale8( 255 - fadeDownAmount);
      setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
    }
  }

  for (uint16_t j = 0; j <= SEGLEN / 50; j++)
  {
    if (random8() <= SEGMENT.intensity) {
      for (uint8_t times = 0; times < 5; times++) //attempt to spawn a new pixel 5 times
      {
        int i = SEGMENT.start + random16(SEGLEN);
        if(getPixelColor(i) == 0) {
          fastled_col = ColorFromPalette(currentPalette, random8(), 64, NOBLEND);
          uint16_t index = (i - SEGMENT.start) >> 3;
          uint8_t  bitNum = (i - SEGMENT.start) & 0x07;
          bitWrite(SEGENV.data[index], bitNum, true);
          setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
          break; //only spawn 1 new pixel per frame per 50 LEDs
        }
      }
    }
  }
  return FRAMETIME;
}


//Calm effect, like a lake at night
uint16_t WS2812FX::mode_lake() {
  uint8_t sp = SEGMENT.speed/10;
  int wave1 = beatsin8(sp +2, -64,64);
  int wave2 = beatsin8(sp +1, -64,64);
  uint8_t wave3 = beatsin8(sp +2,   0,80);
  CRGB fastled_col;

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++)
  {
    int index = cos8((i*15)+ wave1)/2 + cubicwave8((i*23)+ wave2)/2;           
    uint8_t lum = (index > wave3) ? index - wave3 : 0;
    fastled_col = ColorFromPalette(currentPalette, map(index,0,255,0,240), lum, LINEARBLEND);
    setPixelColor(i, fastled_col.red, fastled_col.green, fastled_col.blue);
  }
  return FRAMETIME;
}


// meteor effect
// send a meteor from begining to to the end of the strip with a trail that randomly decays.
// adapted from https://www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/#LEDStripEffectMeteorRain
uint16_t WS2812FX::mode_meteor() {
  if (!SEGENV.allocateData(SEGLEN)) return mode_static(); //allocation failed

  byte* trail = SEGENV.data;
  
  byte meteorSize= 1+ SEGLEN / 10;
  uint16_t counter = now * ((SEGMENT.speed >> 2) +8);
  uint16_t in = counter * SEGLEN >> 16;

  // fade all leds to colors[1] in LEDs one step
  for (uint16_t i = 0; i < SEGLEN; i++) {
    if (random8() <= 255 - SEGMENT.intensity)
    {
      byte meteorTrailDecay = 128 + random8(127);
      trail[i] = scale8(trail[i], meteorTrailDecay);
      setPixelColor(SEGMENT.start + i, color_from_palette(trail[i], false, true, 255));
    }
  }

  // draw meteor
  for(int j = 0; j < meteorSize; j++) {
    uint16_t index = in + j;
    if(index >= SEGLEN) {
      index = (in + j - SEGLEN);
    }

    trail[index] = 240;
    setPixelColor(SEGMENT.start + index, color_from_palette(trail[index], false, true, 255));
  }

  return FRAMETIME;
}


// smooth meteor effect
// send a meteor from begining to to the end of the strip with a trail that randomly decays.
// adapted from https://www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/#LEDStripEffectMeteorRain
uint16_t WS2812FX::mode_meteor_smooth() {
  if (!SEGENV.allocateData(SEGLEN)) return mode_static(); //allocation failed

  byte* trail = SEGENV.data;
  
  byte meteorSize= 1+ SEGLEN / 10;
  uint16_t in = map((SEGENV.step >> 6 & 0xFF), 0, 255, 0, SEGLEN -1);

  // fade all leds to colors[1] in LEDs one step
  for (uint16_t i = 0; i < SEGLEN; i++) {
    if (trail[i] != 0 && random8() <= 255 - SEGMENT.intensity)
    {
      int change = 3 - random8(12); //change each time between -8 and +3
      trail[i] += change;
      if (trail[i] > 245) trail[i] = 0;
      if (trail[i] > 240) trail[i] = 240;
      setPixelColor(SEGMENT.start + i, color_from_palette(trail[i], false, true, 255));
    }
  }
  
  // draw meteor
  for(int j = 0; j < meteorSize; j++) {  
    uint16_t index = in + j;   
    if(in + j >= SEGLEN) {
      index = (in + j - SEGLEN);
    }
    setPixelColor(SEGMENT.start + index, color_blend(getPixelColor(SEGMENT.start + index), color_from_palette(240, false, true, 255), 48));
    trail[index] = 240;
  }

