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[libpng15] Remove simplified interface

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This commit is contained in:
John Bowler
2011-11-23 15:34:43 -06:00
committed by Glenn Randers-Pehrson
parent 12fb29f951
commit 4491fa237f
35 changed files with 298 additions and 5755 deletions
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562
pngwrite.c
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@@ -12,9 +12,6 @@
*/
#include "pngpriv.h"
#if defined PNG_SIMPLIFIED_WRITE_SUPPORTED && defined PNG_STDIO_SUPPORTED
# include <errno.h>
#endif
#ifdef PNG_WRITE_SUPPORTED
@@ -1655,563 +1652,4 @@ png_write_png(png_structp png_ptr, png_infop info_ptr,
PNG_UNUSED(params)
}
#endif
#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
#ifdef PNG_STDIO_SUPPORTED /* currently required for png_image_write_* */
/* Initialize the write structure - general purpose utility. */
static int
png_image_write_init(png_imagep image)
{
png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
png_safe_error, png_safe_warning);
if (png_ptr != NULL)
{
png_infop info_ptr = png_create_info_struct(png_ptr);
if (info_ptr != NULL)
{
png_controlp control = png_voidcast(png_controlp,
png_malloc_warn(png_ptr, sizeof *control));
if (control != NULL)
{
memset(control, 0, sizeof *control);
control->png_ptr = png_ptr;
control->info_ptr = info_ptr;
control->for_write = 1;
image->opaque = control;
return 1;
}
/* Error clean up */
png_destroy_info_struct(png_ptr, &info_ptr);
}
png_destroy_write_struct(&png_ptr, NULL);
}
return png_image_error(image, "png_image_read: out of memory");
}
/* Arguments to png_image_write_main: */
typedef struct
{
/* Arguments: */
png_imagep image;
png_const_voidp buffer;
png_int_32 row_stride;
int convert_to_8bit;
/* Local variables: */
png_const_voidp first_row;
ptrdiff_t row_bytes;
png_voidp local_row;
} png_image_write_control;
/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
* do any necessary byte swapping. The component order is defined by the
* png_image format value.
*/
static int
png_write_image_16bit(png_voidp argument)
{
png_image_write_control *display = png_voidcast(png_image_write_control*,
argument);
png_imagep image = display->image;
png_structp png_ptr = image->opaque->png_ptr;
png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
display->first_row);
png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
png_uint_16p row_end;
int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
int aindex = 0;
png_uint_32 y = image->height;
if (image->format & PNG_FORMAT_FLAG_ALPHA)
{
if (image->format & PNG_FORMAT_FLAG_AFIRST)
{
aindex = -1;
++input_row; /* To point to the first component */
++output_row;
}
else
aindex = channels;
}
else
png_error(png_ptr, "png_write_image: internal call error");
/* Work out the output row end and count over this, note that the increment
* above to 'row' means that row_end can actually be beyond the end of the
* row; this is correct.
*/
row_end = output_row + image->width * (channels+1);
while (y-- > 0)
{
png_const_uint_16p in_ptr = input_row;
png_uint_16p out_ptr = output_row;
while (out_ptr < row_end)
{
png_uint_16 alpha = in_ptr[aindex];
png_uint_32 reciprocal = 0;
int c;
out_ptr[aindex] = alpha;
/* Calculate a reciprocal. The correct calculation is simply
* component/alpha*65535 << 15. (I.e. 15 bits of precision); this
* allows correct rounding by adding .5 before the shift. 'reciprocal'
* is only initialized when required.
*/
if (alpha > 0 && alpha < 65535)
reciprocal = ((0xffff<<15)+(alpha>>1))/alpha;
c = channels;
do /* always at least one channel */
{
png_uint_16 component = *in_ptr++;
/* The following gives 65535 for an alpha of 0, which is fine,
* otherwise if 0/0 is represented as some other value there is more
* likely to be a discontinuity which will probably damage
* compression when moving from a fully transparent area to a
* nearly transparent one. (The assumption here is that opaque
* areas tend not to be 0 intensity.)
*/
if (component >= alpha)
component = 65535;
/* component<alpha, so component/alpha is less than one and
* component*reciprocal is less than 2^31.
*/
else if (component > 0 && alpha < 65535)
{
png_uint_32 calc = component * reciprocal;
calc += 16384; /* round to nearest */
component = (png_uint_16)(calc >> 15);
}
*out_ptr++ = component;
}
while (--c > 0);
/* Skip to next component (skip the intervening alpha channel) */
++in_ptr;
++out_ptr;
}
png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
input_row += display->row_bytes/(sizeof (png_uint_16));
}
return 1;
}
/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel
* is present it must be removed from the components, the components are then
* written in sRGB encoding. No components are added or removed.
