--- /dev/null
+
+/* pngwrite.c - general routines to write a PNG file
+ *
+ * Last changed in libpng 1.6.11 [June 12, 2014]
+ * Copyright (c) 1998-2014 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.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#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
+ * after the image data, put it in png_write_end(). I strongly encourage
+ * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
+ * the chunk, as that will keep the code from breaking if you want to just
+ * write a plain PNG file. If you have long comments, I suggest writing
+ * them in png_write_end(), and compressing them.
+ */
+void PNGAPI
+png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
+{
+ png_debug(1, "in png_write_info_before_PLTE");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+ {
+ /* Write PNG signature */
+ png_write_sig(png_ptr);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
+ (png_ptr->mng_features_permitted))
+ {
+ png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+ png_ptr->mng_features_permitted = 0;
+ }
+#endif
+
+ /* Write IHDR information. */
+ png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+ 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
+#else
+ 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_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_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_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
+ 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_structrp png_ptr, png_const_inforp info_ptr)
+{
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+ int i;
+#endif
+
+ png_debug(1, "in png_write_info");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_write_info_before_PLTE(png_ptr, info_ptr);
+
+ if (info_ptr->valid & PNG_INFO_PLTE)
+ png_write_PLTE(png_ptr, info_ptr->palette,
+ (png_uint_32)info_ptr->num_palette);
+
+ else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_error(png_ptr, "Valid palette required for paletted images");
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_tRNS)
+ {
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ /* Invert the alpha channel (in tRNS) */
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
+ info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ int j;
+ for (j = 0; j<(int)info_ptr->num_trans; j++)
+ info_ptr->trans_alpha[j] =
+ (png_byte)(255 - info_ptr->trans_alpha[j]);
+ }
+#endif
+ png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
+ info_ptr->num_trans, info_ptr->color_type);
+ }
+#endif
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_bKGD)
+ png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_hIST)
+ png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_oFFs)
+ png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
+ info_ptr->offset_unit_type);
+#endif
+
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_pCAL)
+ png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
+ info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
+ info_ptr->pcal_units, info_ptr->pcal_params);
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_sCAL)
+ png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
+ info_ptr->scal_s_width, info_ptr->scal_s_height);
+#endif /* sCAL */
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_pHYs)
+ png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
+ info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
+#endif /* pHYs */
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_tIME)
+ {
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+ png_ptr->mode |= PNG_WROTE_tIME;
+ }
+#endif /* tIME */
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_sPLT)
+ for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+ png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
+#endif /* sPLT */
+
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ /* Check to see if we need to write text chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing header text chunk %d, type %d", i,
+ info_ptr->text[i].compression);
+ /* An internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+ /* Write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+
+ /* If we want a compressed text chunk */
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
+ {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+ /* Write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0,
+ info_ptr->text[i].compression);
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+ }
+
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+ /* Write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text,
+ 0);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+ /* Can't get here */
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+ }
+ }
+#endif /* tEXt */
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
+#endif
+}
+
+/* Writes the end of the PNG file. If you don't want to write comments or
+ * time information, you can pass NULL for info. If you already wrote these
+ * in png_write_info(), do not write them again here. If you have long
+ * comments, I suggest writing them here, and compressing them.
+ */
+void PNGAPI
+png_write_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_debug(1, "in png_write_end");
+
+ if (png_ptr == NULL)
+ return;
+
+ 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)
+ {
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ int i; /* local index variable */
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
+ /* Check to see if user has supplied a time chunk */
+ if ((info_ptr->valid & PNG_INFO_tIME) &&
+ !(png_ptr->mode & PNG_WROTE_tIME))
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+
+#endif
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ /* Loop through comment chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing trailer text chunk %d, type %d", i,
+ info_ptr->text[i].compression);
+ /* An internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+ /* Write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+
+ else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+ {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+ /* Write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0,
+ info_ptr->text[i].compression);
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+ }
+
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+ /* Write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0);
+#else
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ }
+ }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
+#endif
+ }
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ /* Write end of PNG file */
+ png_write_IEND(png_ptr);
+
+ /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
+ * and restored again in libpng-1.2.30, may cause some applications that
+ * do not set png_ptr->output_flush_fn to crash. If your application
+ * experiences a problem, please try building libpng with
+ * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
+ * png-mng-implement at lists.sf.net .
