/* pngwrite.c - general routines to write a PNG file
*
- * Last changed in libpng 1.5.6 [November 3, 2011]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.2 [April 25, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
*/
#include "pngpriv.h"
+#if defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+# include <errno.h>
+#endif
#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+/* Write out all the unknown chunks for the current given location */
+static void
+write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
+ unsigned int where)
+{
+ if (info_ptr->unknown_chunks_num)
+ {
+ png_const_unknown_chunkp up;
+
+ png_debug(5, "writing extra chunks");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ ++up)
+ if (up->location & where)
+ {
+ /* If per-chunk unknown chunk handling is enabled use it, otherwise
+ * just write the chunks the application has set.
+ */
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ int keep = png_handle_as_unknown(png_ptr, up->name);
+
+ /* NOTE: this code is radically different from the read side in the
+ * matter of handling an ancillary unknown chunk. In the read side
+ * the default behavior is to discard it, in the code below the default
+ * behavior is to write it. Critical chunks are, however, only
+ * written if explicitly listed or if the default is set to write all
+ * unknown chunks.
+ *
+ * The default handling is also slightly weird - it is not possible to
+ * stop the writing of all unsafe-to-copy chunks!
+ *
+ * TODO: REVIEW: this would seem to be a bug.
+ */
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ ||
+ keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
+ png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
+#endif
+ {
+ /* TODO: review, what is wrong with a zero length unknown chunk? */
+ if (up->size == 0)
+ png_warning(png_ptr, "Writing zero-length unknown chunk");
+
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+}
+#endif /* PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED */
+
/* Writes all the PNG information. This is the suggested way to use the
* library. If you have a new chunk to add, make a function to write it,
* and put it in the correct location here. If you want the chunk written
* them in png_write_end(), and compressing them.
*/
void PNGAPI
-png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
+png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
{
png_debug(1, "in png_write_info_before_PLTE");
info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
info_ptr->filter_type,
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
- info_ptr->interlace_type);
+ info_ptr->interlace_type
#else
- 0);
+ 0
#endif
+ );
+
/* The rest of these check to see if the valid field has the appropriate
* flag set, and if it does, writes the chunk.
+ *
+ * 1.6.0: COLORSPACE support controls the writing of these chunks too, and
+ * the chunks will be written if the WRITE routine is there and information
+ * is available in the COLORSPACE. (See png_colorspace_sync_info in png.c
+ * for where the valid flags get set.)
+ *
+ * Under certain circumstances the colorspace can be invalidated without
+ * syncing the info_struct 'valid' flags; this happens if libpng detects and
+ * error and calls png_error while the color space is being set, yet the
+ * application continues writing the PNG. So check the 'invalid' flag here
+ * too.
*/
-#ifdef PNG_WRITE_gAMA_SUPPORTED
- if (info_ptr->valid & PNG_INFO_gAMA)
- png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
-#endif
-#ifdef PNG_WRITE_sRGB_SUPPORTED
- if (info_ptr->valid & PNG_INFO_sRGB)
- png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
+#ifdef PNG_GAMMA_SUPPORTED
+# ifdef PNG_WRITE_gAMA_SUPPORTED
+ if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) &&
+ (info_ptr->valid & PNG_INFO_gAMA))
+ png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma);
+# endif
#endif
-#ifdef PNG_WRITE_iCCP_SUPPORTED
- if (info_ptr->valid & PNG_INFO_iCCP)
- png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
- (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
-#endif
+#ifdef PNG_COLORSPACE_SUPPORTED
+ /* Write only one of sRGB or an ICC profile. If a profile was supplied
+ * and it matches one of the known sRGB ones issue a warning.
+ */
+# ifdef PNG_WRITE_iCCP_SUPPORTED
+ if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
+ (info_ptr->valid & PNG_INFO_iCCP))
+ {
+# ifdef PNG_WRITE_sRGB_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_sRGB)
+ png_app_warning(png_ptr,
+ "profile matches sRGB but writing iCCP instead");
+# endif
+
+ png_write_iCCP(png_ptr, info_ptr->iccp_name,
+ info_ptr->iccp_profile);
+ }
+# ifdef PNG_WRITE_sRGB_SUPPORTED
+ else
+# endif
+# endif
+
+# ifdef PNG_WRITE_sRGB_SUPPORTED
+ if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
+ (info_ptr->valid & PNG_INFO_sRGB))
+ png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent);
+# endif /* WRITE_sRGB */
+#endif /* COLORSPACE */
+
#ifdef PNG_WRITE_sBIT_SUPPORTED
if (info_ptr->valid & PNG_INFO_sBIT)
png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
#endif
-#ifdef PNG_WRITE_cHRM_SUPPORTED
- if (info_ptr->valid & PNG_INFO_cHRM)
- png_write_cHRM_fixed(png_ptr,
- info_ptr->x_white, info_ptr->y_white,
- info_ptr->x_red, info_ptr->y_red,
- info_ptr->x_green, info_ptr->y_green,
- info_ptr->x_blue, info_ptr->y_blue);
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+# ifdef PNG_WRITE_cHRM_SUPPORTED
+ if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
+ (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) &&
+ (info_ptr->valid & PNG_INFO_cHRM))
+ png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy);
+# endif
#endif
#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
- if (info_ptr->unknown_chunks_num)
- {
- png_unknown_chunk *up;
-
- png_debug(5, "writing extra chunks");
-
- for (up = info_ptr->unknown_chunks;
- up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
- up++)
- {
- int keep = png_handle_as_unknown(png_ptr, up->name);
-
- if (keep != PNG_HANDLE_CHUNK_NEVER &&
- up->location &&
- !(up->location & PNG_HAVE_PLTE) &&
- !(up->location & PNG_HAVE_IDAT) &&
- !(up->location & PNG_AFTER_IDAT) &&
- ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
- (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
- {
- if (up->size == 0)
- png_warning(png_ptr, "Writing zero-length unknown chunk");
-
- png_write_chunk(png_ptr, up->name, up->data, up->size);
- }
- }
- }
+ write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR);
#endif
+
png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
}
}
void PNGAPI
-png_write_info(png_structp png_ptr, png_infop info_ptr)
+png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
{
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
int i;
#endif /* tEXt */
#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
- if (info_ptr->unknown_chunks_num)
- {
- png_unknown_chunk *up;
-
- png_debug(5, "writing extra chunks");
-
- for (up = info_ptr->unknown_chunks;
- up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
- up++)
- {
- int keep = png_handle_as_unknown(png_ptr, up->name);
- if (keep != PNG_HANDLE_CHUNK_NEVER &&
- up->location &&
- (up->location & PNG_HAVE_PLTE) &&
- !(up->location & PNG_HAVE_IDAT) &&
- !(up->location & PNG_AFTER_IDAT) &&
- ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
- (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
- {
- png_write_chunk(png_ptr, up->name, up->data, up->size);
- }
- }
- }
+ write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
#endif
}
* comments, I suggest writing them here, and compressing them.
