| |
| /* pngwrite.c - general routines to write a PNG file |
| * |
| * Last changed in libpng 1.7.0 [(PENDING RELEASE)] |
| * Copyright (c) 1998-2002,2004,2006-2016 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" |
| #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED |
| # include <errno.h> |
| #endif /* SIMPLIFIED_WRITE_STDIO */ |
| |
| #define PNG_SRC_FILE PNG_SRC_FILE_pngwrite |
| |
| #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 != 0) |
| { |
| 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) != 0) |
| { |
| /* 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 |
| png_write_chunk(png_ptr, up->name, up->data, up->size); |
| } |
| } |
| } |
| #endif /* WRITE_UNKNOWN_CHUNKS */ |
| |
| #ifdef PNG_WRITE_TEXT_SUPPORTED |
| static void |
| png_write_text(png_structrp png_ptr, png_const_inforp info_ptr, png_byte where) |
| /* Text chunk helper */ |
| { |
| int i; |
| |
| /* Check to see if we need to write text chunks */ |
| for (i = 0; i < info_ptr->num_text; i++) |
| { |
| png_debug2(2, "Writing text chunk %d, type %d", i, |
| info_ptr->text[i].compression); |
| |
| /* Text chunks are written at info_ptr->text[i].location, skip the chunk |
| * if we are not writing at that location: |
| */ |
| if ((info_ptr->text[i].location & where) == 0U) |
| continue; |
| |
| switch (info_ptr->text[i].compression) |
| { |
| case PNG_ITXT_COMPRESSION_NONE: |
| case PNG_ITXT_COMPRESSION_zTXt: |
| # 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 /* !WRITE_iTXT */ |
| png_app_error(png_ptr, "Unable to write international text"); |
| # endif /* !WRITE_iTXT */ |
| break; |
| |
| case 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, info_ptr->text[i].compression); |
| # else /* !WRITE_zTXT */ |
| png_app_error(png_ptr, "Unable to write compressed text"); |
| # endif /* !WRITE_zTXT */ |
| break; |
| |
| case 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 /* !WRITE_tEXt */ |
| /* Can't get here TODO: why not? */ |
| png_app_error(png_ptr, "Unable to write uncompressed text"); |
| # endif /* !WRITE_tEXt */ |
| break; |
| |
| default: |
| /* This is an internal error because the libpng checking should |
| * never manage to set any 'compression' except the above values. |
| */ |
| impossible("invalid text compression"); |
| } |
| |
| /* The chunk was written, record where. This allows the location to have |
| * multiple bits set; the first successful write freezes the location. |
| */ |
| info_ptr->text[i].location = where; |
| } |
| } |
| #endif /* WRITE_TEXT */ |
| |
| /* 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_HAVE_IHDR) == 0) |
| { |
| int color_type = PNG_COLOR_TYPE_FROM_FORMAT(info_ptr->format); |
| |
| /* Write PNG signature; doesn't set PNG_HAVE_PNG_SIGNATURE if it has |
| * already been written (or rather, if at least 3 bytes have already been |
| * written; undocumented wackiness, it means the 'PNG' at the start can be |
| * replace by, e.g. "FOO" or "BAR" or "MNG"). |
| */ |
| png_write_sig(png_ptr); |
| |
| # ifdef PNG_MNG_FEATURES_SUPPORTED |
| if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && |
| png_ptr->mng_features_permitted != 0) |
| { |
| png_app_error(png_ptr, |
| "MNG features are not allowed in a PNG datastream"); |
| /* Recovery: disable MNG features: */ |
| png_ptr->mng_features_permitted = 0; |
| } |
| # endif /* MNG_FEATURES */ |
| |
| /* Write IHDR information. */ |
| png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height, |
| info_ptr->bit_depth, color_type, info_ptr->compression_type, |
| info_ptr->filter_type, info_ptr->interlace_type); |
| |
| # ifdef PNG_WRITE_TRANSFORMS_SUPPORTED |
| /* This are used for checking later on: */ |
| png_ptr->info_format = info_ptr->format; |
| # endif /* WRITE_TRANSFORMS */ |
| |
| /* This sets the flag that prevents re-entry to the 'before PLTE' case: */ |
| affirm((png_ptr->mode & PNG_HAVE_IHDR) != 0); |
| |
| /* 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 |
| * an error and calls png_error while the color space is being set, yet |
| * the application continues writing the PNG. So check the 'invalid' |
| * flag here too. |
| */ |
| # ifdef PNG_WRITE_tIME_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_tIME) != 0 && |
| (info_ptr->time_location & PNG_HAVE_IHDR) != 0) |
| png_write_tIME(png_ptr, &(info_ptr->mod_time)); |
| # endif /* WRITE_tIME */ |
| |
| # ifdef PNG_WRITE_gAMA_SUPPORTED /* enables GAMMA */ |
| if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && |
| (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 && |
| (info_ptr->valid & PNG_INFO_gAMA) != 0) |
| { |
| /* This is the inverse of the test in png.c: */ |
| affirm(info_ptr->colorspace.gamma >= 16 && |
| info_ptr->colorspace.gamma <= 625000000); |
| png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma); |
| } |
| # endif /* WRITE_gAMA */ |
| |
| /* 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 /* enables COLORSPACE, GAMMA */ |
| if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && |
| (info_ptr->valid & PNG_INFO_iCCP) != 0) |
| { |
| # ifdef PNG_WRITE_sRGB_SUPPORTED |
| /* The app must have supplied an sRGB iCCP profile (and one that |
| * is recognized and therefore known to be correct) so we write |
| * that profile, even though it increases the size of the PNG |
| * significantly. A warning is reasonable: |
| */ |
| if ((info_ptr->valid & PNG_INFO_sRGB) != 0) |
| png_app_warning(png_ptr, |
| "profile matches sRGB but writing iCCP instead"); |
| # endif /* WRITE_sRGB */ |
| |
| png_write_iCCP(png_ptr, info_ptr->iccp_name, |
| info_ptr->iccp_profile); |
| } |
| # ifdef PNG_WRITE_sRGB_SUPPORTED |
