geo/tcPixelData.cpp

   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 /**
  21  * @file tcPixelData.cpp
  22  * @brief A block of pixel data.
  23  */
  24
  25 #include "tcPixelData.h"
  26
  27 #include <GL/glu.h>
  28
  29 #include <inttypes.h>
  30
  31 /*
  32  * Abstract Pixel Data Constructors + destructor
  33  */
  34
  35 /// Primary constructor.
  36 tcAbstractPixelData::tcAbstractPixelData(int width, int height)
  37 : m_textureId(0)
  38 {
  39   Q_ASSERT(width > 0);
  40   Q_ASSERT(height > 0);
  41   m_size[0] = width;
  42   m_size[1] = height;
  43 }
  44
  45 /// Destructor.
  46 tcAbstractPixelData::~tcAbstractPixelData()
  47 {
  48   discardTexture();
  49 }
  50
  51 /*
  52  * Accessors
  53  */
  54
  55 /// Get the width of the image.
  56 int tcAbstractPixelData::width() const
  57 {
  58   return m_size[0];
  59 }
  60
  61 /// Get the height of the image.
  62 int tcAbstractPixelData::height() const
  63 {
  64   return m_size[1];
  65 }
  66
  67 /// Get (creating if necessary) a GL texture for this image.
  68 GLuint tcAbstractPixelData::texture()
  69 {
  70   if (0 == m_textureId)
  71   {
  72     m_textureId = loadTexture();
  73   }
  74   return m_textureId;
  75 }
  76
  77 /// Discard of any cached texture id for this image.
  78 void tcAbstractPixelData::discardTexture()
  79 {
  80   glDeleteTextures(1, &m_textureId);
  81 }
  82
  83 /*
  84  * Virtual interface for derived classes to implement.
  85  */
  86
  87 /// Load the pixel data into a GL texture.
  88 GLuint tcAbstractPixelData::loadTexture()
  89 {
  90   return 0;
  91 }
  92
  93 /*
  94  * Pixel data texture creation
  95  */
  96
  97 template <>
  98 GLuint tcPixelData<GLubyte>::loadTexture()
  99 {
 100   GLuint textureId = 0;
 101   if (0 != buffer())
 102   {
 103     glGenTextures(1, &textureId);
 104     GLint binding = 0;
 105     glGetIntegerv(GL_TEXTURE_BINDING_2D, &binding);
 106     glBindTexture(GL_TEXTURE_2D, textureId);
 107     if (0 == gluBuild2DMipmaps(GL_TEXTURE_2D, GL_LUMINANCE, m_size[0], m_size[1],
 108                                GL_LUMINANCE, GL_UNSIGNED_BYTE, buffer()))
 109     {
 110       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
 111       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 112       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
 113       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 114     }
 115     else
 116     {
 117       glDeleteTextures(1, &textureId);
 118     }
 119     glBindTexture(GL_TEXTURE_2D, binding);
 120   }
 121   return textureId;
 122 }
 123
 124 template <>
 125 GLuint tcPixelData<GLfloat>::loadTexture()
 126 {
 127   GLuint textureId = 0;
 128   if (0 != buffer())
 129   {
 130     glGenTextures(1, &textureId);
 131     GLint binding = 0;
 132     glGetIntegerv(GL_TEXTURE_BINDING_2D, &binding);
 133     glBindTexture(GL_TEXTURE_2D, textureId);
 134     if (0 == gluBuild2DMipmaps(GL_TEXTURE_2D, GL_LUMINANCE, m_size[0], m_size[1],
 135                                GL_LUMINANCE, GL_FLOAT, buffer()))
 136     {
 137       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
 138       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 139       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
 140       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 141     }
 142     else
 143     {
 144       glDeleteTextures(1, &textureId);
 145     }
 146     glBindTexture(GL_TEXTURE_2D, binding);
 147   }
 148   return textureId;
 149 }