*/
void PNGAPI
-png_write_end(png_structp png_ptr, png_infop info_ptr)
+png_write_end(png_structrp png_ptr, png_inforp info_ptr)
{
png_debug(1, "in png_write_end");
if (!(png_ptr->mode & PNG_HAVE_IDAT))
png_error(png_ptr, "No IDATs written into file");
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ if (png_ptr->num_palette_max > png_ptr->num_palette)
+ png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
+#endif
+
/* See if user wants us to write information chunks */
if (info_ptr != NULL)
{
}
#endif
#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
- if (info_ptr->unknown_chunks_num)
- {
- png_unknown_chunk *up;
-
- png_debug(5, "writing extra chunks");
-
- for (up = info_ptr->unknown_chunks;
- up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
- up++)
- {
- int keep = png_handle_as_unknown(png_ptr, up->name);
- if (keep != PNG_HANDLE_CHUNK_NEVER &&
- up->location &&
- (up->location & PNG_AFTER_IDAT) &&
- ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
- (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
- {
- png_write_chunk(png_ptr, up->name, up->data, up->size);
- }
- }
- }
+ write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
#endif
}
}
#ifdef PNG_CONVERT_tIME_SUPPORTED
-/* "tm" structure is not supported on WindowsCE */
void PNGAPI
-png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm FAR * ttime)
+png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime)
{
png_debug(1, "in png_convert_from_struct_tm");
png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
{
-#ifdef PNG_USER_MEM_SUPPORTED
- return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
- warn_fn, NULL, NULL, NULL));
+#ifndef PNG_USER_MEM_SUPPORTED
+ png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, NULL, NULL, NULL);
+#else
+ return png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, NULL, NULL, NULL);
}
/* Alternate initialize png_ptr structure, and allocate any memory needed */
-static void png_reset_filter_heuristics(png_structp png_ptr); /* forward decl */
-
PNG_FUNCTION(png_structp,PNGAPI
png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
{
+ png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
#endif /* PNG_USER_MEM_SUPPORTED */
- volatile int png_cleanup_needed = 0;
-#ifdef PNG_SETJMP_SUPPORTED
- volatile
-#endif
- png_structp png_ptr;
-#ifdef PNG_SETJMP_SUPPORTED
-#ifdef USE_FAR_KEYWORD
- jmp_buf tmp_jmpbuf;
-#endif
-#endif
-
- png_debug(1, "in png_create_write_struct");
-#ifdef PNG_USER_MEM_SUPPORTED
- png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
- (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
-#else
- png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
-#endif /* PNG_USER_MEM_SUPPORTED */
- if (png_ptr == NULL)
- return (NULL);
-
- /* Added at libpng-1.2.6 */
-#ifdef PNG_SET_USER_LIMITS_SUPPORTED
- png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
- png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
-#endif
-
-#ifdef PNG_SETJMP_SUPPORTED
-/* Applications that neglect to set up their own setjmp() and then
- encounter a png_error() will longjmp here. Since the jmpbuf is
- then meaningless we abort instead of returning. */
-#ifdef USE_FAR_KEYWORD
- if (setjmp(tmp_jmpbuf))
-#else
- if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
-#endif
-#ifdef USE_FAR_KEYWORD
- png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
-#endif
- PNG_ABORT();
-#endif
-
-#ifdef PNG_USER_MEM_SUPPORTED
- png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
-#endif /* PNG_USER_MEM_SUPPORTED */
- png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
-
- if (!png_user_version_check(png_ptr, user_png_ver))
- png_cleanup_needed = 1;
+ /* Set the zlib control values to defaults; they can be overridden by the
+ * application after the struct has been created.
+ */
+ png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
- /* Initialize zbuf - compression buffer */
- png_ptr->zbuf_size = PNG_ZBUF_SIZE;
+ /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
+ * pngwutil.c defaults it according to whether or not filters will be used,
+ * and ignores this setting.
+ */
+ png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
+ png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
+ png_ptr->zlib_mem_level = 8;
+ png_ptr->zlib_window_bits = 15;
+ png_ptr->zlib_method = 8;
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+ png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
+ png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
+ png_ptr->zlib_text_mem_level = 8;
+ png_ptr->zlib_text_window_bits = 15;
+ png_ptr->zlib_text_method = 8;
+#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
+
+ /* This is a highly dubious configuration option; by default it is off, but
+ * it may be appropriate for private builds that are testing extensions not
+ * conformant to the current specification, or of applications that must not
+ * fail to write at all costs!
+ */
+# ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+ /* In stable builds only warn if an application error can be completely
+ * handled.
+ */
+# endif
- if (!png_cleanup_needed)
- {
- png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr,
- png_ptr->zbuf_size);
- if (png_ptr->zbuf == NULL)
- png_cleanup_needed = 1;
- }
+ /* App warnings are warnings in release (or release candidate) builds but
+ * are errors during development.
