Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 1 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 2 | /* pngwtran.c - transforms the data in a row for PNG writers |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 3 | * |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 4 | * Last changed in libpng 1.4.0 [September 23, 2009] |
Glenn Randers-Pehrson | 79134c6 | 2009-02-14 10:32:18 -0600 | [diff] [blame] | 5 | * Copyright (c) 1998-2009 Glenn Randers-Pehrson |
Glenn Randers-Pehrson | d436672 | 2000-06-04 14:29:29 -0500 | [diff] [blame] | 6 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| 7 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
Glenn Randers-Pehrson | 3e61d79 | 2009-06-24 09:31:28 -0500 | [diff] [blame] | 8 | * |
Glenn Randers-Pehrson | bfbf865 | 2009-06-26 21:46:52 -0500 | [diff] [blame] | 9 | * This code is released under the libpng license. |
Glenn Randers-Pehrson | c332bbc | 2009-06-25 13:43:50 -0500 | [diff] [blame] | 10 | * For conditions of distribution and use, see the disclaimer |
Glenn Randers-Pehrson | 037023b | 2009-06-24 10:27:36 -0500 | [diff] [blame] | 11 | * and license in png.h |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 12 | */ |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 13 | |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 14 | #include "png.h" |
Glenn Randers-Pehrson | 3097f61 | 2001-05-07 14:52:45 -0500 | [diff] [blame] | 15 | #ifdef PNG_WRITE_SUPPORTED |
Glenn Randers-Pehrson | beb572e | 2006-08-19 13:59:24 -0500 | [diff] [blame] | 16 | #include "pngpriv.h" |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 17 | |
Glenn Randers-Pehrson | 345bc27 | 1998-06-14 14:43:31 -0500 | [diff] [blame] | 18 | /* Transform the data according to the user's wishes. The order of |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 19 | * transformations is significant. |
| 20 | */ |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 21 | void /* PRIVATE */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 22 | png_do_write_transformations(png_structp png_ptr) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 23 | { |
Glenn Randers-Pehrson | 51650b8 | 2008-08-05 07:44:42 -0500 | [diff] [blame] | 24 | png_debug(1, "in png_do_write_transformations"); |
Glenn Randers-Pehrson | 08a3343 | 1998-03-07 06:06:55 -0600 | [diff] [blame] | 25 | |
Glenn Randers-Pehrson | 166c5a3 | 1999-12-10 09:43:02 -0600 | [diff] [blame] | 26 | if (png_ptr == NULL) |
| 27 | return; |
| 28 | |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 29 | #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED |
Glenn Randers-Pehrson | 08a3343 | 1998-03-07 06:06:55 -0600 | [diff] [blame] | 30 | if (png_ptr->transformations & PNG_USER_TRANSFORM) |
Glenn Randers-Pehrson | 145f5c8 | 2008-07-10 09:13:13 -0500 | [diff] [blame] | 31 | if (png_ptr->write_user_transform_fn != NULL) |
Glenn Randers-Pehrson | 4bb4d01 | 2009-05-20 12:45:29 -0500 | [diff] [blame] | 32 | (*(png_ptr->write_user_transform_fn)) /* User write transform function */ |
Glenn Randers-Pehrson | 08a3343 | 1998-03-07 06:06:55 -0600 | [diff] [blame] | 33 | (png_ptr, /* png_ptr */ |
| 34 | &(png_ptr->row_info), /* row_info: */ |
| 35 | /* png_uint_32 width; width of row */ |
| 36 | /* png_uint_32 rowbytes; number of bytes in row */ |
| 37 | /* png_byte color_type; color type of pixels */ |
| 38 | /* png_byte bit_depth; bit depth of samples */ |
| 39 | /* png_byte channels; number of channels (1-4) */ |
| 40 | /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
| 41 | png_ptr->row_buf + 1); /* start of pixel data for row */ |
| 42 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 43 | #ifdef PNG_WRITE_FILLER_SUPPORTED |
Glenn Randers-Pehrson | 73b029f | 2004-11-26 17:28:09 -0600 | [diff] [blame] | 44 | if (png_ptr->transformations & PNG_FILLER) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 45 | png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
Glenn Randers-Pehrson | 4093607 | 2004-11-20 11:18:40 -0600 | [diff] [blame] | 46 | png_ptr->flags); |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 47 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 48 | #ifdef PNG_WRITE_PACKSWAP_SUPPORTED |
Glenn Randers-Pehrson | 46f61e2 | 1998-01-30 21:45:12 -0600 | [diff] [blame] | 49 | if (png_ptr->transformations & PNG_PACKSWAP) |
| 50 | png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 51 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 52 | #ifdef PNG_WRITE_PACK_SUPPORTED |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 53 | if (png_ptr->transformations & PNG_PACK) |
