/*=============================================================================

  Project:   SharpImage
  Module:    siGdiLookupTable.cs
  Language:  C#
  Author:    Dan Mueller
  Date:      $Date: 2007-07-06 10:57:00 +1000 (Fri, 06 Jul 2007) $
  Revision:  $Revision: 2 $

  Copyright (c) Queensland University of Technology (QUT) 2007.
  All rights reserved.

  This software is distributed WITHOUT ANY WARRANTY; without even
  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  PURPOSE.  See the above copyright notices for more information.
  
=============================================================================*/

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Diagnostics;

namespace SharpImage.Rendering
{
    public class siGdiLookupTable : siLookupTable
    {
        #region Constuction and Disposal
        //=====================================================================
        /// <summary>
        /// Default constructor.
        /// </summary>
        public siGdiLookupTable() : base()
        {

        }
        //=====================================================================
        #endregion

        #region Properties
        //=====================================================================
        
        //=====================================================================
        #endregion

        #region Public Instance Methods
        //=====================================================================
        /// <summary>
        /// Converts the LUT to a GDI ColorPalette. Use GetGdiPixelFormat()
        /// to get the PixelFormat of the ColorPalette. This method reconstructs
        /// a new ColorPalette for each call, so use with care.
        /// </summary>
        /// <returns></returns>
        public virtual ColorPalette GetGdiPalette()
        {
            // Get the format and empty palette
            PixelFormat format = this.GetGdiPixelFormat();
            ColorPalette palette = this.CreateEmptyColorPalette(format);
            
            // Populate the palette entries
            for (int i = 0; i < this.NumberOfTableValues; i++)
                palette.Entries[i] = this.TableValues[i].ValueAsColor;

            //Return result
            return palette;
        }

        /// <summary>
        /// Gets the GDI PixelFormat of the ColorPalette. Use GetGdiPalette()
        /// to get the actual palette.
        /// </summary>
        /// <returns></returns>
        public virtual PixelFormat GetGdiPixelFormat()
        {
            // TODO: We currently only support 8-bit LUTs
            // TODO: Support RGB and RGBA colour maps
            return PixelFormat.Format8bppIndexed;
        }
        //=====================================================================
        #endregion

        #region Protected Methods
        //=====================================================================
        /// <summary>
        /// Creates an empty colour palette of the given format.
        /// </summary>
        /// <param name="format"></param>
        /// <returns></returns>
        protected ColorPalette CreateEmptyColorPalette(PixelFormat format)
        {
            // NOTE: This code is adapted from:
            // http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q319061

            ColorPalette palette;    // The Palette we are stealing
            Bitmap bitmap;           // The source of the stolen palette

            // Make a new Bitmap object to steal its Palette
            bitmap = new Bitmap(1, 1, format);

            palette = bitmap.Palette;   // Grab the palette
            bitmap.Dispose();           // Cleanup the source Bitmap
            return palette;             // Send the palette back
        }
        //=====================================================================
        #endregion
    }
}