/src/libpng/pngwtran.c

Source (jump to first uncovered line)

/* pngwtran.c - transforms the data in a row for PNG writers
 *
 * Copyright (c) 2018 Cosmin Truta
 * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
 * Copyright (c) 1996-1997 Andreas Dilger
 * 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"

#ifdef PNG_WRITE_SUPPORTED
#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED

#ifdef PNG_WRITE_PACK_SUPPORTED
/* Pack pixels into bytes.  Pass the true bit depth in bit_depth.  The
 * row_info bit depth should be 8 (one pixel per byte).  The channels
 * should be 1 (this only happens on grayscale and paletted images).
 */
static void
png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
{
   png_debug(1, "in png_do_pack");

   if (row_info->bit_depth == 8 &&
      row_info->channels == 1)
   {
      switch ((int)bit_depth)
      {
         case 1:
         {
            png_bytep sp, dp;
            int mask, v;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            sp = row;
            dp = row;
            mask = 0x80;
            v = 0;

            for (i = 0; i < row_width; i++)
            {
               if (*sp != 0)
                  v |= mask;

               sp++;

               if (mask > 1)
                  mask >>= 1;

               else
               {
                  mask = 0x80;
                  *dp = (png_byte)v;
                  dp++;
                  v = 0;
               }
            }

            if (mask != 0x80)
               *dp = (png_byte)v;

            break;
         }

         case 2:
         {
            png_bytep sp, dp;
            unsigned int shift;
            int v;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            sp = row;
            dp = row;
            shift = 6;
            v = 0;

            for (i = 0; i < row_width; i++)
            {
               png_byte value;

               value = (png_byte)(*sp & 0x03);
               v |= (value << shift);

               if (shift == 0)
               {
                  shift = 6;
                  *dp = (png_byte)v;
                  dp++;
                  v = 0;
               }

               else
                  shift -= 2;

               sp++;
            }

            if (shift != 6)
               *dp = (png_byte)v;

            break;
         }

         case 4:
         {
            png_bytep sp, dp;
            unsigned int shift;
            int v;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            sp = row;
            dp = row;
            shift = 4;
            v = 0;

            for (i = 0; i < row_width; i++)
            {
               png_byte value;

               value = (png_byte)(*sp & 0x0f);
               v |= (value << shift);

               if (shift == 0)
               {
                  shift = 4;
                  *dp = (png_byte)v;
                  dp++;
                  v = 0;
               }

               else
                  shift -= 4;

               sp++;
            }

            if (shift != 4)
               *dp = (png_byte)v;

            break;
         }

         default:
            break;
      }

      row_info->bit_depth = (png_byte)bit_depth;
      row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
          row_info->width);
   }
}
#endif

#ifdef PNG_WRITE_SHIFT_SUPPORTED
/* Shift pixel values to take advantage of whole range.  Pass the
 * true number of bits in bit_depth.  The row should be packed
 * according to row_info->bit_depth.  Thus, if you had a row of
 * bit depth 4, but the pixels only had values from 0 to 7, you
 * would pass 3 as bit_depth, and this routine would translate the
 * data to 0 to 15.
 */
static void
png_do_shift(png_row_infop row_info, png_bytep row,
    png_const_color_8p bit_depth)
{
   png_debug(1, "in png_do_shift");

   if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
   {
      int shift_start[4], shift_dec[4];
      unsigned int channels = 0;

      if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
      {
         shift_start[channels] = row_info->bit_depth - bit_depth->red;
         shift_dec[channels] = bit_depth->red;
         channels++;

         shift_start[channels] = row_info->bit_depth - bit_depth->green;
         shift_dec[channels] = bit_depth->green;
         channels++;

         shift_start[channels] = row_info->bit_depth - bit_depth->blue;
         shift_dec[channels] = bit_depth->blue;
         channels++;
      }

      else
      {
         shift_start[channels] = row_info->bit_depth - bit_depth->gray;
         shift_dec[channels] = bit_depth->gray;
         channels++;
      }

      if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
      {
         shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
         shift_dec[channels] = bit_depth->alpha;
         channels++;
      }