| 54 | png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1, |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 55 | (png_uint_32)png_ptr->bit_depth); |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 56 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 57 | #ifdef PNG_WRITE_SWAP_SUPPORTED |
Glenn Randers-Pehrson | 5c6aeb2 | 1998-12-29 11:47:59 -0600 | [diff] [blame] | 58 | if (png_ptr->transformations & PNG_SWAP_BYTES) |
| 59 | png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 60 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 61 | #ifdef PNG_WRITE_SHIFT_SUPPORTED |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 62 | if (png_ptr->transformations & PNG_SHIFT) |
| 63 | png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 64 | &(png_ptr->shift)); |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 65 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 66 | #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED |
Glenn Randers-Pehrson | cbe52d8 | 1998-02-28 07:00:24 -0600 | [diff] [blame] | 67 | if (png_ptr->transformations & PNG_SWAP_ALPHA) |
| 68 | png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 69 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 70 | #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED |
Glenn Randers-Pehrson | 9c3ab68 | 2006-02-20 22:09:05 -0600 | [diff] [blame] | 71 | if (png_ptr->transformations & PNG_INVERT_ALPHA) |
| 72 | png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 73 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 74 | #ifdef PNG_WRITE_BGR_SUPPORTED |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 75 | if (png_ptr->transformations & PNG_BGR) |
| 76 | png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 77 | #endif |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 78 | #ifdef PNG_WRITE_INVERT_SUPPORTED |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 79 | if (png_ptr->transformations & PNG_INVERT_MONO) |
| 80 | png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 81 | #endif |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 82 | } |
| 83 | |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 84 | #ifdef PNG_WRITE_PACK_SUPPORTED |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 85 | /* Pack pixels into bytes. Pass the true bit depth in bit_depth. The |
| 86 | * row_info bit depth should be 8 (one pixel per byte). The channels |
| 87 | * should be 1 (this only happens on grayscale and paletted images). |
| 88 | */ |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 89 | void /* PRIVATE */ |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 90 | png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 91 | { |
Glenn Randers-Pehrson | 51650b8 | 2008-08-05 07:44:42 -0500 | [diff] [blame] | 92 | png_debug(1, "in png_do_pack"); |
Glenn Randers-Pehrson | da00980 | 2009-08-15 13:25:47 -0500 | [diff] [blame] | 93 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 94 | if (row_info->bit_depth == 8 && |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 95 | row_info->channels == 1) |
| 96 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 97 | switch ((int)bit_depth) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 98 | { |
| 99 | case 1: |
| 100 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 101 | png_bytep sp, dp; |
| 102 | int mask, v; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 103 | png_uint_32 i; |
| 104 | png_uint_32 row_width = row_info->width; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 105 | |
| 106 | sp = row; |
| 107 | dp = row; |
| 108 | mask = 0x80; |
| 109 | v = 0; |
Glenn Randers-Pehrson | 5c6aeb2 | 1998-12-29 11:47:59 -0600 | [diff] [blame] | 110 | |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 111 | for (i = 0; i < row_width; i++) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 112 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 113 | if (*sp != 0) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 114 | v |= mask; |
| 115 | sp++; |
| 116 | if (mask > 1) |
| 117 | mask >>= 1; |
| 118 | else |
| 119 | { |
| 120 | mask = 0x80; |
Guy Schalnat | b2e01bd | 1996-01-26 01:38:47 -0600 | [diff] [blame] | 121 | *dp = (png_byte)v; |
| 122 | dp++; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 123 | v = 0; |
| 124 | } |
| 125 | } |
| 126 | if (mask != 0x80) |