+ */
+# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+ png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+# endif
- if (png_cleanup_needed)
+ if (png_ptr != NULL)
{
- /* Clean up PNG structure and deallocate any memory. */
- png_free(png_ptr, png_ptr->zbuf);
- png_ptr->zbuf = NULL;
-#ifdef PNG_USER_MEM_SUPPORTED
- png_destroy_struct_2((png_voidp)png_ptr,
- (png_free_ptr)free_fn, (png_voidp)mem_ptr);
-#else
- png_destroy_struct((png_voidp)png_ptr);
-#endif
- return (NULL);
+ /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
+ * do it itself) avoiding setting the default function if it is not
+ * required.
+ */
+ png_set_write_fn(png_ptr, NULL, NULL, NULL);
}
- png_set_write_fn(png_ptr, NULL, NULL, NULL);
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- png_reset_filter_heuristics(png_ptr);
-#endif
-
- return (png_ptr);
+ return png_ptr;
}
* "write" the image seven times.
*/
void PNGAPI
-png_write_rows(png_structp png_ptr, png_bytepp row,
+png_write_rows(png_structrp png_ptr, png_bytepp row,
png_uint_32 num_rows)
{
png_uint_32 i; /* row counter */
* if you are writing an interlaced image.
*/
void PNGAPI
-png_write_image(png_structp png_ptr, png_bytepp image)
+png_write_image(png_structrp png_ptr, png_bytepp image)
{
png_uint_32 i; /* row index */
int pass, num_pass; /* pass variables */
/* Called by user to write a row of image data */
void PNGAPI
-png_write_row(png_structp png_ptr, png_const_bytep row)
+png_write_row(png_structrp png_ptr, png_const_bytep row)
{
/* 1.5.6: moved from png_struct to be a local structure: */
png_row_info row_info;
png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
/* Copy user's row into buffer, leaving room for filter byte. */
- png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
+ memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
/* Handle interlacing */
}
#endif
+/* Added at libpng-1.5.10 */
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Check for out-of-range palette index */
+ if (row_info.color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max >= 0)
+ png_do_check_palette_indexes(png_ptr, &row_info);
+#endif
+
/* Find a filter if necessary, filter the row and write it out. */
png_write_find_filter(png_ptr, &row_info);
#ifdef PNG_WRITE_FLUSH_SUPPORTED
/* Set the automatic flush interval or 0 to turn flushing off */
void PNGAPI
-png_set_flush(png_structp png_ptr, int nrows)
+png_set_flush(png_structrp png_ptr, int nrows)
{
png_debug(1, "in png_set_flush");
/* Flush the current output buffers now */
void PNGAPI
-png_write_flush(png_structp png_ptr)
+png_write_flush(png_structrp png_ptr)
{
- int wrote_IDAT;
-
png_debug(1, "in png_write_flush");
if (png_ptr == NULL)
if (png_ptr->row_number >= png_ptr->num_rows)
return;
- do
- {
- int ret;
-
- /* Compress the data */
- ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
- wrote_IDAT = 0;
-
- /* Check for compression errors */
- if (ret != Z_OK)
- {
- if (png_ptr->zstream.msg != NULL)
- png_error(png_ptr, png_ptr->zstream.msg);
-
- else
- png_error(png_ptr, "zlib error");
- }
-
- if (!(png_ptr->zstream.avail_out))
- {
- /* Write the IDAT and reset the zlib output buffer */
- png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
- wrote_IDAT = 1;
- }
- } while (wrote_IDAT == 1);
-
- /* If there is any data left to be output, write it into a new IDAT */
- if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
- {
- /* Write the IDAT and reset the zlib output buffer */
- png_write_IDAT(png_ptr, png_ptr->zbuf,
- png_ptr->zbuf_size - png_ptr->zstream.avail_out);
- }
+ png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH);
png_ptr->flush_rows = 0;
png_flush(png_ptr);
}
#endif /* PNG_WRITE_FLUSH_SUPPORTED */
-/* Free all memory used by the write */
-void PNGAPI
-png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
-{
- png_structp png_ptr = NULL;
- png_infop info_ptr = NULL;
-#ifdef PNG_USER_MEM_SUPPORTED
- png_free_ptr free_fn = NULL;
- png_voidp mem_ptr = NULL;
-#endif
-
- png_debug(1, "in png_destroy_write_struct");
-
- if (png_ptr_ptr != NULL)
- png_ptr = *png_ptr_ptr;
-
-#ifdef PNG_USER_MEM_SUPPORTED
- if (png_ptr != NULL)
- {
- free_fn = png_ptr->free_fn;
- mem_ptr = png_ptr->mem_ptr;
- }
-#endif
-
- if (info_ptr_ptr != NULL)
- info_ptr = *info_ptr_ptr;
-
- if (info_ptr != NULL)
- {
- if (png_ptr != NULL)
- {
- png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
-
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- if (png_ptr->num_chunk_list)
- {
- png_free(png_ptr, png_ptr->chunk_list);
- png_ptr->num_chunk_list = 0;
- }
-#endif
- }
-
-#ifdef PNG_USER_MEM_SUPPORTED
- png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
- (png_voidp)mem_ptr);
-#else
- png_destroy_struct((png_voidp)info_ptr);
-#endif
- *info_ptr_ptr = NULL;
- }
-
- if (png_ptr != NULL)
- {
- png_write_destroy(png_ptr);
-#ifdef PNG_USER_MEM_SUPPORTED
- png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
- (png_voidp)mem_ptr);
-#else
- png_destroy_struct((png_voidp)png_ptr);
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+static void png_reset_filter_heuristics(png_structrp png_ptr);/* forward decl */
#endif
- *png_ptr_ptr = NULL;
- }
-}
-
-/* Free any memory used in png_ptr struct (old method) */
-void /* PRIVATE */
-png_write_destroy(png_structp png_ptr)
+/* Free any memory used in png_ptr struct without freeing the struct itself. */
+static void
+png_write_destroy(png_structrp png_ptr)
{
-#ifdef PNG_SETJMP_SUPPORTED
- jmp_buf tmp_jmp; /* Save jump buffer */
-#endif
- png_error_ptr error_fn;
-#ifdef PNG_WARNINGS_SUPPORTED
- png_error_ptr warning_fn;
-#endif
- png_voidp error_ptr;
-#ifdef PNG_USER_MEM_SUPPORTED
- png_free_ptr free_fn;
-#endif
-
png_debug(1, "in png_write_destroy");
/* Free any memory zlib uses */
- if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
+ if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
deflateEnd(&png_ptr->zstream);
/* Free our memory. png_free checks NULL for us. */
- png_free(png_ptr, png_ptr->zbuf);
+ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
png_free(png_ptr, png_ptr->row_buf);
#ifdef PNG_WRITE_FILTER_SUPPORTED
png_free(png_ptr, png_ptr->prev_row);
png_free(png_ptr, png_ptr->inv_filter_costs);
#endif
-#ifdef PNG_SETJMP_SUPPORTED
- /* Reset structure */
- png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ png_free(png_ptr, png_ptr->chunk_list);
#endif
- error_fn = png_ptr->error_fn;
-#ifdef PNG_WARNINGS_SUPPORTED
- warning_fn = png_ptr->warning_fn;
-#endif
- error_ptr = png_ptr->error_ptr;
-#ifdef PNG_USER_MEM_SUPPORTED
- free_fn = png_ptr->free_fn;
-#endif
+ /* The error handling and memory handling information is left intact at this
+ * point: the jmp_buf may still have to be freed. See png_destroy_png_struct
+ * for how this happens.
