/* pngtrans.c - transforms the data in a row (used by both readers and writers)

*

* Last changed in libpng 1.5.11 [June 14, 2012]

* Copyright (c) 1998-2012 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.)

*

* This code is released under the libpng license.

* For conditions of distribution and use, see the disclaimer

* and license in png.h

*/

#include "pngpriv.h"

#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)

#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)

/* Turn on BGR-to-RGB mapping */

void PNGAPI

png_set_bgr(png_structp png_ptr)

{

png_debug(1, "in png_set_bgr");

if (png_ptr == NULL)

return;

png_ptr->transformations |= PNG_BGR;

}

#endif

#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)

/* Turn on 16 bit byte swapping */

void PNGAPI

png_set_swap(png_structp png_ptr)

{

png_debug(1, "in png_set_swap");

if (png_ptr == NULL)

return;

if (png_ptr->bit_depth == 16)

png_ptr->transformations |= PNG_SWAP_BYTES;

}

#endif

#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)

/* Turn on pixel packing */

void PNGAPI

png_set_packing(png_structp png_ptr)

{

png_debug(1, "in png_set_packing");

if (png_ptr == NULL)

return;

if (png_ptr->bit_depth < 8)

{

png_ptr->transformations |= PNG_PACK;

png_ptr->usr_bit_depth = 8;

}

}

#endif

#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)

/* Turn on packed pixel swapping */

void PNGAPI

png_set_packswap(png_structp png_ptr)

{

png_debug(1, "in png_set_packswap");

if (png_ptr == NULL)

return;

if (png_ptr->bit_depth < 8)

png_ptr->transformations |= PNG_PACKSWAP;

}

#endif

#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)

void PNGAPI

png_set_shift(png_structp png_ptr, png_const_color_8p true_bits)

{

png_debug(1, "in png_set_shift");

if (png_ptr == NULL)

return;

png_ptr->transformations |= PNG_SHIFT;

png_ptr->shift = *true_bits;

}

#endif

#if defined(PNG_READ_INTERLACING_SUPPORTED) || \

defined(PNG_WRITE_INTERLACING_SUPPORTED)

int PNGAPI

png_set_interlace_handling(png_structp png_ptr)

{

png_debug(1, "in png_set_interlace handling");

if (png_ptr && png_ptr->interlaced)

{

png_ptr->transformations |= PNG_INTERLACE;

return (7);

}

return (1);

}

#endif

#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)

/* Add a filler byte on read, or remove a filler or alpha byte on write.

* The filler type has changed in v0.95 to allow future 2-byte fillers

* for 48-bit input data, as well as to avoid problems with some compilers

* that don't like bytes as parameters.

*/

void PNGAPI

png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)

{

png_debug(1, "in png_set_filler");

if (png_ptr == NULL)

return;

png_ptr->transformations |= PNG_FILLER;

png_ptr->filler = (png_uint_16)filler;

if (filler_loc == PNG_FILLER_AFTER)

png_ptr->flags |= PNG_FLAG_FILLER_AFTER;

else

png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;

/* This should probably go in the "do_read_filler" routine.

* I attempted to do that in libpng-1.0.1a but that caused problems

* so I restored it in libpng-1.0.2a

*/

if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)

{

png_ptr->usr_channels = 4;

}

/* Also I added this in libpng-1.0.2a (what happens when we expand

* a less-than-8-bit grayscale to GA?) */

if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)

{

png_ptr->usr_channels = 2;

}

}

/* Added to libpng-1.2.7 */

void PNGAPI

png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)

{

png_debug(1, "in png_set_add_alpha");

if (png_ptr == NULL)

return;

png_set_filler(png_ptr, filler, filler_loc);

png_ptr->transformations |= PNG_ADD_ALPHA;

}

#endif

#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \

defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)

void PNGAPI

png_set_swap_alpha(png_structp png_ptr)

{

png_debug(1, "in png_set_swap_alpha");

if (png_ptr == NULL)

return;

png_ptr->transformations |= PNG_SWAP_ALPHA;

}

#endif

#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \

defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)

void PNGAPI

png_set_invert_alpha(png_structp png_ptr)

{

png_debug(1, "in png_set_invert_alpha");

if (png_ptr == NULL)

return;

png_ptr->transformations |= PNG_INVERT_ALPHA;

