[devel] Trivial changes to commentary in pngwrite.c
This commit is contained in:
Glenn Randers-Pehrson
parent
ec323d3036
commit
3dfe93776f
71
pngwrite.c
71
pngwrite.c
@ -1,7 +1,7 @@
|
||||
|
||||
/* pngwrite.c - general routines to write a PNG file
|
||||
*
|
||||
* Last changed in libpng 1.4.0 [August 21, 2009]
|
||||
* Last changed in libpng 1.4.0 [August 22, 2009]
|
||||
* Copyright (c) 1998-2009 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.)
|
||||
@ -11,7 +11,7 @@
|
||||
* and license in png.h
|
||||
*/
|
||||
|
||||
/* get internal access to png.h */
|
||||
/* Get internal access to png.h */
|
||||
#include "png.h"
|
||||
#ifdef PNG_WRITE_SUPPORTED
|
||||
#include "pngpriv.h"
|
||||
@ -34,7 +34,8 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
|
||||
return;
|
||||
if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
|
||||
{
|
||||
png_write_sig(png_ptr); /* write PNG signature */
|
||||
/* Write PNG signature */
|
||||
png_write_sig(png_ptr);
|
||||
#if defined(PNG_MNG_FEATURES_SUPPORTED)
|
||||
if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
|
||||
{
|
||||
@ -42,7 +43,7 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
|
||||
png_ptr->mng_features_permitted=0;
|
||||
}
|
||||
#endif
|
||||
/* write IHDR information. */
|
||||
/* Write IHDR information. */
|
||||
png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
|
||||
info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
|
||||
info_ptr->filter_type,
|
||||
@ -152,7 +153,7 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
|
||||
if (info_ptr->valid & PNG_INFO_tRNS)
|
||||
{
|
||||
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
|
||||
/* invert the alpha channel (in tRNS) */
|
||||
/* Invert the alpha channel (in tRNS) */
|
||||
if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
|
||||
info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
||||
{
|
||||
@ -229,11 +230,11 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
|
||||
{
|
||||
png_debug2(2, "Writing header text chunk %d, type %d", i,
|
||||
info_ptr->text[i].compression);
|
||||
/* an internationalized chunk? */
|
||||
/* An internationalized chunk? */
|
||||
if (info_ptr->text[i].compression > 0)
|
||||
{
|
||||
#if defined(PNG_WRITE_iTXt_SUPPORTED)
|
||||
/* write international chunk */
|
||||
/* Write international chunk */
|
||||
png_write_iTXt(png_ptr,
|
||||
info_ptr->text[i].compression,
|
||||
info_ptr->text[i].key,
|
||||
@ -250,7 +251,7 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
|
||||
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
|
||||
{
|
||||
#if defined(PNG_WRITE_zTXt_SUPPORTED)
|
||||
/* write compressed chunk */
|
||||
/* Write compressed chunk */
|
||||
png_write_zTXt(png_ptr, info_ptr->text[i].key,
|
||||
info_ptr->text[i].text, 0,
|
||||
info_ptr->text[i].compression);
|
||||
@ -263,7 +264,7 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
|
||||
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
|
||||
{
|
||||
#if defined(PNG_WRITE_tEXt_SUPPORTED)
|
||||
/* write uncompressed chunk */
|
||||
/* Write uncompressed chunk */
|
||||
png_write_tEXt(png_ptr, info_ptr->text[i].key,
|
||||
info_ptr->text[i].text,
|
||||
0);
|
||||
@ -317,29 +318,29 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
|
||||
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 */
|
||||
/* See if user wants us to write information chunks */
|
||||
if (info_ptr != NULL)
|
||||
{
|
||||
#if defined(PNG_WRITE_TEXT_SUPPORTED)
|
||||
int i; /* local index variable */
|
||||
#endif
|
||||
#if defined(PNG_WRITE_tIME_SUPPORTED)
|
||||
