diff options
Diffstat (limited to 'png/pngwrite.c')
| -rw-r--r-- | png/pngwrite.c | 2437 |
1 files changed, 0 insertions, 2437 deletions
diff --git a/png/pngwrite.c b/png/pngwrite.c deleted file mode 100644 index 7087d08..0000000 --- a/png/pngwrite.c +++ /dev/null @@ -1,2437 +0,0 @@ - -/* 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 */ |