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
+ png_flush(png_ptr);
+# endif
+#endif
+}
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+void PNGAPI
+png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime)
+{
+ png_debug(1, "in png_convert_from_struct_tm");
+
+ ptime->year = (png_uint_16)(1900 + ttime->tm_year);
+ ptime->month = (png_byte)(ttime->tm_mon + 1);
+ ptime->day = (png_byte)ttime->tm_mday;
+ ptime->hour = (png_byte)ttime->tm_hour;
+ ptime->minute = (png_byte)ttime->tm_min;
+ ptime->second = (png_byte)ttime->tm_sec;
+}
+
+void PNGAPI
+png_convert_from_time_t(png_timep ptime, time_t ttime)
+{
+ struct tm *tbuf;
+
+ png_debug(1, "in png_convert_from_time_t");
+
+ tbuf = gmtime(&ttime);
+ png_convert_from_struct_tm(ptime, tbuf);
+}
+#endif
+
+/* Initialize png_ptr structure, and allocate any memory needed */
+PNG_FUNCTION(png_structp,PNGAPI
+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)
+{
+#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 */
+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 */
+ if (png_ptr != NULL)
+ {
+ /* 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;
+
+ /* 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
+ /* In stable builds only warn if an application error can be completely
+ * handled.
+ */
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+#endif
+
+ /* 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
+
+ /* 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);
+ }
+
+ return png_ptr;
+}
+
+
+/* Write a few rows of image data. If the image is interlaced,
+ * either you will have to write the 7 sub images, or, if you
+ * have called png_set_interlace_handling(), you will have to
+ * "write" the image seven times.
+ */
+void PNGAPI
+png_write_rows(png_structrp png_ptr, png_bytepp row,
+ png_uint_32 num_rows)
+{
+ png_uint_32 i; /* row counter */
+ png_bytepp rp; /* row pointer */
+
+ png_debug(1, "in png_write_rows");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Loop through the rows */
+ for (i = 0, rp = row; i < num_rows; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+}
+
+/* Write the image. You only need to call this function once, even
+ * if you are writing an interlaced image.
+ */
+void PNGAPI
+png_write_image(png_structrp png_ptr, png_bytepp image)
+{
+ png_uint_32 i; /* row index */
+ int pass, num_pass; /* pass variables */
+ png_bytepp rp; /* points to current row */
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug(1, "in png_write_image");
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Initialize interlace handling. If image is not interlaced,
+ * this will set pass to 1
+ */
+ num_pass = png_set_interlace_handling(png_ptr);
+#else
+ num_pass = 1;
+#endif
+ /* Loop through passes */
+ for (pass = 0; pass < num_pass; pass++)
+ {
+ /* Loop through image */
+ for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+ }
+}
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Performs intrapixel differencing */
+static void
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_intrapixel");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)((*rp - *(rp + 1)) & 0xff);
+ *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff);
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
+ png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
+ png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
+ png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
+ png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+ *(rp ) = (png_byte)((red >> 8) & 0xff);
+ *(rp + 1) = (png_byte)(red & 0xff);
+ *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
+ *(rp + 5) = (png_byte)(blue & 0xff);
+ }
+ }
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
+ }
+}
+#endif /* PNG_MNG_FEATURES_SUPPORTED */
+
+/* Called by user to write a row of image data */
+void PNGAPI
+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;
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug2(1, "in png_write_row (row %u, pass %d)",
+ png_ptr->row_number, png_ptr->pass);
+
+ /* Initialize transformations and other stuff if first time */
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* Make sure we wrote the header info */
+ if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+ png_error(png_ptr,
+ "png_write_info was never called before png_write_row");
+
+ /* Check for transforms that have been set but were defined out */
+#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
+ if (png_ptr->transformations & PNG_FILLER)
+ png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+ defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_warning(png_ptr,
+ "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACK)