/* check to see if user has supplied a time chunk */
|
||||
/* Check to see if user has supplied a time chunk */
|
||||
if ((info_ptr->valid & PNG_INFO_tIME) &&
|
||||
!(png_ptr->mode & PNG_WROTE_tIME))
|
||||
png_write_tIME(png_ptr, &(info_ptr->mod_time));
|
||||
#endif
|
||||
#if defined(PNG_WRITE_TEXT_SUPPORTED)
|
||||
/* loop through comment chunks */
|
||||
/* Loop through comment chunks */
|
||||
for (i = 0; i < info_ptr->num_text; i++)
|
||||
{
|
||||
png_debug2(2, "Writing trailer text chunk %d, type %d", i,
|
||||
info_ptr->text[i].compression);
|
||||
/* an internationalized chunk? */
|
||||
/* An internationalized chunk? */
|
||||
if (info_ptr->text[i].compression > 0)
|
||||
{
|
||||
#if defined(PNG_WRITE_iTXt_SUPPORTED)
|
||||
/* write international chunk */
|
||||
/* Write international chunk */
|
||||
png_write_iTXt(png_ptr,
|
||||
info_ptr->text[i].compression,
|
||||
info_ptr->text[i].key,
|
||||
@ -355,7 +356,7 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
|
||||
else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
|
||||
{
|
||||
#if defined(PNG_WRITE_zTXt_SUPPORTED)
|
||||
/* write compressed chunk */
|
||||
/* Write compressed chunk */
|
||||
png_write_zTXt(png_ptr, info_ptr->text[i].key,
|
||||
info_ptr->text[i].text, 0,
|
||||
info_ptr->text[i].compression);
|
||||
@ -368,7 +369,7 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
|
||||
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
|
||||
{
|
||||
#if defined(PNG_WRITE_tEXt_SUPPORTED)
|
||||
/* write uncompressed chunk */
|
||||
/* Write uncompressed chunk */
|
||||
png_write_tEXt(png_ptr, info_ptr->text[i].key,
|
||||
info_ptr->text[i].text, 0);
|
||||
#else
|
||||
@ -406,7 +407,7 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
|
||||
|
||||
png_ptr->mode |= PNG_AFTER_IDAT;
|
||||
|
||||
/* write end of PNG file */
|
||||
/* 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
|
||||
@ -487,7 +488,7 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
|
||||
if (png_ptr == NULL)
|
||||
return (NULL);
|
||||
|
||||
/* added at libpng-1.2.6 */
|
||||
/* Added at libpng-1.2.6 */
|
||||
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
|
||||
png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
|
||||
png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
|
||||
@ -554,7 +555,7 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
|
||||
}
|
||||
}
|
||||
|
||||
/* initialize zbuf - compression buffer */
|
||||
/* Initialize zbuf - compression buffer */
|
||||
png_ptr->zbuf_size = PNG_ZBUF_SIZE;
|
||||
if (!png_cleanup_needed)
|
||||
{
|
||||
@ -605,7 +606,7 @@ png_write_rows(png_structp png_ptr, png_bytepp row,
|
||||
if (png_ptr == NULL)
|
||||
return;
|
||||
|
||||
/* loop through the rows */
|
||||
/* Loop through the rows */
|
||||
for (i = 0, rp = row; i < num_rows; i++, rp++)
|
||||
{
|
||||
png_write_row(png_ptr, *rp);
|
||||
@ -635,10 +636,10 @@ png_write_image(png_structp png_ptr, png_bytepp image)
|
||||
#else
|
||||
num_pass = 1;
|
||||
#endif
|
||||
/* loop through passes */
|
||||
/* Loop through passes */
|
||||
for (pass = 0; pass < num_pass; pass++)
|
||||
{
|
||||
/* loop through image */
|
||||
/* Loop through image */
|
||||
for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
|
||||
{
|
||||
png_write_row(png_ptr, *rp);
|
||||
@ -646,7 +647,7 @@ png_write_image(png_structp png_ptr, png_bytepp image)
|
||||
}
|
||||
}
|
||||
|
||||
/* called by user to write a row of image data */
|
||||
/* Called by user to write a row of image data */
|
||||
void PNGAPI
|
||||
png_write_row(png_structp png_ptr, png_bytep row)
|
||||
{
|
||||