      /* With low row depths, could only be grayscale, so one channel */
      if (row_info->bit_depth < 8)
      {
         png_bytep bp = row;
         size_t i;
         unsigned int mask;
         size_t row_bytes = row_info->rowbytes;

         if (bit_depth->gray == 1 && row_info->bit_depth == 2)
            mask = 0x55;

         else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
            mask = 0x11;

         else
            mask = 0xff;

         for (i = 0; i < row_bytes; i++, bp++)
         {
            int j;
            unsigned int v, out;

            v = *bp;
            out = 0;

            for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
            {
               if (j > 0)
                  out |= v << j;

               else
                  out |= (v >> (-j)) & mask;
            }

            *bp = (png_byte)(out & 0xff);
         }
      }

      else if (row_info->bit_depth == 8)
      {
         png_bytep bp = row;
         png_uint_32 i;
         png_uint_32 istop = channels * row_info->width;

         for (i = 0; i < istop; i++, bp++)
         {
            unsigned int c = i%channels;
            int j;
            unsigned int v, out;

            v = *bp;
            out = 0;

            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
            {
               if (j > 0)
                  out |= v << j;

               else
                  out |= v >> (-j);
            }

            *bp = (png_byte)(out & 0xff);
         }
      }

      else
      {
         png_bytep bp;
         png_uint_32 i;
         png_uint_32 istop = channels * row_info->width;

         for (bp = row, i = 0; i < istop; i++)
         {
            unsigned int c = i%channels;
            int j;
            unsigned int value, v;

            v = png_get_uint_16(bp);
            value = 0;

            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
            {
               if (j > 0)
                  value |= v << j;

               else
                  value |= v >> (-j);
            }
            *bp++ = (png_byte)((value >> 8) & 0xff);
            *bp++ = (png_byte)(value & 0xff);
         }
      }
   }
}
#endif

#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
static void
png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
{
   png_debug(1, "in png_do_write_swap_alpha");

   {
      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
      {
         if (row_info->bit_depth == 8)
         {
            /* This converts from ARGB to RGBA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               png_byte save = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = save;
            }
         }

#ifdef PNG_WRITE_16BIT_SUPPORTED
         else
         {
            /* This converts from AARRGGBB to RRGGBBAA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               png_byte save[2];
               save[0] = *(sp++);
               save[1] = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = save[0];
               *(dp++) = save[1];
            }
         }
#endif /* WRITE_16BIT */
      }

      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
      {
         if (row_info->bit_depth == 8)
         {
            /* This converts from AG to GA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               png_byte save = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = save;
            }
         }

#ifdef PNG_WRITE_16BIT_SUPPORTED
         else
         {
            /* This converts from AAGG to GGAA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               png_byte save[2];
               save[0] = *(sp++);
               save[1] = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = save[0];
               *(dp++) = save[1];
            }
         }
#endif /* WRITE_16BIT */
      }
   }
}
#endif

#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
static void
png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
{
   png_debug(1, "in png_do_write_invert_alpha");

   {
      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
      {
         if (row_info->bit_depth == 8)
         {
            /* This inverts the alpha channel in RGBA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               /* Does nothing
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               */
               sp+=3; dp = sp;
               *dp = (png_byte)(255 - *(sp++));
            }
         }

#ifdef PNG_WRITE_16BIT_SUPPORTED
         else
         {
            /* This inverts the alpha channel in RRGGBBAA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               /* Does nothing
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               */
               sp+=6; dp = sp;
               *(dp++) = (png_byte)(255 - *(sp++));
               *dp     = (png_byte)(255 - *(sp++));
            }
         }
#endif /* WRITE_16BIT */
      }

      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
      {
         if (row_info->bit_depth == 8)
         {
            /* This inverts the alpha channel in GA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               *(dp++) = *(sp++);
               *(dp++) = (png_byte)(255 - *(sp++));
            }
         }