| else /* iCCP not written */ |
| # endif /* WRITE_sRGB */ |
| # endif /* WRITE_iCCP */ |
| |
| # ifdef PNG_WRITE_sRGB_SUPPORTED /* enables COLORSPACE, GAMMA */ |
| if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && |
| (info_ptr->valid & PNG_INFO_sRGB) != 0) |
| png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent); |
| # endif /* WRITE_sRGB */ |
| |
| # ifdef PNG_WRITE_sBIT_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_sBIT) != 0) |
| png_write_sBIT(png_ptr, &(info_ptr->sig_bit), color_type); |
| # endif /* WRITE_sBIT */ |
| |
| # ifdef PNG_WRITE_cHRM_SUPPORTED /* enables COLORSPACE */ |
| if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && |
| (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 && |
| (info_ptr->valid & PNG_INFO_cHRM) != 0) |
| png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy); |
| # endif /* WRITE_cHRM */ |
| |
| # ifdef PNG_WRITE_TEXT_SUPPORTED |
| if (info_ptr->num_text > 0) |
| png_write_text(png_ptr, info_ptr, PNG_HAVE_IHDR); |
| # endif /* WRITE_TEXT */ |
| |
| # ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED |
| /* The third arugment must encode only one bit, otherwise chunks will |
| * be written twice because the test in write_unknown_chunks is |
| * 'location & where'. |
| */ |
| write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR); |
| # endif |
| } |
| |
| else /* 1.7.0: flag multiple calls; previously ignored */ |
| png_app_error(png_ptr, |
| "png_write_info_before_PLTE called more than once"); |
| } |
| |
| void PNGAPI |
| png_write_info(png_structrp png_ptr, png_const_inforp info_ptr) |
| { |
| png_debug(1, "in png_write_info"); |
| |
| if (png_ptr == NULL || info_ptr == NULL) |
| return; |
| |
| if ((png_ptr->mode & (PNG_HAVE_PLTE+PNG_HAVE_IDAT)) != 0) |
| { |
| png_app_error(png_ptr, "late call to png_write_info"); |
| return; |
| } |
| |
| /* The app may do this for us, and in 1.7.0 multiple calls are flagged as an |
| * application error, so this code must check: |
| */ |
| if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) |
| png_write_info_before_PLTE(png_ptr, info_ptr); |
| |
| if ((info_ptr->valid & PNG_INFO_PLTE) != 0) |
| png_write_PLTE(png_ptr, info_ptr->palette, info_ptr->num_palette); |
| |
| /* Validate the consistency of the PNG being produced; a palette must have |
| * been written if a palette mapped PNG is to be valid: |
| */ |
| if ((png_ptr->mode & PNG_HAVE_PLTE) == 0 && |
| png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| png_error(png_ptr, "Valid palette required for paletted images"); |
| |
| /* But always set the mode flag because without this we don't know when to |
| * write the post-palette text or unknown chunks. |
| */ |
| png_ptr->mode |= PNG_HAVE_PLTE; |
| |
| # ifdef PNG_WRITE_tRNS_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_tRNS) !=0) |
| { |
| png_write_tRNS(png_ptr, info_ptr->trans_alpha, |
| &(info_ptr->trans_color), info_ptr->num_trans, |
| PNG_COLOR_TYPE_FROM_FORMAT(info_ptr->format)); |
| } |
| # endif /* WRITE_tRNS */ |
| |
| # ifdef PNG_WRITE_bKGD_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_bKGD) != 0) |
| png_write_bKGD(png_ptr, &(info_ptr->background), |
| PNG_COLOR_TYPE_FROM_FORMAT(info_ptr->format)); |
| # endif /* WRITE_bKGD */ |
| |
| # ifdef PNG_WRITE_hIST_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_hIST) != 0) |
| png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette); |
| # endif /* WRITE_hIST */ |
| |
| # ifdef PNG_WRITE_oFFs_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_oFFs) != 0) |
| png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset, |
| info_ptr->offset_unit_type); |
| # endif /* WRITE_oFFs */ |
| |
| # ifdef PNG_WRITE_pCAL_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_pCAL) != 0) |
| 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 /* WRITE_pCAL */ |
| |
| # ifdef PNG_WRITE_sCAL_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_sCAL) != 0) |
| png_write_sCAL_s(png_ptr, info_ptr->scal_unit, info_ptr->scal_s_width, |
| info_ptr->scal_s_height); |
| # endif /* WRITE_sCAL */ |
| |
| # ifdef PNG_WRITE_pHYs_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_pHYs) != 0) |
| png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit, |
| info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type); |
| # endif /* WRITE_pHYs */ |
| |
| # ifdef PNG_WRITE_tIME_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_tIME) != 0 && |
| (info_ptr->time_location & PNG_HAVE_PLTE) != 0) |
| png_write_tIME(png_ptr, &(info_ptr->mod_time)); |
| # endif /* WRITE_tIME */ |
| |
| # ifdef PNG_WRITE_sPLT_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_sPLT) != 0) |
| { |
| int i; |
| |
| for (i = 0; i < info_ptr->splt_palettes_num; i++) |
| png_write_sPLT(png_ptr, info_ptr->splt_palettes + i); |
| } |
| # endif /* WRITE_sPLT */ |
| |
| # ifdef PNG_WRITE_TEXT_SUPPORTED |
| if (info_ptr->num_text > 0) |
| png_write_text(png_ptr, info_ptr, PNG_HAVE_PLTE); |
| # endif /* WRITE_TEXT */ |
| |
| # ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED |
| write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE); |
| # endif /* WRITE_UNKNOWN_CHUNKS */ |
| } |
| |
| /* 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_IHDR+PNG_HAVE_IDAT+PNG_AFTER_IDAT+PNG_HAVE_IEND)) != |
| (PNG_HAVE_IHDR+PNG_HAVE_IDAT+PNG_AFTER_IDAT)) |
| { |
| /* Out of place png_write_end: */ |
| if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) |
| png_error(png_ptr, "Missing call to png_write_info"); |
| |
| else if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 && png_ptr->zowner == 0) |
