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//
// "$Id$"
//
// Fl_PNG_Image routines.
//
// Copyright 1997-2005 by Easy Software Products.
// Image support donated by Matthias Melcher, Copyright 2000.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems to "fltk-bugs@fltk.org".
//
// Contents:
//
// Fl_PNG_Image::Fl_PNG_Image() - Load a PNG image file.
//
//
// Include necessary header files...
//
#include <FL/Fl.H>
#include <FL/Fl_PNG_Image.H>
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
extern "C"
{
#if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
# include <zlib.h>
# ifdef HAVE_PNG_H
# include <png.h>
# else
# include <libpng/png.h>
# endif // HAVE_PNG_H
#endif // HAVE_LIBPNG && HAVE_LIBZ
}
//
// 'Fl_PNG_Image::Fl_PNG_Image()' - Load a PNG image file.
//
Fl_PNG_Image::Fl_PNG_Image(const char *png) // I - File to read
: Fl_RGB_Image(0,0,0) {
#if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
int i; // Looping var
FILE *fp; // File pointer
int channels; // Number of color channels
png_structp pp; // PNG read pointer
png_infop info; // PNG info pointers
png_bytep *rows; // PNG row pointers
// Open the PNG file...
if ((fp = fopen(png, "rb")) == NULL) return;
// Setup the PNG data structures...
pp = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
info = png_create_info_struct(pp);
if (setjmp(pp->jmpbuf))
{
Fl::warning("PNG file \"%s\" contains errors!\n", png);
return;
}
// Initialize the PNG read "engine"...
png_init_io(pp, fp);
// Get the image dimensions and convert to grayscale or RGB...
png_read_info(pp, info);
if (info->color_type == PNG_COLOR_TYPE_PALETTE)
png_set_expand(pp);
if (info->color_type & PNG_COLOR_MASK_COLOR)
channels = 3;
else
channels = 1;
if ((info->color_type & PNG_COLOR_MASK_ALPHA) || info->num_trans)
channels ++;
w((int)(info->width));
h((int)(info->height));
d(channels);
if (info->bit_depth < 8)
{
png_set_packing(pp);
png_set_expand(pp);
}
else if (info->bit_depth == 16)
png_set_strip_16(pp);
# if defined(HAVE_PNG_GET_VALID) && defined(HAVE_PNG_SET_TRNS_TO_ALPHA)
// Handle transparency...
if (png_get_valid(pp, info, PNG_INFO_tRNS))
png_set_tRNS_to_alpha(pp);
# endif // HAVE_PNG_GET_VALID && HAVE_PNG_SET_TRNS_TO_ALPHA
array = new uchar[w() * h() * d()];
alloc_array = 1;
// Allocate pointers...
rows = new png_bytep[h()];
for (i = 0; i < h(); i ++)
rows[i] = (png_bytep)(array + i * w() * d());
// Read the image, handling interlacing as needed...
for (i = png_set_interlace_handling(pp); i > 0; i --)
png_read_rows(pp, rows, NULL, h());
#ifdef WIN32
// Some Windows graphics drivers don't honor transparency when RGB == white
if (channels == 4) {
// Convert RGB to 0 when alpha == 0...
uchar *ptr = (uchar *)array;
for (i = w() * h(); i > 0; i --, ptr += 4)
if (!ptr[3]) ptr[0] = ptr[1] = ptr[2] = 0;
}
#endif // WIN32
// Free memory and return...
delete[] rows;
png_read_end(pp, info);
png_destroy_read_struct(&pp, &info, NULL);
fclose(fp);
#endif // HAVE_LIBPNG && HAVE_LIBZ
}
//
// End of "$Id$".
//
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