vu8.ino

/*
 * VU: Hue cycling, three bars (shatter, mono)
 */

void vu8() {
  const uint8_t DRAW_MAX = 30;
  const uint8_t SEGMENTS = 3;
  
  static int origin = 0;
  static uint8_t scroll_color = 0;
  static int last_intensity = 0;
  static int intensity_max = 0;
  static int origin_at_flip = 0;
  static CHSV draw[DRAW_MAX];
  static bool growing = false;
  static bool fall_from_left = true;
  
  int intensity = auxReading(0);
  
  //// Update Origin ////
  // detect peak change and save origin at curve vertex
  if (growing && intensity < last_intensity) {
    growing = false;
    intensity_max = last_intensity;
    fall_from_left = !fall_from_left;
    origin_at_flip = origin;
  } else if (intensity > last_intensity) {
    growing = true;
    origin_at_flip = origin;
  }
  last_intensity = intensity;
  
  // adjust origin if falling
  if (!growing) {
    if (fall_from_left) {
      origin = origin_at_flip + ((intensity_max - intensity) / 2);
    } else {
      origin = origin_at_flip - ((intensity_max - intensity) / 2);
    }
    // correct for origin out of bounds
    if (origin < 0) {
      origin = DRAW_MAX - abs(origin);
    } else if (origin > DRAW_MAX - 1) {
      origin = origin - DRAW_MAX - 1;
    }
  }
  
  //// Assign draw values ///
  // draw amplitue as 1/2 intensity both directions from origin
  int min_lit = origin - (intensity / 2);
  int max_lit = origin + (intensity / 2);
  if (min_lit < 0) {
    min_lit = min_lit + DRAW_MAX;
  }
  if (max_lit >= DRAW_MAX) {
    max_lit = max_lit - DRAW_MAX;
  }
  for (int i=0; i < DRAW_MAX; i++) {
    // if i is within origin +/- 1/2 intensity
    if (
      (min_lit < max_lit && min_lit < i && i < max_lit) // range is within bounds and i is within range
      || (min_lit > max_lit && (i > min_lit || i < max_lit)) // range wraps out of bounds and i is within that wrap
    ) {
      draw[i] = CHSV(scroll_color,255,255);
    } else {
      draw[i] = CHSV(scroll_color,0,0);
    }
  }

  //// Write Segmented ////
  int seg_len = N_PIXELS / SEGMENTS;

  for (int s = 0; s < SEGMENTS; s++) {
    for (int i = 0; i < seg_len; i++) {
       ledsLeft[i + (s*seg_len)] = draw[map(i, 0, seg_len, 0, DRAW_MAX)];
    }
  }

  FastLED.show();
  
  averageReadings(0);

  EVERY_N_MILLISECONDS(20) {
    scroll_color = ++scroll_color % 255;
  }
}