+ png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
+ if (png_ptr->transformations & PNG_BGR)
+ png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
+#endif
+
+ png_write_start_row(png_ptr);
+ }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced and not interested in row, return */
+ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+ {
+ switch (png_ptr->pass)
+ {
+ case 0:
+ if (png_ptr->row_number & 0x07)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 1:
+ if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 2:
+ if ((png_ptr->row_number & 0x07) != 4)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 3:
+ if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 4:
+ if ((png_ptr->row_number & 0x03) != 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 5:
+ if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 6:
+ if (!(png_ptr->row_number & 0x01))
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ default: /* error: ignore it */
+ break;
+ }
+ }
+#endif
+
+ /* Set up row info for transformations */
+ row_info.color_type = png_ptr->color_type;
+ row_info.width = png_ptr->usr_width;
+ row_info.channels = png_ptr->usr_channels;
+ row_info.bit_depth = png_ptr->usr_bit_depth;
+ row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
+ row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+ png_debug1(3, "row_info->color_type = %d", row_info.color_type);
+ png_debug1(3, "row_info->width = %u", row_info.width);
+ png_debug1(3, "row_info->channels = %d", row_info.channels);
+ png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
+ png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
+ png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
+
+ /* Copy user's row into buffer, leaving room for filter byte. */
+ memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Handle interlacing */
+ if (png_ptr->interlaced && png_ptr->pass < 6 &&
+ (png_ptr->transformations & PNG_INTERLACE))
+ {
+ png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
+ /* This should always get caught above, but still ... */
+ if (row_info.width == 0)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ }
+#endif
+
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+ /* Handle other transformations */
+ if (png_ptr->transformations)
+ png_do_write_transformations(png_ptr, &row_info);
+#endif
+
+ /* At this point the row_info pixel depth must match the 'transformed' depth,
+ * which is also the output depth.
+ */
+ if (row_info.pixel_depth != png_ptr->pixel_depth ||
+ row_info.pixel_depth != png_ptr->transformed_pixel_depth)
+ png_error(png_ptr, "internal write transform logic error");
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ /* Write filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not write a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
+ }
+#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);
+
+ if (png_ptr->write_row_fn != NULL)
+ (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set the automatic flush interval or 0 to turn flushing off */
+void PNGAPI
+png_set_flush(png_structrp png_ptr, int nrows)
+{
+ png_debug(1, "in png_set_flush");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
+}
+
+/* Flush the current output buffers now */
+void PNGAPI
+png_write_flush(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_flush");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* We have already written out all of the data */
+ if (png_ptr->row_number >= png_ptr->num_rows)
+ return;
+
+ png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH);
+ png_ptr->flush_rows = 0;
+ png_flush(png_ptr);
+}
+#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+static void png_reset_filter_heuristics(png_structrp png_ptr);/* forward decl */
+#endif
+
+/* Free any memory used in png_ptr struct without freeing the struct itself. */
+static void
+png_write_destroy(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_destroy");
+
+ /* Free any memory zlib uses */
+ if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
+ deflateEnd(&png_ptr->zstream);
+
+ /* Free our memory. png_free checks NULL for us. */
+ 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->sub_row);
+ png_free(png_ptr, png_ptr->up_row);
+ png_free(png_ptr, png_ptr->avg_row);
+ png_free(png_ptr, png_ptr->paeth_row);
+#endif
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+ /* Use this to save a little code space, it doesn't free the filter_costs */
+ png_reset_filter_heuristics(png_ptr);
+ png_free(png_ptr, png_ptr->filter_costs);
+ png_free(png_ptr, png_ptr->inv_filter_costs);
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ png_free(png_ptr, png_ptr->chunk_list);
+#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.
