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[devel] Revert png_get_current_row_number() to previous (1.5.2beta01) behavior.

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This commit is contained in:
John Bowler 2011-02-16 06:13:46 -06:00 committed by Glenn Randers-Pehrson
parent 8ea598b1d1
commit 9616ad9828
3 changed files with 30 additions and 20 deletions
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28
png.h
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@ -808,6 +808,17 @@ typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
/* The following callback receives png_uint_32 row_number, int pass for the
* png_bytep data of the row. When transforming an interlaced image the
* row number is the row number within the sub-image of the interlace pass, so
* the value will increase to the height of the sub-image (not the full image)
* then reset to 0 for the next pass.
*
* Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
* find the output pixel (x,y) given an interlaced sub-image pixel
* (row,col,pass). (See below for these macros.)
*/
typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
png_uint_32, int));
#endif
@ -1481,13 +1492,13 @@ PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
/* Return information about the row currently being processed. Note that these
* APIs do not fail but will return unexpected results if called outside a user
* transform callback. Also note that when transforming an interlaced image the
* row number is still the row in the final, de-interlaced, image but the row
* only contains the data of the current pass - consult png_row_info for the
* actual width of the row!
* row number is the row number within the sub-image of the interlace pass, so
* the value will increase to the height of the sub-image (not the full image)
* then reset to 0 for the next pass.
*
* In contrast the row numbers passed to the progressive reader and sequential
* reader callbacks are actually the rows in the input data - so the row in the
* interlaced pass for an interlaced image.
* Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
* find the output pixel (x,y) given an interlaced sub-image pixel
* (row,col,pass). (See below for these macros.)
*/
PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp));
PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp));
@ -2152,8 +2163,9 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
-1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
/* For the progressive reader it is necessary to find the row in the output
* image given a row in an interlaced image, so two more macros:
/* For the reader row callbacks (both progressive and sequential) it is
* necessary to find the row in the output image given a row in an interlaced
* image, so two more macros:
*/
#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
(((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))

11
pngtrans.c
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@ -652,16 +652,11 @@ png_get_user_transform_ptr(png_const_structp png_ptr)
png_uint_32 PNGAPI
png_get_current_row_number(png_const_structp png_ptr)
{
/* This API returns the row in output, not the input row: */
/* See the comments in png.h - this is the sub-image row when reading and
* interlaced image.
*/
if (png_ptr != NULL)
{
if (png_ptr->interlaced == PNG_INTERLACE_NONE)
return png_ptr->row_number;
else if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
return PNG_ROW_FROM_PASS_ROW(png_ptr->row_number, png_ptr->pass);
/* Else something bad is happening: */
}
return PNG_UINT_32_MAX; /* help the app not to fail silently */
}

9
pngvalid.c
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@ -3073,11 +3073,14 @@ progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass)
*/
if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7)
{
if (pass != png_get_current_pass_number(pp))
png_error(pp, "png_get_current_pass_number is broken");
y = PNG_ROW_FROM_PASS_ROW(y, pass);
/* Use this opportunity to validate the png 'current' APIs: */
if (y != png_get_current_row_number(pp))
png_error(pp, "png_get_current_row_number is broken");
if (pass != png_get_current_pass_number(pp))
png_error(pp, "png_get_current_pass_number is broken");
y = PNG_ROW_FROM_PASS_ROW(y, pass);
}
/* Validate this just in case. */