| |
| /* pngwrite.c - general routines to write a png file |
| |
| libpng 1.0 beta 3 - version 0.89 |
| For conditions of distribution and use, see copyright notice in png.h |
| Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| May 25, 1996 |
| */ |
| |
| /* get internal access to png.h */ |
| #define PNG_INTERNAL |
| #include "png.h" |
| |
| /* 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 encurage you to supply a PNG_INFO_ flag, and check |
| info->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 |
| png_write_info(png_structp png_ptr, png_infop info) |
| { |
| png_write_sig(png_ptr); /* write PNG signature */ |
| /* write IHDR information. */ |
| png_write_IHDR(png_ptr, info->width, info->height, info->bit_depth, |
| info->color_type, info->compression_type, info->filter_type, |
| info->interlace_type); |
| /* the rest of these check to see if the valid field has the appropriate |
| flag set, and if it does, writes the chunk. */ |
| #if defined(PNG_WRITE_gAMA_SUPPORTED) |
| if (info->valid & PNG_INFO_gAMA) |
| png_write_gAMA(png_ptr, info->gamma); |
| #endif |
| #if defined(PNG_WRITE_sBIT_SUPPORTED) |
| if (info->valid & PNG_INFO_sBIT) |
| png_write_sBIT(png_ptr, &(info->sig_bit), info->color_type); |
| #endif |
| #if defined(PNG_WRITE_cHRM_SUPPORTED) |
| if (info->valid & PNG_INFO_cHRM) |
| png_write_cHRM(png_ptr, |
| info->x_white, info->y_white, |
| info->x_red, info->y_red, |
| info->x_green, info->y_green, |
| info->x_blue, info->y_blue); |
| #endif |
| if (info->valid & PNG_INFO_PLTE) |
| png_write_PLTE(png_ptr, info->palette, info->num_palette); |
| else if (info->color_type == PNG_COLOR_TYPE_PALETTE) |
| png_error(png_ptr, "Valid palette required for paletted images\n"); |
| #if defined(PNG_WRITE_tRNS_SUPPORTED) |
| if (info->valid & PNG_INFO_tRNS) |
| png_write_tRNS(png_ptr, info->trans, &(info->trans_values), |
| info->num_trans, info->color_type); |
| #endif |
| #if defined(PNG_WRITE_bKGD_SUPPORTED) |
| if (info->valid & PNG_INFO_bKGD) |
| png_write_bKGD(png_ptr, &(info->background), info->color_type); |
| #endif |
| #if defined(PNG_WRITE_hIST_SUPPORTED) |
| if (info->valid & PNG_INFO_hIST) |
| png_write_hIST(png_ptr, info->hist, info->num_palette); |
| #endif |
| #if defined(PNG_WRITE_pHYs_SUPPORTED) |
| if (info->valid & PNG_INFO_pHYs) |
| png_write_pHYs(png_ptr, info->x_pixels_per_unit, |
| info->y_pixels_per_unit, info->phys_unit_type); |
| #endif |
| #if defined(PNG_WRITE_oFFs_SUPPORTED) |
| if (info->valid & PNG_INFO_oFFs) |
| png_write_oFFs(png_ptr, info->x_offset, info->y_offset, |
| info->offset_unit_type); |
| #endif |
| #if defined(PNG_WRITE_tIME_SUPPORTED) |
| if (info->valid & PNG_INFO_tIME) |
| { |
| png_write_tIME(png_ptr, &(info->mod_time)); |
| png_ptr->flags |= PNG_FLAG_WROTE_tIME; |
| } |
| #endif |
| #if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) |
| /* Check to see if we need to write text chunks */ |
| if (info->num_text) |
| { |
| int i; /* local counter */ |
| |
| /* loop through the text chunks */ |
| for (i = 0; i < info->num_text; i++) |
| { |
| /* if chunk is compressed */ |
| if (info->text[i].compression >= 0) |
| { |
| #if defined(PNG_WRITE_zTXt_SUPPORTED) |
| /* write compressed chunk */ |
| png_write_zTXt(png_ptr, info->text[i].key, |
| info->text[i].text, info->text[i].text_length, |
| info->text[i].compression); |
| #else |
| png_warning(png_ptr, "Unable to write compressed text\n"); |
| #endif |
| } |
| else |
| { |
| #if defined(PNG_WRITE_tEXt_SUPPORTED) |
| /* write uncompressed chunk */ |
| png_write_tEXt(png_ptr, info->text[i].key, |
