content: package tim.prune.save;
  
  import tim.prune.data.Track;
  import tim.prune.data.TrackExtents;
  
  /**
   * Extract image size logic into single place
   */
  public abstract class ImageSizeLimits
  {
  	private static final int MIN_PIXELS_ALLOWED = 100;
  	private static final int MAX_PIXELS_ALLOWED = 8000;
  
  
  	/**
  	 * @param inTrack track object
  	 * @param inZoom selected zoom level
  	 * @return true if the image size is acceptable
  	 */
  	public static boolean isZoomLevelOk(Track inTrack, int inZoom)
  	{
  		final int pixelCount = getPixelCount(inTrack, inZoom);
  		return pixelCount > MIN_PIXELS_ALLOWED
  				&& pixelCount < MAX_PIXELS_ALLOWED;
  	}
  
  	/** @return the pixel width / height of the resulting image including border */
  	private static int getPixelCount(Track inTrack, int inZoom)
  	{
  		// Get the extents of the track including a standard (10%) border around the data
  		TrackExtents extents = new TrackExtents(inTrack);
  		extents.applySquareBorder();
  
  		// Work out how big the final image will be
  		final int zoomFactor = 1 << inZoom;
  		return (int) (extents.getXRange().getRange() * zoomFactor * 256);
  	}
  }
  