  SEGENV.step += SEGMENT.speed +1;
  return FRAMETIME;
}


//Railway Crossing / Christmas Fairy lights
uint16_t WS2812FX::mode_railway()
{
  uint16_t dur = 40 + (255 - SEGMENT.speed) * 10;
  uint16_t rampdur = (dur * SEGMENT.intensity) >> 8;
  if (SEGENV.step > dur)
  {
    //reverse direction
    SEGENV.step = 0;
    SEGENV.aux0 = !SEGENV.aux0;
  }
  uint8_t pos = 255;
  if (rampdur != 0)
  {
    uint16_t p0 = (SEGENV.step * 255) / rampdur;
    if (p0 < 255) pos = p0;
  }
  if (SEGENV.aux0) pos = 255 - pos;
  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i += 2)
  {
    setPixelColor(i, color_from_palette(255 - pos, false, false, 255));
    if (i < SEGMENT.stop -1)
    {
      setPixelColor(i + 1, color_from_palette(pos, false, false, 255));
    }
  }
  SEGENV.step += FRAMETIME;
  return FRAMETIME;
}


//Water ripple
//propagation velocity from speed
//drop rate from intensity

//4 bytes
typedef struct Ripple {
  uint8_t state;
  uint8_t color;
  uint16_t pos;
} ripple;

uint16_t WS2812FX::mode_ripple()
{
  uint16_t maxRipples = 1 + (SEGLEN >> 2);
  if (maxRipples > 100) maxRipples = 100;
  uint16_t dataSize = sizeof(ripple) * maxRipples;

  if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed
 
  Ripple* ripples = reinterpret_cast<Ripple*>(SEGENV.data);

  fill(SEGCOLOR(1));

  //draw wave
  for (uint16_t i = 0; i < maxRipples; i++)
  {
    uint16_t ripplestate = ripples[i].state;
    if (ripplestate)
    {
      uint8_t rippledecay = (SEGMENT.speed >> 4) +1; //faster decay if faster propagation
      uint16_t rippleorigin = ripples[i].pos;
      uint32_t col = color_from_palette(ripples[i].color, false, false, 255);
      uint16_t propagation = ((ripplestate/rippledecay -1) * SEGMENT.speed);
      int16_t propI = propagation >> 8;
      uint8_t propF = propagation & 0xFF;
      int16_t left = rippleorigin - propI -1;
      uint8_t amp = (ripplestate < 17) ? triwave8((ripplestate-1)*8) : map(ripplestate,17,255,255,2);

      for (int16_t v = left; v < left +4; v++)
      {
        uint8_t mag = scale8(cubicwave8((propF>>2)+(v-left)*64), amp);
        if (v < SEGMENT.stop && v >= SEGMENT.start)
        {
          setPixelColor(v, color_blend(getPixelColor(v), col, mag));
        }
        int16_t w = left + propI*2 + 3 -(v-left);
        if (w < SEGMENT.stop && w >= SEGMENT.start)
        {
          setPixelColor(w, color_blend(getPixelColor(w), col, mag));
        }
      }  
      ripplestate += rippledecay;
      ripples[i].state = (ripplestate > 254) ? 0 : ripplestate;
    } else //randomly create new wave
    {
      if (random16(IBN + 10000) <= SEGMENT.intensity)
      {
        ripples[i].state = 1;
        ripples[i].pos = SEGMENT.start + random16(SEGLEN);
        ripples[i].color = random8(); //color
      }
    }
  }
  return FRAMETIME;
}


//  TwinkleFOX by Mark Kriegsman: https://gist.github.com/kriegsman/756ea6dcae8e30845b5a
//
//  TwinkleFOX: Twinkling 'holiday' lights that fade in and out.
//  Colors are chosen from a palette. Read more about this effect using the link above!

// If COOL_LIKE_INCANDESCENT is set to 1, colors will
// fade out slighted 'reddened', similar to how
// incandescent bulbs change color as they get dim down.
#define COOL_LIKE_INCANDESCENT 1

CRGB WS2812FX::twinklefox_one_twinkle(uint32_t ms, uint8_t salt, bool cat)
{
  // Overall twinkle speed (changed)
  uint16_t ticks = ms / (32 - (SEGMENT.speed >> 3));
  uint8_t fastcycle8 = ticks;
  uint16_t slowcycle16 = (ticks >> 8) + salt;
  slowcycle16 += sin8(slowcycle16);
  slowcycle16 = (slowcycle16 * 2053) + 1384;
  uint8_t slowcycle8 = (slowcycle16 & 0xFF) + (slowcycle16 >> 8);
  