| { |
| /* TODO: write unknown IDAT here, for the moment allow the app to write |
| * IDAT then call write_end: |
| */ |
| png_app_error(png_ptr, "No IDATs written into file"); |
| png_ptr->mode |= PNG_HAVE_IDAT+PNG_AFTER_IDAT; |
| } |
| |
| else if ((png_ptr->mode & PNG_AFTER_IDAT) == 0) |
| { |
| affirm(png_ptr->zowner == png_IDAT); |
| png_error(png_ptr, "incomplete PNG image"); /* unrecoverable */ |
| } |
| |
| else if ((png_ptr->mode & PNG_HAVE_IEND) != 0) |
| { |
| png_app_error(png_ptr, "multiple calls to png_write_end"); |
| return; |
| } |
| |
| else |
| impossible("not reached"); |
| } |
| |
| /* And double check that the image rows were all written; this is actually |
| * a harmless error on an interlaced image because the image rows with |
| * data were all passed in or the above check would not work. |
| * |
| * Don't do this if the IDAT came from unknowns (TBD) or the app, above. |
| * |
| * The check depends on the precise logic in png_write_row. |
| */ |
| else if (png_ptr->pass != 7U) |
| png_app_error(png_ptr, "png_write_row not called to last row"); |
| |
| else |
| debug(png_ptr->row_number == 0U); |
| |
| /* See if user wants us to write information chunks */ |
| if (info_ptr != NULL) |
| { |
| # ifdef PNG_WRITE_tIME_SUPPORTED |
| /* Check to see if user has supplied a time chunk */ |
| if ((info_ptr->valid & PNG_INFO_tIME) != 0 && |
| (info_ptr->time_location & PNG_AFTER_IDAT) != 0) |
| png_write_tIME(png_ptr, &(info_ptr->mod_time)); |
| # endif |
| |
| # ifdef PNG_WRITE_TEXT_SUPPORTED |
| if (info_ptr->num_text > 0) |
| png_write_text(png_ptr, info_ptr, PNG_AFTER_IDAT); |
| # endif /* WRITE_TEXT */ |
| |
| # ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED |
| write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT); |
| # endif |
| } |
| |
| /* 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 |
| if (png_ptr->output_flush_fn != NULL) |
| png_ptr->output_flush_fn(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_check_u16(0/*TODO: fixme*/, 1900 + ttime->tm_year); |
| ptime->month = png_check_byte(0/*TODO: fixme*/, ttime->tm_mon + 1); |
| ptime->day = png_check_byte(0/*TODO: fixme*/, ttime->tm_mday); |
| ptime->hour = png_check_byte(0/*TODO: fixme*/, ttime->tm_hour); |
| ptime->minute = png_check_byte(0/*TODO: fixme*/, ttime->tm_min); |
| ptime->second = png_check_byte(0/*TODO: fixme*/, 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 /* USER_MEM */ |
| |
| if (png_ptr != NULL) |
| { |
| # ifdef PNG_BENIGN_ERRORS_SUPPORTED |
| # if !PNG_RELEASE_BUILD |
| /* Always quit on error prior to release */ |
| png_ptr->benign_error_action = PNG_ERROR; |
| png_ptr->app_warning_action = PNG_WARN; |
| png_ptr->app_error_action = PNG_ERROR; |
| # else /* RELEASE_BUILD */ |
| /* Allow benign errors on write, subject to app control. */ |
| # ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED |
| png_ptr->benign_error_action = PNG_WARN; |
| png_ptr->app_error_action = PNG_WARN; |
| png_ptr->app_warning_action = PNG_WARN; |
| # else /* !BENIGN_WRITE_ERRORS */ |
| /* libpng build without benign error support; the application |
| * author has to be assumed to be correct, so: |
| */ |
| png_ptr->benign_error_action = PNG_ERROR; |
| png_ptr->app_warning_action = PNG_WARN; |
| png_ptr->app_error_action = PNG_ERROR; |
| # endif /* !BENIGN_WRITE_ERRORS */ |
| # endif /* RELEASE_BUILD */ |
| # endif /* BENIGN_ERRORS */ |
| } |
| |
| return png_ptr; |
| } |
| |
| |
| #if defined(PNG_WRITE_INTERLACING_SUPPORTED) ||\ |
| defined(PNG_WRITE_TRANSFORMS_SUPPORTED) |
| static void |
| write_row_buffered(png_structrp png_ptr, |
| png_const_bytep row, unsigned int row_info_flags, |
| void (*copy_fn)(png_const_structrp png_ptr, png_bytep row_buffer, |
| png_const_bytep row, png_uint_32 x, unsigned int count, unsigned int p), |
| unsigned int copy_parameter) |
| { |
| unsigned int max_pixels = png_max_pixel_block(png_ptr); |
| const unsigned int pass = png_ptr->pass; |
| const png_uint_32 width = png_ptr->interlaced == PNG_INTERLACE_NONE ? |
| png_ptr->width : PNG_PASS_COLS(png_ptr->width, pass); |
| png_uint_32 x; |
| png_byte prev_pixels[4*2*2]; /* 2 pixels up to 4 2-byte channels each */ |
| |
| memset(prev_pixels, 0U, sizeof prev_pixels); |
| |
| for (x = 0U; x < width; x += max_pixels) |
| { |
| union |
| { |
| PNG_ROW_BUFFER_ALIGN_TYPE force_buffer_alignment; |
| png_byte buffer[PNG_ROW_BUFFER_SIZE]; |
| } pixel_buffer; |
| |
| if (max_pixels > width - x) |
| max_pixels = (unsigned int)/*SAFE*/(width - x); |
| |
| debug((row_info_flags & png_row_end) == 0U); /* must be set here at end */ |
| if (x + max_pixels >= width) |
| row_info_flags |= png_row_end; |
| |
| /* Copy a block of input pixels into the buffer, effecting the interlace |
| * on the way if required. The argument is the number of pixels in the |
| * buffer, not the number handled from the input which will be larger in |
| * the interlaced case. |
| */ |
| copy_fn(png_ptr, pixel_buffer.buffer, row, x, max_pixels, copy_parameter); |
| |
| /* Now pixel_buffer[0..max_pixels-1] contains max_pixels pixels which may |
| * need to be transformed (the interlace has already been handled). |
| */ |
| # ifdef PNG_WRITE_TRANSFORMS_SUPPORTED |
| if (png_ptr->transform_list != NULL) |
| { |
| png_transform_control tc; |
| |
| /* The initial values are the memory format; this was worked out in |
| * png_init_row_info below. |
| */ |
| memset(&tc, 0, sizeof tc); |
| tc.png_ptr = png_ptr; |
| tc.sp = tc.dp = pixel_buffer.buffer; |
| |
| tc.width = max_pixels; /* width of block that we have */ |
| tc.format = png_ptr->row_format; |