+ */
+}
- png_memset(png_ptr, 0, png_sizeof(png_struct));
+/* Free all memory used by the write.
+ * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for
+ * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free
+ * the passed in info_structs but it would quietly fail to free any of the data
+ * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it
+ * has no png_ptr.)
+ */
+void PNGAPI
+png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
+{
+ png_debug(1, "in png_destroy_write_struct");
- png_ptr->error_fn = error_fn;
-#ifdef PNG_WARNINGS_SUPPORTED
- png_ptr->warning_fn = warning_fn;
-#endif
- png_ptr->error_ptr = error_ptr;
-#ifdef PNG_USER_MEM_SUPPORTED
- png_ptr->free_fn = free_fn;
-#endif
+ if (png_ptr_ptr != NULL)
+ {
+ png_structrp png_ptr = *png_ptr_ptr;
-#ifdef PNG_SETJMP_SUPPORTED
- png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
-#endif
+ if (png_ptr != NULL) /* added in libpng 1.6.0 */
+ {
+ png_destroy_info_struct(png_ptr, info_ptr_ptr);
+
+ *png_ptr_ptr = NULL;
+ png_write_destroy(png_ptr);
+ png_destroy_png_struct(png_ptr);
+ }
+ }
}
/* Allow the application to select one or more row filters to use. */
void PNGAPI
-png_set_filter(png_structp png_ptr, int method, int filters)
+png_set_filter(png_structrp png_ptr, int method, int filters)
{
png_debug(1, "in png_set_filter");
#ifdef PNG_WRITE_FILTER_SUPPORTED
case 5:
case 6:
- case 7: png_warning(png_ptr, "Unknown row filter for method 0");
+ case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
+ /* FALL THROUGH */
#endif /* PNG_WRITE_FILTER_SUPPORTED */
case PNG_FILTER_VALUE_NONE:
png_ptr->do_filter = PNG_FILTER_NONE; break;
png_ptr->do_filter = (png_byte)filters; break;
#else
default:
- png_warning(png_ptr, "Unknown row filter for method 0");
+ png_app_error(png_ptr, "Unknown row filter for method 0");
#endif /* PNG_WRITE_FILTER_SUPPORTED */
}
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
/* Convenience reset API. */
static void
-png_reset_filter_heuristics(png_structp png_ptr)
+png_reset_filter_heuristics(png_structrp png_ptr)
{
/* Clear out any old values in the 'weights' - this must be done because if
* the app calls set_filter_heuristics multiple times with different
}
static int
-png_init_filter_heuristics(png_structp png_ptr, int heuristic_method,
+png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
int num_weights)
{
if (png_ptr == NULL)
if (num_weights > 0)
{
png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(png_sizeof(png_byte) * num_weights));
+ (png_uint_32)((sizeof (png_byte)) * num_weights));
/* To make sure that the weighting starts out fairly */
for (i = 0; i < num_weights; i++)
}
png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+ (png_uint_32)((sizeof (png_uint_16)) * num_weights));
png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
+ (png_uint_32)((sizeof (png_uint_16)) * num_weights));
for (i = 0; i < num_weights; i++)
{
if (png_ptr->filter_costs == NULL)
{
png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+ (png_uint_32)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
+ (png_uint_32)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
}
for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
/* Provide floating and fixed point APIs */
#ifdef PNG_FLOATING_POINT_SUPPORTED
void PNGAPI
-png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
+png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method,
int num_weights, png_const_doublep filter_weights,
png_const_doublep filter_costs)
{
#ifdef PNG_FIXED_POINT_SUPPORTED
void PNGAPI
-png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method,
+png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
int num_weights, png_const_fixed_point_p filter_weights,
png_const_fixed_point_p filter_costs)
{
#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
void PNGAPI
-png_set_compression_level(png_structp png_ptr, int level)
+png_set_compression_level(png_structrp png_ptr, int level)
{
png_debug(1, "in png_set_compression_level");
if (png_ptr == NULL)
return;
- png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
png_ptr->zlib_level = level;
}
void PNGAPI
-png_set_compression_mem_level(png_structp png_ptr, int mem_level)
+png_set_compression_mem_level(png_structrp png_ptr, int mem_level)
{
png_debug(1, "in png_set_compression_mem_level");
if (png_ptr == NULL)
return;
- png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
png_ptr->zlib_mem_level = mem_level;
}
void PNGAPI
-png_set_compression_strategy(png_structp png_ptr, int strategy)
+png_set_compression_strategy(png_structrp png_ptr, int strategy)
{
png_debug(1, "in png_set_compression_strategy");
if (png_ptr == NULL)
return;
+ /* The flag setting here prevents the libpng dynamic selection of strategy.