| info->text[i].text, info->text[i].text_length); |
| #else |
| png_warning(png_ptr, "Unable to write uncompressed text\n"); |
| #endif |
| } |
| } |
| } |
| #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 |
| png_write_end(png_structp png_ptr, png_infop info) |
| { |
| if (!(png_ptr->mode & PNG_HAVE_IDAT)) |
| png_error(png_ptr, "No IDATs written into file"); |
| |
| /* see if user wants us to write information chunks */ |
| if (info) |
| { |
| #if defined(PNG_WRITE_tIME_SUPPORTED) |
| /* check to see if user has supplied a time chunk */ |
| if (info->valid & PNG_INFO_tIME && |
| !(png_ptr->flags & PNG_FLAG_WROTE_tIME)) |
| png_write_tIME(png_ptr, &(info->mod_time)); |
| #endif |
| #if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) |
| /* check to see if we need to write comment chunks */ |
| if (info->num_text) |
| { |
| int i; /* local index variable */ |
| |
| /* loop through comment chunks */ |
| for (i = 0; i < info->num_text; i++) |
| { |
| #if defined(PNG_WRITE_zTXt_SUPPORTED) |
| /* check to see if comment is to be compressed */ |
| if (info->text[i].compression >= 0) |
| { |
| /* write compressed chunk */ |
| png_write_zTXt(png_ptr, info->text[i].key, |
| info->text[i].text, info->text[i].text_length, |
| info->text[i].compression); |
| } |
| #if defined(PNG_WRITE_tEXt_SUPPORTED) |
| else |
| #endif |
| #endif |
| #if defined(PNG_WRITE_tEXt_SUPPORTED) |
| { |
| /* write uncompressed chunk */ |
| png_write_tEXt(png_ptr, info->text[i].key, |
| info->text[i].text, info->text[i].text_length); |
| } |
| #endif |
| } |
| } |
| #endif |
| } |
| |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| |
| /* write end of png file */ |
| png_write_IEND(png_ptr); |
| } |
| |
| #if defined(PNG_WRITE_tIME_SUPPORTED) |
| void |
| png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime) |
| { |
| 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 |
| png_convert_from_time_t(png_timep ptime, time_t ttime) |
| { |
| struct tm *tbuf; |
| |
| tbuf = gmtime(&ttime); |
| png_convert_from_struct_tm(ptime, tbuf); |
| } |
| #endif |
| |
| /* initialize png structure, and allocate any memory needed */ |
| png_structp |
| png_create_write_struct(png_const_charp user_png_ver, voidp error_ptr, |
| png_error_ptr warn_fn, png_error_ptr error_fn) |
| { |
| png_structp png_ptr; |
| |
| if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL) |
| { |
| return (png_structp)NULL; |
| } |
| |
| if (setjmp(png_ptr->jmpbuf)) |
| { |
| png_large_free(png_ptr, png_ptr->zbuf); |
| png_free(png_ptr, png_ptr->zstream); |
| png_destroy_struct(png_ptr); |
| return (png_structp)NULL; |
| } |
| |
| png_set_error_fn(png_ptr, error_ptr, warn_fn, error_fn); |
| |
| if (user_png_ver == NULL || strcmp(user_png_ver, png_libpng_ver)) |
| { |
| if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0]) |
| { |
| png_error(png_ptr, "Incompatible libpng versions"); |
| } |
| else |
| { |
| png_warning(png_ptr, "Different libpng versions"); |
| } |
| } |
| |
| /* initialize zbuf - compression buffer */ |
| png_ptr->zbuf_size = PNG_ZBUF_SIZE; |
| png_ptr->zbuf = png_large_malloc(png_ptr, png_ptr->zbuf_size); |
| |
| png_set_write_fn(png_ptr, NULL, NULL, NULL); |
| |
| png_ptr->do_free |= PNG_FREE_STRUCT; |
| |
| return (png_ptr); |
| } |
| |
| |
| /* initialize png structure, and allocate any memory needed */ |
| void |
| png_write_init(png_structp png_ptr) |
| { |
| jmp_buf tmp_jmp; /* to save current jump buffer */ |
| |
| /* save jump buffer and error functions */ |
| png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); |
