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[libpng16] Implement previously untested libpng transforms in pngvalid.c

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John Bowler 2014-12-29 16:31:58 -06:00 committed by Glenn Randers-Pehrson
parent cde8cd6b30
commit b6788ccaff
3 changed files with 656 additions and 80 deletions
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1
ANNOUNCE
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@ -32,6 +32,7 @@ Version 1.6.17beta01 [December 29, 2014]
png_read_row to skip the unnecessary row de-interlace stuff.
Added testing of png_set_packing() to pngvalid.c
Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
Implement previously untested cases of libpng transforms in pngvalid.c
Fixed byte order in 2-byte filler, in png_do_read_filler().
Send comments/corrections/commendations to png-mng-implement at lists.sf.net

1
CHANGES
View File

@ -5132,6 +5132,7 @@ Version 1.6.17beta01 [December 29, 2014]
png_read_row to skip the unnecessary row de-interlace stuff.
Added testing of png_set_packing() to pngvalid.c
Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
Implement previously untested cases of libpng transforms in pngvalid.c
Fixed byte order in 2-byte filler, in png_do_read_filler().
Send comments/corrections/commendations to png-mng-implement at lists.sf.net

734
contrib/libtests/pngvalid.c
View File

@ -278,7 +278,8 @@ random_mod(unsigned int max)
return x % max; /* 0 .. max-1 */
}
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
#if (defined PNG_READ_RGB_TO_GRAY_SUPPORTED) ||\
(defined PNG_READ_FILLER_SUPPORTED)
static int
random_choice(void)
{
@ -303,7 +304,7 @@ random_choice(void)
#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U))
#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU))
#define PALETTE_FROM_ID(id) (((id) >> 8) & 0x1f)
#define INTERLACE_FROM_ID(id) ((int)(((id) >> 13) & 0x3))
#define INTERLACE_FROM_ID(id) ((png_byte)(((id) >> 13) & 0x3))
#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1))
#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff)
#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff)
@ -440,7 +441,7 @@ next_format(png_bytep colour_type, png_bytep bit_depth,
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
static unsigned int
sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth,
png_uint_32 x, unsigned int sample_index)
png_uint_32 x, unsigned int sample_index, int swap16, int littleendian)
{
png_uint_32 bit_index, result;
@ -469,11 +470,23 @@ sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth,
return result;
else if (bit_depth > 8)
return (result << 8) + *++row;
{
if (swap16)
return (*++row << 8) + result;
else
return (result << 8) + *++row;
}
/* Less than 8 bits per sample. */
/* Less than 8 bits per sample. By default PNG has the big end of
* the egg on the left of the screen, but if littleendian is set
* then the big end is on the right.
*/
bit_index &= 7;
return (result >> (8-bit_index-bit_depth)) & ((1U<<bit_depth)-1);
if (!littleendian)
bit_index = 8-bit_index-bit_depth;
return (result >> bit_index) & ((1U<<bit_depth)-1);
}
#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
@ -1565,7 +1578,7 @@ set_store_for_write(png_store *ps, png_infopp ppi,
else
# endif
ps->pwrite = png_create_write_struct(png_get_libpng_ver(NULL),
ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING,
ps, store_error, store_warning);
png_set_write_fn(ps->pwrite, ps, store_write, store_flush);
@ -3172,10 +3185,10 @@ init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette,
for (; i<256; ++i)
tRNS[i] = 24;
# ifdef PNG_WRITE_tRNS_SUPPORTED
# ifdef PNG_WRITE_tRNS_SUPPORTED
if (j > 0)
png_set_tRNS(pp, pi, tRNS, j, 0/*color*/);
# endif
# endif
}
}
@ -4263,7 +4276,8 @@ typedef struct standard_display
png_byte green_sBIT;
png_byte blue_sBIT;
png_byte alpha_sBIT;
int interlace_type;
png_byte interlace_type;
png_byte filler; /* Output has a filler */
png_uint_32 id; /* Calculated file ID */
png_uint_32 w; /* Width of image */
png_uint_32 h; /* Height of image */
