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Diffstat (limited to 'contrib/libpng/contrib/gregbook/readppm.c')
| -rw-r--r-- | contrib/libpng/contrib/gregbook/readppm.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/contrib/libpng/contrib/gregbook/readppm.c b/contrib/libpng/contrib/gregbook/readppm.c new file mode 100644 index 0000000..be9a56d --- /dev/null +++ b/contrib/libpng/contrib/gregbook/readppm.c @@ -0,0 +1,179 @@ +/*--------------------------------------------------------------------------- + + rpng - simple PNG display program readppm.c + + --------------------------------------------------------------------------- + + This is a special-purpose replacement for readpng.c that allows binary + PPM files to be used in place of PNG images. + + --------------------------------------------------------------------------- + + Copyright (c) 1998-2007 Greg Roelofs. All rights reserved. + + This software is provided "as is," without warranty of any kind, + express or implied. In no event shall the author or contributors + be held liable for any damages arising in any way from the use of + this software. + + The contents of this file are DUAL-LICENSED. You may modify and/or + redistribute this software according to the terms of one of the + following two licenses (at your option): + + + LICENSE 1 ("BSD-like with advertising clause"): + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute + it freely, subject to the following restrictions: + + 1. Redistributions of source code must retain the above copyright + notice, disclaimer, and this list of conditions. + 2. Redistributions in binary form must reproduce the above copyright + notice, disclaimer, and this list of conditions in the documenta- + tion and/or other materials provided with the distribution. + 3. All advertising materials mentioning features or use of this + software must display the following acknowledgment: + + This product includes software developed by Greg Roelofs + and contributors for the book, "PNG: The Definitive Guide," + published by O'Reilly and Associates. + + + LICENSE 2 (GNU GPL v2 or later): + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + ---------------------------------------------------------------------------*/ + +#include <stdio.h> +#include <stdlib.h> + +#include "readpng.h" /* typedefs, common macros, public prototypes */ + + +ulg width, height; +int bit_depth, color_type, channels; +uch *image_data = NULL; +FILE *saved_infile; + + +void readpng_version_info() +{ + fprintf(stderr, " Compiled without libpng, zlib or PBMPLUS/NetPBM.\n"); +} + + +/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */ + +int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight) +{ + static uch ppmline[256]; + int maxval; + + + saved_infile = infile; + + fgets(ppmline, 256, infile); + if (ppmline[0] != 'P' || ppmline[1] != '6') { + fprintf(stderr, "ERROR: not a PPM file\n"); + return 1; + } + /* possible color types: P5 = grayscale (0), P6 = RGB (2), P8 = RGBA (6) */ + if (ppmline[1] == '6') { + color_type = 2; + channels = 3; + } else if (ppmline[1] == '8') { + color_type = 6; + channels = 4; + } else /* if (ppmline[1] == '5') */ { + color_type = 0; + channels = 1; + } + + do { + fgets(ppmline, 256, infile); + } while (ppmline[0] == '#'); + sscanf(ppmline, "%lu %lu", &width, &height); + + do { + fgets(ppmline, 256, infile); + } while (ppmline[0] == '#'); + sscanf(ppmline, "%d", &maxval); + if (maxval != 255) { + fprintf(stderr, "ERROR: maxval = %d\n", maxval); + return 2; + } + bit_depth = 8; + + *pWidth = width; + *pHeight = height; + + return 0; +} + + + + +/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error; + * scales values to 8-bit if necessary */ + +int readpng_get_bgcolor(uch *red, uch *green, uch *blue) +{ + return 1; +} + + + + +/* display_exponent == LUT_exponent * CRT_exponent */ + +uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes) +{ + ulg rowbytes; + + + /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits, + * transparency chunks to full alpha channel; strip 16-bit-per-sample + * images to 8 bits per sample; and convert grayscale to RGB[A] */ + + /* GRR WARNING: grayscale needs to be expanded and channels reset! */ + + *pRowbytes = rowbytes = channels*width; + *pChannels = channels; + + if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) { + return NULL; + } + + Trace((stderr, "readpng_get_image: rowbytes = %ld, height = %ld\n", rowbytes, height)); + + + /* now we can go ahead and just read the whole image */ + + fread(image_data, 1L, rowbytes*height, saved_infile); + + + return image_data; +} + + +void readpng_cleanup(int free_image_data) +{ + if (free_image_data && image_data) { + free(image_data); + image_data = NULL; + } +} |