| tc.range = png_ptr->row_range; |
| tc.bit_depth = png_ptr->row_bit_depth; |
| /* tc.init == 0 */ |
| /* tc.caching: not used */ |
| /* tc.palette: not used */ |
| debug(PNG_TC_PIXEL_DEPTH(tc) == png_ptr->row_input_pixel_depth); |
| |
| /* Run the list. */ |
| png_run_transform_list_backwards(png_ptr, &tc); |
| |
| /* Make sure the format that resulted is compatible with PNG: */ |
| affirm((tc.format & PNG_BIC_MASK(PNG_FORMAT_FLAG_ALPHA + |
| PNG_FORMAT_FLAG_COLOR + PNG_FORMAT_FLAG_LINEAR + |
| PNG_FORMAT_FLAG_COLORMAP)) == 0); |
| |
| /* Now we must have the PNG format from the IHDR: */ |
| affirm(png_ptr->bit_depth == tc.bit_depth && |
| png_ptr->color_type == PNG_COLOR_TYPE_FROM_FORMAT(tc.format)); |
| } |
| # endif /* WRITE_TRANSFORMS */ |
| |
| /* Call png_write_png_data to write this block of data, the test on |
| * maxpixels says if this is the final block in the row. |
| */ |
| png_write_png_data(png_ptr, prev_pixels, pixel_buffer.buffer, x, |
| max_pixels, row_info_flags); |
| } |
| } |
| #endif /* WRITE { INTERLACING || TRANSFORMS } */ |
| |
| #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED |
| static void |
| copy_row(png_const_structrp png_ptr, png_bytep row_buffer, |
| png_const_bytep row, png_uint_32 x, unsigned int count, |
| unsigned int pixel_depth) |
| { |
| /* Copy row[x..x+count] pixels to row_buffer. */ |
| png_copy_row(png_ptr, row_buffer, row, x, count, pixel_depth, 1/*clear*/, |
| 0/* x_in_dest; row[x]->row_buffer */); |
| } |
| #endif /* WRITE_TRANSFORMS */ |
| |
| #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| static void |
| interlace_row_lbd(png_const_structrp png_ptr, png_bytep dp, png_const_bytep sp, |
| png_uint_32 x, unsigned int count, const unsigned int B) |
| { |
| /* Pick out the correct pixels for the interlace pass. The basic idea here |
| * is to go through the row with a source pointer and a destination pointer |
| * (sp and dp), and copy the correct pixels for the pass. As the row gets |
| * compacted, sp will always be >= dp, so we should never overwrite anything. |
| * See the default: case for the easiest code to understand. |
| */ |
| const unsigned int pass = png_ptr->pass; |
| png_uint_32 i = PNG_COL_FROM_PASS_COL(x, pass); |
| const unsigned int inc = PNG_PASS_COL_OFFSET(pass); |
| |
| /* For pixels less than one byte wide the correct pixels have to be |
| * extracted from the input bytes. Because we are reading data in |
| * the application memory format we cannot rely on the PNG big |
| * endian order. Notice that this was apparently broken before |
| * 1.7.0. |
| * |
| * In libpng 1.7.0 libpng uses a classic bit-pump to optimize the |
| * extraction. In all passes before the last (6/7) no two pixels |
| * are adjacent in the input, so we are always extracting 1 bit. |
| * At present the code uses an 8-bit buffer to avoid coding for |
| * different byte sexes, but this could easily be changed. |
| * |
| * 'i' is the bit-index of bit in the input (sp[]), so, |
| * considering the 1-bit per pixel case, sp[i>>3] is the byte |
| * and the bit is bit (i&7) (0 lowest) on swapped (little endian) |
| * data or 7-(i&7) on PNG default (big-endian) data. |
| * |
| * Define these macros, where: |
| * |
| * B: the log2 bit depth (0, 1, 2 for 1bpp, 2bpp or 4bpp) of |
| * the data; this should be a constant. |
| * sp: the source pointer (sp) (a png_const_bytep) |
| * i: the pixel index in the input (png_uint_32) |
| * j: the bit index in the output (unsigned int) |
| * |
| * Unlike 'i', 'j' is interpreted directly; for LSB bytes it counts |
| * up, for MSB it counts down. |
| * |
| * NOTE: this could all be expanded to eliminate the code below by |
| * the time honoured copy'n'paste into three separate functions. This |
| * might be worth doing in the future. |
| */ |
| # define PIXEL_MASK ((1U << (1<<B))-1U) |
| # define BIT_MASK ((1U << (3-(B)))-1U) /* within a byte */ |
| # define SP_BYTE (sp[i>>(3-(B))]) /* byte to use */ |
| # define SP_OFFSET_LSB ((BIT_MASK & i) << (B)) |
| # define SP_OFFSET_MSB ((BIT_MASK & ~i) << (B)) |
| # define SP_PIXEL(sex) ((SP_BYTE >> SP_OFFSET_ ## sex) & PIXEL_MASK) |
| { |
| unsigned int j; |
| unsigned int d; |
| |
| /* The data is always in the PNG, big-endian, format: */ |
| for (j = 8U, d = 0U; count > 0U; --count, i += inc) |
| { /* big-endian */ |
| j -= 1U<<B; |
| d |= SP_PIXEL(MSB) << j; |
| if (j == 0U) *dp++ = png_check_byte(png_ptr, d), j = 8U, d = 0U; |
| } |
| |
| /* The end condition: if j is not 0 the last byte was not |
| * written: |
| */ |
| if (j != 0U) *dp = png_check_byte(png_ptr, d); |
| } |
| # undef PIXEL_MASK |
| # undef BIT_MASK |
| # undef SP_BYTE |
| # undef SP_OFFSET_MSB |
| # undef SP_OFFSET_LSB |
| # undef SP_PIXEL |
| } |
| |
| static void |
| interlace_row_byte(png_const_structrp png_ptr, png_bytep dp, png_const_bytep sp, |
| png_uint_32 x, unsigned int count, unsigned int cbytes) |
| { |
| const unsigned int pass = png_ptr->pass; |
| const unsigned int inc = PNG_PASS_COL_OFFSET(pass); |
| |
| /* Loop through the input copying each pixel to the correct place |
| * in the output. Note that the loop may be executed 0 times if |
| * this is called on a narrow image that does not contain this |
| * pass. |
| */ |
| for (sp += PNG_COL_FROM_PASS_COL(x, pass) * cbytes; count > 0; |
| --count, sp += inc * cbytes, dp += cbytes) |
| memcpy(dp, sp, cbytes); |
| } |
| #endif /* WRITE_INTERLACING */ |
| |
| #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED |
| static void |
| write_row_core(png_structrp png_ptr, png_const_bytep row, |
| unsigned int row_info_flags) |
| { |
| # ifdef PNG_WRITE_TRANSFORMS_SUPPORTED |