#ifdef PNG_WRITE_16BIT_SUPPORTED
         else
         {
            /* This inverts the alpha channel in GGAA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               /* Does nothing
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               */
               sp+=2; dp = sp;
               *(dp++) = (png_byte)(255 - *(sp++));
               *dp     = (png_byte)(255 - *(sp++));
            }
         }
#endif /* WRITE_16BIT */
      }
   }
}
#endif

/* Transform the data according to the user's wishes.  The order of
 * transformations is significant.
 */
void /* PRIVATE */
png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
{
   png_debug(1, "in png_do_write_transformations");

   if (png_ptr == NULL)
      return;

#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
      if (png_ptr->write_user_transform_fn != NULL)
         (*(png_ptr->write_user_transform_fn)) /* User write transform
                                                 function */
             (png_ptr,  /* png_ptr */
             row_info,  /* row_info: */
                /*  png_uint_32 width;       width of row */
                /*  size_t rowbytes;         number of bytes in row */
                /*  png_byte color_type;     color type of pixels */
                /*  png_byte bit_depth;      bit depth of samples */
                /*  png_byte channels;       number of channels (1-4) */
                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
             png_ptr->row_buf + 1);      /* start of pixel data for row */
#endif

#ifdef PNG_WRITE_FILLER_SUPPORTED
   if ((png_ptr->transformations & PNG_FILLER) != 0)
      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
          !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
#endif

#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
      png_do_packswap(row_info, png_ptr->row_buf + 1);
#endif

#ifdef PNG_WRITE_PACK_SUPPORTED
   if ((png_ptr->transformations & PNG_PACK) != 0)
      png_do_pack(row_info, png_ptr->row_buf + 1,
          (png_uint_32)png_ptr->bit_depth);
#endif

#ifdef PNG_WRITE_SWAP_SUPPORTED
#  ifdef PNG_16BIT_SUPPORTED
   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
      png_do_swap(row_info, png_ptr->row_buf + 1);
#  endif
#endif

#ifdef PNG_WRITE_SHIFT_SUPPORTED
   if ((png_ptr->transformations & PNG_SHIFT) != 0)
      png_do_shift(row_info, png_ptr->row_buf + 1,
           &(png_ptr->shift));
#endif

#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
   if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
      png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
#endif

#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
   if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
      png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
#endif

#ifdef PNG_WRITE_BGR_SUPPORTED
   if ((png_ptr->transformations & PNG_BGR) != 0)
      png_do_bgr(row_info, png_ptr->row_buf + 1);
#endif

#ifdef PNG_WRITE_INVERT_SUPPORTED
   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
      png_do_invert(row_info, png_ptr->row_buf + 1);
#endif
}
#endif /* WRITE_TRANSFORMS */
#endif /* WRITE */

