png_byte header[8];  int flags;  png_bytep* row_pointers;  FILE *fp = fopen( fn, "rb");  // 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";  }    png_structp pngfile = png_create_read_struct(    PNG_LIBPNG_VER_STRING,    NULL, NULL, NULL );  png_infop pnginfo = png_create_info_struct( pngfile );  png_infop pngendinfo = png_create_info_struct( pngfile );  // 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!";  }  png_init_io( pngfile, fp );  png_set_sig_bytes( pngfile, 8 ); // we read 8 bytes to verify    flags = PNG_TRANSFORM_STRIP_16|PNG_TRANSFORM_PACKING;  // you can set additional transforms here to convert unuseable formats as you need it    // "the hard way"  png_read_png( pngfile, pnginfo, flags, NULL );    // get pointers to each row of the image  row_pointers = png_get_rows( pngfile, pnginfo );  // read the image into the target buffer. sucks but works, could stand a little reworking  if( PNGNeedFree ) free( Textures[l] );  Textures[l] = (GLubyte*)malloc( pnginfo->rowbytes * pnginfo->height * sizeof(GLubyte) );  PNGNeedFree[l] = true;  for( int i=0; i<pnginfo->height; i++ ) {    memcpy( &(Textures[l][i*pnginfo->rowbytes]), row_pointers[i], pnginfo->rowbytes );  }  // this will clear all memory used other than the stored texture  png_destroy_read_struct( &pngfile, &pnginfo, &pngendinfo );  fclose( fp );