| if (png_ptr->transform_list != NULL) |
| write_row_buffered(png_ptr, row, row_info_flags, |
| copy_row, png_ptr->row_input_pixel_depth); |
| |
| else |
| # endif /* WRITE_TRANSFORMS */ |
| |
| /* If control reaches this point the intermediate buffer is not required and |
| * the input data can be used unmodified. |
| */ |
| png_write_png_rows(png_ptr, &row, 1U); |
| PNG_UNUSED(row_info_flags) |
| } |
| |
| /* Write a single non-interlaced row. */ |
| static void |
| write_row_non_interlaced(png_structrp png_ptr, png_const_bytep row) |
| { |
| const png_uint_32 row_number = png_ptr->row_number+1U; |
| /* There is only one pass, so this is the last pass: */ |
| const unsigned int row_info_flags = |
| (row_number == 1U ? png_pass_first_row : 0) | |
| (row_number >= png_ptr->height ? png_pass_last_row : 0) | |
| png_pass_last; |
| |
| debug(png_ptr->interlaced == PNG_INTERLACE_NONE); |
| |
| write_row_core(png_ptr, row, row_info_flags); |
| } |
| |
| /* Write a single interlaced row. */ |
| static void |
| write_row_interlaced(png_structrp png_ptr, png_const_bytep row) |
| { |
| const png_uint_32 row_number = png_ptr->row_number+1U; |
| const png_uint_32 height = png_ptr->height; |
| const unsigned int pass = png_ptr->pass; |
| const unsigned int row_info_flags = |
| (row_number == 1U ? png_pass_first_row : 0) | |
| (row_number == PNG_PASS_ROWS(height, pass) ? png_pass_last_row : 0) | |
| (pass == PNG_LAST_PASS(png_ptr->width, height) ? png_pass_last : 0); |
| |
| # ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| /* Check that libpng is not doing the interlace: */ |
| debug(png_ptr->interlaced != PNG_INTERLACE_NONE && |
| !png_ptr->do_interlace); |
| # endif /* WRITE_INTERLACING */ |
| |
| write_row_core(png_ptr, row, row_info_flags); |
| } |
| #endif /* WRITE_TRANSFORMS */ |
| |
| #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| /* Interlace a row then write it out. */ |
| static void |
| interlace_row(png_structrp png_ptr, png_const_bytep row) |
| { |
| /* The row may not exist in the image (for this pass). */ |
| const png_uint_32 row_number = png_ptr->row_number; /* in image */ |
| const unsigned int pass = png_ptr->pass; |
| |
| if (png_ptr->width > PNG_PASS_START_COL(pass) && |
| PNG_ROW_IN_INTERLACE_PASS(row_number, pass)) |
| { |
| const unsigned int row_info_flags = |
| (row_number == PNG_PASS_START_ROW(pass) ? png_pass_first_row : 0) | |
| (PNG_LAST_PASS_ROW(row_number, pass, png_ptr->height) ? |
| png_pass_last_row : 0) | |
| (pass == PNG_LAST_PASS(png_ptr->width, png_ptr->height) ? |
| png_pass_last : 0); |
| |
| if (pass < 6) |
| { |
| /* Libpng is doing the interlacing and pixels need to be selected |
| * from the input row for this pass. |
| */ |
| /* row interlacing uses either the log bit depth for low bit |
| * depth input or the byte count for 8bpp or bigger pixels. |
| */ |
| const unsigned int input_depth = png_ptr->row_input_pixel_depth; |
| unsigned int B = 0; /* log2(input_depth) */ |
| |
| switch (input_depth) |
| { |
| case 4U: /* B will be 2 */ |
| ++B; |
| /*FALL THROUGH*/ |
| case 2U: /* B will be 1 */ |
| ++B; |
| /*FALL THROUGH*/ |
| case 1U: /* B will be 0 */ |
| write_row_buffered(png_ptr, row, row_info_flags, |
| interlace_row_lbd, B); |
| break; |
| |
| default: /* Parameter is the pixel size in bytes */ |
| write_row_buffered(png_ptr, row, row_info_flags, |
| interlace_row_byte, input_depth >> 3); |
| break; |
| } |
| } /* pass < 6 */ |
| |
| else /* pass 6: no interlacing required */ |
| write_row_core(png_ptr, row, row_info_flags); |
| } |
| |
| else |
| { |
| /* This code must advance row_number/pass itself; the row has been |
| * skipped. |
| */ |
| if (row_number+1U < png_ptr->height) |
| png_ptr->row_number = row_number+1U; |
| |
| else |
| { |
| png_ptr->row_number = 0U; |
| png_ptr->pass = 0x7U & (pass+1U); |
| } |
| } |
| } |
| #endif /* WRITE_INTERLACING */ |
| |
| /* Bottleneck API to actually write a number of rows, only exists because the |
| * rows parameter to png_write_rows is wrong. |
| */ |
| static void |
| png_write_rows_internal(png_structrp png_ptr, png_const_bytep *rows, |
| png_uint_32 num_rows) |
| { |
| if (png_ptr != NULL && num_rows > 0U && rows != NULL) |
| { |
| /* Unlike the read code initialization happens automatically: */ |
| if (png_ptr->row_number == 0U && png_ptr->pass == 0U) |
| { |
| png_init_row_info(png_ptr); |
| |
| # ifdef PNG_WRITE_TRANSFORMS_SUPPORTED |
| /* If the app takes a png_info from a read operation and if the app has |
| * performed transforms on the data the png_info can contain IHDR |
| * information that cannot be represented in PNG. The code that writes |
| * the IHDR takes the color type from the png_info::format. The app |
| * adds transforms, before or after writing the IHDR, then the IHDR |
| * color_type stored in png_struct::color_type is used in |
| * png_init_row_info above to work out the actual row format. |
| * |
| * Prior to 1.7.0 this was not verified (there was no easy way to do |
| * so). Now we can check it here, however this is an: |
| * |
| * API CHANGE: in 1.7.0 an error may be flagged against bogus |
| * info_struct formats even though the app had removed them itself. |
| * It's just a warning at present. |
| * |
| * The test is that either the row_format produced by the write |
| * transforms exactly matches that in the original info_struct::format |
| * or that the info_struct::format was a simple mapping of the |
| * color_type that ended up in the IHDR: |
| */ |
| if (png_ptr->row_format != png_ptr->info_format && |
| PNG_FORMAT_FROM_COLOR_TYPE(png_ptr->color_type) != |