| |
| /* reset all variables to 0 */ |
| png_memset(png_ptr, 0, sizeof (png_struct)); |
| |
| /* restore jump buffer */ |
| png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); |
| |
| /* initialize zbuf - compression buffer */ |
| png_ptr->zbuf_size = PNG_ZBUF_SIZE; |
| png_ptr->zbuf = png_large_malloc(png_ptr, png_ptr->zbuf_size); |
| png_set_write_fn(png_ptr, NULL, NULL, NULL); |
| } |
| |
| /* 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 |
| png_write_rows(png_structp png_ptr, png_bytepp row, |
| png_uint_32 num_rows) |
| { |
| png_uint_32 i; /* row counter */ |
| png_bytepp rp; /* row pointer */ |
| |
| /* 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 |
| png_write_image(png_structp png_ptr, png_bytepp image) |
| { |
| png_uint_32 i; /* row index */ |
| int pass, num_pass; /* pass variables */ |
| png_bytepp rp; /* points to current row */ |
| |
| /* intialize interlace handling. If image is not interlaced, |
| this will set pass to 1 */ |
| num_pass = png_set_interlace_handling(png_ptr); |
| /* 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); |
| } |
| } |
| } |
| |
| /* called by user to write a row of image data */ |
| void |
| png_write_row(png_structp png_ptr, png_bytep row) |
| { |
| /* initialize transformations and other stuff if first time */ |
| if (png_ptr->row_number == 0 && png_ptr->pass == 0) |
| { |
| png_write_start_row(png_ptr); |
| } |
| |
| #if defined(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 & 7) |
| { |
| png_write_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 1: |
| if ((png_ptr->row_number & 7) || png_ptr->width < 5) |
| { |
| png_write_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 2: |
| if ((png_ptr->row_number & 7) != 4) |
| { |
| png_write_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 3: |
| if ((png_ptr->row_number & 3) || png_ptr->width < 3) |
| { |
| png_write_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 4: |
| if ((png_ptr->row_number & 3) != 2) |
| { |
| png_write_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 5: |
| if ((png_ptr->row_number & 1) || png_ptr->width < 2) |
| { |
| png_write_finish_row(png_ptr); |
| return; |
| } |
| break; |
| case 6: |
| if (!(png_ptr->row_number & 1)) |
| { |
| png_write_finish_row(png_ptr); |
| return; |
| } |
| break; |
| } |
| } |
| #endif |
| |
| /* set up row info for transformations */ |
| png_ptr->row_info.color_type = png_ptr->color_type; |
| png_ptr->row_info.width = png_ptr->usr_width; |
| png_ptr->row_info.channels = png_ptr->usr_channels; |
| png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth; |
| png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * |
| png_ptr->row_info.channels); |
| png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * |
| (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); |
| |
| /* copy users row into buffer, leaving room for filter byte */ |
| png_memcpy(png_ptr->row_buf + 1, row, (png_size_t)png_ptr->row_info.rowbytes); |
| |
| #if defined(PNG_WRITE_INTERLACING_SUPPORTED) |
| /* handle interlacing */ |
| if (png_ptr->interlaced && png_ptr->pass < 6 && |
| (png_ptr->transformations & PNG_INTERLACE)) |
| { |
| png_do_write_interlace(&(png_ptr->row_info), |
| png_ptr->row_buf + 1, png_ptr->pass); |
| /* this should always get caught above, but still ... */ |
| if (!(png_ptr->row_info.width)) |
| { |
| png_write_finish_row(png_ptr); |
| return; |
| } |
| } |
| #endif |
| |
| /* handle other transformations */ |
| if (png_ptr->transformations) |
| png_do_write_transformations(png_ptr); |
| |
