+++ /dev/null
-/*---------------------------------------------------------------------------
-
- wpng - simple PNG-writing program writepng.c
-
- ---------------------------------------------------------------------------
-
- Copyright (c) 1998-2000 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 <stdlib.h> /* for exit() prototype */
-
-#include "png.h" /* libpng header; includes zlib.h and setjmp.h */
-#include "writepng.h" /* typedefs, common macros, public prototypes */
-
-
-/* local prototype */
-
-static void writepng_error_handler(png_structp png_ptr, png_const_charp msg);
-
-
-
-void writepng_version_info(void)
-{
- 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);
-}
-
-
-
-
-/* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for
- * unexpected pnmtype; note that outfile might be stdout */
-
-int writepng_init(mainprog_info *mainprog_ptr)
-{
- png_structp png_ptr; /* note: temporary variables! */
- png_infop info_ptr;
- int color_type, interlace_type;
-
-
- /* could also replace libpng warning-handler (final NULL), but no need: */
-
- png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
- writepng_error_handler, NULL);
- if (!png_ptr)
- return 4; /* out of memory */
-
- info_ptr = png_create_info_struct(png_ptr);
- if (!info_ptr) {
- png_destroy_write_struct(&png_ptr, NULL);
- return 4; /* out of memory */
- }
-
-
- /* setjmp() must be called in every function that calls a PNG-writing
- * libpng function, unless an alternate error handler was installed--
- * but compatible error handlers must either use longjmp() themselves
- * (as in this program) or exit immediately, so here we go: */
-
- if (setjmp(mainprog_ptr->jmpbuf)) {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- return 2;
- }
-
-
- /* make sure outfile is (re)opened in BINARY mode */
-
- png_init_io(png_ptr, mainprog_ptr->outfile);
-
-
- /* set the compression levels--in general, always want to leave filtering
- * turned on (except for palette images) and allow all of the filters,
- * which is the default; want 32K zlib window, unless entire image buffer
- * is 16K or smaller (unknown here)--also the default; usually want max
- * compression (NOT the default); and remaining compression flags should
- * be left alone */
-
- png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
-/*
- >> this is default for no filtering; Z_FILTERED is default otherwise:
- png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
- >> these are all defaults:
- png_set_compression_mem_level(png_ptr, 8);
- png_set_compression_window_bits(png_ptr, 15);
- png_set_compression_method(png_ptr, 8);
- */
-
-
- /* set the image parameters appropriately */
-
- if (mainprog_ptr->pnmtype == 5)
- color_type = PNG_COLOR_TYPE_GRAY;
- else if (mainprog_ptr->pnmtype == 6)
- color_type = PNG_COLOR_TYPE_RGB;
- else if (mainprog_ptr->pnmtype == 8)
- color_type = PNG_COLOR_TYPE_RGB_ALPHA;
- else {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- return 11;
- }
-
- interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 :
- PNG_INTERLACE_NONE;
-
- png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height,
- mainprog_ptr->sample_depth, color_type, interlace_type,
- PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
-
- if (mainprog_ptr->gamma > 0.0)
- png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma);
-
- if (mainprog_ptr->have_bg) { /* we know it's RGBA, not gray+alpha */
- png_color_16 background;
-
- background.red = mainprog_ptr->bg_red;
- background.green = mainprog_ptr->bg_green;
- background.blue = mainprog_ptr->bg_blue;
- png_set_bKGD(png_ptr, info_ptr, &background);
- }
-
- if (mainprog_ptr->have_time) {
- png_time modtime;
-
- png_convert_from_time_t(&modtime, mainprog_ptr->modtime);
- png_set_tIME(png_ptr, info_ptr, &modtime);
- }
-
- if (mainprog_ptr->have_text) {
- png_text text[6];
- int num_text = 0;
-
- if (mainprog_ptr->have_text & TEXT_TITLE) {
- text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
- text[num_text].key = "Title";
- text[num_text].text = mainprog_ptr->title;
- ++num_text;
- }
- if (mainprog_ptr->have_text & TEXT_AUTHOR) {
- text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
- text[num_text].key = "Author";
- text[num_text].text = mainprog_ptr->author;
- ++num_text;
- }
- if (mainprog_ptr->have_text & TEXT_DESC) {
- text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
- text[num_text].key = "Description";
- text[num_text].text = mainprog_ptr->desc;
- ++num_text;
- }
- if (mainprog_ptr->have_text & TEXT_COPY) {
- text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
- text[num_text].key = "Copyright";
- text[num_text].text = mainprog_ptr->copyright;
- ++num_text;
- }
- if (mainprog_ptr->have_text & TEXT_EMAIL) {
- text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
- text[num_text].key = "E-mail";