| png_ptr->info_format) |
| png_app_warning(png_ptr, "info_struct format does not match IHDR"); |
| # endif /* WRITE_TRANSFORMS */ |
| |
| /* Perform initialization required before IDATs are written. */ |
| png_write_start_IDAT(png_ptr); |
| } |
| |
| else if (png_ptr->pass >= 7U) /* too many calls; write already ended */ |
| { |
| debug(png_ptr->row_number == 0U); |
| png_app_error(png_ptr, "Too many calls to png_write_row"); |
| return; |
| } |
| |
| /* The remainder of these tests detect internal errors in libpng */ |
| else if (png_ptr->interlaced == PNG_INTERLACE_NONE) |
| affirm(png_ptr->row_number < png_ptr->height && png_ptr->pass == 0U); |
| |
| # ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| else if (png_ptr->do_interlace) |
| affirm(png_ptr->row_number < png_ptr->height); |
| # endif /* WRITE_INTERLACING */ |
| |
| else /* app does interlace */ |
| affirm( |
| PNG_PASS_IN_IMAGE(png_ptr->width, png_ptr->height, png_ptr->pass) && |
| png_ptr->row_number < PNG_PASS_ROWS(png_ptr->height, png_ptr->pass) |
| ); |
| |
| /* First handle rows that require buffering because of the need to |
| * interlace them or the need to perform write transforms. |
| */ |
| # ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| /* libpng is doing the interlacing, but this only makes a difference to |
| * the first six passes (numbered, in libpng, 0..5); the seventh pass |
| * (numbered 6 by libpng) consists of complete image rows. |
| */ |
| if (png_ptr->do_interlace) while (num_rows > 0U && png_ptr->pass < 6) |
| interlace_row(png_ptr, *rows++), --num_rows; |
| # endif /* WRITE_INTERLACING */ |
| |
| # ifdef PNG_WRITE_TRANSFORMS_SUPPORTED |
| /* Transforms required however the row interlacing has already been |
| * handled and we have a complete (PNG) row. |
| */ |
| if (png_ptr->transform_list != NULL) |
| { |
| if (png_ptr->interlaced == PNG_INTERLACE_NONE) |
| while (num_rows > 0U) |
| write_row_non_interlaced(png_ptr, *rows++), --num_rows; |
| |
| # ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| else if (png_ptr->do_interlace) |
| while (num_rows > 0U) |
| interlace_row(png_ptr, *rows++), --num_rows; |
| # endif /* WRITE_INTERLACING */ |
| |
| else /* app does the interlacing */ |
| while (num_rows > 0U) |
| write_row_interlaced(png_ptr, *rows++), --num_rows; |
| } |
| # endif /* WRITE_TRANSFORMS */ |
| |
| /* Finally handle any remaining rows that require no (libpng) interlace |
| * and no transforms. |
| */ |
| if (num_rows > 0U) |
| png_write_png_rows(png_ptr, rows, num_rows); |
| |
| /* Repeat the checks above, but allow for end-of-image. */ |
| if (png_ptr->pass < 7U) |
| { |
| if (png_ptr->interlaced == PNG_INTERLACE_NONE) |
| affirm(png_ptr->row_number < png_ptr->height && |
| png_ptr->pass == 0U); |
| |
| # ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| else if (png_ptr->do_interlace) |
| affirm(png_ptr->row_number < png_ptr->height); |
| # endif /* WRITE_INTERLACING */ |
| |
| else /* app does interlace */ |
| affirm(PNG_PASS_IN_IMAGE(png_ptr->width, png_ptr->height, |
| png_ptr->pass) && |
| png_ptr->row_number < |
| PNG_PASS_ROWS(png_ptr->height, png_ptr->pass)); |
| } |
| } /* png_ptr, rows, num_rows all valid */ |
| |
| else if (png_ptr != NULL) |
| png_app_warning(png_ptr, "Missing rows to row write API"); |
| } |
| |
| /* ROW WRITE APIs */ |
| /* Called by user to write a single row of image data */ |
| void PNGAPI |
| png_write_row(png_structrp png_ptr, png_const_bytep row) |
| { |
| png_debug(1, "in png_write_row"); |
| png_write_rows_internal(png_ptr, &row, 1U); |
| } |
| |
| /* 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 rows, png_uint_32 num_rows) |
| { |
| png_debug(1, "in png_write_rows"); |
| |
| if (png_ptr != NULL) |
| png_write_rows_internal(png_ptr, png_constcast(png_const_bytep*,rows), |
| num_rows); |
| } |
| |
| /* 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_debug(1, "in png_write_image"); |
| |
| if (png_ptr != NULL) |
| { |
| int num_pass = 1; |
| |
| /* The image is always an non-interlaced image. To write it as interlaced |
| * interlace handling must be present: |
| */ |
| if (png_ptr->interlaced) |
| { |
| # ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| num_pass = png_set_interlace_handling(png_ptr); |
| # else /* !WRITE_INTERLACING */ |
| /* There is no recovery because the IHDR has already been written. |
| */ |
| png_error(png_ptr, "No interlace support"); |
| # endif /* !WRITE_INTERLACING */ |
| } |
| |
| /* And write the whole thing, 7 times if interlacing it: */ |
| for (; num_pass > 0; --num_pass) |
| png_write_rows(png_ptr, image, png_ptr->height); |
| } |
| } |
| |
| /* 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"); |
| |
| png_deflate_destroy(png_ptr); |
| |
| #ifdef PNG_TRANSFORM_MECH_SUPPORTED |
| png_transform_free(png_ptr, &png_ptr->transform_list); |
| #endif |
| |
| #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED |
| png_free(png_ptr, png_ptr->chunk_list); |
| png_ptr->chunk_list = NULL; |
| #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); |
| } |
| } |
| } |
| |
| 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_PNG_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) != 0) |
| #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) != 0) |
| #ifdef PNG_WRITE_SHIFT_SUPPORTED |
| if ((info_ptr->valid & PNG_INFO_sBIT) != 0) |
| 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) != 0) |
| #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) != 0) |
| #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)) != 0) |
| { |
| #ifdef PNG_WRITE_FILLER_SUPPORTED |