Guy Schalnat | b2e01bd | 1996-01-26 01:38:47 -0600 | [diff] [blame] | 127 | *dp = (png_byte)v; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 128 | break; |
| 129 | } |
| 130 | case 2: |
| 131 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 132 | png_bytep sp, dp; |
| 133 | int shift, v; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 134 | png_uint_32 i; |
| 135 | png_uint_32 row_width = row_info->width; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 136 | |
| 137 | sp = row; |
| 138 | dp = row; |
| 139 | shift = 6; |
| 140 | v = 0; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 141 | for (i = 0; i < row_width; i++) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 142 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 143 | png_byte value; |
| 144 | |
Glenn Randers-Pehrson | 61c32d9 | 2000-02-04 23:40:16 -0600 | [diff] [blame] | 145 | value = (png_byte)(*sp & 0x03); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 146 | v |= (value << shift); |
| 147 | if (shift == 0) |
| 148 | { |
| 149 | shift = 6; |
Guy Schalnat | b2e01bd | 1996-01-26 01:38:47 -0600 | [diff] [blame] | 150 | *dp = (png_byte)v; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 151 | dp++; |
| 152 | v = 0; |
| 153 | } |
| 154 | else |
| 155 | shift -= 2; |
| 156 | sp++; |
| 157 | } |
| 158 | if (shift != 6) |
Guy Schalnat | b2e01bd | 1996-01-26 01:38:47 -0600 | [diff] [blame] | 159 | *dp = (png_byte)v; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 160 | break; |
| 161 | } |
| 162 | case 4: |
| 163 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 164 | png_bytep sp, dp; |
| 165 | int shift, v; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 166 | png_uint_32 i; |
| 167 | png_uint_32 row_width = row_info->width; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 168 | |
| 169 | sp = row; |
| 170 | dp = row; |
| 171 | shift = 4; |
| 172 | v = 0; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 173 | for (i = 0; i < row_width; i++) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 174 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 175 | png_byte value; |
| 176 | |
Glenn Randers-Pehrson | 61c32d9 | 2000-02-04 23:40:16 -0600 | [diff] [blame] | 177 | value = (png_byte)(*sp & 0x0f); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 178 | v |= (value << shift); |
| 179 | |
| 180 | if (shift == 0) |
| 181 | { |
| 182 | shift = 4; |
Guy Schalnat | b2e01bd | 1996-01-26 01:38:47 -0600 | [diff] [blame] | 183 | *dp = (png_byte)v; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 184 | dp++; |
| 185 | v = 0; |
| 186 | } |
| 187 | else |
| 188 | shift -= 4; |
| 189 | |
| 190 | sp++; |
| 191 | } |
| 192 | if (shift != 4) |
Guy Schalnat | b2e01bd | 1996-01-26 01:38:47 -0600 | [diff] [blame] | 193 | *dp = (png_byte)v; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 194 | break; |
| 195 | } |
| 196 | } |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 197 | row_info->bit_depth = (png_byte)bit_depth; |
| 198 | row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); |
Glenn Randers-Pehrson | 272489d | 2004-08-04 06:34:52 -0500 | [diff] [blame] | 199 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
| 200 | row_info->width); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 201 | } |
| 202 | } |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 203 | #endif |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 204 | |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 205 | #ifdef PNG_WRITE_SHIFT_SUPPORTED |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 206 | /* Shift pixel values to take advantage of whole range. Pass the |
| 207 | * true number of bits in bit_depth. The row should be packed |
| 208 | * according to row_info->bit_depth. Thus, if you had a row of |
| 209 | * bit depth 4, but the pixels only had values from 0 to 7, you |
| 210 | * would pass 3 as bit_depth, and this routine would translate the |
| 211 | * data to 0 to 15. |
| 212 | */ |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 213 | void /* PRIVATE */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 214 | png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 215 | { |
Glenn Randers-Pehrson | 51650b8 | 2008-08-05 07:44:42 -0500 | [diff] [blame] | 216 | png_debug(1, "in png_do_shift"); |
Glenn Randers-Pehrson | da00980 | 2009-08-15 13:25:47 -0500 | [diff] [blame] | 217 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 218 | if ( |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 219 | row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
