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Imported from libpng-0.97.tar

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This commit is contained in:
Glenn Randers-Pehrson
1998-01-01 07:13:13 -06:00
parent 47a0c422ca
commit b6ce43d6ff
24 changed files with 1297 additions and 763 deletions
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100
pngread.c
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@@ -1,19 +1,22 @@
/* pngread.c - read a PNG file
libpng 1.0 beta 6 - version 0.96
For conditions of distribution and use, see copyright notice in png.h
Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
Copyright (c) 1996, 1997 Andreas Dilger
May 12, 1997
*/
*
* libpng 1.00.97
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger
* May 28, 1997
*
* This file contains routines that an application calls directly to
* read a PNG file or stream.
*/
#define PNG_INTERNAL
#include "png.h"
/* Create a PNG structure for reading, and allocate any memory needed. */
png_structp
png_create_read_struct(png_charp user_png_ver, png_voidp error_ptr,
png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn)
{
png_structp png_ptr;
@@ -76,7 +79,6 @@ png_create_read_struct(png_charp user_png_ver, png_voidp error_ptr,
return (png_ptr);
}
/* Initialize PNG structure for reading, and allocate any memory needed.
This interface is depreciated in favour of the png_create_read_struct(),
and it will eventually disappear. */
@@ -215,6 +217,10 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
png_handle_tEXt(png_ptr, info_ptr, length);
@@ -247,10 +253,11 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
png_read_transform_info(png_ptr, info_ptr);
}
/* initialize palette, background, etc, after transformations
are set, but before any reading takes place. This allows
the user to obtail a gamma corrected palette, for example.
If the user doesn't call this, we will do it ourselves. */
/* Initialize palette, background, etc, after transformations
* are set, but before any reading takes place. This allows
* the user to obtail a gamma corrected palette, for example.
* If the user doesn't call this, we will do it ourselves.
*/
void
png_start_read_image(png_structp png_ptr)
{
@@ -439,23 +446,26 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
}
/* Read one or more rows of image data. If the image is interlaced,
and png_set_interlace_handling() has been called, the rows need to
to contain the contents of the rows from the previous pass. If
the image has alpha or transparency, and png_handle_alpha() has been
called, the rows contents must be initialized to the contents of the
screen. "row" holds the actual image, and pixels are placed in it
as they arrive. If the image is displayed after each pass, it will
appear to "sparkle" in. "display_row" can be used to display a
"chunky" progressive image, with finer detail added as it becomes
available. If you do not want this "chunky" display, you may pass
NULL for display_row. If you do not want the sparkle display, and
you have not called png_handle_alpha(), you may pass NULL for rows.
If you have called png_handle_alpha(), and the image has either an
alpha channel or a transparency chunk, you must provide a buffer for
rows. In this case, you do not have to provide a display_row buffer
also, but you may. If the image is not interlaced, or if you have
not called png_set_interlace_handling(), the display_row buffer will
be ignored, so pass NULL to it. */
* and png_set_interlace_handling() has been called, the rows need to
* contain the contents of the rows from the previous pass. If the
* image has alpha or transparency, and png_handle_alpha() has been
* called, the rows contents must be initialized to the contents of the
* screen.
*
* "row" holds the actual image, and pixels are placed in it
* as they arrive. If the image is displayed after each pass, it will
* appear to "sparkle" in. "display_row" can be used to display a
* "chunky" progressive image, with finer detail added as it becomes
* available. If you do not want this "chunky" display, you may pass
* NULL for display_row. If you do not want the sparkle display, and
* you have not called png_handle_alpha(), you may pass NULL for rows.
* If you have called png_handle_alpha(), and the image has either an
* alpha channel or a transparency chunk, you must provide a buffer for
* rows. In this case, you do not have to provide a display_row buffer
* also, but you may. If the image is not interlaced, or if you have
* not called png_set_interlace_handling(), the display_row buffer will
* be ignored, so pass NULL to it.
*/
void
png_read_rows(png_structp png_ptr, png_bytepp row,
@@ -491,14 +501,15 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
}
/* Read the entire image. If the image has an alpha channel or a tRNS
chunk, and you have called png_handle_alpha(), you will need to
initialize the image to the current image that PNG will be overlaying.
We set the num_rows again here, in case it was incorrectly set in
png_read_start_row() by a call to png_read_update_info() or
png_start_read_image() if png_set_interlace_handling() wasn't called
prior to either of these functions like it should have been. You can
only call this function once. If you desire to have an image for
each pass of a interlaced image, use png_read_rows() instead */
* chunk, and you have called png_handle_alpha(), you will need to
* initialize the image to the current image that PNG will be overlaying.
* We set the num_rows again here, in case it was incorrectly set in
* png_read_start_row() by a call to png_read_update_info() or
* png_start_read_image() if png_set_interlace_handling() wasn't called
* prior to either of these functions like it should have been. You can
* only call this function once. If you desire to have an image for
* each pass of a interlaced image, use png_read_rows() instead.
*/
void
png_read_image(png_structp png_ptr, png_bytepp image)
{
@@ -524,8 +535,9 @@ png_read_image(png_structp png_ptr, png_bytepp image)
}
/* Read the end of the PNG file. Will not read past the end of the
file, will verify the end is accurate, and will read any comments
or time information at the end of the file, if info is not NULL. */
* file, will verify the end is accurate, and will read any comments
* or time information at the end of the file, if info is not NULL.
*/
void
png_read_end(png_structp png_ptr, png_infop info_ptr)
{
@@ -594,6 +606,10 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
png_handle_tEXt(png_ptr, info_ptr, length);
@@ -659,7 +675,6 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
void
png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
{
int i;
jmp_buf tmp_jmp;
png_error_ptr error_fn;
png_error_ptr warning_fn;
@@ -700,6 +715,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
#if defined(PNG_READ_GAMMA_SUPPORTED)
if (png_ptr->gamma_16_table != NULL)
{
int i;
for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++)
{
png_free(png_ptr, png_ptr->gamma_16_table[i]);
@@ -710,6 +726,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
png_free(png_ptr, png_ptr->gamma_16_table);
if (png_ptr->gamma_16_from_1 != NULL)
{
int i;
for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++)
{
png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
@@ -718,6 +735,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
png_free(png_ptr, png_ptr->gamma_16_from_1);
if (png_ptr->gamma_16_to_1 != NULL)
{
int i;
for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++)
{
png_free(png_ptr, png_ptr->gamma_16_to_1[i]);