@ -4650,8 +4664,16 @@ standard_info_part2(standard_display *dp, png_const_structp pp,
png_const_infop pi, int nImages)
{
/* Record cbRow now that it can be found. */
dp->pixel_size = bit_size(pp, png_get_color_type(pp, pi),
png_get_bit_depth(pp, pi));
{
png_byte ct = png_get_color_type(pp, pi);
png_byte bd = png_get_bit_depth(pp, pi);
if (bd >= 8 && (ct == PNG_COLOR_TYPE_RGB || ct == PNG_COLOR_TYPE_GRAY) &&
dp->filler)
ct |= 4; /* handle filler as faked alpha channel */
dp->pixel_size = bit_size(pp, ct, bd);
}
dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size;
dp->cbRow = png_get_rowbytes(pp, pi);
@ -5291,10 +5313,17 @@ typedef struct image_pixel
*/
unsigned int red, green, blue, alpha; /* For non-palette images. */
unsigned int palette_index; /* For a palette image. */
png_byte colour_type; /* As in the spec. */
png_byte bit_depth; /* Defines bit size in row */
png_byte sample_depth; /* Scale of samples */
int have_tRNS; /* tRNS chunk may need processing */
png_byte colour_type; /* As in the spec. */
png_byte bit_depth; /* Defines bit size in row */
png_byte sample_depth; /* Scale of samples */
unsigned int have_tRNS :1; /* tRNS chunk may need processing */
unsigned int swap_rgb :1; /* RGB swapped to BGR */
unsigned int alpha_first :1; /* Alpha at start, not end */
unsigned int alpha_inverted :1; /* Alpha channel inverted */
unsigned int mono_inverted :1; /* Gray channel inverted */
unsigned int swap16 :1; /* Byte swap 16-bit components */
unsigned int littleendian :1; /* High bits on right */
unsigned int sig_bits :1; /* Pixel shifted (sig bits only) */
/* For checking the code calculates double precision floating point values
* along with an error value, accumulated from the transforms. Because an
@ -5302,6 +5331,9 @@ typedef struct image_pixel
* up to just less than +/-1 in the scaled value) the *lowest* sBIT for each
* channel is stored. This sBIT value is folded in to the stored error value
* at the end of the application of the transforms to the pixel.
*
* If sig_bits is set above the red, green, blue and alpha values have been
* scaled so they only contain the significant bits of the component values.
*/
double redf, greenf, bluef, alphaf;
double rede, greene, bluee, alphae;
@ -5310,26 +5342,27 @@ typedef struct image_pixel
/* Shared utility function, see below. */
static void
image_pixel_setf(image_pixel *this, unsigned int max)
image_pixel_setf(image_pixel *this, unsigned int rMax, unsigned int gMax,
unsigned int bMax, unsigned int aMax)
{
this->redf = this->red / (double)max;
this->greenf = this->green / (double)max;
this->bluef = this->blue / (double)max;
this->alphaf = this->alpha / (double)max;
this->redf = this->red / (double)rMax;
this->greenf = this->green / (double)gMax;
this->bluef = this->blue / (double)bMax;
this->alphaf = this->alpha / (double)aMax;
if (this->red < max)
if (this->red < rMax)
this->rede = this->redf * DBL_EPSILON;
else
this->rede = 0;
if (this->green < max)
if (this->green < gMax)
this->greene = this->greenf * DBL_EPSILON;
else
this->greene = 0;
if (this->blue < max)
if (this->blue < bMax)
this->bluee = this->bluef * DBL_EPSILON;
else
this->bluee = 0;
if (this->alpha < max)
if (this->alpha < aMax)
this->alphae = this->alphaf * DBL_EPSILON;
else
this->alphae = 0;
@ -5341,18 +5374,22 @@ image_pixel_setf(image_pixel *this, unsigned int max)
*/
static void
image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
png_byte bit_depth, png_uint_32 x, store_palette palette)
png_byte bit_depth, png_uint_32 x, store_palette palette,
PNG_CONST image_pixel *format /*from pngvalid transform of input*/)
{
PNG_CONST png_byte sample_depth = (png_byte)(colour_type ==
PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth);
PNG_CONST unsigned int max = (1U<<sample_depth)-1;
PNG_CONST int swap16 = (format != 0 && format->swap16);
PNG_CONST int littleendian = (format != 0 && format->littleendian);
PNG_CONST int sig_bits = (format != 0 && format->sig_bits);
/* Initially just set everything to the same number and the alpha to opaque.