| 220 | { |
| 221 | int shift_start[4], shift_dec[4]; |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 222 | int channels = 0; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 223 | |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 224 | if (row_info->color_type & PNG_COLOR_MASK_COLOR) |
| 225 | { |
| 226 | shift_start[channels] = row_info->bit_depth - bit_depth->red; |
| 227 | shift_dec[channels] = bit_depth->red; |
| 228 | channels++; |
| 229 | shift_start[channels] = row_info->bit_depth - bit_depth->green; |
| 230 | shift_dec[channels] = bit_depth->green; |
| 231 | channels++; |
| 232 | shift_start[channels] = row_info->bit_depth - bit_depth->blue; |
| 233 | shift_dec[channels] = bit_depth->blue; |
| 234 | channels++; |
| 235 | } |
| 236 | else |
| 237 | { |
| 238 | shift_start[channels] = row_info->bit_depth - bit_depth->gray; |
| 239 | shift_dec[channels] = bit_depth->gray; |
| 240 | channels++; |
| 241 | } |
| 242 | if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
| 243 | { |
| 244 | shift_start[channels] = row_info->bit_depth - bit_depth->alpha; |
| 245 | shift_dec[channels] = bit_depth->alpha; |
| 246 | channels++; |
| 247 | } |
| 248 | |
Glenn Randers-Pehrson | 4bb4d01 | 2009-05-20 12:45:29 -0500 | [diff] [blame] | 249 | /* With low row depths, could only be grayscale, so one channel */ |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 250 | if (row_info->bit_depth < 8) |
| 251 | { |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 252 | png_bytep bp = row; |
| 253 | png_uint_32 i; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 254 | png_byte mask; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 255 | png_uint_32 row_bytes = row_info->rowbytes; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 256 | |
| 257 | if (bit_depth->gray == 1 && row_info->bit_depth == 2) |
| 258 | mask = 0x55; |
| 259 | else if (row_info->bit_depth == 4 && bit_depth->gray == 3) |
| 260 | mask = 0x11; |
| 261 | else |
| 262 | mask = 0xff; |
| 263 | |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 264 | for (i = 0; i < row_bytes; i++, bp++) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 265 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 266 | png_uint_16 v; |
| 267 | int j; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 268 | |
| 269 | v = *bp; |
| 270 | *bp = 0; |
| 271 | for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0]) |
| 272 | { |
| 273 | if (j > 0) |
| 274 | *bp |= (png_byte)((v << j) & 0xff); |
| 275 | else |
| 276 | *bp |= (png_byte)((v >> (-j)) & mask); |
| 277 | } |
| 278 | } |
| 279 | } |
| 280 | else if (row_info->bit_depth == 8) |
| 281 | { |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 282 | png_bytep bp = row; |
| 283 | png_uint_32 i; |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 284 | png_uint_32 istop = channels * row_info->width; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 285 | |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 286 | for (i = 0; i < istop; i++, bp++) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 287 | { |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 288 | |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 289 | png_uint_16 v; |
| 290 | int j; |
| 291 | int c = (int)(i%channels); |
| 292 | |
| 293 | v = *bp; |
| 294 | *bp = 0; |
| 295 | for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 296 | { |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 297 | if (j > 0) |
| 298 | *bp |= (png_byte)((v << j) & 0xff); |
| 299 | else |
| 300 | *bp |= (png_byte)((v >> (-j)) & 0xff); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 301 | } |
| 302 | } |
| 303 | } |
| 304 | else |
| 305 | { |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 306 | png_bytep bp; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 307 | png_uint_32 i; |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 308 | png_uint_32 istop = channels * row_info->width; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 309 | |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 310 | for (bp = row, i = 0; i < istop; i++) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 311 | { |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 312 | int c = (int)(i%channels); |
| 313 | png_uint_16 value, v; |
| 314 | int j; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 315 | |
