| |
| /* pngwrite.c - general routines to write a png file |
| |
| libpng 1.0 beta 1 - version 0.71 |
| For conditions of distribution and use, see copyright notice in png.h |
| Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc. |
| June 26, 1995 |
| */ |
| |
| /* 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_struct *png_ptr, png_info *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 (info->valid & PNG_INFO_gAMA) |
| png_write_gAMA(png_ptr, info->gamma); |
| if (info->valid & PNG_INFO_sBIT) |
| png_write_sBIT(png_ptr, &(info->sig_bit), info->color_type); |
| 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); |
| if (info->valid & PNG_INFO_PLTE) |
| png_write_PLTE(png_ptr, info->palette, info->num_palette); |
| if (info->valid & PNG_INFO_tRNS) |
| png_write_tRNS(png_ptr, info->trans, &(info->trans_values), |
| info->num_trans, info->color_type); |
| if (info->valid & PNG_INFO_bKGD) |
| png_write_bKGD(png_ptr, &(info->background), info->color_type); |
| if (info->valid & PNG_INFO_hIST) |
| png_write_hIST(png_ptr, info->hist, info->num_palette); |
| 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); |
| if (info->valid & PNG_INFO_oFFs) |
| png_write_oFFs(png_ptr, info->x_offset, info->y_offset, |
| info->offset_unit_type); |
| if (info->valid & PNG_INFO_tIME) |
| png_write_tIME(png_ptr, &(info->mod_time)); |
| /* 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) |
| { |
| /* 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 |
| { |
| /* write uncompressed chunk */ |
| png_write_tEXt(png_ptr, info->text[i].key, |
| info->text[i].text, info->text[i].text_length); |
| } |
| } |
| } |
| } |
| |
| /* 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_struct *png_ptr, png_info *info) |
| { |
| /* see if user wants us to write information chunks */ |
| if (info) |
| { |
| /* check to see if user has supplied a time chunk */ |
| if (info->valid & PNG_INFO_tIME) |
| png_write_tIME(png_ptr, &(info->mod_time)); |
| /* 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++) |
| { |
| /* 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); |
| } |
| else |
| { |
| /* write uncompressed chunk */ |
| png_write_tEXt(png_ptr, info->text[i].key, |
| info->text[i].text, info->text[i].text_length); |
| } |
| } |
| } |
| } |
| /* write end of png file */ |
| png_write_IEND(png_ptr); |
| } |
| |
| /* initialize the info structure */ |
| void |
| png_info_init(png_info *info) |
| { |
| /* set everything to 0 */ |
| memset(info, 0, sizeof (png_info)); |
| } |
| |
| void |
| png_convert_from_struct_tm(png_time *ptime, struct tm *ttime) |
| { |
| ptime->year = 1900 + ttime->tm_year; |
| ptime->month = ttime->tm_mon + 1; |
| ptime->day = ttime->tm_mday; |
| ptime->hour = ttime->tm_hour; |
| ptime->minute = ttime->tm_min; |
| ptime->second = ttime->tm_sec; |
| } |
| |
| void |
| png_convert_from_time_t(png_time *ptime, time_t ttime) |
| { |
| struct tm *tbuf; |
| |
| tbuf = gmtime(&ttime); |
| png_convert_from_struct_tm(ptime, tbuf); |
| } |
| |
| /* initialize png structure, and allocate any memory needed */ |
| void |
| png_write_init(png_struct *png_ptr) |
| { |
| jmp_buf tmp_jmp; /* to save current jump buffer */ |
| |
| /* save jump buffer */ |
| memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); |
| /* reset all variables to 0 */ |
| memset(png_ptr, 0, sizeof (png_struct)); |
| /* restore jump buffer */ |
| 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); |
| /* initialize zlib */ |
| png_ptr->zstream = &(png_ptr->zstream_struct); |
| png_ptr->zstream->zalloc = png_zalloc; |
| png_ptr->zstream->zfree = png_zfree; |
| png_ptr->zstream->opaque = (voidp)png_ptr; |
| deflateInit(png_ptr->zstream, Z_BEST_COMPRESSION); |
| png_ptr->zstream->next_out = png_ptr->zbuf; |
| png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size; |
| } |
| |
| /* 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_struct *png_ptr, png_byte **row, |
| png_uint_32 num_rows) |
| { |
| png_uint_32 i; /* row counter */ |
| png_byte **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_struct *png_ptr, png_byte **image) |
| { |
| png_uint_32 i; /* row index */ |
| int pass, num_pass; /* pass variables */ |
| png_byte **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); |
| } |
| } |
| } |
| |
| /* write a row of image data */ |
| void |
| png_write_row(png_struct *png_ptr, png_byte *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 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; |
| } |
| } |
| |
| /* 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_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 */ |
| memcpy(png_ptr->row_buf + 1, row, (png_size_t)png_ptr->row_info.rowbytes); |
| |
| /* 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; |
| } |
| } |
| |
| /* handle other transformations */ |
| if (png_ptr->transformations) |
| png_do_write_transformations(png_ptr); |
| |
| /* filter rows that have been proved to help */ |
| if (png_ptr->bit_depth >= 8 && png_ptr->color_type != 3) |
| { |
| /* save row to previous row */ |
| memcpy(png_ptr->save_row, png_ptr->row_buf, |
| (png_size_t)png_ptr->row_info.rowbytes + 1); |
| |
| /* filter row */ |
| png_write_filter_row(&(png_ptr->row_info), png_ptr->row_buf, |
| png_ptr->prev_row); |
| |
| /* trade saved pointer and prev pointer so next row references are correctly */ |
| { /* scope limiter */ |
| png_byte *tptr; |
| |
| tptr = png_ptr->prev_row; |
| png_ptr->prev_row = png_ptr->save_row; |
| png_ptr->save_row = tptr; |
| } |
| } |
| else |
| /* set filter row to "none" */ |
| png_ptr->row_buf[0] = 0; |
| |
| /* set up the zlib input buffer */ |
| png_ptr->zstream->next_in = png_ptr->row_buf; |
| png_ptr->zstream->avail_in = (uInt)png_ptr->row_info.rowbytes + 1; |
| |
| #ifdef zlibinout |
| /* temp zlib problem */ |
| { |
| extern FILE *fpzlibin; |
| |
| fwrite(png_ptr->row_buf, 1, png_ptr->zstream->avail_in, fpzlibin); |
| } |
| /* end temp zlib problem */ |
| #endif |
| |
| /* repeat until we have compressed all the data */ |
| do |
| { |
| int ret; /* return of zlib */ |
| |
| /* compress the data */ |
| ret = deflate(png_ptr->zstream, Z_NO_FLUSH); |
| /* 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"); |
| } |
| |
| /* see if it is time to write another IDAT */ |
| 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; |
| } |
| /* repeat until all data has been compressed */ |
| } while (png_ptr->zstream->avail_in); |
| |
| /* finish row - updates counters and flushes zlib if last row */ |
| png_write_finish_row(png_ptr); |
| } |
| |
| /* free any memory used in png struct */ |
| void |
| png_write_destroy(png_struct *png_ptr) |
| { |
| jmp_buf tmp_jmp; /* save jump buffer */ |
| |
| /* free any memory zlib uses */ |
| deflateEnd(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->save_row); |
| /* reset structure */ |
| memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); |
| memset(png_ptr, 0, sizeof (png_struct)); |
| memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); |
| } |
| |