* Note that this currently assumes a simple palette where entry x has colour
* rgb(x,x,x)!
*/
this->palette_index = this->red = this->green = this->blue =
sample(row, colour_type, bit_depth, x, 0);
sample(row, colour_type, bit_depth, x, 0, swap16, littleendian);
this->alpha = max;
this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT =
sample_depth;
@ -5376,21 +5413,52 @@ image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
{
unsigned int i = 0;
if ((colour_type & 4) != 0 && format != 0 && format->alpha_first)
{
this->alpha = this->red;
/* This handles the gray case for 'AG' pixels */
this->palette_index = this->red = this->green = this->blue =
sample(row, colour_type, bit_depth, x, 1, swap16, littleendian);
i = 1;
}
if (colour_type & 2)
{
this->green = sample(row, colour_type, bit_depth, x, 1);
this->blue = sample(row, colour_type, bit_depth, x, 2);
i = 2;
/* Green is second for both BGR and RGB: */
this->green = sample(row, colour_type, bit_depth, x, ++i, swap16,
littleendian);
if (format != 0 && format->swap_rgb) /* BGR */
this->red = sample(row, colour_type, bit_depth, x, ++i, swap16,
littleendian);
else
this->blue = sample(row, colour_type, bit_depth, x, ++i, swap16,
littleendian);
}
else /* grayscale */ if (format != 0 && format->mono_inverted)
this->red = this->green = this->blue = this->red ^ max;
if ((colour_type & 4) != 0) /* alpha */
{
if (format == 0 || !format->alpha_first)
this->alpha = sample(row, colour_type, bit_depth, x, ++i, swap16,
littleendian);
if (format != 0 && format->alpha_inverted)
this->alpha ^= max;
}
if (colour_type & 4)
this->alpha = sample(row, colour_type, bit_depth, x, ++i);
}
/* Calculate the scaled values, these are simply the values divided by
* 'max' and the error is initialized to the double precision epsilon value
* from the header file.
*/
image_pixel_setf(this, max);
image_pixel_setf(this,
sig_bits ? (1U << format->red_sBIT)-1 : max,
sig_bits ? (1U << format->green_sBIT)-1 : max,
sig_bits ? (1U << format->blue_sBIT)-1 : max,
sig_bits ? (1U << format->alpha_sBIT)-1 : max);
/* Store the input information for use in the transforms - these will
* modify the information.
@ -5399,6 +5467,13 @@ image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
this->bit_depth = bit_depth;
this->sample_depth = sample_depth;
this->have_tRNS = 0;
this->swap_rgb = 0;
this->alpha_first = 0;
this->alpha_inverted = 0;
this->mono_inverted = 0;
this->swap16 = 0;
this->littleendian = 0;
this->sig_bits = 0;
}
/* Convert a palette image to an rgb image. This necessarily converts the tRNS
@ -5636,6 +5711,7 @@ image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that,
png_const_structp pp, PNG_CONST transform_display *display)
{
PNG_CONST unsigned int scale = (1U<<that->sample_depth)-1;
PNG_CONST int sig_bits = that->sig_bits;
UNUSED(this)
UNUSED(pp)
@ -5650,6 +5726,13 @@ image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that,
*/
that->red = sample_scale(that->redf, scale);
/* This is a bit bogus; really the above calculation should use the red_sBIT
* value, not sample_depth, but because libpng does png_set_shift by just
* shifting the bits we get errors if we don't do it the same way.