+ */
+}
+
+/* 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");
+
+ if (png_ptr_ptr != NULL)
+ {
+ png_structrp png_ptr = *png_ptr_ptr;
+
+ 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_structrp png_ptr, int method, int filters)
+{
+ png_debug(1, "in png_set_filter");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (method == PNG_INTRAPIXEL_DIFFERENCING))
+ method = PNG_FILTER_TYPE_BASE;
+
+#endif
+ if (method == PNG_FILTER_TYPE_BASE)
+ {
+ switch (filters & (PNG_ALL_FILTERS | 0x07))
+ {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ case 5:
+ case 6:
+ 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;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ case PNG_FILTER_VALUE_SUB:
+ png_ptr->do_filter = PNG_FILTER_SUB; break;
+
+ case PNG_FILTER_VALUE_UP:
+ png_ptr->do_filter = PNG_FILTER_UP; break;
+
+ case PNG_FILTER_VALUE_AVG:
+ png_ptr->do_filter = PNG_FILTER_AVG; break;
+
+ case PNG_FILTER_VALUE_PAETH:
+ png_ptr->do_filter = PNG_FILTER_PAETH; break;
+
+ default:
+ png_ptr->do_filter = (png_byte)filters; break;
+#else
+ default:
+ png_app_error(png_ptr, "Unknown row filter for method 0");
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+ }
+
+ /* If we have allocated the row_buf, this means we have already started
+ * with the image and we should have allocated all of the filter buffers
+ * that have been selected. If prev_row isn't already allocated, then
+ * it is too late to start using the filters that need it, since we
+ * will be missing the data in the previous row. If an application
+ * wants to start and stop using particular filters during compression,
+ * it should start out with all of the filters, and then add and
+ * remove them after the start of compression.
+ */
+ if (png_ptr->row_buf != NULL)
+ {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
+ {
+ png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+ }
+
+ if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Up filter after starting");
+ png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
+ ~PNG_FILTER_UP);
+ }
+
+ else
+ {
+ png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
+ }
+ }
+
+ if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Average filter after starting");
+ png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
+ ~PNG_FILTER_AVG);
+ }
+
+ else
+ {
+ png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
+ }
+ }
+
+ if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
+ png_ptr->paeth_row == NULL)
+ {
+ if (png_ptr->prev_row == NULL)
+ {
+ png_warning(png_ptr, "Can't add Paeth filter after starting");
+ png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
+ }
+
+ else
+ {
+ png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
+ (png_ptr->rowbytes + 1));
+ png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
+ }
+ }
+
+ if (png_ptr->do_filter == PNG_NO_FILTERS)
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
+ png_ptr->do_filter = PNG_FILTER_NONE;
+ }
+ }
+ else
+ png_error(png_ptr, "Unknown custom filter method");
+}
+
+/* This allows us to influence the way in which libpng chooses the "best"
+ * filter for the current scanline. While the "minimum-sum-of-absolute-
+ * differences metric is relatively fast and effective, there is some
+ * question as to whether it can be improved upon by trying to keep the
+ * filtered data going to zlib more consistent, hopefully resulting in
+ * better compression.
+ */
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
+/* Convenience reset API. */
+static void
+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
+ * 'num_weights' values we would otherwise potentially have wrong sized
+ * arrays.
+ */
+ png_ptr->num_prev_filters = 0;
+ png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
+ if (png_ptr->prev_filters != NULL)
+ {
+ png_bytep old = png_ptr->prev_filters;
+ png_ptr->prev_filters = NULL;
+ png_free(png_ptr, old);
+ }
+ if (png_ptr->filter_weights != NULL)
+ {
+ png_uint_16p old = png_ptr->filter_weights;
+ png_ptr->filter_weights = NULL;
+ png_free(png_ptr, old);
+ }
+
+ if (png_ptr->inv_filter_weights != NULL)
+ {
+ png_uint_16p old = png_ptr->inv_filter_weights;
+ png_ptr->inv_filter_weights = NULL;
+ png_free(png_ptr, old);
+ }
+
+ /* Leave the filter_costs - this array is fixed size. */
+}
+
+static int
+png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method,
+ int num_weights)
+{
+ if (png_ptr == NULL)
+ return 0;
+
+ /* Clear out the arrays */
+ png_reset_filter_heuristics(png_ptr);
+
+ /* Check arguments; the 'reset' function makes the correct settings for the
+ * unweighted case, but we must handle the weight case by initializing the
+ * arrays for the caller.
+ */
+ if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int i;
+
+ if (num_weights > 0)
+ {
+ png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
+ (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->prev_filters[i] = 255;
+ }
+
+ png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)((sizeof (png_uint_16)) * num_weights));
+
+ png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)((sizeof (png_uint_16)) * num_weights));
+
+ for (i = 0; i < num_weights; i++)
+ {
+ png_ptr->inv_filter_weights[i] =
+ png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+ }
+
+ /* Safe to set this now */
+ png_ptr->num_prev_filters = (png_byte)num_weights;
+ }
+
+ /* If, in the future, there are other filter methods, this would
+ * need to be based on png_ptr->filter.
