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Rev | Author | Line No. | Line |
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1897 | serge | 1 | |
2 | * |
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3 | * Last changed in libpng 1.6.0 [February 14, 2013] |
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3928 | Serge | 4 | * Copyright (c) 1998-2013 Glenn Randers-Pehrson |
5 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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1897 | serge | 6 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
7 | * |
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8 | * This code is released under the libpng license. |
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9 | * For conditions of distribution and use, see the disclaimer |
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10 | * and license in png.h |
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11 | */ |
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12 | |||
13 | |||
14 | |||
15 | |||
16 | |||
17 | |||
3928 | Serge | 18 | /* Transform the data according to the user's wishes. The order of |
1897 | serge | 19 | * transformations is significant. |
20 | */ |
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21 | void /* PRIVATE */ |
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22 | png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info) |
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3928 | Serge | 23 | { |
1897 | serge | 24 | png_debug(1, "in png_do_write_transformations"); |
25 | |||
26 | |||
27 | return; |
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28 | |||
29 | |||
30 | if (png_ptr->transformations & PNG_USER_TRANSFORM) |
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31 | if (png_ptr->write_user_transform_fn != NULL) |
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32 | (*(png_ptr->write_user_transform_fn)) /* User write transform |
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33 | function */ |
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34 | (png_ptr, /* png_ptr */ |
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3928 | Serge | 35 | row_info, /* row_info: */ |
36 | /* png_uint_32 width; width of row */ |
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1897 | serge | 37 | /* png_size_t rowbytes; number of bytes in row */ |
38 | /* png_byte color_type; color type of pixels */ |
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39 | /* png_byte bit_depth; bit depth of samples */ |
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40 | /* png_byte channels; number of channels (1-4) */ |
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41 | /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
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42 | png_ptr->row_buf + 1); /* start of pixel data for row */ |
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43 | #endif |
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44 | |||
45 | |||
46 | if (png_ptr->transformations & PNG_FILLER) |
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47 | png_do_strip_channel(row_info, png_ptr->row_buf + 1, |
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3928 | Serge | 48 | !(png_ptr->flags & PNG_FLAG_FILLER_AFTER)); |
49 | #endif |
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1897 | serge | 50 | |
51 | |||
52 | if (png_ptr->transformations & PNG_PACKSWAP) |
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53 | png_do_packswap(row_info, png_ptr->row_buf + 1); |
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3928 | Serge | 54 | #endif |
1897 | serge | 55 | |
56 | |||
57 | if (png_ptr->transformations & PNG_PACK) |
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58 | png_do_pack(row_info, png_ptr->row_buf + 1, |
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3928 | Serge | 59 | (png_uint_32)png_ptr->bit_depth); |
1897 | serge | 60 | #endif |
61 | |||
62 | |||
63 | if (png_ptr->transformations & PNG_SWAP_BYTES) |
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64 | png_do_swap(row_info, png_ptr->row_buf + 1); |
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3928 | Serge | 65 | #endif |
1897 | serge | 66 | |
67 | |||
68 | if (png_ptr->transformations & PNG_SHIFT) |
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69 | png_do_shift(row_info, png_ptr->row_buf + 1, |
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3928 | Serge | 70 | &(png_ptr->shift)); |
1897 | serge | 71 | #endif |
72 | |||
73 | |||
74 | if (png_ptr->transformations & PNG_SWAP_ALPHA) |
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75 | png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1); |
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3928 | Serge | 76 | #endif |
1897 | serge | 77 | |
78 | |||
79 | if (png_ptr->transformations & PNG_INVERT_ALPHA) |
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80 | png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1); |
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3928 | Serge | 81 | #endif |
1897 | serge | 82 | |
83 | |||
84 | if (png_ptr->transformations & PNG_BGR) |
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85 | png_do_bgr(row_info, png_ptr->row_buf + 1); |
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3928 | Serge | 86 | #endif |
1897 | serge | 87 | |
88 | |||
89 | if (png_ptr->transformations & PNG_INVERT_MONO) |
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90 | png_do_invert(row_info, png_ptr->row_buf + 1); |
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3928 | Serge | 91 | #endif |
1897 | serge | 92 | } |
93 | |||
94 | |||
95 | /* Pack pixels into bytes. Pass the true bit depth in bit_depth. The |
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96 | * row_info bit depth should be 8 (one pixel per byte). The channels |
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97 | * should be 1 (this only happens on grayscale and paletted images). |
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98 | */ |
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99 | void /* PRIVATE */ |
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100 | png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) |
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101 | { |
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102 | png_debug(1, "in png_do_pack"); |
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103 | |||
104 | |||
105 | row_info->channels == 1) |
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106 | { |
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107 | switch ((int)bit_depth) |
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108 | { |
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109 | case 1: |
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110 | { |
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111 | png_bytep sp, dp; |
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112 | int mask, v; |
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113 | png_uint_32 i; |
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114 | png_uint_32 row_width = row_info->width; |