*/
if (sig_bits && that->red_sBIT < that->sample_depth)
that->red >>= that->sample_depth - that->red_sBIT;
/* The error value is increased, at the end, according to the lowest sBIT
* value seen. Common sense tells us that the intermediate integer
* representations are no more accurate than +/- 0.5 in the integral values,
@ -5665,7 +5748,13 @@ image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that,
if (that->colour_type & PNG_COLOR_MASK_COLOR)
{
that->green = sample_scale(that->greenf, scale);
if (sig_bits && that->green_sBIT < that->sample_depth)
that->green >>= that->sample_depth - that->green_sBIT;
that->blue = sample_scale(that->bluef, scale);
if (sig_bits && that->blue_sBIT < that->sample_depth)
that->blue >>= that->sample_depth - that->blue_sBIT;
that->greene += 1./(2*((1U<<that->green_sBIT)-1));
that->bluee += 1./(2*((1U<<that->blue_sBIT)-1));
}
@ -5685,9 +5774,12 @@ image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that,
else
{
that->alpha = scale; /* opaque */
that->alpha = 1; /* Override this. */
that->alphaf = 1; /* Override this. */
that->alphae = 0; /* It's exact ;-) */
}
if (sig_bits && that->alpha_sBIT < that->sample_depth)
that->alpha >>= that->sample_depth - that->alpha_sBIT;
}
/* Static 'end' structure: */
@ -5753,6 +5845,13 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
dp->output_colour_type = png_get_color_type(pp, pi);
dp->output_bit_depth = png_get_bit_depth(pp, pi);
/* If png_set_filler is in action then fake the output color type to include
* an alpha channel where appropriate.
*/
if (dp->output_bit_depth >= 8 && (dp->output_colour_type == PNG_COLOR_TYPE_RGB ||
dp->output_colour_type == PNG_COLOR_TYPE_GRAY) && dp->this.filler)
dp->output_colour_type |= 4;
/* Validate the combination of colour type and bit depth that we are getting
* out of libpng; the semantics of something not in the PNG spec are, at
* best, unclear.
@ -5803,7 +5902,7 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
/* Don't need sBIT here, but it must be set to non-zero to avoid
* arithmetic overflows.
*/
test_pixel.have_tRNS = dp->this.is_transparent;
test_pixel.have_tRNS = dp->this.is_transparent != 0;
test_pixel.red_sBIT = test_pixel.green_sBIT = test_pixel.blue_sBIT =
test_pixel.alpha_sBIT = test_pixel.sample_depth;
@ -6015,13 +6114,14 @@ transform_image_validate(transform_display *dp, png_const_structp pp,
unsigned int r, g, b, a;
/* Find out what we think the pixel should be: */
image_pixel_init(&in_pixel, std, in_ct, in_bd, x, dp->this.palette);
image_pixel_init(&in_pixel, std, in_ct, in_bd, x, dp->this.palette,
NULL);
in_pixel.red_sBIT = red_sBIT;
in_pixel.green_sBIT = green_sBIT;
in_pixel.blue_sBIT = blue_sBIT;
in_pixel.alpha_sBIT = alpha_sBIT;
in_pixel.have_tRNS = have_tRNS;
in_pixel.have_tRNS = have_tRNS != 0;
/* For error detection, below. */
r = in_pixel.red;
@ -6029,12 +6129,18 @@ transform_image_validate(transform_display *dp, png_const_structp pp,
b = in_pixel.blue;
a = in_pixel.alpha;
/* This applies the transforms to the input date, including output
* format operations which must be used when reading the output
* pixel that libpng produces.
*/
dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp);
/* Read the output pixel and compare it to what we got, we don't
* use the error field here, so no need to update sBIT.
* use the error field here, so no need to update sBIT. in_pixel
* says whether we expect libpng to change the output format.
*/
image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette);
image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette,
&in_pixel);
/* We don't expect changes to the index here even if the bit depth is
* changed.
@ -6815,14 +6921,14 @@ image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this,
* conversion adds another +/-2 in the 16-bit case and
* +/-(1<<(15-PNG_MAX_GAMMA_8)) in the 8-bit case.
*/
that->pm->limit +=
# if PNG_MAX_GAMMA_8 < 14
pow((that->this.bit_depth == 16 ?
8. : 6. + (1<<(15-PNG_MAX_GAMMA_8)))/65535, data.gamma);
# else
pow((that->this.bit_depth == 16 ?