- text[num_text].text = mainprog_ptr->email;
- ++num_text;
- }
- if (mainprog_ptr->have_text & TEXT_URL) {
- text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
- text[num_text].key = "URL";
- text[num_text].text = mainprog_ptr->url;
- ++num_text;
- }
- png_set_text(png_ptr, info_ptr, text, num_text);
- }
-
-
- /* write all chunks up to (but not including) first IDAT */
-
- png_write_info(png_ptr, info_ptr);
-
-
- /* if we wanted to write any more text info *after* the image data, we
- * would set up text struct(s) here and call png_set_text() again, with
- * just the new data; png_set_tIME() could also go here, but it would
- * have no effect since we already called it above (only one tIME chunk
- * allowed) */
-
-
- /* set up the transformations: for now, just pack low-bit-depth pixels
- * into bytes (one, two or four pixels per byte) */
-
- png_set_packing(png_ptr);
-/* png_set_shift(png_ptr, &sig_bit); to scale low-bit-depth values */
-
-
- /* make sure we save our pointers for use in writepng_encode_image() */
-
- mainprog_ptr->png_ptr = png_ptr;
- mainprog_ptr->info_ptr = info_ptr;
-
-
- /* OK, that's all we need to do for now; return happy */
-
- return 0;
-}
-
-
-
-
-
-/* returns 0 for success, 2 for libpng (longjmp) problem */
-
-int writepng_encode_image(mainprog_info *mainprog_ptr)
-{
- png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
- png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-
- /* as always, setjmp() must be called in every function that calls a
- * PNG-writing libpng function */
-
- if (setjmp(mainprog_ptr->jmpbuf)) {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- mainprog_ptr->png_ptr = NULL;
- mainprog_ptr->info_ptr = NULL;
- return 2;
- }
-
-
- /* and now we just write the whole image; libpng takes care of interlacing
- * for us */
-
- png_write_image(png_ptr, mainprog_ptr->row_pointers);
-
-
- /* since that's it, we also close out the end of the PNG file now--if we
- * had any text or time info to write after the IDATs, second argument
- * would be info_ptr, but we optimize slightly by sending NULL pointer: */
-
- png_write_end(png_ptr, NULL);
-
- return 0;
-}
-
-
-
-
-
-/* returns 0 if succeeds, 2 if libpng problem */
-
-int writepng_encode_row(mainprog_info *mainprog_ptr) /* NON-interlaced only! */
-{
- png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
- png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-
- /* as always, setjmp() must be called in every function that calls a
- * PNG-writing libpng function */
-
- if (setjmp(mainprog_ptr->jmpbuf)) {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- mainprog_ptr->png_ptr = NULL;
- mainprog_ptr->info_ptr = NULL;
- return 2;
- }
-
-
- /* image_data points at our one row of image data */
-
- png_write_row(png_ptr, mainprog_ptr->image_data);
-
- return 0;
-}
-
-
-
-
-
-/* returns 0 if succeeds, 2 if libpng problem */
-
-int writepng_encode_finish(mainprog_info *mainprog_ptr) /* NON-interlaced! */
-{
- png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
- png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-
- /* as always, setjmp() must be called in every function that calls a
- * PNG-writing libpng function */
-
- if (setjmp(mainprog_ptr->jmpbuf)) {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- mainprog_ptr->png_ptr = NULL;
- mainprog_ptr->info_ptr = NULL;
- return 2;
- }
-
-
- /* close out PNG file; if we had any text or time info to write after
- * the IDATs, second argument would be info_ptr: */
-
- png_write_end(png_ptr, NULL);
-
- return 0;
-}
-
-
-
-
-
-void writepng_cleanup(mainprog_info *mainprog_ptr)
-{
- png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
- png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
- if (png_ptr && info_ptr)
- png_destroy_write_struct(&png_ptr, &info_ptr);
-}
-
-
-
-
-
-static void writepng_error_handler(png_structp png_ptr, png_const_charp msg)
-{
- mainprog_info *mainprog_ptr;
-
- /* This function, aside from the extra step of retrieving the "error
- * pointer" (below) and the fact that it exists within the application
- * rather than within libpng, is essentially identical to libpng's
- * default error handler. The second point is critical: since both
- * setjmp() and longjmp() are called from the same code, they are
- * guaranteed to have compatible notions of how big a jmp_buf is,
- * regardless of whether _BSD_SOURCE or anything else has (or has not)
- * been defined. */
-
- fprintf(stderr, "writepng libpng error: %s\n", msg);
- fflush(stderr);
-
- mainprog_ptr = png_get_error_ptr(png_ptr);
- if (mainprog_ptr == NULL) { /* we are completely hosed now */
- fprintf(stderr,
- "writepng severe error: jmpbuf not recoverable; terminating.\n");
- fflush(stderr);
- exit(99);
- }
-
- longjmp(mainprog_ptr->jmpbuf, 1);
-}
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