+ */
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
png_ptr->zlib_strategy = strategy;
}
* smaller value of window_bits if it can do so safely.
*/
void PNGAPI
-png_set_compression_window_bits(png_structp png_ptr, int window_bits)
+png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
{
if (png_ptr == NULL)
return;
+ /* Prior to 1.6.0 this would warn but then set the window_bits value, this
+ * meant that negative window bits values could be selected which would cause
+ * libpng to write a non-standard PNG file with raw deflate or gzip
+ * compressed IDAT or ancillary chunks. Such files can be read and there is
+ * no warning on read, so this seems like a very bad idea.
+ */
if (window_bits > 15)
+ {
png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+ window_bits = 15;
+ }
else if (window_bits < 8)
+ {
png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+ window_bits = 8;
+ }
-#ifndef WBITS_8_OK
- /* Avoid libpng bug with 256-byte windows */
- if (window_bits == 8)
- {
- png_warning(png_ptr, "Compression window is being reset to 512");
- window_bits = 9;
- }
-
-#endif
- png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
png_ptr->zlib_window_bits = window_bits;
}
void PNGAPI
-png_set_compression_method(png_structp png_ptr, int method)
+png_set_compression_method(png_structrp png_ptr, int method)
{
png_debug(1, "in png_set_compression_method");
if (png_ptr == NULL)
return;
+ /* This would produce an invalid PNG file if it worked, but it doesn't and
+ * deflate will fault it, so it is harmless to just warn here.
+ */
if (method != 8)
png_warning(png_ptr, "Only compression method 8 is supported by PNG");
- png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
png_ptr->zlib_method = method;
}
/* The following were added to libpng-1.5.4 */
#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
void PNGAPI
-png_set_text_compression_level(png_structp png_ptr, int level)
+png_set_text_compression_level(png_structrp png_ptr, int level)
{
png_debug(1, "in png_set_text_compression_level");
if (png_ptr == NULL)
return;
- png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_LEVEL;
png_ptr->zlib_text_level = level;
}
void PNGAPI
-png_set_text_compression_mem_level(png_structp png_ptr, int mem_level)
+png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level)
{
png_debug(1, "in png_set_text_compression_mem_level");
if (png_ptr == NULL)
return;
- png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL;
png_ptr->zlib_text_mem_level = mem_level;
}
void PNGAPI
-png_set_text_compression_strategy(png_structp png_ptr, int strategy)
+png_set_text_compression_strategy(png_structrp png_ptr, int strategy)
{
png_debug(1, "in png_set_text_compression_strategy");
if (png_ptr == NULL)
return;
- png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_STRATEGY;
png_ptr->zlib_text_strategy = strategy;
}
* smaller value of window_bits if it can do so safely.
*/
void PNGAPI
-png_set_text_compression_window_bits(png_structp png_ptr, int window_bits)
+png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits)
{
if (png_ptr == NULL)
return;
if (window_bits > 15)
+ {
png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+ window_bits = 15;
+ }
else if (window_bits < 8)
+ {
png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+ window_bits = 8;
+ }
-#ifndef WBITS_8_OK
- /* Avoid libpng bug with 256-byte windows */
- if (window_bits == 8)
- {
- png_warning(png_ptr, "Text compression window is being reset to 512");
- window_bits = 9;
- }
-
-#endif
- png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS;
png_ptr->zlib_text_window_bits = window_bits;
}
void PNGAPI
-png_set_text_compression_method(png_structp png_ptr, int method)
+png_set_text_compression_method(png_structrp png_ptr, int method)
{
png_debug(1, "in png_set_text_compression_method");
if (method != 8)
png_warning(png_ptr, "Only compression method 8 is supported by PNG");
- png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD;
png_ptr->zlib_text_method = method;
}
#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
/* end of API added to libpng-1.5.4 */
void PNGAPI
-png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
+png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
{
if (png_ptr == NULL)
return;
#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
void PNGAPI
-png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
+png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
write_user_transform_fn)
{
png_debug(1, "in png_set_write_user_transform_fn");
#ifdef PNG_INFO_IMAGE_SUPPORTED
void PNGAPI
-png_write_png(png_structp png_ptr, png_infop info_ptr,
+png_write_png(png_structrp png_ptr, png_inforp info_ptr,
int transforms, voidp params)
{
if (png_ptr == NULL || info_ptr == NULL)
PNG_UNUSED(params)
}
#endif
+
+
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+#ifdef PNG_STDIO_SUPPORTED /* currently required for png_image_write_* */
+/* Initialize the write structure - general purpose utility. */
+static int
+png_image_write_init(png_imagep image)
+{
+ png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
+ png_safe_error, png_safe_warning);
+
+ if (png_ptr != NULL)
+ {
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+
+ if (info_ptr != NULL)
+ {
+ png_controlp control = png_voidcast(png_controlp,
+ png_malloc_warn(png_ptr, (sizeof *control)));
+
+ if (control != NULL)
+ {
+ memset(control, 0, (sizeof *control));
+
+ control->png_ptr = png_ptr;
+ control->info_ptr = info_ptr;
+ control->for_write = 1;
+
+ image->opaque = control;
+ return 1;
+ }
+
+ /* Error clean up */
+ png_destroy_info_struct(png_ptr, &info_ptr);
+ }
+
+ png_destroy_write_struct(&png_ptr, NULL);
+ }
+
+ return png_image_error(image, "png_image_write_: out of memory");
+}
+
+/* Arguments to png_image_write_main: */
+typedef struct
+{
+ /* Arguments: */
+ png_imagep image;
+ png_const_voidp buffer;
+ png_int_32 row_stride;
+ png_const_voidp colormap;
+ int convert_to_8bit;
+ /* Local variables: */
+ png_const_voidp first_row;
+ ptrdiff_t row_bytes;
+ png_voidp local_row;
+} png_image_write_control;
+
+/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
+ * do any necessary byte swapping. The component order is defined by the
+ * png_image format value.