  // Overall twinkle density.
  // 0 (NONE lit) to 8 (ALL lit at once).
  // Default is 5.
  uint8_t twinkleDensity = (SEGMENT.intensity >> 5) +1;

  uint8_t bright = 0;
  if (((slowcycle8 & 0x0E)/2) < twinkleDensity) {
    uint8_t ph = fastcycle8;
    // This is like 'triwave8', which produces a
    // symmetrical up-and-down triangle sawtooth waveform, except that this
    // function produces a triangle wave with a faster attack and a slower decay
    if (cat) //twinklecat, variant where the leds instantly turn on
    {
      bright = 255 - ph;
    } else { //vanilla twinklefox
      if (ph < 86) {
      bright = ph * 3;
      } else {
        ph -= 86;
        bright = 255 - (ph + (ph/2));
      }
    }
  }

  uint8_t hue = slowcycle8 - salt;
  CRGB c;
  if (bright > 0) {
    c = ColorFromPalette(currentPalette, hue, bright, NOBLEND);
    if(COOL_LIKE_INCANDESCENT == 1) {
      // This code takes a pixel, and if its in the 'fading down'
      // part of the cycle, it adjusts the color a little bit like the
      // way that incandescent bulbs fade toward 'red' as they dim.
      if (fastcycle8 >= 128) 
      {
        uint8_t cooling = (fastcycle8 - 128) >> 4;
        c.g = qsub8(c.g, cooling);
        c.b = qsub8(c.b, cooling * 2);
      }
    }
  } else {
    c = CRGB::Black;
  }
  return c;
}

//  This function loops over each pixel, calculates the
//  adjusted 'clock' that this pixel should use, and calls
//  "CalculateOneTwinkle" on each pixel.  It then displays
//  either the twinkle color of the background color,
//  whichever is brighter.
uint16_t WS2812FX::twinklefox_base(bool cat)
{
  // "PRNG16" is the pseudorandom number generator
  // It MUST be reset to the same starting value each time
  // this function is called, so that the sequence of 'random'
  // numbers that it generates is (paradoxically) stable.
  uint16_t PRNG16 = 11337;

  // Set up the background color, "bg".
  // if AUTO_SELECT_BACKGROUND_COLOR == 1, and the first two colors of
  // the current palette are identical, then a deeply faded version of
  // that color is used for the background color
  CRGB bg;
  bg = col_to_crgb(SEGCOLOR(1));
  uint8_t bglight = bg.getAverageLight();
  if (bglight > 64) {
    bg.nscale8_video(16); // very bright, so scale to 1/16th
  } else if (bglight > 16) {
    bg.nscale8_video(64); // not that bright, so scale to 1/4th
  } else {
    bg.nscale8_video(86); // dim, scale to 1/3rd.
  }

  uint8_t backgroundBrightness = bg.getAverageLight();

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {
  
    PRNG16 = (uint16_t)(PRNG16 * 2053) + 1384; // next 'random' number
    uint16_t myclockoffset16= PRNG16; // use that number as clock offset
    PRNG16 = (uint16_t)(PRNG16 * 2053) + 1384; // next 'random' number
    // use that number as clock speed adjustment factor (in 8ths, from 8/8ths to 23/8ths)
    uint8_t myspeedmultiplierQ5_3 =  ((((PRNG16 & 0xFF)>>4) + (PRNG16 & 0x0F)) & 0x0F) + 0x08;
    uint32_t myclock30 = (uint32_t)((now * myspeedmultiplierQ5_3) >> 3) + myclockoffset16;
    uint8_t  myunique8 = PRNG16 >> 8; // get 'salt' value for this pixel

    // We now have the adjusted 'clock' for this pixel, now we call
    // the function that computes what color the pixel should be based
    // on the "brightness = f( time )" idea.
    CRGB c = twinklefox_one_twinkle(myclock30, myunique8, cat);

    uint8_t cbright = c.getAverageLight();
    int16_t deltabright = cbright - backgroundBrightness;
    if (deltabright >= 32 || (!bg)) {
      // If the new pixel is significantly brighter than the background color,
      // use the new color.
      setPixelColor(i, c.red, c.green, c.blue);
    } else if (deltabright > 0) {
      // If the new pixel is just slightly brighter than the background color,
      // mix a blend of the new color and the background color
      setPixelColor(i, color_blend(crgb_to_col(bg), crgb_to_col(c), deltabright * 8));
    } else {
      // if the new pixel is not at all brighter than the background color,
      // just use the background color.
      setPixelColor(i, bg.r, bg.g, bg.b);
    }
  }
  return FRAMETIME;
}