*/
static int
png_write_image_8bit(png_voidp argument)
{
png_image_write_control *display = png_voidcast(png_image_write_control*,
argument);
png_imagep image = display->image;
png_structp png_ptr = image->opaque->png_ptr;
png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
display->first_row);
png_bytep output_row = png_voidcast(png_bytep, display->local_row);
png_uint_32 y = image->height;
int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
if (image->format & PNG_FORMAT_FLAG_ALPHA)
{
png_bytep row_end;
int aindex;
if (image->format & PNG_FORMAT_FLAG_AFIRST)
{
aindex = -1;
++input_row; /* To point to the first component */
++output_row;
}
else
aindex = channels;
/* Use row_end in place of a loop counter: */
row_end = output_row + image->width * (channels+1);
while (y-- > 0)
{
png_const_uint_16p in_ptr = input_row;
png_bytep out_ptr = output_row;
if (aindex != 0) while (out_ptr < row_end) /* Alpha channel case */
{
png_uint_16 alpha = in_ptr[aindex];
png_uint_32 reciprocal = 0;
int c;
/* Scale and write the alpha channel. See pngrtran.c
* png_do_scale_16_to_8 for a discussion of this calculation. The
* code here has machine native values, so use:
*
* (V * 255 + 32895) >> 16
*/
out_ptr[aindex] = (png_byte)((alpha * 255 + 32895) >> 16);
/* Calculate a reciprocal. As above the calculation can be done to
* 15 bits of accuracy, however the output needs to be scaled in the
* range 0..255*65535, so include that scaling here.
*/
if (alpha > 0 && alpha < 65535)
reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha;
c = channels;
do /* always at least one channel */
{
/* Need 32 bit accuracy in the sRGB tables */
png_uint_32 component = *in_ptr++;
/* The following gives 1.0 for an alpha of 0, which is fine,
* otherwise if 0/0 is represented as some other value there is
* more likely to be a discontinuity which will probably damage
* compression when moving from a fully transparent area to a
* nearly transparent one. (The assumption here is that opaque
* areas tend not to be 0 intensity.)
*/
if (component >= alpha)
*out_ptr++ = 255;
/* component<alpha, so component/alpha is less than one and
* component*reciprocal is less than 2^31.
*/
else if (component > 0)
{
if (alpha < 65535)
{
component *= reciprocal;
component += 64; /* round to nearest */
component >>= 7;
}
else
component *= 255;
/* Convert the component to sRGB. */
*out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
}
else
*out_ptr++ = 0;
}
while (--c > 0);
/* Skip to next component (skip the intervening alpha channel) */
++in_ptr;
++out_ptr;
} /* while out_ptr < row_end */
png_write_row(png_ptr, png_voidcast(png_const_bytep,
display->local_row));
input_row += display->row_bytes/(sizeof (png_uint_16));
} /* while y */
}
else
{
/* No alpha channel, so the row_end really is the end of the row and it
* is sufficient to loop over the components one by one.
*/
png_bytep row_end = output_row + image->width * channels;
while (y-- > 0)
{
png_const_uint_16p in_ptr = input_row;
png_bytep out_ptr = output_row;
while (out_ptr < row_end)
{
png_uint_32 component = *in_ptr++;
component *= 255;
*out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
}
png_write_row(png_ptr, output_row);
input_row += display->row_bytes/(sizeof (png_uint_16));
}
}
return 1;
}
static int
png_image_write_main(png_voidp argument)
{
png_image_write_control *display = png_voidcast(png_image_write_control*,
argument);
png_imagep image = display->image;
png_structp png_ptr = image->opaque->png_ptr;
png_infop info_ptr = image->opaque->info_ptr;
png_uint_32 format = image->format;
int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0; /* input */
int alpha = (format & PNG_FORMAT_FLAG_ALPHA) != 0;
int write_16bit = linear && !display->convert_to_8bit;
/* Default the 'row_stride' parameter if required. */
if (display->row_stride == 0)
display->row_stride = PNG_IMAGE_ROW_STRIDE(*image);
/* Set the required transforms then write the rows in the correct order. */
png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
write_16bit ? 16 : 8,
((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
/* Counter-intuitively the data transformations must be called *after*
* png_write_info, not before as in the read code, but the 'set' functions
* must still be called before. Just set the color space information, never
* write an interlaced image.
*/
if (write_16bit)
{
/* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
png_set_cHRM_fixed(png_ptr, info_ptr,
/* color x y */
/* white */ 31270, 32900,
/* red */ 64000, 33000,
/* green */ 30000, 60000,
/* blue */ 15000, 6000
);
}
else if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
/* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
* space must still be gamma encoded.
