/*
* CVS identifier:
*
* $Id: SubbandROIMask.java,v 1.2 2001/02/28 15:12:44 grosbois Exp $
*
* Class:                   ROI
*
* Description:             This class describes the ROI mask for a subband
*
*
*
* COPYRIGHT:
* 
* This software module was originally developed by Raphaël Grosbois and
* Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
* Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
* Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
* Centre France S.A) in the course of development of the JPEG2000
* standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
* software module is an implementation of a part of the JPEG 2000
* Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
* Systems AB and Canon Research Centre France S.A (collectively JJ2000
* Partners) agree not to assert against ISO/IEC and users of the JPEG
* 2000 Standard (Users) any of their rights under the copyright, not
* including other intellectual property rights, for this software module
* with respect to the usage by ISO/IEC and Users of this software module
* or modifications thereof for use in hardware or software products
* claiming conformance to the JPEG 2000 Standard. Those intending to use
* this software module in hardware or software products are advised that
* their use may infringe existing patents. The original developers of
* this software module, JJ2000 Partners and ISO/IEC assume no liability
* for use of this software module or modifications thereof. No license
* or right to this software module is granted for non JPEG 2000 Standard
* conforming products. JJ2000 Partners have full right to use this
* software module for his/her own purpose, assign or donate this
* software module to any third party and to inhibit third parties from
* using this software module for non JPEG 2000 Standard conforming
* products. This copyright notice must be included in all copies or
* derivative works of this software module.
* 
* Copyright (c) 1999/2000 JJ2000 Partners.
*  */
using System;
using CSJ2K.j2k.codestream.writer;
using CSJ2K.j2k.wavelet.analysis;
using CSJ2K.j2k.quantization;
using CSJ2K.j2k.wavelet;
using CSJ2K.j2k.image;
using CSJ2K.j2k.util;
using CSJ2K.j2k.roi;
namespace CSJ2K.j2k.roi.encoder
{
	
	/// <summary> This abstract class describes the ROI mask for a single subband. Each
	/// object of the class contains the mask for a particular subband and also has
	/// references to the masks of the children subbands of the subband
	/// corresponding to this mask.  
	/// </summary>
	public abstract class SubbandROIMask
	{
		
		/// <summary>The subband masks of the child LL </summary>
		protected internal SubbandROIMask ll;
		
		/// <summary>The subband masks of the child LH </summary>
		protected internal SubbandROIMask lh;
		
		/// <summary>The subband masks of the child HL </summary>
		protected internal SubbandROIMask hl;
		
		/// <summary>The subband masks of the child HH </summary>
		protected internal SubbandROIMask hh;
		
		/// <summary>Flag indicating whether this subband mask is a node or not </summary>
		protected internal bool isNode;
		
		/// <summary>Horizontal uper-left coordinate of the subband mask </summary>
		public int ulx;
		
		/// <summary>Vertical uper-left coordinate of the subband mask </summary>
		public int uly;
		
		/// <summary>Width of the subband mask </summary>
		public int w;
		
		/// <summary>Height of the subband mask </summary>
		public int h;
		
		/// <summary> The constructor of the SubbandROIMask takes the dimensions of the
		/// subband as parameters
		/// 
		/// </summary>
		/// <param name="ulx">The upper left x coordinate of corresponding subband
		/// 
		/// </param>
		/// <param name="uly">The upper left y coordinate of corresponding subband
		/// 
		/// </param>
		/// <param name="w">The width of corresponding subband
		/// 
		/// </param>
		/// <param name="h">The height of corresponding subband
		/// 
		/// </param>
		public SubbandROIMask(int ulx, int uly, int w, int h)
		{
			this.ulx = ulx;
			this.uly = uly;
			this.w = w;
			this.h = h;
		}
		
		/// <summary> Returns a reference to the Subband mask element to which the specified
		/// point belongs. The specified point must be inside this (i.e. the one
		/// defined by this object) subband mask. This method searches through the
		/// tree.
		/// 
		/// </summary>
		/// <param name="x">horizontal coordinate of the specified point.
		/// 
		/// </param>
		/// <param name="y">horizontal coordinate of the specified point.
		/// 
		/// </param>
		public virtual SubbandROIMask getSubbandRectROIMask(int x, int y)
		{
			SubbandROIMask cur, hhs;
			
			// Check that we are inside this subband
			if (x < ulx || y < uly || x >= ulx + w || y >= uly + h)
			{
				throw new System.ArgumentException();
			}
			
			cur = this;
			while (cur.isNode)
			{
				hhs = cur.hh;
				// While we are still at a node -> continue
				if (x < hhs.ulx)
				{
					// Is the result of horizontal low-pass
					if (y < hhs.uly)
					{
						// Vertical low-pass
						cur = cur.ll;
					}
					else
					{
						// Vertical high-pass
						cur = cur.lh;
					}
				}
				else
				{
					// Is the result of horizontal high-pass
					if (y < hhs.uly)
					{
						// Vertical low-pass
						cur = cur.hl;
					}
					else
					{
						// Vertical high-pass
						cur = cur.hh;
					}
				}
			}
			return cur;
		}
	}
}