| if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0) |
| { |
| if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) |
| 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) != 0) |
| 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) != 0) |
| #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) != 0) |
| #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) != 0) |
| #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) != 0) |
| #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 /* WRITE_PNG */ |
| |
| |
| #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED |
| /* 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; |
| ptrdiff_t 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; |
| /* Byte count for memory writing */ |
| png_bytep memory; |
| png_alloc_size_t memory_bytes; /* not used for STDIO */ |
| png_alloc_size_t output_bytes; /* running total */ |
| } 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) != 0 ? 3 : 1; |
| int aindex = 0; |
| png_uint_32 y = image->height; |
| |
| if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) |
| { |
| # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED |
| if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) |
| { |
| 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_check_u16(png_ptr, 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_const_structrp png_ptr, 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_sRGB_FROM_LINEAR(png_ptr, component); |
| } |
| |
| else |
| return 0; |
| |
| PNG_UNUSEDRC(png_ptr) |
| } |
| |
| 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) != 0 ? 3 : 1; |
| |
| if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) |
| { |
| png_bytep row_end; |
| int aindex; |
| |
| # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED |
| if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) |
| { |
| 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_check_byte(png_ptr, 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(png_ptr, *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_sRGB_FROM_LINEAR(png_ptr, 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) != 0 ? 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) != 0) |
| { |
| png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap); |
| |
| entry += i * channels; |
| |
| if ((channels & 1) != 0) /* no alpha */ |
| { |
| if (channels >= 3) /* RGB */ |
| { |
| palette[i].blue = PNG_sRGB_FROM_LINEAR( |
| display->image->opaque->png_ptr, 255 * entry[(2 ^ bgr)]); |
| palette[i].green = PNG_sRGB_FROM_LINEAR( |
| display->image->opaque->png_ptr, 255 * entry[1]); |
| palette[i].red = PNG_sRGB_FROM_LINEAR( |
| display->image->opaque->png_ptr, 255 * entry[bgr]); |
| } |
| |
| else /* Gray */ |
| palette[i].blue = palette[i].red = palette[i].green = |
| PNG_sRGB_FROM_LINEAR(display->image->opaque->png_ptr, |
| 255 * *entry); |
| } |
| |
| else /* alpha */ |
| { |
| png_uint_16 alpha = entry[afirst ? 0 : channels-1]; |
| png_byte alphabyte = png_check_byte( |
| display->image->opaque->png_ptr, 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( |
| display->image->opaque->png_ptr, entry[afirst + (2 ^ bgr)], |
| alpha, reciprocal); |
| palette[i].green = png_unpremultiply( |
| display->image->opaque->png_ptr, entry[afirst + 1], alpha, |
| reciprocal); |
| palette[i].red = png_unpremultiply( |
| display->image->opaque->png_ptr, entry[afirst + bgr], alpha, |
| reciprocal); |
| } |
| |
| else /* gray */ |
| palette[i].blue = palette[i].red = palette[i].green = |
| png_unpremultiply(display->image->opaque->png_ptr, |
| 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; |
| |
| /* The following four ints are actually booleans */ |
| int colormap = (format & PNG_FORMAT_FLAG_COLORMAP); |
| int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */ |
| int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA); |
| int write_16bit = linear && !colormap && (display->convert_to_8bit == 0); |
| |
| # 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, also check the row stride |
| * and total image size to ensure that they are within the system limits. |
| */ |
| { |
| const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); |
| |
| /* The test is slightly evil: it assumes that a signed pointer difference |
| * (ptrdiff_t) can hold a maximum value of half, rounded down, of the |
| * maximum of a (size_t). This is almost certain to be true. |
| */ |
| if (image->width <= (PNG_SIZE_MAX >> 1)/channels) /* no overflow */ |
| { |
| png_alloc_size_t check; |
| const png_alloc_size_t png_row_stride = |
| (png_alloc_size_t)/*SAFE*/image->width * channels; |
| |
| if (display->row_stride == 0) |
| display->row_stride = (ptrdiff_t)png_row_stride; |
| |
| if (display->row_stride < 0) |
| check = -display->row_stride; |
| |
| else |
| check = display->row_stride; |
| |
| if (check >= png_row_stride) |
| { |
| /* Now check for overflow of the image buffer calculation; check for |
| * (size_t) overflow here. This detects issues with the |
| * PNG_IMAGE_BUFFER_SIZE macro. |
| */ |
| if (image->height > PNG_SIZE_MAX/png_row_stride) |
| png_error(image->opaque->png_ptr, "memory image too large"); |
| } |
| |
| else |
| png_error(image->opaque->png_ptr, "supplied row stride too small"); |
| } |
| |
| else |
| png_error(image->opaque->png_ptr, "image row stride too large"); |
| } |
| |
| /* Set the required transforms then write the rows in the correct order. */ |
| if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0) |
| { |
| 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) == 0) |
| 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) == 0) |