Glenn Randers-Pehrson | 860ab2b | 1999-10-14 07:43:10 -0500 | [diff] [blame] | 316 | v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1)); |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 317 | value = 0; |
| 318 | for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 319 | { |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 320 | if (j > 0) |
| 321 | value |= (png_uint_16)((v << j) & (png_uint_16)0xffff); |
| 322 | else |
| 323 | value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 324 | } |
Glenn Randers-Pehrson | d0dce40 | 1998-05-09 10:02:29 -0500 | [diff] [blame] | 325 | *bp++ = (png_byte)(value >> 8); |
| 326 | *bp++ = (png_byte)(value & 0xff); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 327 | } |
| 328 | } |
| 329 | } |
| 330 | } |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 331 | #endif |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 332 | |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 333 | #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 334 | void /* PRIVATE */ |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 335 | png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 336 | { |
Glenn Randers-Pehrson | 51650b8 | 2008-08-05 07:44:42 -0500 | [diff] [blame] | 337 | png_debug(1, "in png_do_write_swap_alpha"); |
Glenn Randers-Pehrson | da00980 | 2009-08-15 13:25:47 -0500 | [diff] [blame] | 338 | |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 339 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 340 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 341 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 342 | /* This converts from ARGB to RGBA */ |
| 343 | if (row_info->bit_depth == 8) |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 344 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 345 | png_bytep sp, dp; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 346 | png_uint_32 i; |
| 347 | png_uint_32 row_width = row_info->width; |
| 348 | for (i = 0, sp = dp = row; i < row_width; i++) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 349 | { |
Glenn Randers-Pehrson | 896239b | 1998-04-21 15:03:57 -0500 | [diff] [blame] | 350 | png_byte save = *(sp++); |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 351 | *(dp++) = *(sp++); |
| 352 | *(dp++) = *(sp++); |
| 353 | *(dp++) = *(sp++); |
| 354 | *(dp++) = save; |
| 355 | } |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 356 | } |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 357 | /* This converts from AARRGGBB to RRGGBBAA */ |
| 358 | else |
| 359 | { |
| 360 | png_bytep sp, dp; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 361 | png_uint_32 i; |
| 362 | png_uint_32 row_width = row_info->width; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 363 | |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 364 | for (i = 0, sp = dp = row; i < row_width; i++) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 365 | { |
Glenn Randers-Pehrson | 896239b | 1998-04-21 15:03:57 -0500 | [diff] [blame] | 366 | png_byte save[2]; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 367 | save[0] = *(sp++); |
| 368 | save[1] = *(sp++); |
| 369 | *(dp++) = *(sp++); |
| 370 | *(dp++) = *(sp++); |
| 371 | *(dp++) = *(sp++); |
| 372 | *(dp++) = *(sp++); |
| 373 | *(dp++) = *(sp++); |
| 374 | *(dp++) = *(sp++); |
| 375 | *(dp++) = save[0]; |
| 376 | *(dp++) = save[1]; |
| 377 | } |
| 378 | } |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 379 | } |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 380 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 381 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 382 | /* This converts from AG to GA */ |
| 383 | if (row_info->bit_depth == 8) |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 384 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 385 | png_bytep sp, dp; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 386 | png_uint_32 i; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 387 | png_uint_32 row_width = row_info->width; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 388 | |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 389 | for (i = 0, sp = dp = row; i < row_width; i++) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 390 | { |
Glenn Randers-Pehrson | 896239b | 1998-04-21 15:03:57 -0500 | [diff] [blame] | 391 | png_byte save = *(sp++); |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 392 | *(dp++) = *(sp++); |
| 393 | *(dp++) = save; |