*/
else
png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
/* Write the file header. */
png_write_info(png_ptr, info_ptr);
/* Now set up the data transformations (*after* the header is written),
* remove the handled transformations from the 'format' flags for checking.
*
* First check for a little endian system if writing 16 bit files.
*/
if (write_16bit)
{
PNG_CONST png_uint_16 le = 0x0001;
if (*(png_const_bytep)&le)
png_set_swap(png_ptr);
}
# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
if (format & PNG_FORMAT_FLAG_BGR)
{
if (format & PNG_FORMAT_FLAG_COLOR)
png_set_bgr(png_ptr);
format &= ~PNG_FORMAT_FLAG_BGR;
}
# endif
# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
if (format & PNG_FORMAT_FLAG_AFIRST)
{
if (format & PNG_FORMAT_FLAG_ALPHA)
png_set_swap_alpha(png_ptr);
format &= ~PNG_FORMAT_FLAG_AFIRST;
}
# endif
/* That should have handled all (both) the transforms. */
if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR |
PNG_FORMAT_FLAG_ALPHA)) != 0)
png_error(png_ptr, "png_write_image: unsupported transformation");
{
png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
ptrdiff_t row_bytes = display->row_stride;
if (linear)
row_bytes *= sizeof (png_uint_16);
if (row_bytes < 0)
row += (image->height-1) * (-row_bytes);
display->first_row = row;
display->row_bytes = row_bytes;
}
/* Check for the cases that currently require a pre-transform on the row
* before it is written. This only applies when the input is 16-bit and
* either there is an alpha channel or it is converted to 8-bit.
*/
if ((linear && alpha) || display->convert_to_8bit)
{
png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
png_get_rowbytes(png_ptr, info_ptr)));
int result;
display->local_row = row;
if (write_16bit)
result = png_safe_execute(image, png_write_image_16bit, display);
else
result = png_safe_execute(image, png_write_image_8bit, display);
display->local_row = NULL;
png_free(png_ptr, row);
/* Skip the 'write_end' on error: */
if (!result)
return 0;
}
/* Otherwise this is the case where the input is in a format currently
* supported by the rest of the libpng write code; call it directly.
*/
else
{
png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
ptrdiff_t row_bytes = display->row_bytes;
png_uint_32 y = image->height;
while (y-- > 0)
{
png_write_row(png_ptr, row);
row += row_bytes;
}
}
png_write_end(png_ptr, info_ptr);
return 1;
}
int PNGAPI
png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
const void *buffer, png_int_32 row_stride)
{
/* Write the image to the given (FILE*). */
if (image != NULL)
{
if (file != NULL)
{
if (png_image_write_init(image))
{
png_image_write_control display;
int result;
/* This is slightly evil, but png_init_io doesn't do anything other
* than this and we haven't changed the standard IO functions so
* this saves a 'safe' function.
*/
image->opaque->png_ptr->io_ptr = file;
memset(&display, 0, sizeof display);
display.image = image;
display.buffer = buffer;
display.row_stride = row_stride;
display.convert_to_8bit = convert_to_8bit;
result = png_safe_execute(image, png_image_write_main, &display);
png_image_free(image);
return result;
}
else
return 0;
}
else
return png_image_error(image,
"png_image_write_to_stdio: invalid argument");
}
else
return 0;
}
int PNGAPI
png_image_write_to_file(png_imagep image, const char *file_name,
int convert_to_8bit, const void *buffer, png_int_32 row_stride)
{
/* Write the image to the named file. */
if (image != NULL)
{
if (file_name != NULL)
{
FILE *fp = fopen(file_name, "wb");
if (fp != NULL)
{
if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
row_stride))
{
int error; /* from fflush/fclose */
/* Make sure the file is flushed correctly. */
if (fflush(fp) == 0 && ferror(fp) == 0)
{
if (fclose(fp) == 0)
return 1;
error = errno; /* from fclose */
}
else
{
error = errno; /* from fflush or ferror */
(void)fclose(fp);
}
(void)remove(file_name);
/* The image has already been cleaned up; this is just used to
* set the error (because the original write succeeded).
*/
return png_image_error(image, strerror(error));
}
else
{
/* Clean up: just the opened file. */
(void)fclose(fp);
(void)remove(file_name);
return 0;
}
}
else
return png_image_error(image, strerror(errno));
}
else
return png_image_error(image,
"png_image_write_to_file: invalid argument");
}
else
return 0;
}
#endif /* PNG_STDIO_SUPPORTED */
#endif /* SIMPLIFIED_WRITE */
#endif /* PNG_WRITE_SUPPORTED */