+ */
+static int
+png_write_image_16bit(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+
+ png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+ display->first_row);
+ png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
+ png_uint_16p row_end;
+ const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
+ int aindex = 0;
+ png_uint_32 y = image->height;
+
+ if (image->format & PNG_FORMAT_FLAG_ALPHA)
+ {
+ if (image->format & PNG_FORMAT_FLAG_AFIRST)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+
+ else
+ aindex = channels;
+ }
+
+ else
+ png_error(png_ptr, "png_write_image: internal call error");
+
+ /* Work out the output row end and count over this, note that the increment
+ * above to 'row' means that row_end can actually be beyond the end of the
+ * row; this is correct.
+ */
+ row_end = output_row + image->width * (channels+1);
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_uint_16p out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ const png_uint_16 alpha = in_ptr[aindex];
+ png_uint_32 reciprocal = 0;
+ int c;
+
+ out_ptr[aindex] = alpha;
+
+ /* Calculate a reciprocal. The correct calculation is simply
+ * component/alpha*65535 << 15. (I.e. 15 bits of precision); this
+ * allows correct rounding by adding .5 before the shift. 'reciprocal'
+ * is only initialized when required.
+ */
+ if (alpha > 0 && alpha < 65535)
+ reciprocal = ((0xffff<<15)+(alpha>>1))/alpha;
+
+ c = channels;
+ do /* always at least one channel */
+ {
+ png_uint_16 component = *in_ptr++;
+
+ /* The following gives 65535 for an alpha of 0, which is fine,
+ * otherwise if 0/0 is represented as some other value there is more
+ * likely to be a discontinuity which will probably damage
+ * compression when moving from a fully transparent area to a
+ * nearly transparent one. (The assumption here is that opaque
+ * areas tend not to be 0 intensity.)
+ */
+ if (component >= alpha)
+ component = 65535;
+
+ /* component<alpha, so component/alpha is less than one and
+ * component*reciprocal is less than 2^31.
+ */
+ else if (component > 0 && alpha < 65535)
+ {
+ png_uint_32 calc = component * reciprocal;
+ calc += 16384; /* round to nearest */
+ component = (png_uint_16)(calc >> 15);
+ }
+
+ *out_ptr++ = component;
+ }
+ while (--c > 0);
+
+ /* Skip to next component (skip the intervening alpha channel) */
+ ++in_ptr;
+ ++out_ptr;
+ }
+
+ png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ }
+
+ return 1;
+}
+
+/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel
+ * is present it must be removed from the components, the components are then
+ * written in sRGB encoding. No components are added or removed.
+ *
+ * Calculate an alpha reciprocal to reverse pre-multiplication. As above the
+ * calculation can be done to 15 bits of accuracy; however, the output needs to
+ * be scaled in the range 0..255*65535, so include that scaling here.
+ */
+#define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha)
+
+static png_byte
+png_unpremultiply(png_uint_32 component, png_uint_32 alpha,
+ png_uint_32 reciprocal/*from the above macro*/)
+{
+ /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
+ * is represented as some other value there is more likely to be a
+ * discontinuity which will probably damage compression when moving from a
+ * fully transparent area to a nearly transparent one. (The assumption here
+ * is that opaque areas tend not to be 0 intensity.)
+ *
+ * There is a rounding problem here; if alpha is less than 128 it will end up
+ * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the
+ * output change for this too.
+ */
+ if (component >= alpha || alpha < 128)
+ return 255;
+
+ /* component<alpha, so component/alpha is less than one and
+ * component*reciprocal is less than 2^31.
+ */
+ else if (component > 0)
+ {
+ /* The test is that alpha/257 (rounded) is less than 255, the first value
+ * that becomes 255 is 65407.
+ * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore,
+ * be exact!) [Could also test reciprocal != 0]
+ */
+ if (alpha < 65407)
+ {
+ component *= reciprocal;
+ component += 64; /* round to nearest */
+ component >>= 7;
+ }
+
+ else
+ component *= 255;
+
+ /* Convert the component to sRGB. */
+ return (png_byte)PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ else
+ return 0;
+}
+
+static int
+png_write_image_8bit(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+
+ png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+ display->first_row);
+ png_bytep output_row = png_voidcast(png_bytep, display->local_row);
+ png_uint_32 y = image->height;
+ const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
+
+ if (image->format & PNG_FORMAT_FLAG_ALPHA)
+ {
+ png_bytep row_end;
+ int aindex;
+
+ if (image->format & PNG_FORMAT_FLAG_AFIRST)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+
+ else
+ aindex = channels;
+
+ /* Use row_end in place of a loop counter: */
+ row_end = output_row + image->width * (channels+1);
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_bytep out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_16 alpha = in_ptr[aindex];
+ png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+ png_uint_32 reciprocal = 0;
+ int c;
+
+ /* Scale and write the alpha channel. */
+ out_ptr[aindex] = alphabyte;
+
+ if (alphabyte > 0 && alphabyte < 255)
+ reciprocal = UNP_RECIPROCAL(alpha);
+
+ c = channels;
+ do /* always at least one channel */
+ *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal);
+ while (--c > 0);
+
+ /* Skip to next component (skip the intervening alpha channel) */
+ ++in_ptr;
+ ++out_ptr;
+ } /* while out_ptr < row_end */
+
+ png_write_row(png_ptr, png_voidcast(png_const_bytep,
+ display->local_row));
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ } /* while y */
+ }
+
+ else
+ {
+ /* No alpha channel, so the row_end really is the end of the row and it
+ * is sufficient to loop over the components one by one.