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115 | |||
116 | |||
117 | dp = row; |
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118 | mask = 0x80; |
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119 | v = 0; |
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120 | |||
121 | |||
122 | { |
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123 | if (*sp != 0) |
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124 | v |= mask; |
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125 | |||
126 | |||
127 | |||
128 | |||
129 | mask >>= 1; |
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130 | |||
131 | |||
132 | { |
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133 | mask = 0x80; |
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134 | *dp = (png_byte)v; |
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135 | dp++; |
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136 | v = 0; |
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137 | } |
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138 | } |
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139 | |||
140 | |||
141 | *dp = (png_byte)v; |
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142 | |||
143 | |||
144 | } |
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145 | |||
146 | |||
147 | { |
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148 | png_bytep sp, dp; |
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149 | int shift, v; |
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150 | png_uint_32 i; |
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151 | png_uint_32 row_width = row_info->width; |
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152 | |||
153 | |||
154 | dp = row; |
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155 | shift = 6; |
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156 | v = 0; |
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157 | |||
158 | |||
159 | { |
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160 | png_byte value; |
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161 | |||
162 | |||
163 | v |= (value << shift); |
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164 | |||
165 | |||
166 | { |
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167 | shift = 6; |
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168 | *dp = (png_byte)v; |
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169 | dp++; |
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170 | v = 0; |
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171 | } |
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172 | |||
173 | |||
174 | shift -= 2; |
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175 | |||
176 | |||
177 | } |
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178 | |||
179 | |||
180 | *dp = (png_byte)v; |
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181 | |||
182 | |||
183 | } |
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184 | |||
185 | |||
186 | { |
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187 | png_bytep sp, dp; |
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188 | int shift, v; |
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189 | png_uint_32 i; |
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190 | png_uint_32 row_width = row_info->width; |
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191 | |||
192 | |||
193 | dp = row; |
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194 | shift = 4; |
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195 | v = 0; |
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196 | |||
197 | |||
198 | { |
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199 | png_byte value; |
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200 | |||
201 | |||
202 | v |= (value << shift); |
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203 | |||
204 | |||
205 | { |
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206 | shift = 4; |
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207 | *dp = (png_byte)v; |
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208 | dp++; |
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209 | v = 0; |
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210 | } |
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211 | |||
212 | |||
213 | shift -= 4; |
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214 | |||
215 | |||
216 | } |
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217 | |||
218 | |||
219 | *dp = (png_byte)v; |
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220 | |||
221 | |||
222 | } |
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223 | |||
224 | |||
225 | break; |
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226 | } |
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227 | |||
228 | |||
229 | row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); |
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230 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
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231 | row_info->width); |
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232 | } |
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233 | } |
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234 | #endif |
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235 | |||
236 | |||
237 | /* Shift pixel values to take advantage of whole range. Pass the |
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238 | * true number of bits in bit_depth. The row should be packed |
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239 | * according to row_info->bit_depth. Thus, if you had a row of |
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240 | * bit depth 4, but the pixels only had values from 0 to 7, you |
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241 | * would pass 3 as bit_depth, and this routine would translate the |
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242 | * data to 0 to 15. |
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243 | */ |
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244 | void /* PRIVATE */ |
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245 | png_do_shift(png_row_infop row_info, png_bytep row, |
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246 | png_const_color_8p bit_depth) |
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247 | { |
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248 | png_debug(1, "in png_do_shift"); |
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249 | |||
250 | |||
251 | { |
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252 | int shift_start[4], shift_dec[4]; |
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253 | int channels = 0; |
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254 | |||
255 | |||
256 | { |
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257 | shift_start[channels] = row_info->bit_depth - bit_depth->red; |
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258 | shift_dec[channels] = bit_depth->red; |
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259 | channels++; |