+ */
+ if (png_ptr->filter_costs == NULL)
+ {
+ png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
+ (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)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST));
+ }
+
+ for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
+ {
+ png_ptr->inv_filter_costs[i] =
+ png_ptr->filter_costs[i] = PNG_COST_FACTOR;
+ }
+
+ /* All the arrays are inited, safe to set this: */
+ png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED;
+
+ /* Return the 'ok' code. */
+ return 1;
+ }
+ else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT ||
+ heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
+ {
+ return 1;
+ }
+ else
+ {
+ png_warning(png_ptr, "Unknown filter heuristic method");
+ return 0;
+ }
+}
+
+/* Provide floating and fixed point APIs */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method,
+ int num_weights, png_const_doublep filter_weights,
+ png_const_doublep filter_costs)
+{
+ png_debug(1, "in png_set_filter_heuristics");
+
+ /* The internal API allocates all the arrays and ensures that the elements of
+ * those arrays are set to the default value.
+ */
+ if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
+ return;
+
+ /* If using the weighted method copy in the weights. */
+ if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int i;
+ for (i = 0; i < num_weights; i++)
+ {
+ if (filter_weights[i] <= 0.0)
+ {
+ png_ptr->inv_filter_weights[i] =
+ png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+ }
+
+ else
+ {
+ png_ptr->inv_filter_weights[i] =
+ (png_uint_16)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5);
+
+ png_ptr->filter_weights[i] =
+ (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5);
+ }
+ }
+
+ /* Here is where we set the relative costs of the different filters. We
+ * should take the desired compression level into account when setting
+ * the costs, so that Paeth, for instance, has a high relative cost at low
+ * compression levels, while it has a lower relative cost at higher
+ * compression settings. The filter types are in order of increasing
+ * relative cost, so it would be possible to do this with an algorithm.
+ */
+ for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) if (filter_costs[i] >= 1.0)
+ {
+ png_ptr->inv_filter_costs[i] =
+ (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5);
+
+ png_ptr->filter_costs[i] =
+ (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5);
+ }
+ }
+}
+#endif /* FLOATING_POINT */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+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)
+{
+ png_debug(1, "in png_set_filter_heuristics_fixed");
+
+ /* The internal API allocates all the arrays and ensures that the elements of
+ * those arrays are set to the default value.
+ */
+ if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
+ return;
+
+ /* If using the weighted method copy in the weights. */
+ if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ {
+ int i;
+ for (i = 0; i < num_weights; i++)
+ {
+ if (filter_weights[i] <= 0)
+ {
+ png_ptr->inv_filter_weights[i] =
+ png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
+ }
+
+ else
+ {
+ png_ptr->inv_filter_weights[i] = (png_uint_16)
+ ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1);
+
+ png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR*
+ PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]);
+ }
+ }
+
+ /* Here is where we set the relative costs of the different filters. We
+ * should take the desired compression level into account when setting
+ * the costs, so that Paeth, for instance, has a high relative cost at low
+ * compression levels, while it has a lower relative cost at higher
+ * compression settings. The filter types are in order of increasing
+ * relative cost, so it would be possible to do this with an algorithm.
+ */
+ for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
+ if (filter_costs[i] >= PNG_FP_1)
+ {
+ png_uint_32 tmp;
+
+ /* Use a 32 bit unsigned temporary here because otherwise the
+ * intermediate value will be a 32 bit *signed* integer (ANSI rules)
+ * and this will get the wrong answer on division.
