// pixels may contain any float number (e.g. for a distance map)

static final class FloatBWImage is IBWImage {

  int width, height;

  float[] pixels; // 0 to 1 usually

  // color returned when getPixel is called with a position outside the actual image

  float borderColor = 0.0f;

  // for unstructure()

  *() {}

  // BLACK!

  *(int *width, int *height) {

    pixels = new float[width*height];

  }

  *(int *width, int *height, float brightness) {

    pixels = new float[width*height];

    fillArrayUnlessZero(pixels, brightness);

  }

  *(int *width, int *height, float[] *pixels) {}

  public float getPixel aka getFloatPixel(int x, int y) {

    ret inRange(x, y) ? getPixel_noRangeCheck(x, y) : borderColor;

  }

  public float getFloatPixel(int index) {

    ret pixels[index];

  }

  float getPixel(Pt p) { ret getPixel(p.x, p.y); }

  private boolean inRange(int x, int y) {

    return x >= 0 && x < width && y >= 0 && y < height;

  }

  public int getWidth() { return width; }

  public int getHeight() { return height; }

  public void setPixel(int x, int y, float brightness) {

    pixels[y*width+x] = brightness;

  }

  float getPixel_noRangeCheck(int x, int y) {

    return pixels[y*width+x];

  }

  public byte getByte(int x, int y) {

    return inRange(x, y) ? getByte_noRangeCheck(x, y) : _toByte(borderColor);

  }

  byte getByte_noRangeCheck(int x, int y) {

    ret _toByte(pixels[y*width+x]);

  }

  static byte _toByte(float pixel) {

    return (byte) (Math.max(0, Math.min(1, pixel))*255f);

  }

  // TODO: optimize

  public BufferedImage getBufferedImage() {

    BufferedImage img = bufferedImage(width, height);

    for (int y = 0; y < height; y++)

      for (int x = 0; x < width; x++) {

        int b = ((int) getByte(x, y) & 0xFF);

        img.setRGB(x, y, b*0x010101);

      }

    ret img; 

  }

  public double averageBrightness() {

    ret floatSumAsDouble(pixels)/(width*height);

  }

}