uint16_t WS2812FX::mode_twinklefox()
{
  return twinklefox_base(false);
}

uint16_t WS2812FX::mode_twinklecat()
{
  return twinklefox_base(true);
}


//inspired by https://www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/#LEDStripEffectBlinkingHalloweenEyes
#define HALLOWEEN_EYE_SPACE 3
#define HALLOWEEN_EYE_WIDTH 1

uint16_t WS2812FX::mode_halloween_eyes()
{  
  uint16_t eyeLength = (2*HALLOWEEN_EYE_WIDTH) + HALLOWEEN_EYE_SPACE;
  if (eyeLength > SEGLEN) return mode_static(); //bail if segment too short

  fill(SEGCOLOR(1)); //fill background

  uint8_t state = SEGENV.aux1 >> 8;
  uint16_t stateTime = SEGENV.call;
  if (stateTime == 0) stateTime = 2000;

  if (state == 0) { //spawn eyes
    SEGENV.aux0 = random16(SEGMENT.start, SEGMENT.stop - eyeLength); //start pos
    SEGENV.aux1 = random8(); //color
    state = 1;
  }
  
  if (state < 2) { //fade eyes
    uint16_t startPos    = SEGENV.aux0;
    uint16_t start2ndEye = startPos + HALLOWEEN_EYE_WIDTH + HALLOWEEN_EYE_SPACE;
    
    uint32_t fadestage = (now - SEGENV.step)*255 / stateTime;
    if (fadestage > 255) fadestage = 255;
    uint32_t c = color_blend(color_from_palette(SEGENV.aux1 & 0xFF, false, false, 0), SEGCOLOR(1), fadestage);
    
    for (uint16_t i = 0; i < HALLOWEEN_EYE_WIDTH; i++)
    {
      setPixelColor(startPos    + i, c);
      setPixelColor(start2ndEye + i, c);
    }
  }

  if (now - SEGENV.step > stateTime)
  {
    state++;
    if (state > 2) state = 0;
    
    if (state < 2)
    {
      stateTime = 100 + (255 - SEGMENT.intensity)*10; //eye fade time
    } else {
      uint16_t eyeOffTimeBase = (255 - SEGMENT.speed)*10;
      stateTime = eyeOffTimeBase + random16(eyeOffTimeBase);
    }
    SEGENV.step = now;
    SEGENV.call = stateTime;
  }

  SEGENV.aux1 = (SEGENV.aux1 & 0xFF) + (state << 8); //save state
  
  return FRAMETIME;
}


//Speed slider sets amount of LEDs lit, intensity sets unlit
uint16_t WS2812FX::mode_static_pattern()
{
  uint16_t lit = 1 + SEGMENT.speed;
  uint16_t unlit = 1 + SEGMENT.intensity;
  bool drawingLit = true;
  uint16_t cnt = 0;

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, (drawingLit) ? color_from_palette(i, true, PALETTE_SOLID_WRAP, 0) : SEGCOLOR(1));
    cnt++;
    if (cnt >= ((drawingLit) ? lit : unlit)) {
      cnt = 0;
      drawingLit = !drawingLit;
    }
  }
  
  return FRAMETIME;
}

uint16_t WS2812FX::mode_tri_static_pattern()
{
  uint8_t segSize = (SEGMENT.intensity >> 5) +1;
  uint8_t currSeg = 0;
  uint16_t currSegCount = 0;

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {
    if ( currSeg % 3 == 0 ) {
      setPixelColor(i, SEGCOLOR(0));
    } else if( currSeg % 3 == 1) {
      setPixelColor(i, SEGCOLOR(1));
    } else {
      setPixelColor(i, (SEGCOLOR(2) > 0 ? SEGCOLOR(2) : WHITE));
    }
    currSegCount += 1;
    if (currSegCount >= segSize) {
      currSeg +=1;
      currSegCount = 0;
    }
  }

  return FRAMETIME;
}


uint16_t WS2812FX::spots_base(uint16_t threshold)
{
  fill(SEGCOLOR(1));
  
  uint16_t maxZones = SEGLEN >> 2;
  uint16_t zones = 1 + ((SEGMENT.intensity * maxZones) >> 8);
  uint16_t zoneLen = SEGLEN / zones;
  uint16_t offset = (SEGLEN - zones * zoneLen) >> 1;

  for (uint16_t z = 0; z < zones; z++)
  {
    uint16_t pos = offset + z * zoneLen;
    for (uint16_t i = 0; i < zoneLen; i++)
    {
      uint16_t wave = triwave16((i * 0xFFFF) / zoneLen);
      if (wave > threshold) {
        uint16_t index = SEGMENT.start + pos + i;
        uint8_t s = (wave - threshold)*255 / (0xFFFF - threshold);
        setPixelColor(index, color_blend(color_from_palette(index, true, PALETTE_SOLID_WRAP, 0), SEGCOLOR(1), 255-s));
      }
    }
  }
  
  return FRAMETIME;
}


//Intensity slider sets number of "lights", speed sets LEDs per light
uint16_t WS2812FX::mode_spots()
{
  return spots_base((255 - SEGMENT.speed) << 8);
}