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260 | |||
261 | |||
262 | shift_dec[channels] = bit_depth->green; |
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263 | channels++; |
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264 | |||
265 | |||
266 | shift_dec[channels] = bit_depth->blue; |
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267 | channels++; |
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268 | } |
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269 | |||
270 | |||
271 | { |
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272 | shift_start[channels] = row_info->bit_depth - bit_depth->gray; |
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273 | shift_dec[channels] = bit_depth->gray; |
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274 | channels++; |
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275 | } |
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276 | |||
277 | |||
278 | { |
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279 | shift_start[channels] = row_info->bit_depth - bit_depth->alpha; |
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280 | shift_dec[channels] = bit_depth->alpha; |
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281 | channels++; |
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282 | } |
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283 | |||
284 | |||
285 | if (row_info->bit_depth < 8) |
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286 | { |
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287 | png_bytep bp = row; |
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288 | png_size_t i; |
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289 | unsigned int mask; |
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3928 | Serge | 290 | png_size_t row_bytes = row_info->rowbytes; |
1897 | serge | 291 | |
292 | |||
293 | mask = 0x55; |
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294 | |||
295 | |||
296 | mask = 0x11; |
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297 | |||
298 | |||
299 | mask = 0xff; |
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300 | |||
301 | |||
302 | { |
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303 | int j; |
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304 | unsigned int v, out; |
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3928 | Serge | 305 | |
1897 | serge | 306 | |
307 | out = 0; |
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3928 | Serge | 308 | |
1897 | serge | 309 | |
310 | { |
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311 | if (j > 0) |
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312 | out |= v << j; |
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3928 | Serge | 313 | |
1897 | serge | 314 | |
315 | out |= (v >> (-j)) & mask; |
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3928 | Serge | 316 | } |
1897 | serge | 317 | |
3928 | Serge | 318 | |
319 | } |
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1897 | serge | 320 | } |
321 | |||
322 | |||
323 | { |
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324 | png_bytep bp = row; |
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325 | png_uint_32 i; |
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326 | png_uint_32 istop = channels * row_info->width; |
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327 | |||
328 | |||
329 | { |
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330 | |||
331 | |||
3928 | Serge | 332 | int j; |
1897 | serge | 333 | unsigned int v, out; |
3928 | Serge | 334 | |
1897 | serge | 335 | |
336 | out = 0; |
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3928 | Serge | 337 | |
1897 | serge | 338 | |
339 | { |
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340 | if (j > 0) |
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341 | out |= v << j; |
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3928 | Serge | 342 | |
1897 | serge | 343 | |
344 | out |= v >> (-j); |
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3928 | Serge | 345 | } |
1897 | serge | 346 | |
3928 | Serge | 347 | |
348 | } |
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1897 | serge | 349 | } |
350 | |||
351 | |||
352 | { |
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353 | png_bytep bp; |
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354 | png_uint_32 i; |
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355 | png_uint_32 istop = channels * row_info->width; |
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356 | |||
357 | |||
358 | { |
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359 | const unsigned int c = i%channels; |
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3928 | Serge | 360 | int j; |
1897 | serge | 361 | unsigned int value, v; |
3928 | Serge | 362 | |
1897 | serge | 363 | |
3928 | Serge | 364 | value = 0; |
1897 | serge | 365 | |
366 | |||
367 | { |
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368 | if (j > 0) |
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369 | value |= v << j; |
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3928 | Serge | 370 | |
1897 | serge | 371 | |
372 | value |= v >> (-j); |
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3928 | Serge | 373 | } |
1897 | serge | 374 | *bp++ = (png_byte)((value >> 8) & 0xff); |
3928 | Serge | 375 | *bp++ = (png_byte)(value & 0xff); |
1897 | serge | 376 | } |
377 | } |
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378 | } |
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379 | } |
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380 | #endif |
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381 | |||
382 | |||
383 | void /* PRIVATE */ |
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384 | png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) |
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385 | { |
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386 | png_debug(1, "in png_do_write_swap_alpha"); |
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387 | |||
388 | |||
389 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
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390 | { |
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391 | if (row_info->bit_depth == 8) |
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392 | { |
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393 | /* This converts from ARGB to RGBA */ |
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394 | png_bytep sp, dp; |
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395 | png_uint_32 i; |
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396 | png_uint_32 row_width = row_info->width; |
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397 | |||
398 | |||
399 | { |
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400 | png_byte save = *(sp++); |
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401 | *(dp++) = *(sp++); |
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402 | *(dp++) = *(sp++); |
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403 | *(dp++) = *(sp++); |