8. : 8. + (1<<(15-PNG_MAX_GAMMA_8)))/65535, data.gamma);
# endif
that->pm->limit += pow(
# if PNG_MAX_GAMMA_8 < 14
(that->this.bit_depth == 16 ? 8. :
6. + (1<<(15-PNG_MAX_GAMMA_8)))
# else
8.
# endif
/65535, data.gamma);
}
else
@ -6834,18 +6940,18 @@ image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this,
* When DIGITIZE is set because a pre-1.7 version of libpng is being
* tested allow a bigger slack.
*
* NOTE: this magic number was determined by experiment to be 1.1 (when
* using fixed point arithmetic). There's no great merit to the value
* below, however it only affects the limit used for checking for
* internal calculation errors, not the actual limit imposed by
* pngvalid on the output errors.
* NOTE: this magic number was determined by experiment to be 1.25.
* There's no great merit to the value below, however it only affects
* the limit used for checking for internal calculation errors, not
* the actual limit imposed by pngvalid on the output errors.
*/
that->pm->limit +=
that->pm->limit += pow(
# if DIGITIZE
pow(1.1 /255, data.gamma);
1.25
# else
pow(1.0 /255, data.gamma);
1.0
# endif
/255, data.gamma);
}
}
@ -7328,7 +7434,7 @@ image_transform_png_set_background_set(PNG_CONST image_transform *this,
}
image_pixel_init(&data, random_bytes, colour_type,
bit_depth, 0/*x*/, 0/*unused: palette*/);
bit_depth, 0/*x*/, 0/*unused: palette*/, NULL/*format*/);
/* Extract the background colour from this image_pixel, but make sure the
* unused fields of 'back' are garbage.
@ -7434,22 +7540,329 @@ IT(background);
* right answer.
*/
/* png_set_invert_alpha */
/*NOTE: TBD NYI */
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
/* Invert the alpha channel
*
* png_set_invert_alpha(png_structrp png_ptr)
*/
static void
image_transform_png_set_invert_alpha_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
png_set_invert_alpha(pp);
this->next->set(this->next, that, pp, pi);
}
static void
image_transform_png_set_invert_alpha_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
if (that->colour_type & 4)
that->alpha_inverted = 1;
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_invert_alpha_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
UNUSED(bit_depth)
this->next = *that;
*that = this;
/* Only has an effect on pixels with alpha: */
return (colour_type & 4) != 0;
}
IT(invert_alpha);
#undef PT
#define PT ITSTRUCT(invert_alpha)
#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */
/* png_set_bgr */
/*NOTE: TBD NYI */
#ifdef PNG_READ_BGR_SUPPORTED
/* Swap R,G,B channels to order B,G,R.
*
* png_set_bgr(png_structrp png_ptr)
*
* This only has an effect on RGB and RGBA pixels.
*/
static void
image_transform_png_set_bgr_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
png_set_bgr(pp);
this->next->set(this->next, that, pp, pi);
}
static void
image_transform_png_set_bgr_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
if (that->colour_type == PNG_COLOR_TYPE_RGB ||
that->colour_type == PNG_COLOR_TYPE_RGBA)
that->swap_rgb = 1;
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_bgr_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
UNUSED(bit_depth)
this->next = *that;
*that = this;
return colour_type == PNG_COLOR_TYPE_RGB ||
colour_type == PNG_COLOR_TYPE_RGBA;
}
IT(bgr);
#undef PT
#define PT ITSTRUCT(bgr)
#endif /* PNG_READ_BGR_SUPPORTED */
/* png_set_swap_alpha */
/*NOTE: TBD NYI */
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
/* Put the alpha channel first.
*
* png_set_swap_alpha(png_structrp png_ptr)
*
* This only has an effect on GA and RGBA pixels.