Coverage Report

Created: 2024-06-18 06:05

Line	Count	Source (jump to first uncovered line)
1
2		/* pngwtran.c - transforms the data in a row for PNG writers
3		*
4		* Copyright (c) 2018 Cosmin Truta
5		* Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
6		* Copyright (c) 1996-1997 Andreas Dilger
7		* Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
8		*
9		* This code is released under the libpng license.
10		* For conditions of distribution and use, see the disclaimer
11		* and license in png.h
12		*/
13
14		#include "pngpriv.h"
15
16		#ifdef PNG_WRITE_SUPPORTED
17		#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
18
19		#ifdef PNG_WRITE_PACK_SUPPORTED
20		/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
21		* row_info bit depth should be 8 (one pixel per byte). The channels
22		* should be 1 (this only happens on grayscale and paletted images).
23		*/
24		static void
25		png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
26	0	{
27	0	png_debug(1, "in png_do_pack");
28
29	0	if (row_info->bit_depth == 8 &&
30	0	row_info->channels == 1)
31	0	{
32	0	switch ((int)bit_depth)
33	0	{
34	0	case 1:
35	0	{
36	0	png_bytep sp, dp;
37	0	int mask, v;
38	0	png_uint_32 i;
39	0	png_uint_32 row_width = row_info->width;
40
41	0	sp = row;
42	0	dp = row;
43	0	mask = 0x80;
44	0	v = 0;
45
46	0	for (i = 0; i < row_width; i++)
47	0	{
48	0	if (*sp != 0)
49	0	v \|= mask;
50
51	0	sp++;
52
53	0	if (mask > 1)
54	0	mask >>= 1;
55
56	0	else
57	0	{
58	0	mask = 0x80;
59	0	*dp = (png_byte)v;
60	0	dp++;
61	0	v = 0;
62	0	}
63	0	}
64
65	0	if (mask != 0x80)
66	0	*dp = (png_byte)v;
67
68	0	break;
69	0	}
70
71	0	case 2:
72	0	{
73	0	png_bytep sp, dp;
74	0	unsigned int shift;
75	0	int v;
76	0	png_uint_32 i;
77	0	png_uint_32 row_width = row_info->width;
78
79	0	sp = row;
80	0	dp = row;
81	0	shift = 6;
82	0	v = 0;
83
84	0	for (i = 0; i < row_width; i++)
85	0	{
86	0	png_byte value;
87
88	0	value = (png_byte)(*sp & 0x03);
89	0	v \|= (value << shift);
90
91	0	if (shift == 0)
92	0	{
93	0	shift = 6;
94	0	*dp = (png_byte)v;
95	0	dp++;
96	0	v = 0;
97	0	}
98
99	0	else
100	0	shift -= 2;
101
102	0	sp++;
103	0	}
104
105	0	if (shift != 6)
106	0	*dp = (png_byte)v;
107
108	0	break;
109	0	}
110
111	0	case 4:
112	0	{
113	0	png_bytep sp, dp;
114	0	unsigned int shift;
115	0	int v;
116	0	png_uint_32 i;
117	0	png_uint_32 row_width = row_info->width;
118
119	0	sp = row;
120	0	dp = row;
121	0	shift = 4;
122	0	v = 0;
123
124	0	for (i = 0; i < row_width; i++)
125	0	{
126	0	png_byte value;
127
128	0	value = (png_byte)(*sp & 0x0f);
129	0	v \|= (value << shift);
130
131	0	if (shift == 0)
132	0	{
133	0	shift = 4;
134	0	*dp = (png_byte)v;
135	0	dp++;
136	0	v = 0;
137	0	}
138
139	0	else
140	0	shift -= 4;
141
142	0	sp++;
143	0	}
144
145	0	if (shift != 4)
146	0	*dp = (png_byte)v;
147
148	0	break;
149	0	}
150
151	0	default:
152	0	break;
153	0	}
154
155	0	row_info->bit_depth = (png_byte)bit_depth;
156	0	row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
157	0	row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
158	0	row_info->width);
159	0	}
160	0	}
161		#endif
162
163		#ifdef PNG_WRITE_SHIFT_SUPPORTED
164		/* Shift pixel values to take advantage of whole range. Pass the
165		* true number of bits in bit_depth. The row should be packed
166		* according to row_info->bit_depth. Thus, if you had a row of
167		* bit depth 4, but the pixels only had values from 0 to 7, you
168		* would pass 3 as bit_depth, and this routine would translate the