//Intensity slider sets number of "lights", LEDs per light fade in and out
uint16_t WS2812FX::mode_spots_fade()
{
  uint16_t counter = now * ((SEGMENT.speed >> 2) +8);
  uint16_t t = triwave16(counter);
  uint16_t tr = (t >> 1) + (t >> 2);
  return spots_base(tr);
}


//each needs 12 bytes
//Spark type is used for popcorn and 1D fireworks
typedef struct Ball {
  unsigned long lastBounceTime;
  float impactVelocity;
  float height;
} ball;

/*
*  Bouncing Balls Effect
*/
uint16_t WS2812FX::mode_bouncing_balls(void) {
  //allocate segment data
  uint16_t maxNumBalls = 16; 
  uint16_t dataSize = sizeof(ball) * maxNumBalls;
  if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed
  
  Ball* balls = reinterpret_cast<Ball*>(SEGENV.data);
  
  // number of balls based on intensity setting to max of 7 (cycles colors)
  // non-chosen color is a random color
  uint8_t numBalls = int(((SEGMENT.intensity * (maxNumBalls - 0.8f)) / 255) + 1);
  
  float gravity                           = -9.81; // standard value of gravity
  float impactVelocityStart               = sqrt( -2 * gravity);

  unsigned long time = millis();

  if (SEGENV.call == 0) {
    for (uint8_t i = 0; i < maxNumBalls; i++) balls[i].lastBounceTime = time;
  }
  
  bool hasCol2 = SEGCOLOR(2);
  fill(hasCol2 ? BLACK : SEGCOLOR(1));
  
  for (uint8_t i = 0; i < numBalls; i++) {
    float timeSinceLastBounce = (time - balls[i].lastBounceTime)/((255-SEGMENT.speed)*8/256 +1);
    balls[i].height = 0.5 * gravity * pow(timeSinceLastBounce/1000 , 2.0) + balls[i].impactVelocity * timeSinceLastBounce/1000;

    if (balls[i].height < 0) { //start bounce
      balls[i].height = 0;
      //damping for better effect using multiple balls
      float dampening = 0.90 - float(i)/pow(numBalls,2);
      balls[i].impactVelocity = dampening * balls[i].impactVelocity;
      balls[i].lastBounceTime = time;

      if (balls[i].impactVelocity < 0.015) {
        balls[i].impactVelocity = impactVelocityStart;
      }
    }
    
    uint32_t color = SEGCOLOR(0);
    if (SEGMENT.palette) {
      color = color_wheel(i*(256/max(numBalls, 8)));
    } else if (hasCol2) {
      color = SEGCOLOR(i % NUM_COLORS);
    }

    uint16_t pos = round(balls[i].height * (SEGLEN - 1));
    setPixelColor(SEGMENT.start + pos, color);
  }

  return FRAMETIME;
}


/*
* Sinelon stolen from FASTLED examples
*/
uint16_t WS2812FX::sinelon_base(bool dual, bool rainbow=false) {
  fade_out(SEGMENT.intensity);
  int pos = beatsin16(SEGMENT.speed/10,0,SEGLEN-1);
  
  uint32_t color1 = color_from_palette(pos, true, false, 0);
  if (rainbow) {
    color1 = color_wheel((pos & 0x07) * 32);
  }
  setPixelColor(SEGMENT.start + pos, color1);

  if (dual) {
    uint32_t color2 = SEGCOLOR(2);
   
    if (!color2) color2 = color_from_palette(pos, true, false, 0);
    if (rainbow) color2 = color1; //rainbow

    setPixelColor(SEGMENT.start + SEGLEN-1-pos, color2);
  }

  return FRAMETIME;
}

uint16_t WS2812FX::mode_sinelon(void) {
  return sinelon_base(false);
}

uint16_t WS2812FX::mode_sinelon_dual(void) {
  return sinelon_base(true);
}

uint16_t WS2812FX::mode_sinelon_rainbow(void) {
  return sinelon_base(true, true);
}


