From d1a8285f818eb7e5c3d6a05709ea21a808490b8c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Mon, 19 Mar 2018 19:55:58 +0100 Subject: New upstream version 5.1.0 --- app/help/readpng.c | 275 ----------------------------------------------------- 1 file changed, 275 deletions(-) delete mode 100644 app/help/readpng.c (limited to 'app/help/readpng.c') diff --git a/app/help/readpng.c b/app/help/readpng.c deleted file mode 100644 index 1f1d145..0000000 --- a/app/help/readpng.c +++ /dev/null @@ -1,275 +0,0 @@ -/*--------------------------------------------------------------------------- - - rpng - simple PNG display program readpng.c - - --------------------------------------------------------------------------- - - Copyright (c) 1998-1999 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. - - 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. - - ---------------------------------------------------------------------------*/ - -#include -#include - -#include "png.h" /* libpng header; includes zlib.h */ -#include "readpng.h" /* typedefs, common macros, public prototypes */ - - -static png_structp png_ptr = NULL; -static png_infop info_ptr = NULL; - -png_uint_32 width, height; -int bit_depth, color_type; -uch *image_data = NULL; - - -void readpng_version_info() -{ - fprintf(stderr, " Compiled with libpng %s; using libpng %s.\n", - PNG_LIBPNG_VER_STRING, png_libpng_ver); - fprintf(stderr, " Compiled with zlib %s; using zlib %s.\n", - ZLIB_VERSION, zlib_version); -} - - -/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */ - -int readpng_init(FILE *infile, long *pWidth, long *pHeight) -{ - uch sig[8]; - - - /* first do a quick check that the file really is a PNG image; could - * have used slightly more general png_sig_cmp() function instead */ - - fread(sig, 1, 8, infile); - if (!png_check_sig(sig, 8)) - return 1; /* bad signature */ - - - /* could pass pointers to user-defined error handlers instead of NULLs: */ - - png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); - if (!png_ptr) - return 4; /* out of memory */ - - info_ptr = png_create_info_struct(png_ptr); - if (!info_ptr) { - png_destroy_read_struct(&png_ptr, NULL, NULL); - return 4; /* out of memory */ - } - - - /* we could create a second info struct here (end_info), but it's only - * useful if we want to keep pre- and post-IDAT chunk info separated - * (mainly for PNG-aware image editors and converters) */ - - - /* setjmp() must be called in every function that calls a PNG-reading - * libpng function */ - - if (setjmp(png_ptr->jmpbuf)) { - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); - return 2; - } - - - png_init_io(png_ptr, infile); - png_set_sig_bytes(png_ptr, 8); /* we already read the 8 signature bytes */ - - png_read_info(png_ptr, info_ptr); /* read all PNG info up to image data */ - - - /* alternatively, could make separate calls to png_get_image_width(), - * etc., but want bit_depth and color_type for later [don't care about - * compression_type and filter_type => NULLs] */ - - png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, - NULL, NULL, NULL); - *pWidth = width; - *pHeight = height; - - - /* OK, that's all we need for now; return happy */ - - 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) -{ - png_color_16p pBackground; - - - /* setjmp() must be called in every function that calls a PNG-reading - * libpng function */ - - if (setjmp(png_ptr->jmpbuf)) { - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); - return 2; - } - - - if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD)) - return 1; - - /* it is not obvious from the libpng documentation, but this function - * takes a pointer to a pointer, and it always returns valid red, green - * and blue values, regardless of color_type: */ - - png_get_bKGD(png_ptr, info_ptr, &pBackground); - - - /* however, it always returns the raw bKGD data, regardless of any - * bit-depth transformations, so check depth and adjust if necessary */ - - if (bit_depth == 16) { - *red = pBackground->red >> 8; - *green = pBackground->green >> 8; - *blue = pBackground->blue >> 8; - } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) { - if (bit_depth == 1) - *red = *green = *blue = pBackground->gray? 255 : 0; - else if (bit_depth == 2) - *red = *green = *blue = (255/3) * pBackground->gray; - else /* bit_depth == 4 */ - *red = *green = *blue = (255/15) * pBackground->gray; - } else { - *red = (uch)pBackground->red; - *green = (uch)pBackground->green; - *blue = (uch)pBackground->blue; - } - - return 0; -} - - - - -/* display_exponent == LUT_exponent * CRT_exponent */ - -uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes) -{ - double gamma; - png_uint_32 i, rowbytes; - png_bytepp row_pointers = NULL; - - - /* setjmp() must be called in every function that calls a PNG-reading - * libpng function */ - - if (setjmp(png_ptr->jmpbuf)) { - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); - return NULL; - } - - - /* 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] */ - - if (color_type == PNG_COLOR_TYPE_PALETTE) - png_set_expand(png_ptr); - if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) - png_set_expand(png_ptr); - if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) - png_set_expand(png_ptr); - if (bit_depth == 16) - png_set_strip_16(png_ptr); - if (color_type == PNG_COLOR_TYPE_GRAY || - color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - png_set_gray_to_rgb(png_ptr); - - - /* unlike the example in the libpng documentation, we have *no* idea where - * this file may have come from--so if it doesn't have a file gamma, don't - * do any correction ("do no harm") */ - - if (png_get_gAMA(png_ptr, info_ptr, &gamma)) - png_set_gamma(png_ptr, display_exponent, gamma); - - - /* all transformations have been registered; now update info_ptr data, - * get rowbytes and channels, and allocate image memory */ - - png_read_update_info(png_ptr, info_ptr); - - *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr); - *pChannels = (int)png_get_channels(png_ptr, info_ptr); - - if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) { - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); - return NULL; - } - if ((row_pointers = (png_bytepp)malloc(height*sizeof(png_bytep))) == NULL) { - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); - free(image_data); - image_data = NULL; - return NULL; - } - - Trace((stderr, "readpng_get_image: rowbytes = %ld, height = %ld\n", rowbytes, height)); - - - /* set the individual row_pointers to point at the correct offsets */ - - for (i = 0; i < height; ++i) - row_pointers[height-1-i] = image_data + i*rowbytes; - - - /* now we can go ahead and just read the whole image */ - - png_read_image(png_ptr, row_pointers); - - - /* and we're done! (png_read_end() can be omitted if no processing of - * post-IDAT text/time/etc. is desired) */ - - free(row_pointers); - row_pointers = NULL; - - png_read_end(png_ptr, NULL); - - return image_data; -} - - -void readpng_cleanup(int free_image_data) -{ - if (free_image_data && image_data) { - free(image_data); - image_data = NULL; - } - - if (png_ptr && info_ptr) { - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); - png_ptr = NULL; - info_ptr = NULL; - } -} -- cgit v1.2.3