+ */
+ png_bytep row_end = output_row + image->width * channels;
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_bytep out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_32 component = *in_ptr++;
+
+ component *= 255;
+ *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ png_write_row(png_ptr, output_row);
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ }
+ }
+
+ return 1;
+}
+
+static void
+png_image_set_PLTE(png_image_write_control *display)
+{
+ const png_imagep image = display->image;
+ const void *cmap = display->colormap;
+ const int entries = image->colormap_entries > 256 ? 256 :
+ (int)image->colormap_entries;
+
+ /* NOTE: the caller must check for cmap != NULL and entries != 0 */
+ const png_uint_32 format = image->format;
+ const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
+ (format & PNG_FORMAT_FLAG_ALPHA) != 0;
+# else
+# define afirst 0
+# endif
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ const int bgr = (format & PNG_FORMAT_FLAG_BGR) ? 2 : 0;
+# else
+# define bgr 0
+# endif
+
+ int i, num_trans;
+ png_color palette[256];
+ png_byte tRNS[256];
+
+ memset(tRNS, 255, (sizeof tRNS));
+ memset(palette, 0, (sizeof palette));
+
+ for (i=num_trans=0; i<entries; ++i)
+ {
+ /* This gets automatically converted to sRGB with reversal of the
+ * pre-multiplication if the color-map has an alpha channel.
+ */
+ if (format & PNG_FORMAT_FLAG_LINEAR)
+ {
+ png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap);
+
+ entry += i * channels;
+
+ if (channels & 1) /* no alpha */
+ {
+ if (channels >= 3) /* RGB */
+ {
+ palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[(2 ^ bgr)]);
+ palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[1]);
+ palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[bgr]);
+ }
+
+ else /* Gray */
+ palette[i].blue = palette[i].red = palette[i].green =
+ (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry);
+ }
+
+ else /* alpha */
+ {
+ png_uint_16 alpha = entry[afirst ? 0 : channels-1];
+ png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+ png_uint_32 reciprocal = 0;
+
+ /* Calculate a reciprocal, as in the png_write_image_8bit code above
+ * this is designed to produce a value scaled to 255*65535 when
+ * divided by 128 (i.e. asr 7).
+ */
+ if (alphabyte > 0 && alphabyte < 255)
+ reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha;
+
+ tRNS[i] = alphabyte;
+ if (alphabyte < 255)
+ num_trans = i+1;
+
+ if (channels >= 3) /* RGB */
+ {
+ palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)],
+ alpha, reciprocal);
+ palette[i].green = png_unpremultiply(entry[afirst + 1], alpha,
+ reciprocal);
+ palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha,
+ reciprocal);
+ }
+
+ else /* gray */
+ palette[i].blue = palette[i].red = palette[i].green =
+ png_unpremultiply(entry[afirst], alpha, reciprocal);
+ }
+ }
+
+ else /* Color-map has sRGB values */
+ {
+ png_const_bytep entry = png_voidcast(png_const_bytep, cmap);
+
+ entry += i * channels;
+
+ switch (channels)
+ {
+ case 4:
+ tRNS[i] = entry[afirst ? 0 : 3];
+ if (tRNS[i] < 255)
+ num_trans = i+1;
+ /* FALL THROUGH */
+ case 3:
+ palette[i].blue = entry[afirst + (2 ^ bgr)];
+ palette[i].green = entry[afirst + 1];
+ palette[i].red = entry[afirst + bgr];
+ break;
+
+ case 2:
+ tRNS[i] = entry[1 ^ afirst];
+ if (tRNS[i] < 255)
+ num_trans = i+1;
+ /* FALL THROUGH */
+ case 1:
+ palette[i].blue = palette[i].red = palette[i].green =
+ entry[afirst];
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+
+# ifdef afirst
+# undef afirst
+# endif
+# ifdef bgr
+# undef bgr
+# endif
+
+ png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette,
+ entries);
+
+ if (num_trans > 0)
+ png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS,
+ num_trans, NULL);
+
+ image->colormap_entries = entries;
+}
+
+static int
+png_image_write_main(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+ png_uint_32 format = image->format;
+
+ int colormap = (format & PNG_FORMAT_FLAG_COLORMAP) != 0;
+ int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR) != 0; /* input */
+ int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0;
+ int write_16bit = linear && !colormap && !display->convert_to_8bit;
+
+# ifdef PNG_BENIGN_ERRORS_SUPPORTED
+ /* Make sure we error out on any bad situation */
+ png_set_benign_errors(png_ptr, 0/*error*/);
+# endif
+
+ /* Default the 'row_stride' parameter if required. */
+ if (display->row_stride == 0)
+ display->row_stride = PNG_IMAGE_ROW_STRIDE(*image);
+
+ /* Set the required transforms then write the rows in the correct order. */
+ if (format & PNG_FORMAT_FLAG_COLORMAP)
+ {
+ if (display->colormap != NULL && image->colormap_entries > 0)
+ {
+ png_uint_32 entries = image->colormap_entries;
+
+ png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+ entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
+ PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ png_image_set_PLTE(display);
+ }
+
+ else
+ png_error(image->opaque->png_ptr,
+ "no color-map for color-mapped image");
+ }
+
+ else
+ png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+ write_16bit ? 16 : 8,
+ ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
+ ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
+ PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ /* Counter-intuitively the data transformations must be called *after*
+ * png_write_info, not before as in the read code, but the 'set' functions
+ * must still be called before. Just set the color space information, never
+ * write an interlaced image.
+ */
+
+ if (write_16bit)
+ {
+ /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
+
+ if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ /* color x y */
+ /* white */ 31270, 32900,
+ /* red */ 64000, 33000,
+ /* green */ 30000, 60000,
+ /* blue */ 15000, 6000
+ );
+ }
+
+ else if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
+ png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
+
+ /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
+ * space must still be gamma encoded.