*/
static void
image_transform_png_set_swap_alpha_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
png_set_swap_alpha(pp);
this->next->set(this->next, that, pp, pi);
}
static void
image_transform_png_set_swap_alpha_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
if (that->colour_type == PNG_COLOR_TYPE_GA ||
that->colour_type == PNG_COLOR_TYPE_RGBA)
that->alpha_first = 1;
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_swap_alpha_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
UNUSED(bit_depth)
this->next = *that;
*that = this;
return colour_type == PNG_COLOR_TYPE_GA ||
colour_type == PNG_COLOR_TYPE_RGBA;
}
IT(swap_alpha);
#undef PT
#define PT ITSTRUCT(swap_alpha)
#endif /* PNG_READ_SWAP_ALPHA_SUPPORTED */
/* png_set_swap */
/*NOTE: TBD NYI */
#ifdef PNG_READ_SWAP_SUPPORTED
/* Byte swap 16-bit components.
*
* png_set_swap(png_structrp png_ptr)
*/
static void
image_transform_png_set_swap_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
png_set_swap(pp);
this->next->set(this->next, that, pp, pi);
}
/* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); */
/*NOTE: TBD NYI */
static void
image_transform_png_set_swap_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
if (that->bit_depth == 16)
that->swap16 = 1;
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_swap_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
UNUSED(colour_type)
this->next = *that;
*that = this;
return bit_depth == 16;
}
IT(swap);
#undef PT
#define PT ITSTRUCT(swap)
#endif /* PNG_READ_SWAP_SUPPORTED */
#ifdef PNG_READ_FILLER_SUPPORTED
/* Add a filler byte to 8-bit Gray or 24-bit RGB images.
*
* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags));
*
* Flags:
*
* PNG_FILLER_BEFORE
* PNG_FILLER_AFTER
*/
#define data ITDATA(filler)
static struct
{
png_uint_32 filler;
int flags;
} data;
static void
image_transform_png_set_filler_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
/* Need a random choice for 'before' and 'after' as well as for the
* filler. The 'filler' value has all 32 bits set, but only bit_depth
* will be used. At this point we don't know bit_depth.
*/
RANDOMIZE(data.filler);
data.flags = random_choice();
png_set_filler(pp, data.filler, data.flags);
/* The standard display handling stuff also needs to know that
* there is a filler, so set that here.
*/
that->this.filler = 1;
this->next->set(this->next, that, pp, pi);
}
static void
image_transform_png_set_filler_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
if (that->bit_depth >= 8 &&
(that->colour_type == PNG_COLOR_TYPE_RGB ||
that->colour_type == PNG_COLOR_TYPE_GRAY))
{
PNG_CONST unsigned int max = (1U << that->bit_depth)-1;
that->alpha = data.filler & max;
that->alphaf = ((double)that->alpha) / max;
that->alphae = 0;
/* The filler has been stored in the alpha channel, we must record
* that this has been done for the checking later on, the color
* type is faked to have an alpha channel, but libpng won't report
* this; the app has to know the extra channel is there and this
* was recording in standard_display::filler above.
*/
that->colour_type |= 4; /* alpha added */
that->alpha_first = data.flags == PNG_FILLER_BEFORE;
}
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_filler_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
this->next = *that;
*that = this;
return bit_depth >= 8 && (colour_type == PNG_COLOR_TYPE_RGB ||
colour_type == PNG_COLOR_TYPE_GRAY);
}
#undef data
IT(filler);
#undef PT
#define PT ITSTRUCT(filler)
/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */
/*NOTE: TBD NYI */
/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
#define data ITDATA(add_alpha)
static struct
{
png_uint_32 filler;
int flags;
} data;
static void
image_transform_png_set_add_alpha_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
/* Need a random choice for 'before' and 'after' as well as for the
* filler. The 'filler' value has all 32 bits set, but only bit_depth
* will be used. At this point we don't know bit_depth.