@ -656,15 +657,15 @@ png_write_row(png_structp png_ptr, png_bytep row)
|
||||
png_debug2(1, "in png_write_row (row %ld, pass %d)",
|
||||
png_ptr->row_number, png_ptr->pass);
|
||||
|
||||
/* initialize transformations and other stuff if first time */
|
||||
/* Initialize transformations and other stuff if first time */
|
||||
if (png_ptr->row_number == 0 && png_ptr->pass == 0)
|
||||
{
|
||||
/* make sure we wrote the header info */
|
||||
/* Make sure we wrote the header info */
|
||||
if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
|
||||
png_error(png_ptr,
|
||||
"png_write_info was never called before png_write_row");
|
||||
|
||||
/* check for transforms that have been set but were defined out */
|
||||
/* Check for transforms that have been set but were defined out */
|
||||
#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
|
||||
if (png_ptr->transformations & PNG_INVERT_MONO)
|
||||
png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
|
||||
@ -698,7 +699,7 @@ png_write_row(png_structp png_ptr, png_bytep row)
|
||||
}
|
||||
|
||||
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
|
||||
/* if interlaced and not interested in row, return */
|
||||
/* If interlaced and not interested in row, return */
|
||||
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
|
||||
{
|
||||
switch (png_ptr->pass)
|
||||
@ -756,7 +757,7 @@ png_write_row(png_structp png_ptr, png_bytep row)
|
||||
}
|
||||
#endif
|
||||
|
||||
/* set up row info for transformations */
|
||||
/* 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;
|
||||
@ -834,7 +835,7 @@ png_set_flush(png_structp png_ptr, int nrows)
|
||||
png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
|
||||
}
|
||||
|
||||
/* flush the current output buffers now */
|
||||
/* Flush the current output buffers now */
|
||||
void PNGAPI
|
||||
png_write_flush(png_structp png_ptr)
|
||||
{
|
||||
@ -852,11 +853,11 @@ png_write_flush(png_structp png_ptr)
|
||||
{
|
||||
int ret;
|
||||
|
||||
/* compress the data */
|
||||
/* Compress the data */
|
||||
ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
|
||||
wrote_IDAT = 0;
|
||||
|
||||
/* check for compression errors */
|
||||
/* Check for compression errors */
|
||||
if (ret != Z_OK)
|
||||
{
|
||||
if (png_ptr->zstream.msg != NULL)
|
||||
@ -867,7 +868,7 @@ png_write_flush(png_structp png_ptr)
|
||||
|
||||
if (!(png_ptr->zstream.avail_out))
|
||||
{
|
||||
/* write the IDAT and reset the zlib output buffer */
|
||||
/* 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;
|
||||
@ -879,7 +880,7 @@ png_write_flush(png_structp png_ptr)
|
||||
/* 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 */
|
||||
/* 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;
|
||||
@ -1312,7 +1313,7 @@ png_set_compression_window_bits(png_structp png_ptr, int window_bits)
|
||||
else if (window_bits < 8)
|
||||
png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
|
||||
#ifndef WBITS_8_OK
|
||||
/* avoid libpng bug with 256-byte windows */
|
||||
/* Avoid libpng bug with 256-byte windows */
|
||||
if (window_bits == 8)
|
||||
{
|
||||
png_warning(png_ptr, "Compression window is being reset to 512");
|
||||
@ -1446,7 +1447,7 @@ png_write_png(png_structp png_ptr, png_infop info_ptr,
|
||||
/* It is REQUIRED to call this to finish writing the rest of the file */
|
||||
png_write_end(png_ptr, info_ptr);
|
||||
|
||||
transforms = transforms; /* quiet compiler warnings */
|
||||
transforms = transforms; /* Quiet compiler warnings */
|
||||
params = params;
|
||||
}
|
||||
#endif
|
||||
|
||||
Loading…
Reference in New Issue
Block a user