//Rainbow with glitter, inspired by https://gist.github.com/kriegsman/062e10f7f07ba8518af6
uint16_t WS2812FX::mode_glitter()
{
  mode_palette();

  if (SEGMENT.intensity > random8())
  {
    setPixelColor(SEGMENT.start + random16(SEGLEN), ULTRAWHITE);
  }
  
  return FRAMETIME;
}



//each needs 12 bytes
//Spark type is used for popcorn and 1D fireworks
typedef struct Spark {
  float pos;
  float vel;
  uint16_t col;
  uint8_t colIndex;
} spark;

/*
*  POPCORN
*  modified from https://github.com/kitesurfer1404/WS2812FX/blob/master/src/custom/Popcorn.h
*/
uint16_t WS2812FX::mode_popcorn(void) {
  //allocate segment data
  uint16_t maxNumPopcorn = 24; 
  uint16_t dataSize = sizeof(spark) * maxNumPopcorn;
  if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed
  
  Spark* popcorn = reinterpret_cast<Spark*>(SEGENV.data);

  float gravity = -0.0001 - (SEGMENT.speed/200000.0); // m/s/s
  gravity *= SEGLEN;

  bool hasCol2 = SEGCOLOR(2);
  fill(hasCol2 ? BLACK : SEGCOLOR(1));

  uint8_t numPopcorn = SEGMENT.intensity*maxNumPopcorn/255;
  if (numPopcorn == 0) numPopcorn = 1;

  for(uint8_t i = 0; i < numPopcorn; i++) {
    bool isActive = popcorn[i].pos >= 0.0f;

    if(isActive) { // if kernel is active, update its position
      popcorn[i].pos += popcorn[i].vel;
      popcorn[i].vel += gravity;
      uint32_t col = color_wheel(popcorn[i].colIndex);
      if (!SEGMENT.palette && popcorn[i].colIndex < NUM_COLORS) col = SEGCOLOR(popcorn[i].colIndex);
      
      uint16_t ledIndex = SEGMENT.start + popcorn[i].pos;
      if(ledIndex >= SEGMENT.start && ledIndex < SEGMENT.stop) setPixelColor(ledIndex, col);
    } else { // if kernel is inactive, randomly pop it
      if(random8() < 2) { // POP!!!
        popcorn[i].pos = 0.01f;
        
        uint16_t peakHeight = 128 + random8(128); //0-255
        peakHeight = (peakHeight * (SEGLEN -1)) >> 8;
        popcorn[i].vel = sqrt(-2.0 * gravity * peakHeight);
        
        if (SEGMENT.palette)
        {
          popcorn[i].colIndex = random8();
        } else {
          byte col = random8(0, NUM_COLORS);
          if (!hasCol2 || !SEGCOLOR(col)) col = 0;
          popcorn[i].colIndex = col;
        }
      }
    }
  }

  return FRAMETIME;
}


//values close to 100 produce 5Hz flicker, which looks very candle-y
//Inspired by https://github.com/avanhanegem/ArduinoCandleEffectNeoPixel
//and https://cpldcpu.wordpress.com/2016/01/05/reverse-engineering-a-real-candle/

uint16_t WS2812FX::mode_candle()
{
  if (SEGENV.call == 0) {
    SEGENV.aux0 = 128; SEGENV.aux1 = 132; SEGENV.step = 1;
  }
  bool newTarget = false;
  
  uint8_t s = SEGENV.aux0, target = SEGENV.aux1, fadeStep = SEGENV.step;
  
  if (target > s) { //fade up
    s = qadd8(s, fadeStep);
    if (s >= target) newTarget = true;
  } else {
    s = qsub8(s, fadeStep);
    if (s <= target) newTarget = true;
  }
  SEGENV.aux0 = s;

  for (uint16_t i = SEGMENT.start; i < SEGMENT.stop; i++) {
    setPixelColor(i, color_blend(color_from_palette(i, true, PALETTE_SOLID_WRAP, 0), SEGCOLOR(1), 255-s));
  }

  if (newTarget)
  {
    uint8_t valrange = SEGMENT.intensity;
    uint8_t rndval = valrange >> 1;
    target = random8(rndval) + random8(rndval);
    if (target < (rndval >> 1)) target = (rndval >> 1) + random8(rndval);
    uint8_t offset = (255 - valrange) >> 1;
    target += offset;

    uint8_t dif = (target > s) ? target - s : s - target;
  
    //how much to move closer to target per frame
    fadeStep = dif >> 2; //mode called every ~25 ms, so 4 frames to have a new target every 100ms
    if (fadeStep == 0) fadeStep = 1;
    