*/
RANDOMIZE(data.filler);
data.flags = random_choice();
png_set_add_alpha(pp, data.filler, data.flags);
this->next->set(this->next, that, pp, pi);
}
static void
image_transform_png_set_add_alpha_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
if (that->bit_depth >= 8 &&
(that->colour_type == PNG_COLOR_TYPE_RGB ||
that->colour_type == PNG_COLOR_TYPE_GRAY))
{
PNG_CONST unsigned int max = (1U << that->bit_depth)-1;
that->alpha = data.filler & max;
that->alphaf = ((double)that->alpha) / max;
that->alphae = 0;
that->colour_type |= 4; /* alpha added */
that->alpha_first = data.flags == PNG_FILLER_BEFORE;
}
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_add_alpha_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
this->next = *that;
*that = this;
return bit_depth >= 8 && (colour_type == PNG_COLOR_TYPE_RGB ||
colour_type == PNG_COLOR_TYPE_GRAY);
}
#undef data
IT(add_alpha);
#undef PT
#define PT ITSTRUCT(add_alpha)
#endif /* PNG_READ_FILLER_SUPPORTED */
/* png_set_packing */
#ifdef PNG_READ_PACK_SUPPORTED
@ -7504,13 +7917,174 @@ IT(packing);
#endif /* PNG_READ_PACK_SUPPORTED */
/* png_set_packswap */
/*NOTE: TBD NYI */
#ifdef PNG_READ_PACKSWAP_SUPPORTED
/* Swap pixels packed into bytes; reverses the order on screen so that
* the high order bits correspond to the rightmost pixels.
*
* png_set_packswap(png_structrp png_ptr)
*/
static void
image_transform_png_set_packswap_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
png_set_packswap(pp);
this->next->set(this->next, that, pp, pi);
}
static void
image_transform_png_set_packswap_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
if (that->bit_depth < 8)
that->littleendian = 1;
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_packswap_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
UNUSED(colour_type)
this->next = *that;
*that = this;
return bit_depth < 8;
}
IT(packswap);
#undef PT
#define PT ITSTRUCT(packswap)
#endif /* PNG_READ_PACKSWAP_SUPPORTED */
/* png_set_invert_mono */
/*NOTE: TBD NYI */
#ifdef PNG_READ_INVERT_MONO_SUPPORTED
/* Invert the gray channel
*
* png_set_invert_mono(png_structrp png_ptr)
*/
static void
image_transform_png_set_invert_mono_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
png_set_invert_mono(pp);
this->next->set(this->next, that, pp, pi);
}
/* png_set_shift(png_structp, png_const_color_8p true_bits) */
/*NOTE: TBD NYI */
static void
image_transform_png_set_invert_mono_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
if (that->colour_type & 4)
that->mono_inverted = 1;
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_invert_mono_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
UNUSED(bit_depth)
this->next = *that;
*that = this;
/* Only has an effect on pixels with no colour: */
return (colour_type & 2) == 0;
}
IT(invert_mono);
#undef PT
#define PT ITSTRUCT(invert_mono)
#endif /* PNG_READ_INVERT_MONO_SUPPORTED */
#ifdef PNG_READ_SHIFT_SUPPORTED
/* png_set_shift(png_structp, png_const_color_8p true_bits)
*
* The output pixels will be shifted by the given true_bits
* values.
*/
#define data ITDATA(shift)
static png_color_8 data;
static void
image_transform_png_set_shift_set(PNG_CONST image_transform *this,
transform_display *that, png_structp pp, png_infop pi)
{
/* Get a random set of shifts. The shifts need to do something
* to test the transform, so they are limited to the bit depth
* of the input image. Notice that in the following the 'gray'
* field is randomized independently. This acts as a check that
* libpng does use the correct field.
*/
PNG_CONST unsigned int depth = that->this.bit_depth;
data.red = (png_byte)/*SAFE*/(random_mod(depth)+1);
data.green = (png_byte)/*SAFE*/(random_mod(depth)+1);
data.blue = (png_byte)/*SAFE*/(random_mod(depth)+1);
data.gray = (png_byte)/*SAFE*/(random_mod(depth)+1);
data.alpha = (png_byte)/*SAFE*/(random_mod(depth)+1);
png_set_shift(pp, &data);
this->next->set(this->next, that, pp, pi);
}
static void
image_transform_png_set_shift_mod(PNG_CONST image_transform *this,
image_pixel *that, png_const_structp pp,
PNG_CONST transform_display *display)
{
/* Copy the correct values into the sBIT fields, libpng does not do
* anything to palette data:
*/
if (that->colour_type != PNG_COLOR_TYPE_PALETTE)
{
that->sig_bits = 1;
/* The sBIT fields are reset to the values previously sent to
* png_set_shift according to the colour type.
