static final class FloatBWImage implements MakesBufferedImage, IBWImage {
  int width, height;
  float[] pixels; // 0 to 255 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) {
    this.height = height;
    this.width = width;
    this.pixels = pixels;
  }

  public float getPixel(int x, int y) {
    return inRange(x, y) ? getPixel_noRangeCheck(x, y) : borderColor;
  }
  
  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; }
  int w() { return width; }

  public int getHeight() { return height; }
  int h() { 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 BufferedImage getBufferedImage() {
    for (int y = 0; y < height; y++)
      for (int x = 0; x < width; x++) {
        int b = ((int) getByte(x, y) & 0xFF);
        bufferedImage.setRGB(x, y, b*0x010101);
      }
    ret bufferedImage; 
  }
}