| /* find a filter if necessary, filter the row and write it out */ |
| png_write_find_filter(png_ptr, &(png_ptr->row_info)); |
| } |
| |
| #if defined(PNG_WRITE_FLUSH_SUPPORTED) |
| /* Set the automatic flush interval or 0 to turn flushing off */ |
| void |
| png_set_flush(png_structp png_ptr, int nrows) |
| { |
| png_ptr->flush_dist = (nrows < 0 ? 0 : nrows); |
| } |
| |
| /* flush the current output buffers now */ |
| void |
| png_write_flush(png_structp png_ptr) |
| { |
| int wrote_IDAT; |
| |
| /* We have already written out all of the data */ |
| if (png_ptr->row_number >= png_ptr->num_rows) |
| return; |
| |
| do |
| { |
| int ret; |
| |
| /* compress the data */ |
| ret = deflate(png_ptr->zstream, Z_SYNC_FLUSH); |
| wrote_IDAT = 0; |
| |
| /* check for compression errors */ |
| if (ret != Z_OK) |
| { |
| if (png_ptr->zstream->msg) |
| png_error(png_ptr, png_ptr->zstream->msg); |
| else |
| png_error(png_ptr, "zlib error"); |
| } |
| |
| if (!png_ptr->zstream->avail_out) |
| { |
| /* write the IDAT and reset the zlib output buffer */ |
| png_write_IDAT(png_ptr, png_ptr->zbuf, |
| png_ptr->zbuf_size); |
| png_ptr->zstream->next_out = png_ptr->zbuf; |
| png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size; |
| wrote_IDAT = 1; |
| } |
| } while(wrote_IDAT == 1); |
| |
| /* If there is any data left to be output, write it into a new IDAT */ |
| if (png_ptr->zbuf_size != png_ptr->zstream->avail_out) |
| { |
| /* write the IDAT and reset the zlib output buffer */ |
| png_write_IDAT(png_ptr, png_ptr->zbuf, |
| png_ptr->zbuf_size - png_ptr->zstream->avail_out); |
| png_ptr->zstream->next_out = png_ptr->zbuf; |
| png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size; |
| } |
| png_ptr->flush_rows = 0; |
| png_flush(png_ptr); |
| } |
| #endif /* PNG_WRITE_FLUSH_SUPPORTED */ |
| |
| /* free all memory used by the write */ |
| void |
| png_destroy_write_struct(png_structpp png_ptr, png_infopp info_ptr) |
| { |
| if (info_ptr && *info_ptr) |
| { |
| png_destroy_struct((voidp)*info_ptr); |
| *info_ptr = (png_infop)NULL; |
| } |
| |
| if (png_ptr && *png_ptr) |
| { |
| png_write_destroy(*png_ptr); |
| png_destroy_struct((voidp)*png_ptr); |
| *png_ptr = (png_structp)NULL; |
| } |
| } |
| |
| |
| /* free any memory used in png struct (old) */ |
| void |
| png_write_destroy(png_structp png_ptr) |
| { |
| jmp_buf tmp_jmp; /* save jump buffer */ |
| png_error_ptr error_fn; |
| png_error_ptr warning_fn; |
| png_voidp error_ptr; |
| |
| /* free any memory zlib uses */ |
| deflateEnd(png_ptr->zstream); |
| png_free(png_ptr, png_ptr->zstream); |
| |
| /* free our memory. png_free checks NULL for us. */ |
| png_large_free(png_ptr, png_ptr->zbuf); |
| png_large_free(png_ptr, png_ptr->row_buf); |
| png_large_free(png_ptr, png_ptr->prev_row); |
| png_large_free(png_ptr, png_ptr->sub_row); |
| png_large_free(png_ptr, png_ptr->up_row); |
| png_large_free(png_ptr, png_ptr->avg_row); |
| png_large_free(png_ptr, png_ptr->paeth_row); |
| |
| /* reset structure */ |
| png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); |
| |
| error_fn = png_ptr->error_fn; |
| warning_fn = png_ptr->warning_fn; |
| error_ptr = png_ptr->error_ptr; |
| |
| png_memset(png_ptr, 0, sizeof (png_struct)); |
| |
| png_ptr->error_fn = error_fn; |
| png_ptr->warning_fn = warning_fn; |
| png_ptr->error_ptr = error_ptr; |
| |
| png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); |
| } |
| |
| /* Allow the application to select one or more filters to use */ |
| void |
| png_set_filter(png_structp png_ptr, int method, int filters) |