| 394 | } |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 395 | } |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 396 | /* This converts from AAGG to GGAA */ |
| 397 | else |
| 398 | { |
| 399 | png_bytep sp, dp; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 400 | png_uint_32 i; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 401 | png_uint_32 row_width = row_info->width; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 402 | |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 403 | for (i = 0, sp = dp = row; i < row_width; i++) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 404 | { |
Glenn Randers-Pehrson | 896239b | 1998-04-21 15:03:57 -0500 | [diff] [blame] | 405 | png_byte save[2]; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 406 | save[0] = *(sp++); |
| 407 | save[1] = *(sp++); |
| 408 | *(dp++) = *(sp++); |
| 409 | *(dp++) = *(sp++); |
| 410 | *(dp++) = save[0]; |
| 411 | *(dp++) = save[1]; |
| 412 | } |
| 413 | } |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 414 | } |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 415 | } |
| 416 | } |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 417 | #endif |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 418 | |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 419 | #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 420 | void /* PRIVATE */ |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 421 | png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) |
| 422 | { |
Glenn Randers-Pehrson | 51650b8 | 2008-08-05 07:44:42 -0500 | [diff] [blame] | 423 | png_debug(1, "in png_do_write_invert_alpha"); |
Glenn Randers-Pehrson | da00980 | 2009-08-15 13:25:47 -0500 | [diff] [blame] | 424 | |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 425 | { |
| 426 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| 427 | { |
| 428 | /* This inverts the alpha channel in RGBA */ |
| 429 | if (row_info->bit_depth == 8) |
| 430 | { |
| 431 | png_bytep sp, dp; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 432 | png_uint_32 i; |
| 433 | png_uint_32 row_width = row_info->width; |
| 434 | for (i = 0, sp = dp = row; i < row_width; i++) |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 435 | { |
Glenn Randers-Pehrson | 4bb4d01 | 2009-05-20 12:45:29 -0500 | [diff] [blame] | 436 | /* Does nothing |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 437 | *(dp++) = *(sp++); |
| 438 | *(dp++) = *(sp++); |
| 439 | *(dp++) = *(sp++); |
Glenn Randers-Pehrson | 9c3ab68 | 2006-02-20 22:09:05 -0600 | [diff] [blame] | 440 | */ |
| 441 | sp+=3; dp = sp; |
Glenn Randers-Pehrson | 860ab2b | 1999-10-14 07:43:10 -0500 | [diff] [blame] | 442 | *(dp++) = (png_byte)(255 - *(sp++)); |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 443 | } |
| 444 | } |
| 445 | /* This inverts the alpha channel in RRGGBBAA */ |
| 446 | else |
| 447 | { |
| 448 | png_bytep sp, dp; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 449 | png_uint_32 i; |
| 450 | png_uint_32 row_width = row_info->width; |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 451 | |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 452 | for (i = 0, sp = dp = row; i < row_width; i++) |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 453 | { |
Glenn Randers-Pehrson | 4bb4d01 | 2009-05-20 12:45:29 -0500 | [diff] [blame] | 454 | /* Does nothing |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 455 | *(dp++) = *(sp++); |
| 456 | *(dp++) = *(sp++); |
| 457 | *(dp++) = *(sp++); |
| 458 | *(dp++) = *(sp++); |
| 459 | *(dp++) = *(sp++); |
| 460 | *(dp++) = *(sp++); |
Glenn Randers-Pehrson | 9c3ab68 | 2006-02-20 22:09:05 -0600 | [diff] [blame] | 461 | */ |
| 462 | sp+=6; dp = sp; |
Glenn Randers-Pehrson | 860ab2b | 1999-10-14 07:43:10 -0500 | [diff] [blame] | 463 | *(dp++) = (png_byte)(255 - *(sp++)); |
| 464 | *(dp++) = (png_byte)(255 - *(sp++)); |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 465 | } |
| 466 | } |
| 467 | } |
| 468 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| 469 | { |
| 470 | /* This inverts the alpha channel in GA */ |
| 471 | if (row_info->bit_depth == 8) |
| 472 | { |
| 473 | png_bytep sp, dp; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 474 | png_uint_32 i; |
| 475 | png_uint_32 row_width = row_info->width; |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 476 | |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 477 | for (i = 0, sp = dp = row; i < row_width; i++) |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 478 | { |