    SEGENV.step = fadeStep;
    SEGENV.aux1 = target;
  }

  return FRAMETIME;
}


/*
/ Fireworks in starburst effect
/ based on the video: https://www.reddit.com/r/arduino/comments/c3sd46/i_made_this_fireworks_effect_for_my_led_strips/
/ Speed sets frequency of new starbursts, intensity is the intensity of the burst
*/
#define STARBURST_MAX_FRAG 12

//each needs 64 byte
typedef struct particle {
  CRGB     color;
  uint32_t birth  =0;
  uint32_t last   =0;
  float    vel    =0;
  uint16_t pos    =-1;
  float    fragment[STARBURST_MAX_FRAG];
} star;

uint16_t WS2812FX::mode_starburst(void) {
  uint8_t numStars = 1 + (SEGLEN >> 3);
  if (numStars > 15) numStars = 15;
  uint16_t dataSize = sizeof(star) * numStars;

  if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed
  
  uint32_t it = millis();
  
  star* stars = reinterpret_cast<star*>(SEGENV.data);
  
  float          maxSpeed                = 375.0f;  // Max velocity
  float          particleIgnition        = 250.0f;  // How long to "flash"
  float          particleFadeTime        = 1500.0f; // Fade out time
     
  for (int j = 0; j < numStars; j++)
  {
    // speed to adjust chance of a burst, max is nearly always.
    if (random8((144-(SEGMENT.speed >> 1))) == 0 && stars[j].birth == 0)
    {
      // Pick a random color and location.  
      uint16_t startPos = random16(SEGLEN-1);
      float multiplier = (float)(random8())/255.0 * 1.0;

      stars[j].color = col_to_crgb(color_wheel(random8()));
      stars[j].pos = startPos; 
      stars[j].vel = maxSpeed * (float)(random8())/255.0 * multiplier;
      stars[j].birth = it;
      stars[j].last = it;
      // more fragments means larger burst effect
      int num = random8(3,6 + (SEGMENT.intensity >> 5));

      for (int i=0; i < STARBURST_MAX_FRAG; i++) {
        if (i < num) stars[j].fragment[i] = startPos;
        else stars[j].fragment[i] = -1;
      }
    }
  }
  
  fill(SEGCOLOR(1));
  
  for (int j=0; j<numStars; j++)
  {
    if (stars[j].birth != 0) {
      float dt = (it-stars[j].last)/1000.0;

      for (int i=0; i < STARBURST_MAX_FRAG; i++) {
        int var = i >> 1;
        
        if (stars[j].fragment[i] > 0) {
          //all fragments travel right, will be mirrored on other side
          stars[j].fragment[i] += stars[j].vel * dt * (float)var/3.0;
        }
      }
      stars[j].last = it;
      stars[j].vel -= 3*stars[j].vel*dt;
    }
  
    CRGB c = stars[j].color;

    // If the star is brand new, it flashes white briefly.  
    // Otherwise it just fades over time.
    float fade = 0.0f;
    float age = it-stars[j].birth;

    if (age < particleIgnition) {
      c = col_to_crgb(color_blend(WHITE, crgb_to_col(c), 254.5f*((age / particleIgnition))));
    } else {
      // Figure out how much to fade and shrink the star based on 
      // its age relative to its lifetime
      if (age > particleIgnition + particleFadeTime) {
        fade = 1.0f;                  // Black hole, all faded out
        stars[j].birth = 0;
        c = col_to_crgb(SEGCOLOR(1));
      } else {
        age -= particleIgnition;
        fade = (age / particleFadeTime);  // Fading star
        byte f = 254.5f*fade;
        c = col_to_crgb(color_blend(crgb_to_col(c), SEGCOLOR(1), f));
      }
    }
    
    float particleSize = (1.0 - fade) * 2;

    for (uint8_t index=0; index < STARBURST_MAX_FRAG*2; index++) {
      bool mirrored = index & 0x1;
      uint8_t i = index >> 1;
      if (stars[j].fragment[i] > 0) {
        float loc = stars[j].fragment[i];
        if (mirrored) loc -= (loc-stars[j].pos)*2;
        int start = loc - particleSize;
        int end = loc + particleSize;
        if (start < 0) start = 0;
        if (start == end) end++;
        if (end > SEGLEN) end = SEGLEN;    
        for (int p = start; p < end; p++) {
          setPixelColor(SEGMENT.start+p, c.r, c.g, c.b);
        }
      }
    }
  }
  return FRAMETIME;
}