| { |
| /* We allow 'method' only for future expansion of the base filter method */ |
| if (method == 0) |
| { |
| switch (filters & (PNG_ALL_FILTERS | 0x07)) |
| { |
| case 5: |
| case 6: |
| case 7: png_warning(png_ptr, "Unknown custom row filter for method 0"); |
| case 0: png_ptr->do_filter = PNG_FILTER_NONE; break; |
| case 1: png_ptr->do_filter = PNG_FILTER_SUB; break; |
| case 2: png_ptr->do_filter = PNG_FILTER_UP; break; |
| case 3: png_ptr->do_filter = PNG_FILTER_AVG; break; |
| case 4: png_ptr->do_filter = PNG_FILTER_PAETH; break; |
| default: png_ptr->do_filter = (png_byte)filters; break; |
| } |
| |
| /* If we have allocated the row_buf, then we should have also allocated |
| * all of the filter buffers that have been selected. |
| */ |
| if (png_ptr->row_buf) |
| { |
| if (png_ptr->do_filter & PNG_FILTER_SUB && !(png_ptr->sub_row)) |
| { |
| png_ptr->sub_row = (png_bytep )png_large_malloc(png_ptr, |
| png_ptr->rowbytes + 1); |
| png_ptr->sub_row[0] = 1; /* Set the row filter type */ |
| } |
| |
| if (png_ptr->do_filter & PNG_FILTER_UP && !(png_ptr->up_row)) |
| { |
| if (!(png_ptr->prev_row)) |
| { |
| png_warning(png_ptr, "Can't to add up filter after starting"); |
| png_ptr->do_filter &= ~PNG_FILTER_UP; |
| } |
| else |
| { |
| png_ptr->up_row = (png_bytep )png_large_malloc(png_ptr, |
| png_ptr->rowbytes + 1); |
| png_ptr->up_row[0] = 2; /* Set the row filter type */ |
| } |
| } |
| |
| if (png_ptr->do_filter & PNG_FILTER_AVG && !(png_ptr->avg_row)) |
| { |
| if (!(png_ptr->prev_row)) |
| { |
| png_warning(png_ptr, "Can't add average filter after starting"); |
| png_ptr->do_filter &= ~PNG_FILTER_AVG; |
| } |
| else |
| { |
| png_ptr->up_row = (png_bytep )png_large_malloc(png_ptr, |
| png_ptr->rowbytes + 1); |
| png_ptr->up_row[0] = 3; /* Set the row filter type */ |
| } |
| } |
| |
| if (png_ptr->do_filter & PNG_FILTER_PAETH && !(png_ptr->paeth_row)) |
| { |
| if (!(png_ptr->prev_row)) |
| { |
| png_warning(png_ptr, "Can't add Paeth filter after starting"); |
| png_ptr->do_filter &= ~PNG_FILTER_PAETH; |
| } |
| else |
| { |
| png_ptr->paeth_row = (png_bytep )png_large_malloc(png_ptr, |
| png_ptr->rowbytes + 1); |
| png_ptr->paeth_row[0] = 4; /* Set the row filter type */ |
| } |
| } |
| |
| if (png_ptr->do_filter == PNG_NO_FILTERS) |
| png_ptr->do_filter = PNG_FILTER_NONE; |
| } |
| } |
| else |
| png_error(png_ptr, "Unknown custom filter method"); |
| } |
| |
| void |
| png_set_compression_level(png_structp png_ptr, int level) |
| { |
| png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL; |
| png_ptr->zlib_level = level; |
| } |
| |
| void |
| png_set_compression_mem_level(png_structp png_ptr, int mem_level) |
| { |
| png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL; |
| png_ptr->zlib_mem_level = mem_level; |
| } |
| |
| void |
| png_set_compression_strategy(png_structp png_ptr, int strategy) |
| { |
| png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; |
| png_ptr->zlib_strategy = strategy; |
| } |
| |
| void |
| png_set_compression_window_bits(png_structp png_ptr, int window_bits) |
| { |
| if (window_bits > 15) |
| png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); |
| png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS; |
| png_ptr->zlib_window_bits = window_bits; |
| } |
| |
| void |
| png_set_compression_method(png_structp png_ptr, int method) |
| { |
| if (method != 8) |
| png_warning(png_ptr, "Only compression method 8 is supported by PNG"); |
| png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD; |
| png_ptr->zlib_method = method; |
| } |
| |