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404 | *(dp++) = save; |
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405 | } |
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406 | } |
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407 | |||
408 | |||
409 | else |
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410 | { |
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411 | /* This converts from AARRGGBB to RRGGBBAA */ |
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412 | png_bytep sp, dp; |
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413 | png_uint_32 i; |
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414 | png_uint_32 row_width = row_info->width; |
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415 | |||
416 | |||
417 | { |
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418 | png_byte save[2]; |
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419 | save[0] = *(sp++); |
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420 | save[1] = *(sp++); |
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421 | *(dp++) = *(sp++); |
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422 | *(dp++) = *(sp++); |
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423 | *(dp++) = *(sp++); |
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424 | *(dp++) = *(sp++); |
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425 | *(dp++) = *(sp++); |
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426 | *(dp++) = *(sp++); |
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427 | *(dp++) = save[0]; |
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428 | *(dp++) = save[1]; |
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429 | } |
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430 | } |
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431 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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432 | } |
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433 | |||
434 | |||
435 | { |
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436 | if (row_info->bit_depth == 8) |
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437 | { |
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438 | /* This converts from AG to GA */ |
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439 | png_bytep sp, dp; |
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440 | png_uint_32 i; |
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441 | png_uint_32 row_width = row_info->width; |
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442 | |||
443 | |||
444 | { |
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445 | png_byte save = *(sp++); |
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446 | *(dp++) = *(sp++); |
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447 | *(dp++) = save; |
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448 | } |
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449 | } |
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450 | |||
451 | |||
452 | else |
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453 | { |
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454 | /* This converts from AAGG to GGAA */ |
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455 | png_bytep sp, dp; |
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456 | png_uint_32 i; |
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457 | png_uint_32 row_width = row_info->width; |
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458 | |||
459 | |||
460 | { |
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461 | png_byte save[2]; |
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462 | save[0] = *(sp++); |
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463 | save[1] = *(sp++); |
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464 | *(dp++) = *(sp++); |
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465 | *(dp++) = *(sp++); |
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466 | *(dp++) = save[0]; |
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467 | *(dp++) = save[1]; |
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468 | } |
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469 | } |
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470 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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471 | } |
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472 | } |
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473 | } |
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474 | #endif |
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475 | |||
476 | |||
477 | void /* PRIVATE */ |
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478 | png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) |
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479 | { |
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480 | png_debug(1, "in png_do_write_invert_alpha"); |
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481 | |||
482 | |||
483 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
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484 | { |
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485 | if (row_info->bit_depth == 8) |
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486 | { |
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487 | /* This inverts the alpha channel in RGBA */ |
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488 | png_bytep sp, dp; |
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489 | png_uint_32 i; |
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490 | png_uint_32 row_width = row_info->width; |
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491 | |||
492 | |||
493 | { |
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494 | /* Does nothing |
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495 | *(dp++) = *(sp++); |
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496 | *(dp++) = *(sp++); |
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497 | *(dp++) = *(sp++); |
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498 | */ |
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499 | sp+=3; dp = sp; |
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500 | *(dp++) = (png_byte)(255 - *(sp++)); |
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501 | } |
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502 | } |
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503 | |||
504 | |||
505 | else |
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506 | { |
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507 | /* This inverts the alpha channel in RRGGBBAA */ |
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508 | png_bytep sp, dp; |
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509 | png_uint_32 i; |
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510 | png_uint_32 row_width = row_info->width; |
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511 | |||
512 | |||
513 | { |
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514 | /* Does nothing |