| 479 | *(dp++) = *(sp++); |
Glenn Randers-Pehrson | 860ab2b | 1999-10-14 07:43:10 -0500 | [diff] [blame] | 480 | *(dp++) = (png_byte)(255 - *(sp++)); |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 481 | } |
| 482 | } |
| 483 | /* This inverts the alpha channel in GGAA */ |
| 484 | else |
| 485 | { |
| 486 | png_bytep sp, dp; |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 487 | png_uint_32 i; |
| 488 | png_uint_32 row_width = row_info->width; |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 489 | |
Glenn Randers-Pehrson | 1d96361 | 1998-05-02 12:52:25 -0500 | [diff] [blame] | 490 | for (i = 0, sp = dp = row; i < row_width; i++) |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 491 | { |
Glenn Randers-Pehrson | 4bb4d01 | 2009-05-20 12:45:29 -0500 | [diff] [blame] | 492 | /* Does nothing |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 493 | *(dp++) = *(sp++); |
| 494 | *(dp++) = *(sp++); |
Glenn Randers-Pehrson | 9c3ab68 | 2006-02-20 22:09:05 -0600 | [diff] [blame] | 495 | */ |
| 496 | sp+=2; dp = sp; |
Glenn Randers-Pehrson | 860ab2b | 1999-10-14 07:43:10 -0500 | [diff] [blame] | 497 | *(dp++) = (png_byte)(255 - *(sp++)); |
| 498 | *(dp++) = (png_byte)(255 - *(sp++)); |
Glenn Randers-Pehrson | c4a2ae6 | 1998-01-16 22:06:18 -0600 | [diff] [blame] | 499 | } |
| 500 | } |
| 501 | } |
| 502 | } |
| 503 | } |
| 504 | #endif |
Glenn Randers-Pehrson | 2ad31ae | 2000-12-15 08:54:42 -0600 | [diff] [blame] | 505 | |
Glenn Randers-Pehrson | e26c095 | 2009-09-23 11:22:08 -0500 | [diff] [blame^] | 506 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
Glenn Randers-Pehrson | 4bb4d01 | 2009-05-20 12:45:29 -0500 | [diff] [blame] | 507 | /* Undoes intrapixel differencing */ |
Glenn Randers-Pehrson | 2ad31ae | 2000-12-15 08:54:42 -0600 | [diff] [blame] | 508 | void /* PRIVATE */ |
| 509 | png_do_write_intrapixel(png_row_infop row_info, png_bytep row) |
| 510 | { |
Glenn Randers-Pehrson | 51650b8 | 2008-08-05 07:44:42 -0500 | [diff] [blame] | 511 | png_debug(1, "in png_do_write_intrapixel"); |
Glenn Randers-Pehrson | da00980 | 2009-08-15 13:25:47 -0500 | [diff] [blame] | 512 | |
Glenn Randers-Pehrson | 2ad31ae | 2000-12-15 08:54:42 -0600 | [diff] [blame] | 513 | if ( |
Glenn Randers-Pehrson | 2ad31ae | 2000-12-15 08:54:42 -0600 | [diff] [blame] | 514 | (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
| 515 | { |
| 516 | int bytes_per_pixel; |
| 517 | png_uint_32 row_width = row_info->width; |
| 518 | if (row_info->bit_depth == 8) |
| 519 | { |
| 520 | png_bytep rp; |
| 521 | png_uint_32 i; |
| 522 | |
| 523 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
| 524 | bytes_per_pixel = 3; |
| 525 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| 526 | bytes_per_pixel = 4; |
| 527 | else |
| 528 | return; |
| 529 | |
| 530 | for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
| 531 | { |
| 532 | *(rp) = (png_byte)((*rp - *(rp+1))&0xff); |
| 533 | *(rp+2) = (png_byte)((*(rp+2) - *(rp+1))&0xff); |
| 534 | } |
| 535 | } |
| 536 | else if (row_info->bit_depth == 16) |
| 537 | { |
| 538 | png_bytep rp; |
| 539 | png_uint_32 i; |
| 540 | |
| 541 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
| 542 | bytes_per_pixel = 6; |
| 543 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| 544 | bytes_per_pixel = 8; |
| 545 | else |
| 546 | return; |
| 547 | |
| 548 | for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
| 549 | { |
Glenn Randers-Pehrson | 5b5dcf8 | 2004-07-17 22:45:44 -0500 | [diff] [blame] | 550 | png_uint_32 s0 = (*(rp ) << 8) | *(rp+1); |
| 551 | png_uint_32 s1 = (*(rp+2) << 8) | *(rp+3); |
| 552 | png_uint_32 s2 = (*(rp+4) << 8) | *(rp+5); |
Glenn Randers-Pehrson | 145f5c8 | 2008-07-10 09:13:13 -0500 | [diff] [blame] | 553 | png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); |
| 554 | png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); |
Glenn Randers-Pehrson | 5b5dcf8 | 2004-07-17 22:45:44 -0500 | [diff] [blame] | 555 | *(rp ) = (png_byte)((red >> 8) & 0xff); |
| 556 | *(rp+1) = (png_byte)(red & 0xff); |
| 557 | *(rp+4) = (png_byte)((blue >> 8) & 0xff); |
| 558 | *(rp+5) = (png_byte)(blue & 0xff); |
Glenn Randers-Pehrson | 2ad31ae | 2000-12-15 08:54:42 -0600 | [diff] [blame] | 559 | } |
| 560 | } |
| 561 | } |
| 562 | } |
| 563 | #endif /* PNG_MNG_FEATURES_SUPPORTED */ |
Glenn Randers-Pehrson | 3097f61 | 2001-05-07 14:52:45 -0500 | [diff] [blame] | 564 | #endif /* PNG_WRITE_SUPPORTED */ |