}

#endif

#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)

void PNGAPI

png_set_invert_mono(png_structp png_ptr)

{

png_debug(1, "in png_set_invert_mono");

if (png_ptr == NULL)

return;

png_ptr->transformations |= PNG_INVERT_MONO;

}

/* Invert monochrome grayscale data */

void /* PRIVATE */

png_do_invert(png_row_infop row_info, png_bytep row)

{

png_debug(1, "in png_do_invert");

/* This test removed from libpng version 1.0.13 and 1.2.0:

* if (row_info->bit_depth == 1 &&

*/

if (row_info->color_type == PNG_COLOR_TYPE_GRAY)

{

png_bytep rp = row;

png_size_t i;

png_size_t istop = row_info->rowbytes;

for (i = 0; i < istop; i++)

{

*rp = (png_byte)(~(*rp));

rp++;

}

}

else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&

row_info->bit_depth == 8)

{

png_bytep rp = row;

png_size_t i;

png_size_t istop = row_info->rowbytes;

for (i = 0; i < istop; i += 2)

{

*rp = (png_byte)(~(*rp));

rp += 2;

}

}

#ifdef PNG_16BIT_SUPPORTED

else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&

row_info->bit_depth == 16)

{

png_bytep rp = row;

png_size_t i;

png_size_t istop = row_info->rowbytes;

for (i = 0; i < istop; i += 4)

{

*rp = (png_byte)(~(*rp));

*(rp + 1) = (png_byte)(~(*(rp + 1)));

rp += 4;

}

}

#endif

}

#endif

#ifdef PNG_16BIT_SUPPORTED

#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)

/* Swaps byte order on 16 bit depth images */

void /* PRIVATE */

png_do_swap(png_row_infop row_info, png_bytep row)

{

png_debug(1, "in png_do_swap");

if (row_info->bit_depth == 16)

{

png_bytep rp = row;

png_uint_32 i;

png_uint_32 istop= row_info->width * row_info->channels;

for (i = 0; i < istop; i++, rp += 2)

{

png_byte t = *rp;

*rp = *(rp + 1);

*(rp + 1) = t;

}

}

}

#endif

#endif

#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)

static PNG_CONST png_byte onebppswaptable[256] = {

0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,

0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,

0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,

0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,

0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,

0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,

0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,

0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,

0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,

0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,

0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,

0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,

0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,

0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,

0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,

0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,

0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,

0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,

0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,

0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,

0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,

0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,

0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,

0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,

0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,

0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,

0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,

0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,

0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,

0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,

0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,

0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF

};

static PNG_CONST png_byte twobppswaptable[256] = {

0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,

0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,

0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,

0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,

0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,

0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,

0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,

0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,

0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,

0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,

0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,

0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,

0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,

0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,

0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,

0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,

0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,

0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,

0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,

0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,

0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,

0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,

0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,

0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,

0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,

0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,

0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,

0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,

0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,

0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,

0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,

0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF

};

static PNG_CONST png_byte fourbppswaptable[256] = {

0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,

0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,

0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,

0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,

0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,

0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,

0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,

0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,

0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,

0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,

0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,

0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,

0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,

0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,

0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,

0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,

0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,

0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,

0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,

0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,

0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,

0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,

0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,

0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,

0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,

0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,

0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,

0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,

0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,

0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,

0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,

0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF

};

/* Swaps pixel packing order within bytes */

void /* PRIVATE */

png_do_packswap(png_row_infop row_info, png_bytep row)

{

png_debug(1, "in png_do_packswap");

if (row_info->bit_depth < 8)

{

png_bytep rp;

png_const_bytep end, table;

end = row + row_info->rowbytes;

if (row_info->bit_depth == 1)

table = onebppswaptable;

else if (row_info->bit_depth == 2)

table = twobppswaptable;

else if (row_info->bit_depth == 4)

table = fourbppswaptable;

else

return;

for (rp = row; rp < end; rp++)

*rp = table[*rp];

}

}

#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */

#if defined(PNG_WRITE_FILLER_SUPPORTED) || \

defined(PNG_READ_STRIP_ALPHA_SUPPORTED)

/* Remove a channel - this used to be 'png_do_strip_filler' but it used a

* somewhat weird combination of flags to determine what to do. All the calls

* to png_do_strip_filler are changed in 1.5.2 to call this instead with the

* correct arguments.

