#ifndef _GLTEXTURELOADER_H_#define _GLTEXTURELOADER_H_#include <GL/gl.h> // for types#include <GL/glu.h>namespace NSoft {  using namespace std;  class GLTextureLoader {   protected:    GLubyte** Textures;    GLsizei Width, Height;    GLuint NumLevels;    GLenum Type, Format;    bool NeedFree;   public:    /*! \brief Constructor     *     * Creates a new GLTextureLoader object     *     * \param f The texture format (hardcoded to GL_UNSIGNED_BYTE, this     *   parameter is currently ignored.     * \param t The texture type (GL_RGB, GL_RGBA, ...)     * \param nl The number of mipmap levels (currently ignored, set to 1)     */    GLTextureLoader( int f, int t, int nl );        virtual ~GLTextureLoader();    /*! \brief Returns a pointer to a texture map     *     * This method returns a pointer to a texture map of a given Mipmap     * level, suitable for use in GL functions.     *     * \param mml The required mipmap level     * \return A pointer to the pixel data array     */    inline GLubyte* getTexture( int mml ) { return Textures[mml]; }        /*! \brief Returns the texture type     *     * This method is currently hardcoded to return GL_UNSIGNED_BYTE     *     * \return the texture type     */    inline GLenum getType( void ) { return GL_UNSIGNED_BYTE; } //FIXME hardcoded        /*! \brief Returns the texture format     *     * Returns the format of the texture (RGB, RGBA, ...)     *     * \return the texture format     */    inline GLenum getFormat( void ) { return Format; }        inline GLsizei getWidth( void ) { return Width; }    inline GLsizei getHeight( void ) { return Height; }    inline GLuint getLevels( void ) { return NumLevels; }  };    class GLTextureLoaderPNG : public GLTextureLoader {   private:    bool* PNGNeedFree;       public:    GLTextureLoaderPNG( int f, int t, int nl );        ~GLTextureLoaderPNG( void );        void addTexture( int l, char* fn );  };}#endif //_TEXTURELOADER_H_

#include "gltextureloader.hpp"#include <iostream>#include <cstdio>#include <cstdlib>#include <png.h>using namespace NSoft;using namespace std;GLTextureLoader::GLTextureLoader( int f, int t, int nl ) {  NumLevels = nl;  Type = t;  Format = f;  NeedFree = false;  Textures = NULL;    Textures = new (GLubyte*)(NULL);    if( !Textures ) {    cerr << "Error in constructor!" << endl;    throw "Error in constructor!"; //FIXME  }    NeedFree = true;  cerr << "Base constructor reached! Settings:" << endl   << " NumLevels: " << NumLevels << endl   << " Type: " << Type << "(" << GL_UNSIGNED_BYTE << ")" << endl   << " Format: " << Format << "(" << GL_RGB << ")" << endl << endl;}GLTextureLoader::~GLTextureLoader( void ) {  if( NeedFree ) {        delete[] Textures;  }}GLTextureLoaderPNG::GLTextureLoaderPNG( int f, int t, int nl ) :  GLTextureLoader( f, t, nl ){  PNGNeedFree = new bool(false);};    GLTextureLoaderPNG::~GLTextureLoaderPNG( void ) {  for( int i=0; i<NumLevels; i++ ) {    if( PNGNeedFree ) free( Textures );  }    delete[] PNGNeedFree;}void GLTextureLoaderPNG::addTexture( int l, char* fn ) {  png_byte header[8];  int flags;  png_bytep* row_pointers;  FILE *fp = fopen( fn, "rb");    if (!fp) {    throw "Error opening file"; //FIXME ERROR opening file  }  // check if this is a PNG file  fread( (char*)header, 1, 8, fp );  if ( png_sig_cmp(header, 0, 8) ) {    throw "Not a PNG file"; //FIXME NOT_PNG  }    png_structp pngfile = png_create_read_struct(    PNG_LIBPNG_VER_STRING,    NULL, NULL, NULL );  if( !pngfile ) {    throw "Error creating read structure"; //FIXME ERROR  }    png_infop pnginfo = png_create_info_struct( pngfile );  if( !pnginfo ) {    png_destroy_read_struct( &pngfile, NULL, NULL );    throw "Error creating info structure"; //FIXME  }    png_infop pngendinfo = png_create_info_struct( pngfile );  if( !pngendinfo ) {    png_destroy_read_struct( &pngfile, &pnginfo, NULL );  }    // In case of an error, we want to die here!  if( setjmp( png_jmpbuf(pngfile) ) ) {    png_destroy_read_struct(&pngfile, &pnginfo, &pngendinfo);    fclose(fp);    throw "Error! longjmp() called!"; //FIXME  }  png_init_io( pngfile, fp );  png_set_sig_bytes( pngfile, 8 ); // we read 8 bytes to verify  cerr << "PNG: IO initiated." << endl;    flags = PNG_TRANSFORM_STRIP_16|PNG_TRANSFORM_PACKING;  switch( Format ) {   case GL_RGB:    // strip alpha channel    cerr << "PNG texture DEBUG: stripping alpha channel" << endl;    flags |= PNG_TRANSFORM_STRIP_ALPHA;    break;       case GL_RED:   case GL_GREEN:   case GL_BLUE:   case GL_ALPHA:   case GL_LUMINANCE:    // single-element map    cerr << "Specified unsupported texture type!" << endl;    throw "Unsupported texture type!"; //FIXME not implemented    break;       default:    cerr << "PNG texture DEBUG: unknown type given!" << endl;    break;  }    cerr << "Calling png_read_png()...";  png_read_png( pngfile, pnginfo, flags, NULL );  cerr << "done." << endl;    // allocate memory  //row_pointers = (png_bytep*)png_malloc( pngfile, pnginfo->height*sizeof(png_bytep) );  row_pointers = png_get_rows( pngfile, pnginfo );  cerr << "Allocating " << pnginfo->rowbytes * pnginfo->height * sizeof(GLubyte) << " bytes" << endl;  if( PNGNeedFree ) free( Textures[l] );  Textures[l] = (GLubyte*)malloc( pnginfo->rowbytes * pnginfo->height * sizeof(GLubyte) );  PNGNeedFree[l] = true;  cerr << "Textures base address: " << Textures << endl;  for( int i=0; i<pnginfo->height; i++ ) {    memcpy( &(Textures[l][i*pnginfo->rowbytes]), row_pointers, pnginfo->rowbytes );    //row_pointers = &(Textures[l][i*pnginfo->rowbytes]);  }    if( pnginfo->bit_depth != 8 ) {    cerr << "Screwy optics? Bit-depth must be 8! Is: " << pnginfo->bit_depth << endl;  }    cerr << "PNG texture DEBUG:" << endl    << " Format: " << pnginfo->width << "x" << pnginfo->height << "x" << pnginfo->bit_depth*pnginfo->channels << endl;    // make the format of an RGB texture RGB even if RGBA was given  if( pnginfo->color_type == PNG_COLOR_TYPE_RGB && Format == GL_RGBA ) {    cerr << " Overriding alpha setting!" << endl;    Format = GL_RGB;  }    Width = pnginfo->width;  Height = pnginfo->height;    png_destroy_read_struct( &pngfile, &pnginfo, &pngendinfo );  fclose( fp );}