169		* data to 0 to 15.
170		*/
171		static void
172		png_do_shift(png_row_infop row_info, png_bytep row,
173		png_const_color_8p bit_depth)
174	0	{
175	0	png_debug(1, "in png_do_shift");
176
177	0	if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
178	0	{
179	0	int shift_start[4], shift_dec[4];
180	0	unsigned int channels = 0;
181
182	0	if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
183	0	{
184	0	shift_start[channels] = row_info->bit_depth - bit_depth->red;
185	0	shift_dec[channels] = bit_depth->red;
186	0	channels++;
187
188	0	shift_start[channels] = row_info->bit_depth - bit_depth->green;
189	0	shift_dec[channels] = bit_depth->green;
190	0	channels++;
191
192	0	shift_start[channels] = row_info->bit_depth - bit_depth->blue;
193	0	shift_dec[channels] = bit_depth->blue;
194	0	channels++;
195	0	}
196
197	0	else
198	0	{
199	0	shift_start[channels] = row_info->bit_depth - bit_depth->gray;
200	0	shift_dec[channels] = bit_depth->gray;
201	0	channels++;
202	0	}
203
204	0	if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
205	0	{
206	0	shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
207	0	shift_dec[channels] = bit_depth->alpha;
208	0	channels++;
209	0	}
210
211		/* With low row depths, could only be grayscale, so one channel */
212	0	if (row_info->bit_depth < 8)
213	0	{
214	0	png_bytep bp = row;
215	0	size_t i;
216	0	unsigned int mask;
217	0	size_t row_bytes = row_info->rowbytes;
218
219	0	if (bit_depth->gray == 1 && row_info->bit_depth == 2)
220	0	mask = 0x55;
221
222	0	else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
223	0	mask = 0x11;
224
225	0	else
226	0	mask = 0xff;
227
228	0	for (i = 0; i < row_bytes; i++, bp++)
229	0	{
230	0	int j;
231	0	unsigned int v, out;
232
233	0	v = *bp;
234	0	out = 0;
235
236	0	for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
237	0	{
238	0	if (j > 0)
239	0	out \|= v << j;
240
241	0	else
242	0	out \|= (v >> (-j)) & mask;
243	0	}
244
245	0	*bp = (png_byte)(out & 0xff);
246	0	}
247	0	}
248
249	0	else if (row_info->bit_depth == 8)
250	0	{
251	0	png_bytep bp = row;
252	0	png_uint_32 i;
253	0	png_uint_32 istop = channels * row_info->width;
254
255	0	for (i = 0; i < istop; i++, bp++)
256	0	{
257	0	unsigned int c = i%channels;
258	0	int j;
259	0	unsigned int v, out;
260
261	0	v = *bp;
262	0	out = 0;
263
264	0	for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
265	0	{
266	0	if (j > 0)
267	0	out \|= v << j;
268
269	0	else
270	0	out \|= v >> (-j);
271	0	}
272
273	0	*bp = (png_byte)(out & 0xff);
274	0	}
275	0	}
276
277	0	else
278	0	{
279	0	png_bytep bp;
280	0	png_uint_32 i;
281	0	png_uint_32 istop = channels * row_info->width;
282
283	0	for (bp = row, i = 0; i < istop; i++)
284	0	{
285	0	unsigned int c = i%channels;
286	0	int j;
287	0	unsigned int value, v;
288
289	0	v = png_get_uint_16(bp);
290	0	value = 0;
291
292	0	for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
293	0	{
294	0	if (j > 0)
295	0	value \|= v << j;
296
297	0	else
298	0	value \|= v >> (-j);
299	0	}
300	0	*bp++ = (png_byte)((value >> 8) & 0xff);
301	0	*bp++ = (png_byte)(value & 0xff);
302	0	}
303	0	}
304	0	}
305	0	}
306		#endif
307
308		#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
309		static void
310		png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
311	0	{
312	0	png_debug(1, "in png_do_write_swap_alpha");
313
314	0	{
315	0	if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
316	0	{
317	0	if (row_info->bit_depth == 8)
318	0	{