* does.
*/
if (that->colour_type & 2) /* RGB channels */
{
that->red_sBIT = data.red;
that->green_sBIT = data.green;
that->blue_sBIT = data.blue;
}
else /* One grey channel */
that->red_sBIT = that->green_sBIT = that->blue_sBIT = data.gray;
that->alpha_sBIT = data.alpha;
}
this->next->mod(this->next, that, pp, display);
}
static int
image_transform_png_set_shift_add(image_transform *this,
PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
{
UNUSED(bit_depth)
this->next = *that;
*that = this;
return colour_type != PNG_COLOR_TYPE_PALETTE;
}
IT(shift);
#undef PT
#define PT ITSTRUCT(shift)
#endif /* PNG_READ_SHIFT_SUPPORTED */
#ifdef THIS_IS_THE_PROFORMA
static void
@ -8822,9 +9396,9 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
/* Record the palette index for index images. */
PNG_CONST unsigned int in_index =
in_ct == 3 ? sample(std, 3, in_bd, x, 0) : 256;
in_ct == 3 ? sample(std, 3, in_bd, x, 0, 0, 0) : 256;
PNG_CONST unsigned int out_index =
out_ct == 3 ? sample(std, 3, out_bd, x, 0) : 256;
out_ct == 3 ? sample(std, 3, out_bd, x, 0, 0, 0) : 256;
/* Handle input alpha - png_set_background will cause the output
* alpha to disappear so there is nothing to check.
@ -8834,7 +9408,7 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
{
PNG_CONST unsigned int input_alpha = in_ct == 3 ?
dp->this.palette[in_index].alpha :
sample(std, in_ct, in_bd, x, samples_per_pixel);
sample(std, in_ct, in_bd, x, samples_per_pixel, 0, 0);
unsigned int output_alpha = 65536 /* as a flag value */;
@ -8846,7 +9420,7 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
else if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0)
output_alpha = sample(pRow, out_ct, out_bd, x,
samples_per_pixel);
samples_per_pixel, 0, 0);
if (output_alpha != 65536)
alpha = gamma_component_validate("alpha", &vi, input_alpha,
@ -8865,30 +9439,30 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
/* Handle grayscale or RGB components. */
if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */
(void)gamma_component_validate("gray", &vi,
sample(std, in_ct, in_bd, x, 0),
sample(pRow, out_ct, out_bd, x, 0), alpha/*component*/,
vi.background_red);
sample(std, in_ct, in_bd, x, 0, 0, 0),
sample(pRow, out_ct, out_bd, x, 0, 0, 0),
alpha/*component*/, vi.background_red);
else /* RGB or palette */
{
(void)gamma_component_validate("red", &vi,
in_ct == 3 ? in_palette[in_index].red :
sample(std, in_ct, in_bd, x, 0),
sample(std, in_ct, in_bd, x, 0, 0, 0),
out_ct == 3 ? out_palette[out_index].red :
sample(pRow, out_ct, out_bd, x, 0),
sample(pRow, out_ct, out_bd, x, 0, 0, 0),
alpha/*component*/, vi.background_red);
(void)gamma_component_validate("green", &vi,
in_ct == 3 ? in_palette[in_index].green :
sample(std, in_ct, in_bd, x, 1),
sample(std, in_ct, in_bd, x, 1, 0, 0),
out_ct == 3 ? out_palette[out_index].green :
sample(pRow, out_ct, out_bd, x, 1),
sample(pRow, out_ct, out_bd, x, 1, 0, 0),
alpha/*component*/, vi.background_green);
(void)gamma_component_validate("blue", &vi,
in_ct == 3 ? in_palette[in_index].blue :
sample(std, in_ct, in_bd, x, 2),
sample(std, in_ct, in_bd, x, 2, 0, 0),
out_ct == 3 ? out_palette[out_index].blue :
sample(pRow, out_ct, out_bd, x, 2),
sample(pRow, out_ct, out_bd, x, 2, 0, 0),
alpha/*component*/, vi.background_blue);
}
}