+ */
+ else
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
+
+ /* Write the file header. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* Now set up the data transformations (*after* the header is written),
+ * remove the handled transformations from the 'format' flags for checking.
+ *
+ * First check for a little endian system if writing 16 bit files.
+ */
+ if (write_16bit)
+ {
+ PNG_CONST png_uint_16 le = 0x0001;
+
+ if (*(png_const_bytep)&le)
+ png_set_swap(png_ptr);
+ }
+
+# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+ if (format & PNG_FORMAT_FLAG_BGR)
+ {
+ if (!colormap && (format & PNG_FORMAT_FLAG_COLOR) != 0)
+ png_set_bgr(png_ptr);
+ format &= ~PNG_FORMAT_FLAG_BGR;
+ }
+# endif
+
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if (format & PNG_FORMAT_FLAG_AFIRST)
+ {
+ if (!colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ png_set_swap_alpha(png_ptr);
+ format &= ~PNG_FORMAT_FLAG_AFIRST;
+ }
+# endif
+
+ /* If there are 16 or fewer color-map entries we wrote a lower bit depth
+ * above, but the application data is still byte packed.
+ */
+ if (colormap && image->colormap_entries <= 16)
+ png_set_packing(png_ptr);
+
+ /* That should have handled all (both) the transforms. */
+ if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR |
+ PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0)
+ png_error(png_ptr, "png_write_image: unsupported transformation");
+
+ {
+ png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
+ ptrdiff_t row_bytes = display->row_stride;
+
+ if (linear)
+ row_bytes *= (sizeof (png_uint_16));
+
+ if (row_bytes < 0)
+ row += (image->height-1) * (-row_bytes);
+
+ display->first_row = row;
+ display->row_bytes = row_bytes;
+ }
+
+ /* Apply 'fast' options if the flag is set. */
+ if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0)
+ {
+ png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
+ /* NOTE: determined by experiment using pngstest, this reflects some
+ * balance between the time to write the image once and the time to read
+ * it about 50 times. The speed-up in pngstest was about 10-20% of the
+ * total (user) time on a heavily loaded system.
+ */
+ png_set_compression_level(png_ptr, 3);
+ }
+
+ /* Check for the cases that currently require a pre-transform on the row
+ * before it is written. This only applies when the input is 16-bit and
+ * either there is an alpha channel or it is converted to 8-bit.
+ */
+ if ((linear && alpha) || (!colormap && display->convert_to_8bit))
+ {
+ png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
+ png_get_rowbytes(png_ptr, info_ptr)));
+ int result;
+
+ display->local_row = row;
+ if (write_16bit)
+ result = png_safe_execute(image, png_write_image_16bit, display);
+ else
+ result = png_safe_execute(image, png_write_image_8bit, display);
+ display->local_row = NULL;
+
+ png_free(png_ptr, row);
+
+ /* Skip the 'write_end' on error: */
+ if (!result)
+ return 0;
+ }
+
+ /* Otherwise this is the case where the input is in a format currently
+ * supported by the rest of the libpng write code; call it directly.
+ */
+ else
+ {
+ png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
+ ptrdiff_t row_bytes = display->row_bytes;
+ png_uint_32 y = image->height;
+
+ while (y-- > 0)
+ {
+ png_write_row(png_ptr, row);
+ row += row_bytes;
+ }
+ }
+
+ png_write_end(png_ptr, info_ptr);
+ return 1;
+}
+
+int PNGAPI
+png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
+ const void *buffer, png_int_32 row_stride, const void *colormap)
+{
+ /* Write the image to the given (FILE*). */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file != NULL)
+ {
+ if (png_image_write_init(image))
+ {
+ png_image_write_control display;
+ int result;
+
+ /* This is slightly evil, but png_init_io doesn't do anything other
+ * than this and we haven't changed the standard IO functions so
+ * this saves a 'safe' function.
+ */
+ image->opaque->png_ptr->io_ptr = file;
+
+ memset(&display, 0, (sizeof display));
+ display.image = image;
+ display.buffer = buffer;
+ display.row_stride = row_stride;
+ display.colormap = colormap;
+ display.convert_to_8bit = convert_to_8bit;
+
+ result = png_safe_execute(image, png_image_write_main, &display);
+ png_image_free(image);
+ return result;
+ }
+
+ else
+ return 0;
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_stdio: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+
+int PNGAPI
+png_image_write_to_file(png_imagep image, const char *file_name,
+ int convert_to_8bit, const void *buffer, png_int_32 row_stride,
+ const void *colormap)
+{
+ /* Write the image to the named file. */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file_name != NULL)
+ {
+ FILE *fp = fopen(file_name, "wb");
+
+ if (fp != NULL)
+ {
+ if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
+ row_stride, colormap))
+ {
+ int error; /* from fflush/fclose */
+
+ /* Make sure the file is flushed correctly. */
+ if (fflush(fp) == 0 && ferror(fp) == 0)
+ {
+ if (fclose(fp) == 0)
+ return 1;
+
+ error = errno; /* from fclose */
+ }
+
+ else
+ {
+ error = errno; /* from fflush or ferror */
+ (void)fclose(fp);
+ }
+
+ (void)remove(file_name);
+ /* The image has already been cleaned up; this is just used to
+ * set the error (because the original write succeeded).
+ */
+ return png_image_error(image, strerror(error));
+ }
+
+ else
+ {
+ /* Clean up: just the opened file. */
+ (void)fclose(fp);
+ (void)remove(file_name);
+ return 0;
+ }
+ }
+
+ else
+ return png_image_error(image, strerror(errno));
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_file: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+#endif /* PNG_STDIO_SUPPORTED */
+#endif /* SIMPLIFIED_WRITE */
#endif /* PNG_WRITE_SUPPORTED */