319		/* This converts from ARGB to RGBA */
320	0	png_bytep sp, dp;
321	0	png_uint_32 i;
322	0	png_uint_32 row_width = row_info->width;
323
324	0	for (i = 0, sp = dp = row; i < row_width; i++)
325	0	{
326	0	png_byte save = *(sp++);
327	0	(dp++) = (sp++);
328	0	(dp++) = (sp++);
329	0	(dp++) = (sp++);
330	0	*(dp++) = save;
331	0	}
332	0	}
333
334	0	#ifdef PNG_WRITE_16BIT_SUPPORTED
335	0	else
336	0	{
337		/* This converts from AARRGGBB to RRGGBBAA */
338	0	png_bytep sp, dp;
339	0	png_uint_32 i;
340	0	png_uint_32 row_width = row_info->width;
341
342	0	for (i = 0, sp = dp = row; i < row_width; i++)
343	0	{
344	0	png_byte save[2];
345	0	save[0] = *(sp++);
346	0	save[1] = *(sp++);
347	0	(dp++) = (sp++);
348	0	(dp++) = (sp++);
349	0	(dp++) = (sp++);
350	0	(dp++) = (sp++);
351	0	(dp++) = (sp++);
352	0	(dp++) = (sp++);
353	0	*(dp++) = save[0];
354	0	*(dp++) = save[1];
355	0	}
356	0	}
357	0	#endif /* WRITE_16BIT */
358	0	}
359
360	0	else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
361	0	{
362	0	if (row_info->bit_depth == 8)
363	0	{
364		/* This converts from AG to GA */
365	0	png_bytep sp, dp;
366	0	png_uint_32 i;
367	0	png_uint_32 row_width = row_info->width;
368
369	0	for (i = 0, sp = dp = row; i < row_width; i++)
370	0	{
371	0	png_byte save = *(sp++);
372	0	(dp++) = (sp++);
373	0	*(dp++) = save;
374	0	}
375	0	}
376
377	0	#ifdef PNG_WRITE_16BIT_SUPPORTED
378	0	else
379	0	{
380		/* This converts from AAGG to GGAA */
381	0	png_bytep sp, dp;
382	0	png_uint_32 i;
383	0	png_uint_32 row_width = row_info->width;
384
385	0	for (i = 0, sp = dp = row; i < row_width; i++)
386	0	{
387	0	png_byte save[2];
388	0	save[0] = *(sp++);
389	0	save[1] = *(sp++);
390	0	(dp++) = (sp++);
391	0	(dp++) = (sp++);
392	0	*(dp++) = save[0];
393	0	*(dp++) = save[1];
394	0	}
395	0	}
396	0	#endif /* WRITE_16BIT */
397	0	}
398	0	}
399	0	}
400		#endif
401
402		#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
403		static void
404		png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
405	0	{
406	0	png_debug(1, "in png_do_write_invert_alpha");
407
408	0	{
409	0	if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
410	0	{
411	0	if (row_info->bit_depth == 8)
412	0	{
413		/* This inverts the alpha channel in RGBA */
414	0	png_bytep sp, dp;
415	0	png_uint_32 i;
416	0	png_uint_32 row_width = row_info->width;
417
418	0	for (i = 0, sp = dp = row; i < row_width; i++)
419	0	{
420		/* Does nothing
421		(dp++) = (sp++);
422		(dp++) = (sp++);
423		(dp++) = (sp++);
424		*/
425	0	sp+=3; dp = sp;
426	0	dp = (png_byte)(255 - (sp++));
427	0	}
428	0	}
429
430	0	#ifdef PNG_WRITE_16BIT_SUPPORTED
431	0	else
432	0	{
433		/* This inverts the alpha channel in RRGGBBAA */
434	0	png_bytep sp, dp;
435	0	png_uint_32 i;
436	0	png_uint_32 row_width = row_info->width;
437
438	0	for (i = 0, sp = dp = row; i < row_width; i++)
439	0	{
440		/* Does nothing
441		(dp++) = (sp++);
442		(dp++) = (sp++);
443		(dp++) = (sp++);
444		(dp++) = (sp++);
445		(dp++) = (sp++);
446		(dp++) = (sp++);
447		*/
448	0	sp+=6; dp = sp;
449	0	(dp++) = (png_byte)(255 - (sp++));
450	0	dp = (png_byte)(255 - (sp++));
451	0	}
452	0	}
453	0	#endif /* WRITE_16BIT */
454	0	}
455
456	0	else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
457	0	{
458	0	if (row_info->bit_depth == 8)
459	0	{
460		/* This inverts the alpha channel in GA */
461	0	png_bytep sp, dp;
462	0	png_uint_32 i;
463	0	png_uint_32 row_width = row_info->width;
464
465	0	for (i = 0, sp = dp = row; i < row_width; i++)
466	0	{