*

* The routine isn't general - the channel must be the channel at the start or

* end (not in the middle) of each pixel.

*/

void /* PRIVATE */

png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)

{

png_bytep sp = row; /* source pointer */

png_bytep dp = row; /* destination pointer */

png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */

/* At the start sp will point to the first byte to copy and dp to where

* it is copied to. ep always points just beyond the end of the row, so

* the loop simply copies (channels-1) channels until sp reaches ep.

*

* at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.

* nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.

*/

/* GA, GX, XG cases */

if (row_info->channels == 2)

{

if (row_info->bit_depth == 8)

{

if (at_start) /* Skip initial filler */

++sp;

else /* Skip initial channel and, for sp, the filler */

sp += 2, ++dp;

/* For a 1 pixel wide image there is nothing to do */

while (sp < ep)

*dp++ = *sp, sp += 2;

row_info->pixel_depth = 8;

}

else if (row_info->bit_depth == 16)

{

if (at_start) /* Skip initial filler */

sp += 2;

else /* Skip initial channel and, for sp, the filler */

sp += 4, dp += 2;

while (sp < ep)

*dp++ = *sp++, *dp++ = *sp, sp += 3;

row_info->pixel_depth = 16;

}

else

return; /* bad bit depth */

row_info->channels = 1;

/* Finally fix the color type if it records an alpha channel */

if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)

row_info->color_type = PNG_COLOR_TYPE_GRAY;

}

/* RGBA, RGBX, XRGB cases */

else if (row_info->channels == 4)

{

if (row_info->bit_depth == 8)

{

if (at_start) /* Skip initial filler */

++sp;

else /* Skip initial channels and, for sp, the filler */

sp += 4, dp += 3;

/* Note that the loop adds 3 to dp and 4 to sp each time. */

while (sp < ep)

*dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2;

row_info->pixel_depth = 24;

}

else if (row_info->bit_depth == 16)

{

if (at_start) /* Skip initial filler */

sp += 2;

else /* Skip initial channels and, for sp, the filler */

sp += 8, dp += 6;

while (sp < ep)

{

/* Copy 6 bytes, skip 2 */

*dp++ = *sp++, *dp++ = *sp++;

*dp++ = *sp++, *dp++ = *sp++;

*dp++ = *sp++, *dp++ = *sp, sp += 3;

}

row_info->pixel_depth = 48;

}

else

return; /* bad bit depth */

row_info->channels = 3;

/* Finally fix the color type if it records an alpha channel */

if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)

row_info->color_type = PNG_COLOR_TYPE_RGB;

}

else

return; /* The filler channel has gone already */

/* Fix the rowbytes value. */

row_info->rowbytes = dp-row;

}

#endif

#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)

/* Swaps red and blue bytes within a pixel */

void /* PRIVATE */

png_do_bgr(png_row_infop row_info, png_bytep row)

{

png_debug(1, "in png_do_bgr");

if ((row_info->color_type & PNG_COLOR_MASK_COLOR))

{

png_uint_32 row_width = row_info->width;

if (row_info->bit_depth == 8)

{

if (row_info->color_type == PNG_COLOR_TYPE_RGB)

{

png_bytep rp;

png_uint_32 i;

for (i = 0, rp = row; i < row_width; i++, rp += 3)

{

png_byte save = *rp;

*rp = *(rp + 2);

*(rp + 2) = save;

}

}

else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)

{

png_bytep rp;

png_uint_32 i;

for (i = 0, rp = row; i < row_width; i++, rp += 4)

{

png_byte save = *rp;

*rp = *(rp + 2);

*(rp + 2) = save;

}

}

}

#ifdef PNG_16BIT_SUPPORTED

else if (row_info->bit_depth == 16)

{

if (row_info->color_type == PNG_COLOR_TYPE_RGB)

{

png_bytep rp;

png_uint_32 i;

for (i = 0, rp = row; i < row_width; i++, rp += 6)

{

png_byte save = *rp;

*rp = *(rp + 4);

*(rp + 4) = save;

save = *(rp + 1);

*(rp + 1) = *(rp + 5);

*(rp + 5) = save;

}

}

else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)