+ */
+ tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2);
+ tmp /= filter_costs[i];
+
+ png_ptr->inv_filter_costs[i] = (png_uint_16)tmp;
+
+ tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF;
+ tmp /= PNG_FP_1;
+
+ png_ptr->filter_costs[i] = (png_uint_16)tmp;
+ }
+ }
+}
+#endif /* FIXED_POINT */
+#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+
+void PNGAPI
+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->zlib_level = level;
+}
+
+void PNGAPI
+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->zlib_mem_level = mem_level;
+}
+
+void PNGAPI
+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;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+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;
+ }
+
+ png_ptr->zlib_window_bits = window_bits;
+}
+
+void PNGAPI
+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->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_structrp png_ptr, int level)
+{
+ png_debug(1, "in png_set_text_compression_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_text_level = level;
+}
+
+void PNGAPI
+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->zlib_text_mem_level = mem_level;
+}
+
+void PNGAPI
+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->zlib_text_strategy = strategy;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+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;
+ }
+
+ png_ptr->zlib_text_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_text_compression_method(png_structrp png_ptr, int method)
+{
+ png_debug(1, "in png_set_text_compression_method");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (method != 8)
+ png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+
+ 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_structrp png_ptr, png_write_status_ptr write_row_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->write_row_fn = write_row_fn;
+}
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+void PNGAPI
+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");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->write_user_transform_fn = write_user_transform_fn;
+}
+#endif
+
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_write_png(png_structrp png_ptr, png_inforp info_ptr,
+ int transforms, voidp params)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if ((info_ptr->valid & PNG_INFO_IDAT) == 0)
+ {
+ png_app_error(png_ptr, "no rows for png_write_image to write");
+ return;
+ }
+
+ /* Write the file header information. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* ------ these transformations don't touch the info structure ------- */
+
+ /* Invert monochrome pixels */
+ if (transforms & PNG_TRANSFORM_INVERT_MONO)
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+ png_set_invert_mono(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
+#endif
+
+ /* Shift the pixels up to a legal bit depth and fill in
+ * as appropriate to correctly scale the image.
+ */
+ if (transforms & PNG_TRANSFORM_SHIFT)
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+ if (info_ptr->valid & PNG_INFO_sBIT)
+ png_set_shift(png_ptr, &info_ptr->sig_bit);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
+#endif
+
+ /* Pack pixels into bytes */
+ if (transforms & PNG_TRANSFORM_PACKING)
+#ifdef PNG_WRITE_PACK_SUPPORTED
+ png_set_packing(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
+#endif
+
+ /* Swap location of alpha bytes from ARGB to RGBA */
+ if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+ png_set_swap_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
+#endif
+
+ /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into
+ * RGB, note that the code expects the input color type to be G or RGB; no
+ * alpha channel.
+ */
+ if (transforms &
+ (PNG_TRANSFORM_STRIP_FILLER_AFTER|PNG_TRANSFORM_STRIP_FILLER_BEFORE))
+ {
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+ if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
+ {
+ if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
+ png_app_error(png_ptr,
+ "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
+
+ /* Continue if ignored - this is the pre-1.6.10 behavior */
+ png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
+ }
+
+ else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported");
+#endif
+ }
+
+ /* Flip BGR pixels to RGB */
+ if (transforms & PNG_TRANSFORM_BGR)
+#ifdef PNG_WRITE_BGR_SUPPORTED
+ png_set_bgr(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
+#endif
+
+ /* Swap bytes of 16-bit files to most significant byte first */
+ if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+ png_set_swap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
+#endif
+
+ /* Swap bits of 1, 2, 4 bit packed pixel formats */
+ if (transforms & PNG_TRANSFORM_PACKSWAP)
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+ png_set_packswap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
+#endif
+
+ /* Invert the alpha channel from opacity to transparency */
+ if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ png_set_invert_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
+#endif
+
+ /* ----------------------- end of transformations ------------------- */
+
+ /* Write the bits */
+ png_write_image(png_ptr, info_ptr->row_pointers);
+
+ /* It is REQUIRED to call this to finish writing the rest of the file */
+ png_write_end(png_ptr, info_ptr);
+
+ 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)
+ {
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if (image->format & PNG_FORMAT_FLAG_AFIRST)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+
+ else
+# endif
+ 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;
+
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if (image->format & PNG_FORMAT_FLAG_AFIRST)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+
+ else
+# endif
+ 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);
+
+# if defined(PNG_FORMAT_BGR_SUPPORTED) &&\
+ defined(PNG_SIMPLIFIED_WRITE_AFIRST_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 != 0)
+ {
+ /* 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 != 0)
+ {
+ 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 != 0)
+ 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 != 0)
+ 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 == 0)
+ 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 */
Ecere Software / sdk / blobdiff