467	0	(dp++) = (sp++);
468	0	(dp++) = (png_byte)(255 - (sp++));
469	0	}
470	0	}
471
472	0	#ifdef PNG_WRITE_16BIT_SUPPORTED
473	0	else
474	0	{
475		/* This inverts the alpha channel in GGAA */
476	0	png_bytep sp, dp;
477	0	png_uint_32 i;
478	0	png_uint_32 row_width = row_info->width;
479
480	0	for (i = 0, sp = dp = row; i < row_width; i++)
481	0	{
482		/* Does nothing
483		(dp++) = (sp++);
484		(dp++) = (sp++);
485		*/
486	0	sp+=2; dp = sp;
487	0	(dp++) = (png_byte)(255 - (sp++));
488	0	dp = (png_byte)(255 - (sp++));
489	0	}
490	0	}
491	0	#endif /* WRITE_16BIT */
492	0	}
493	0	}
494	0	}
495		#endif
496
497		/* Transform the data according to the user's wishes. The order of
498		* transformations is significant.
499		*/
500		void /* PRIVATE */
501		png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
502	0	{
503	0	png_debug(1, "in png_do_write_transformations");
504
505	0	if (png_ptr == NULL)
506	0	return;
507
508	0	#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
509	0	if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
510	0	if (png_ptr->write_user_transform_fn != NULL)
511	0	((png_ptr->write_user_transform_fn)) / User write transform
512		function */
513	0	(png_ptr, /* png_ptr */
514	0	row_info, /* row_info: */
515		/* png_uint_32 width; width of row */
516		/* size_t rowbytes; number of bytes in row */
517		/* png_byte color_type; color type of pixels */
518		/* png_byte bit_depth; bit depth of samples */
519		/* png_byte channels; number of channels (1-4) */
520		/* png_byte pixel_depth; bits per pixel (depthchannels) /
521	0	png_ptr->row_buf + 1); /* start of pixel data for row */
522	0	#endif
523
524	0	#ifdef PNG_WRITE_FILLER_SUPPORTED
525	0	if ((png_ptr->transformations & PNG_FILLER) != 0)
526	0	png_do_strip_channel(row_info, png_ptr->row_buf + 1,
527	0	!(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
528	0	#endif
529
530	0	#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
531	0	if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
532	0	png_do_packswap(row_info, png_ptr->row_buf + 1);
533	0	#endif
534
535	0	#ifdef PNG_WRITE_PACK_SUPPORTED
536	0	if ((png_ptr->transformations & PNG_PACK) != 0)
537	0	png_do_pack(row_info, png_ptr->row_buf + 1,
538	0	(png_uint_32)png_ptr->bit_depth);
539	0	#endif
540
541	0	#ifdef PNG_WRITE_SWAP_SUPPORTED
542	0	# ifdef PNG_16BIT_SUPPORTED
543	0	if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
544	0	png_do_swap(row_info, png_ptr->row_buf + 1);
545	0	# endif
546	0	#endif
547
548	0	#ifdef PNG_WRITE_SHIFT_SUPPORTED
549	0	if ((png_ptr->transformations & PNG_SHIFT) != 0)
550	0	png_do_shift(row_info, png_ptr->row_buf + 1,
551	0	&(png_ptr->shift));
552	0	#endif
553
554	0	#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
555	0	if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
556	0	png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
557	0	#endif
558
559	0	#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
560	0	if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
561	0	png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
562	0	#endif
563
564	0	#ifdef PNG_WRITE_BGR_SUPPORTED
565	0	if ((png_ptr->transformations & PNG_BGR) != 0)
566	0	png_do_bgr(row_info, png_ptr->row_buf + 1);
567	0	#endif
568
569	0	#ifdef PNG_WRITE_INVERT_SUPPORTED
570	0	if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
571	0	png_do_invert(row_info, png_ptr->row_buf + 1);
572	0	#endif
573	0	}
574		#endif /* WRITE_TRANSFORMS */
575		#endif /* WRITE */