/*
 * Exploding fireworks effect
 * adapted from: http://www.anirama.com/1000leds/1d-fireworks/
 */

uint16_t WS2812FX::mode_exploding_fireworks(void)
{
  //allocate segment data
  uint16_t numSparks = 2 + (SEGLEN >> 1); 
  if (numSparks > 80) numSparks = 80;
  uint16_t dataSize = sizeof(spark) * numSparks;
  if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed

  fill(BLACK);
  
  bool actuallyReverse = SEGMENT.getOption(1);
  //have fireworks start in either direction based on intensity
  SEGMENT.setOption(1, SEGENV.step);
  
  Spark* sparks = reinterpret_cast<Spark*>(SEGENV.data);
  Spark* flare = sparks; //first spark is flare data

  float gravity = -0.0004 - (SEGMENT.speed/800000.0); // m/s/s
  gravity *= SEGLEN;
  
  if (SEGENV.aux0 < 2) { //FLARE
    if (SEGENV.aux0 == 0) { //init flare
      flare->pos = 0;
      uint16_t peakHeight = 75 + random8(180); //0-255
      peakHeight = (peakHeight * (SEGLEN -1)) >> 8;
      flare->vel = sqrt(-2.0 * gravity * peakHeight);
      flare->col = 255; //brightness

      SEGENV.aux0 = 1; 
    }
    
    // launch 
    if (flare->vel > 12 * gravity) {
      // flare
      setPixelColor(SEGMENT.start + int(flare->pos),flare->col,flare->col,flare->col);
  
      flare->pos += flare->vel;
      flare->pos = constrain(flare->pos, 0, SEGLEN-1);
      flare->vel += gravity;
      flare->col -= 2;
    } else {
      SEGENV.aux0 = 2;  // ready to explode
    }
  } else if (SEGENV.aux0 < 4) {
    /*
     * Explode!
     * 
     * Explosion happens where the flare ended.
     * Size is proportional to the height.
     */
    int nSparks = flare->pos;
    nSparks = constrain(nSparks, 0, numSparks);
    static float dying_gravity;
  
    // initialize sparks
    if (SEGENV.aux0 == 2) {
      for (int i = 1; i < nSparks; i++) { 
        sparks[i].pos = flare->pos; 
        sparks[i].vel = (float(random16(0, 20000)) / 10000.0) - 0.9; // from -0.9 to 1.1
        sparks[i].col = 345;//abs(sparks[i].vel * 750.0); // set colors before scaling velocity to keep them bright 
        //sparks[i].col = constrain(sparks[i].col, 0, 345); 
        sparks[i].colIndex = random8();
        sparks[i].vel *= flare->pos/SEGLEN; // proportional to height 
        sparks[i].vel *= -gravity *50;
      } 
      //sparks[1].col = 345; // this will be our known spark 
      dying_gravity = gravity/2; 
      SEGENV.aux0 = 3;
    }
  
    if (sparks[1].col > 4) {//&& sparks[1].pos > 0) { // as long as our known spark is lit, work with all the sparks
      for (int i = 1; i < nSparks; i++) { 
        sparks[i].pos += sparks[i].vel; 
        sparks[i].vel += dying_gravity; 
        if (sparks[i].col > 3) sparks[i].col -= 4; 

        if (sparks[i].pos > 0 && sparks[i].pos < SEGLEN) {
          uint16_t prog = sparks[i].col;
          uint32_t spColor = (SEGMENT.palette) ? color_wheel(sparks[i].colIndex) : SEGCOLOR(0);
          CRGB c = CRGB::Black; //HeatColor(sparks[i].col);
          if (prog > 300) { //fade from white to spark color
            c = col_to_crgb(color_blend(spColor, WHITE, (prog - 300)*5));
          } else if (prog > 45) { //fade from spark color to black
            c = col_to_crgb(color_blend(BLACK, spColor, prog - 45));
            uint8_t cooling = (300 - prog) >> 5;
            c.g = qsub8(c.g, cooling);
            c.b = qsub8(c.b, cooling * 2);
          }
          setPixelColor(SEGMENT.start + int(sparks[i].pos), c.red, c.green, c.blue);
        }
      }
      dying_gravity *= .99; // as sparks burn out they fall slower
    } else {
      SEGENV.aux0 = 6 + random8(10); //wait for this many frames
    }
  } else {
    SEGENV.aux0--;
    if (SEGENV.aux0 < 4) {
      SEGENV.aux0 = 0; //back to flare
      SEGENV.step = (SEGMENT.intensity > random8()); //decide firing side
    }
  }

  SEGMENT.setOption(1, actuallyReverse);
  
  return FRAMETIME;  
}