| 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) != 0) |
| png_set_swap(png_ptr); |
| } |
| |
| # ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED |
| if ((format & PNG_FORMAT_FLAG_BGR) != 0) |
| { |
| if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0) |
| png_set_bgr(png_ptr); |
| format &= PNG_BIC_MASK(PNG_FORMAT_FLAG_BGR); |
| } |
| # endif |
| |
| # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED |
| if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) |
| { |
| if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0) |
| png_set_swap_alpha(png_ptr); |
| format &= PNG_BIC_MASK(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 != 0 && image->colormap_entries <= 16) |
| png_set_packing(png_ptr); |
| |
| /* That should have handled all (both) the transforms. */ |
| if ((format & PNG_BIC_MASK(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; |
| } |
| |
| /* Select the right compression mode based on the presence or absence of the |
| * 'fast' flag. This will use whatever options are available in the libpng |
| * build. It is always supported. |
| */ |
| png_set_compression(png_ptr, (image->flags & PNG_IMAGE_FLAG_FAST) != 0 ? |
| PNG_COMPRESSION_HIGH_SPEED : PNG_COMPRESSION_HIGH); |
| |
| /* 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 != 0 && alpha != 0 ) || |
| (colormap == 0 && display->convert_to_8bit != 0)) |
| { |
| 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; |
| } |
| |
| |
| static void (PNGCBAPI |
| image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, |
| png_size_t size) |
| { |
| png_image_write_control *display = png_voidcast(png_image_write_control*, |
| png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/); |
| const png_alloc_size_t ob = display->output_bytes; |
| |
| /* Check for overflow; this should never happen: */ |
| if (size <= ((png_alloc_size_t)-1) - ob) |
| { |
| /* I don't think libpng ever does this, but just in case: */ |
| if (size > 0) |
| { |
| if (display->memory_bytes >= ob+size) /* writing */ |
| memcpy(display->memory+ob, data, size); |
| |
| /* Always update the size: */ |
| display->output_bytes = ob+size; |
| } |
| } |
| |
| else |
| png_error(png_ptr, "png_image_write_to_memory: PNG too big"); |
| } |
| |
| static void (PNGCBAPI |
| image_memory_flush)(png_structp png_ptr) |
| { |
| PNG_UNUSED(png_ptr) |
| } |
| |
| static int |
| png_image_write_memory(png_voidp argument) |
| { |
| png_image_write_control *display = png_voidcast(png_image_write_control*, |
| argument); |
| |
| /* The rest of the memory-specific init and write_main in an error protected |
| * environment. This case needs to use callbacks for the write operations |
| * since libpng has no built in support for writing to memory. |
| */ |
| png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/, |
| image_memory_write, image_memory_flush); |
| |
| return png_image_write_main(display); |
| } |
| |
| int PNGAPI |
| png_image_write_to_memory(png_imagep image, void *memory, |
| png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit, |
| const void *buffer, ptrdiff_t row_stride, const void *colormap) |
| { |
| /* Write the image to the given buffer, or count the bytes if it is NULL */ |
| if (image != NULL && image->version == PNG_IMAGE_VERSION) |
| { |
| if (memory_bytes != NULL && buffer != NULL) |
| { |
| /* This is to give the caller an easier error detection in the NULL |
| * case and guard against uninitialized variable problems: |
| */ |
| if (memory == NULL) |
| *memory_bytes = 0; |
| |
| if (png_image_write_init(image) != 0) |
| { |
| png_image_write_control display; |
| int result; |
| |
| 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; |
| display.memory = png_voidcast(png_bytep, memory); |
| display.memory_bytes = *memory_bytes; |
| display.output_bytes = 0; |
| |
| result = png_safe_execute(image, png_image_write_memory, &display); |
| png_image_free(image); |
| |
| /* write_memory returns true even if we ran out of buffer. */ |
| if (result) |
| { |
| /* On out-of-buffer this function returns '0' but still updates |
| * memory_bytes: |
| */ |
| if (memory != NULL && display.output_bytes > *memory_bytes) |
| result = 0; |
| |
| *memory_bytes = display.output_bytes; |
| } |
| |
| return result; |
| } |
| |
| else |
| return 0; |
| } |
| |
| else |
| return png_image_error(image, |
| "png_image_write_to_memory: invalid argument"); |
| } |
| |
| else if (image != NULL) |
| return png_image_error(image, |
| "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION"); |
| |
| else |
| return 0; |
| } |
| |
| #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED |
| int PNGAPI |
| png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit, |
| const void *buffer, ptrdiff_t row_stride, const void *colormap) |
| { |
| /* Write the image to the given (FILE*). */ |
| if (image != NULL && image->version == PNG_IMAGE_VERSION) |
| { |
| if (file != NULL && buffer != NULL) |
| { |
| if (png_image_write_init(image) != 0 && |
| png_image_init_io(image, file) != 0) |
| { |
| png_image_write_control display; |
| int result; |
| |
| 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, ptrdiff_t row_stride, |
| const void *colormap) |
| { |
| /* Write the image to the named file. */ |
| if (image != NULL && image->version == PNG_IMAGE_VERSION) |
| { |
| if (file_name != NULL && buffer != 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) != 0) |
| { |
| 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 /* SIMPLIFIED_WRITE_STDIO */ |
| #endif /* SIMPLIFIED_WRITE */ |
| #endif /* WRITE */ |