geo/tcHLImage.h

   1 /***************************************************************************
   2  *   This file is part of Tecorrec.                                        *
   3  *   Copyright 2008 James Hogan <james@albanarts.com>                      *
   4  *                                                                         *
   5  *   Tecorrec is free software: you can redistribute it and/or modify      *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation, either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   Tecorrec is distributed in the hope that it will be useful,           *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with Tecorrec.  If not, write to the Free Software Foundation,  *
  17  *   Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.   *
  18  ***************************************************************************/
  19
  20 #ifndef _tcHLImage_h_
  21 #define _tcHLImage_h_
  22
  23 /**
  24  * @file tcHLImage.h
  25  * @brief Hurrendously Large Images.
  26  */
  27
  28 #include <QString>
  29 #include <GL/gl.h>
  30
  31 class GDALDataset;
  32
  33 /** Hurrendously Large Images.
  34  * This class is designed to help keep very large image files under control.
  35  * This involves partial loading, mipmapping, and loading into GL textures.
  36  * The assumption is that when processing we are only interested in the full
  37  * resolution data (although probably only a small part of it).
  38  */
  39 class tcHLImage
  40 {
  41   public:
  42
  43     /*
  44      * Constructors + destructor
  45      */
  46
  47     /// Primary constructor.
  48     tcHLImage(const QString& filename);
  49
  50     /// Destructor.
  51     virtual ~tcHLImage();
  52
  53     /*
  54      * General accessors
  55      */
  56
  57     /// Get the width of the image.
  58     int width() const;
  59
  60     /// Get the height of the image.
  61     int height() const;
  62
  63     /*
  64      * Main interface
  65      */
  66
  67     /// Get the thumbnail of the entire image.
  68     GLuint thumbnailTexture();
  69
  70     /** Set up the current texture with a full resolution portion of the image.
  71      * Writes back to the coordinates to ensure they are accurate.
  72      * @returns false on failure - in which case perhaps the region is too big
  73      *          try using thumbnailTexture in that case instead
  74      */
  75     bool setupTexture(double* x1, double* y1, double* x2, double* y2);
  76
  77     /// Prefetch a portion of the image.
  78     void prefetch(int x, int y, int w, int h);
  79
  80   private:
  81
  82     /*
  83      * Variables
  84      */
  85
  86     /// Width of the image file.
  87     int m_width;
  88
  89     /// Height of the image file.
  90     int m_height;
  91
  92     /// GDAL dataset object.
  93     GDALDataset* m_dataset;
  94
  95     /// Thumbnail texture.
  96     GLuint m_thumbnail;
  97 };
  98
  99 #endif
 100