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515 | *(dp++) = *(sp++); |
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516 | *(dp++) = *(sp++); |
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517 | *(dp++) = *(sp++); |
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518 | *(dp++) = *(sp++); |
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519 | *(dp++) = *(sp++); |
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520 | *(dp++) = *(sp++); |
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521 | */ |
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522 | sp+=6; dp = sp; |
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523 | *(dp++) = (png_byte)(255 - *(sp++)); |
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524 | *(dp++) = (png_byte)(255 - *(sp++)); |
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525 | } |
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526 | } |
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527 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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528 | } |
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529 | |||
530 | |||
531 | { |
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532 | if (row_info->bit_depth == 8) |
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533 | { |
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534 | /* This inverts the alpha channel in GA */ |
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535 | png_bytep sp, dp; |
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536 | png_uint_32 i; |
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537 | png_uint_32 row_width = row_info->width; |
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538 | |||
539 | |||
540 | { |
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541 | *(dp++) = *(sp++); |
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542 | *(dp++) = (png_byte)(255 - *(sp++)); |
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543 | } |
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544 | } |
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545 | |||
546 | |||
547 | else |
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548 | { |
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549 | /* This inverts the alpha channel in GGAA */ |
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550 | png_bytep sp, dp; |
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551 | png_uint_32 i; |
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552 | png_uint_32 row_width = row_info->width; |
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553 | |||
554 | |||
555 | { |
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556 | /* Does nothing |
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557 | *(dp++) = *(sp++); |
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558 | *(dp++) = *(sp++); |
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559 | */ |
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560 | sp+=2; dp = sp; |
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561 | *(dp++) = (png_byte)(255 - *(sp++)); |
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562 | *(dp++) = (png_byte)(255 - *(sp++)); |
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563 | } |
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564 | } |
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565 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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566 | } |
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567 | } |
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568 | } |
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569 | #endif |
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570 | #endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */ |
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3928 | Serge | 571 | |
1897 | serge | 572 | |
573 | /* Undoes intrapixel differencing */ |
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574 | void /* PRIVATE */ |
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575 | png_do_write_intrapixel(png_row_infop row_info, png_bytep row) |
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576 | { |
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577 | png_debug(1, "in png_do_write_intrapixel"); |
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578 | |||
579 | |||
580 | { |
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581 | int bytes_per_pixel; |
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582 | png_uint_32 row_width = row_info->width; |
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583 | if (row_info->bit_depth == 8) |
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584 | { |
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585 | png_bytep rp; |
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586 | png_uint_32 i; |
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587 | |||
588 | |||
589 | bytes_per_pixel = 3; |
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590 | |||
591 | |||
592 | bytes_per_pixel = 4; |
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593 | |||
594 | |||
595 | return; |
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596 | |||
597 | |||
598 | { |
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599 | *(rp) = (png_byte)((*rp - *(rp + 1)) & 0xff); |
||
600 | *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff); |
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601 | } |
||
602 | } |
||
603 | |||
604 | |||
605 | else if (row_info->bit_depth == 16) |
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606 | { |
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607 | png_bytep rp; |
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608 | png_uint_32 i; |
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609 | |||
610 | |||
611 | bytes_per_pixel = 6; |
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612 | |||
613 | |||
614 | bytes_per_pixel = 8; |
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615 | |||
616 | |||
617 | return; |
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618 | |||
619 | |||
620 | { |
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621 | png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); |
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622 | png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); |
||
623 | png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); |
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624 | png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); |
||
625 | png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); |
||
626 | *(rp ) = (png_byte)((red >> 8) & 0xff); |
||
627 | *(rp + 1) = (png_byte)(red & 0xff); |
||
628 | *(rp + 4) = (png_byte)((blue >> 8) & 0xff); |
||
629 | *(rp + 5) = (png_byte)(blue & 0xff); |
||
630 | } |
||
631 | } |
||
632 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
||
633 | } |
||
634 | } |
||
635 | #endif /* PNG_MNG_FEATURES_SUPPORTED */ |
||
636 | #endif /* PNG_WRITE_SUPPORTED */><>><>><>>>>>>>>>>>><>>><>>><>>>><>>><>>> |
||
637 |