{

png_bytep rp;

png_uint_32 i;

for (i = 0, rp = row; i < row_width; i++, rp += 8)

{

png_byte save = *rp;

*rp = *(rp + 4);

*(rp + 4) = save;

save = *(rp + 1);

*(rp + 1) = *(rp + 5);

*(rp + 5) = save;

}

}

}

#endif

}

}

#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */

#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \

defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)

/* Added at libpng-1.5.10 */

void /* PRIVATE */

png_do_check_palette_indexes(png_structp png_ptr, png_row_infop row_info)

{

if (png_ptr->num_palette < (1 << row_info->bit_depth) &&

png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */

{

/* Calculations moved outside switch in an attempt to stop different

* compiler warnings. 'padding' is in *bits* within the last byte, it is

* an 'int' because pixel_depth becomes an 'int' in the expression below,

* and this calculation is used because it avoids warnings that other

* forms produced on either GCC or MSVC.

*/

int padding = (-row_info->pixel_depth * row_info->width) & 7;

png_bytep rp = png_ptr->row_buf + row_info->rowbytes;

switch (row_info->bit_depth)

{

case 1:

{

/* in this case, all bytes must be 0 so we don't need

* to unpack the pixels except for the rightmost one.

*/

for (; rp > png_ptr->row_buf; rp--)

{

if (*rp >> padding != 0)

png_ptr->num_palette_max = 1;

padding = 0;

}

break;

}

case 2:

{

for (; rp > png_ptr->row_buf; rp--)

{

int i = ((*rp >> padding) & 0x03);

if (i > png_ptr->num_palette_max)

png_ptr->num_palette_max = i;

i = (((*rp >> padding) >> 2) & 0x03);

if (i > png_ptr->num_palette_max)

png_ptr->num_palette_max = i;

i = (((*rp >> padding) >> 4) & 0x03);

if (i > png_ptr->num_palette_max)

png_ptr->num_palette_max = i;

i = (((*rp >> padding) >> 6) & 0x03);

if (i > png_ptr->num_palette_max)

png_ptr->num_palette_max = i;

padding = 0;

}

break;

}

case 4:

{

for (; rp > png_ptr->row_buf; rp--)

{

int i = ((*rp >> padding) & 0x0f);

if (i > png_ptr->num_palette_max)

png_ptr->num_palette_max = i;

i = (((*rp >> padding) >> 4) & 0x0f);

if (i > png_ptr->num_palette_max)

png_ptr->num_palette_max = i;

padding = 0;

}

break;

}

case 8:

{

for (; rp > png_ptr->row_buf; rp--)

{

if (*rp > png_ptr->num_palette_max)

png_ptr->num_palette_max = (int) *rp;

}

break;

}

default:

break;

}

}

}

#endif /* PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED */

#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \

defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)

#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED

void PNGAPI

png_set_user_transform_info(png_structp png_ptr, png_voidp

user_transform_ptr, int user_transform_depth, int user_transform_channels)

{

png_debug(1, "in png_set_user_transform_info");

if (png_ptr == NULL)

return;

png_ptr->user_transform_ptr = user_transform_ptr;

png_ptr->user_transform_depth = (png_byte)user_transform_depth;

png_ptr->user_transform_channels = (png_byte)user_transform_channels;

}

#endif

/* This function returns a pointer to the user_transform_ptr associated with

* the user transform functions. The application should free any memory

* associated with this pointer before png_write_destroy and png_read_destroy

* are called.

*/

#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED

png_voidp PNGAPI

png_get_user_transform_ptr(png_const_structp png_ptr)

{

if (png_ptr == NULL)

return (NULL);

return ((png_voidp)png_ptr->user_transform_ptr);

}

#endif

#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED

png_uint_32 PNGAPI

png_get_current_row_number(png_const_structp png_ptr)

{

/* See the comments in png.h - this is the sub-image row when reading and

* interlaced image.

*/

if (png_ptr != NULL)

return png_ptr->row_number;

return PNG_UINT_32_MAX; /* help the app not to fail silently */

}

png_byte PNGAPI

png_get_current_pass_number(png_const_structp png_ptr)

{

if (png_ptr != NULL)

return png_ptr->pass;

return 8; /* invalid */

}

#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */

#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||

PNG_WRITE_USER_TRANSFORM_SUPPORTED */

#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */