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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 1.5.0 [January 6, 2011] |
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4 | * Copyright (c) 1998-2011 Glenn Randers-Pehrson |
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5 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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6 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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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 | |||
18 | * transformations is significant. |
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19 | */ |
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20 | void /* PRIVATE */ |
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21 | png_do_write_transformations(png_structp png_ptr) |
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22 | { |
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23 | png_debug(1, "in png_do_write_transformations"); |
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24 | |||
25 | |||
26 | return; |
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27 | |||
28 | |||
29 | if (png_ptr->transformations & PNG_USER_TRANSFORM) |
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30 | if (png_ptr->write_user_transform_fn != NULL) |
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31 | (*(png_ptr->write_user_transform_fn)) /* User write transform |
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32 | function */ |
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33 | (png_ptr, /* png_ptr */ |
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34 | &(png_ptr->row_info), /* row_info: */ |
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35 | /* png_uint_32 width; width of row */ |
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36 | /* png_size_t rowbytes; number of bytes in row */ |
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37 | /* png_byte color_type; color type of pixels */ |
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38 | /* png_byte bit_depth; bit depth of samples */ |
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39 | /* png_byte channels; number of channels (1-4) */ |
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40 | /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
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41 | png_ptr->row_buf + 1); /* start of pixel data for row */ |
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42 | #endif |
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43 | |||
44 | |||
45 | if (png_ptr->transformations & PNG_FILLER) |
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46 | png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
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47 | png_ptr->flags); |
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48 | #endif |
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49 | |||
50 | |||
51 | if (png_ptr->transformations & PNG_PACKSWAP) |
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52 | png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
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53 | #endif |
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54 | |||
55 | |||
56 | if (png_ptr->transformations & PNG_PACK) |
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57 | png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1, |
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58 | (png_uint_32)png_ptr->bit_depth); |
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59 | #endif |
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60 | |||
61 | |||
62 | if (png_ptr->transformations & PNG_SWAP_BYTES) |
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63 | png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
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64 | #endif |
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65 | |||
66 | |||
67 | if (png_ptr->transformations & PNG_SHIFT) |
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68 | png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1, |
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69 | &(png_ptr->shift)); |
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70 | #endif |
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71 | |||
72 | |||
73 | if (png_ptr->transformations & PNG_SWAP_ALPHA) |
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74 | png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
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75 | #endif |
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76 | |||
77 | |||
78 | if (png_ptr->transformations & PNG_INVERT_ALPHA) |
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79 | png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
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80 | #endif |
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81 | |||
82 | |||
83 | if (png_ptr->transformations & PNG_BGR) |
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84 | png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); |
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85 | #endif |
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86 | |||
87 | |||
88 | if (png_ptr->transformations & PNG_INVERT_MONO) |
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89 | png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); |
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90 | #endif |
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91 | } |
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92 | |||
93 | |||
94 | /* Pack pixels into bytes. Pass the true bit depth in bit_depth. The |
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95 | * row_info bit depth should be 8 (one pixel per byte). The channels |
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96 | * should be 1 (this only happens on grayscale and paletted images). |
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97 | */ |
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98 | void /* PRIVATE */ |
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99 | png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) |
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100 | { |
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101 | png_debug(1, "in png_do_pack"); |
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102 | |||
103 | |||
104 | row_info->channels == 1) |
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105 | { |
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106 | switch ((int)bit_depth) |
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107 | { |
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108 | case 1: |
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109 | { |
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110 | png_bytep sp, dp; |
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111 | int mask, v; |
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112 | png_uint_32 i; |
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113 | png_uint_32 row_width = row_info->width; |
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114 | |||
115 | |||
116 | dp = row; |
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117 | mask = 0x80; |
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118 | v = 0; |
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119 | |||
120 | |||
121 | { |
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122 | if (*sp != 0) |
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123 | v |= mask; |
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124 | |||
125 | |||
126 | |||
127 | |||
128 | mask >>= 1; |
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129 | |||
130 | |||
131 | { |
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132 | mask = 0x80; |
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133 | *dp = (png_byte)v; |
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134 | dp++; |
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135 | v = 0; |
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136 | } |
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137 | } |
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138 | |||
139 | |||
140 | *dp = (png_byte)v; |
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141 | |||
142 | |||
143 | } |
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144 | |||
145 | |||
146 | { |
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147 | png_bytep sp, dp; |
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148 | int shift, v; |
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149 | png_uint_32 i; |
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150 | png_uint_32 row_width = row_info->width; |
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151 | |||
152 | |||
153 | dp = row; |
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154 | shift = 6; |
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155 | v = 0; |
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156 | |||
157 | |||
158 | { |
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159 | png_byte value; |
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160 | |||
161 | |||
162 | v |= (value << shift); |
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163 | |||
164 | |||
165 | { |
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166 | shift = 6; |
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167 | *dp = (png_byte)v; |
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168 | dp++; |
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169 | v = 0; |
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170 | } |
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171 | |||
172 | |||
173 | shift -= 2; |
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174 | |||
175 | |||
176 | } |
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177 | |||
178 | |||
179 | *dp = (png_byte)v; |
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180 | |||
181 | |||
182 | } |
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183 | |||
184 | |||
185 | { |
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186 | png_bytep sp, dp; |
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187 | int shift, v; |
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188 | png_uint_32 i; |
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189 | png_uint_32 row_width = row_info->width; |
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190 | |||
191 | |||
192 | dp = row; |
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193 | shift = 4; |
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194 | v = 0; |
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195 | |||
196 | |||
197 | { |
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198 | png_byte value; |
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199 | |||
200 | |||
201 | v |= (value << shift); |
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202 | |||
203 | |||
204 | { |
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205 | shift = 4; |
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206 | *dp = (png_byte)v; |
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207 | dp++; |
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208 | v = 0; |
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209 | } |
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210 | |||
211 | |||
212 | shift -= 4; |
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213 | |||
214 | |||
215 | } |
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216 | |||
217 | |||
218 | *dp = (png_byte)v; |
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219 | |||
220 | |||
221 | } |
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222 | |||
223 | |||
224 | break; |
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225 | } |
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226 | |||
227 | |||
228 | row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); |
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229 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
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230 | row_info->width); |
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231 | } |
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232 | } |
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233 | #endif |
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234 | |||
235 | |||
236 | /* Shift pixel values to take advantage of whole range. Pass the |
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237 | * true number of bits in bit_depth. The row should be packed |
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238 | * according to row_info->bit_depth. Thus, if you had a row of |
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239 | * bit depth 4, but the pixels only had values from 0 to 7, you |
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240 | * would pass 3 as bit_depth, and this routine would translate the |
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241 | * data to 0 to 15. |
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242 | */ |
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243 | void /* PRIVATE */ |
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244 | png_do_shift(png_row_infop row_info, png_bytep row, |
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245 | png_const_color_8p bit_depth) |
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246 | { |
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247 | png_debug(1, "in png_do_shift"); |
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248 | |||
249 | |||
250 | { |
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251 | int shift_start[4], shift_dec[4]; |
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252 | int channels = 0; |
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253 | |||
254 | |||
255 | { |
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256 | shift_start[channels] = row_info->bit_depth - bit_depth->red; |
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257 | shift_dec[channels] = bit_depth->red; |
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258 | channels++; |
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259 | |||
260 | |||
261 | shift_dec[channels] = bit_depth->green; |
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262 | channels++; |
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263 | |||
264 | |||
265 | shift_dec[channels] = bit_depth->blue; |
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266 | channels++; |
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267 | } |
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268 | |||
269 | |||
270 | { |
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271 | shift_start[channels] = row_info->bit_depth - bit_depth->gray; |
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272 | shift_dec[channels] = bit_depth->gray; |
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273 | channels++; |
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274 | } |
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275 | |||
276 | |||
277 | { |
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278 | shift_start[channels] = row_info->bit_depth - bit_depth->alpha; |
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279 | shift_dec[channels] = bit_depth->alpha; |
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280 | channels++; |
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281 | } |
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282 | |||
283 | |||
284 | if (row_info->bit_depth < 8) |
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285 | { |
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286 | png_bytep bp = row; |
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287 | png_size_t i; |
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288 | png_byte mask; |
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289 | png_size_t row_bytes = row_info->rowbytes; |
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290 | |||
291 | |||
292 | mask = 0x55; |
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293 | |||
294 | |||
295 | mask = 0x11; |
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296 | |||
297 | |||
298 | mask = 0xff; |
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299 | |||
300 | |||
301 | { |
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302 | png_uint_16 v; |
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303 | int j; |
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304 | |||
305 | |||
306 | *bp = 0; |
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307 | |||
308 | |||
309 | { |
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310 | if (j > 0) |
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311 | *bp |= (png_byte)((v << j) & 0xff); |
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312 | |||
313 | |||
314 | *bp |= (png_byte)((v >> (-j)) & mask); |
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315 | } |
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316 | } |
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317 | } |
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318 | |||
319 | |||
320 | { |
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321 | png_bytep bp = row; |
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322 | png_uint_32 i; |
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323 | png_uint_32 istop = channels * row_info->width; |
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324 | |||
325 | |||
326 | { |
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327 | |||
328 | |||
329 | int j; |
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330 | int c = (int)(i%channels); |
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331 | |||
332 | |||
333 | *bp = 0; |
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334 | |||
335 | |||
336 | { |
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337 | if (j > 0) |
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338 | *bp |= (png_byte)((v << j) & 0xff); |
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339 | |||
340 | |||
341 | *bp |= (png_byte)((v >> (-j)) & 0xff); |
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342 | } |
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343 | } |
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344 | } |
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345 | |||
346 | |||
347 | { |
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348 | png_bytep bp; |
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349 | png_uint_32 i; |
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350 | png_uint_32 istop = channels * row_info->width; |
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351 | |||
352 | |||
353 | { |
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354 | int c = (int)(i%channels); |
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355 | png_uint_16 value, v; |
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356 | int j; |
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357 | |||
358 | |||
359 | value = 0; |
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360 | |||
361 | |||
362 | { |
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363 | if (j > 0) |
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364 | value |= (png_uint_16)((v << j) & (png_uint_16)0xffff); |
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365 | |||
366 | |||
367 | value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff); |
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368 | } |
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369 | *bp++ = (png_byte)(value >> 8); |
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370 | *bp++ = (png_byte)(value & 0xff); |
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371 | } |
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372 | } |
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373 | } |
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374 | } |
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375 | #endif |
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376 | |||
377 | |||
378 | void /* PRIVATE */ |
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379 | png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) |
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380 | { |
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381 | png_debug(1, "in png_do_write_swap_alpha"); |
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382 | |||
383 | |||
384 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
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385 | { |
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386 | if (row_info->bit_depth == 8) |
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387 | { |
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388 | /* This converts from ARGB to RGBA */ |
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389 | png_bytep sp, dp; |
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390 | png_uint_32 i; |
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391 | png_uint_32 row_width = row_info->width; |
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392 | |||
393 | |||
394 | { |
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395 | png_byte save = *(sp++); |
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396 | *(dp++) = *(sp++); |
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397 | *(dp++) = *(sp++); |
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398 | *(dp++) = *(sp++); |
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399 | *(dp++) = save; |
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400 | } |
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401 | } |
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402 | |||
403 | |||
404 | else |
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405 | { |
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406 | /* This converts from AARRGGBB to RRGGBBAA */ |
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407 | png_bytep sp, dp; |
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408 | png_uint_32 i; |
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409 | png_uint_32 row_width = row_info->width; |
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410 | |||
411 | |||
412 | { |
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413 | png_byte save[2]; |
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414 | save[0] = *(sp++); |
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415 | save[1] = *(sp++); |
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416 | *(dp++) = *(sp++); |
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417 | *(dp++) = *(sp++); |
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418 | *(dp++) = *(sp++); |
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419 | *(dp++) = *(sp++); |
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420 | *(dp++) = *(sp++); |
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421 | *(dp++) = *(sp++); |
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422 | *(dp++) = save[0]; |
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423 | *(dp++) = save[1]; |
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424 | } |
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425 | } |
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426 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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427 | } |
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428 | |||
429 | |||
430 | { |
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431 | if (row_info->bit_depth == 8) |
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432 | { |
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433 | /* This converts from AG to GA */ |
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434 | png_bytep sp, dp; |
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435 | png_uint_32 i; |
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436 | png_uint_32 row_width = row_info->width; |
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437 | |||
438 | |||
439 | { |
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440 | png_byte save = *(sp++); |
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441 | *(dp++) = *(sp++); |
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442 | *(dp++) = save; |
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443 | } |
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444 | } |
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445 | |||
446 | |||
447 | else |
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448 | { |
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449 | /* This converts from AAGG to GGAA */ |
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450 | png_bytep sp, dp; |
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451 | png_uint_32 i; |
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452 | png_uint_32 row_width = row_info->width; |
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453 | |||
454 | |||
455 | { |
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456 | png_byte save[2]; |
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457 | save[0] = *(sp++); |
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458 | save[1] = *(sp++); |
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459 | *(dp++) = *(sp++); |
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460 | *(dp++) = *(sp++); |
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461 | *(dp++) = save[0]; |
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462 | *(dp++) = save[1]; |
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463 | } |
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464 | } |
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465 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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466 | } |
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467 | } |
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468 | } |
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469 | #endif |
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470 | |||
471 | |||
472 | void /* PRIVATE */ |
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473 | png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) |
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474 | { |
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475 | png_debug(1, "in png_do_write_invert_alpha"); |
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476 | |||
477 | |||
478 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
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479 | { |
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480 | if (row_info->bit_depth == 8) |
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481 | { |
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482 | /* This inverts the alpha channel in RGBA */ |
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483 | png_bytep sp, dp; |
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484 | png_uint_32 i; |
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485 | png_uint_32 row_width = row_info->width; |
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486 | |||
487 | |||
488 | { |
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489 | /* Does nothing |
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490 | *(dp++) = *(sp++); |
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491 | *(dp++) = *(sp++); |
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492 | *(dp++) = *(sp++); |
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493 | */ |
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494 | sp+=3; dp = sp; |
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495 | *(dp++) = (png_byte)(255 - *(sp++)); |
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496 | } |
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497 | } |
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498 | |||
499 | |||
500 | else |
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501 | { |
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502 | /* This inverts the alpha channel in RRGGBBAA */ |
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503 | png_bytep sp, dp; |
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504 | png_uint_32 i; |
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505 | png_uint_32 row_width = row_info->width; |
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506 | |||
507 | |||
508 | { |
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509 | /* Does nothing |
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510 | *(dp++) = *(sp++); |
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511 | *(dp++) = *(sp++); |
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512 | *(dp++) = *(sp++); |
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513 | *(dp++) = *(sp++); |
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514 | *(dp++) = *(sp++); |
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515 | *(dp++) = *(sp++); |
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516 | */ |
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517 | sp+=6; dp = sp; |
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518 | *(dp++) = (png_byte)(255 - *(sp++)); |
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519 | *(dp++) = (png_byte)(255 - *(sp++)); |
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520 | } |
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521 | } |
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522 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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523 | } |
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524 | |||
525 | |||
526 | { |
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527 | if (row_info->bit_depth == 8) |
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528 | { |
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529 | /* This inverts the alpha channel in GA */ |
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530 | png_bytep sp, dp; |
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531 | png_uint_32 i; |
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532 | png_uint_32 row_width = row_info->width; |
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533 | |||
534 | |||
535 | { |
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536 | *(dp++) = *(sp++); |
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537 | *(dp++) = (png_byte)(255 - *(sp++)); |
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538 | } |
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539 | } |
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540 | |||
541 | |||
542 | else |
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543 | { |
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544 | /* This inverts the alpha channel in GGAA */ |
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545 | png_bytep sp, dp; |
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546 | png_uint_32 i; |
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547 | png_uint_32 row_width = row_info->width; |
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548 | |||
549 | |||
550 | { |
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551 | /* Does nothing |
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552 | *(dp++) = *(sp++); |
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553 | *(dp++) = *(sp++); |
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554 | */ |
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555 | sp+=2; dp = sp; |
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556 | *(dp++) = (png_byte)(255 - *(sp++)); |
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557 | *(dp++) = (png_byte)(255 - *(sp++)); |
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558 | } |
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559 | } |
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560 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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561 | } |
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562 | } |
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563 | } |
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564 | #endif |
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565 | |||
566 | |||
567 | /* Undoes intrapixel differencing */ |
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568 | void /* PRIVATE */ |
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569 | png_do_write_intrapixel(png_row_infop row_info, png_bytep row) |
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570 | { |
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571 | png_debug(1, "in png_do_write_intrapixel"); |
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572 | |||
573 | |||
574 | { |
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575 | int bytes_per_pixel; |
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576 | png_uint_32 row_width = row_info->width; |
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577 | if (row_info->bit_depth == 8) |
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578 | { |
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579 | png_bytep rp; |
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580 | png_uint_32 i; |
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581 | |||
582 | |||
583 | bytes_per_pixel = 3; |
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584 | |||
585 | |||
586 | bytes_per_pixel = 4; |
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587 | |||
588 | |||
589 | return; |
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590 | |||
591 | |||
592 | { |
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593 | *(rp) = (png_byte)((*rp - *(rp + 1)) & 0xff); |
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594 | *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff); |
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595 | } |
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596 | } |
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597 | |||
598 | |||
599 | else if (row_info->bit_depth == 16) |
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600 | { |
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601 | png_bytep rp; |
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602 | png_uint_32 i; |
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603 | |||
604 | |||
605 | bytes_per_pixel = 6; |
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606 | |||
607 | |||
608 | bytes_per_pixel = 8; |
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609 | |||
610 | |||
611 | return; |
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612 | |||
613 | |||
614 | { |
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615 | png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); |
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616 | png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); |
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617 | png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); |
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618 | png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); |
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619 | png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); |
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620 | *(rp ) = (png_byte)((red >> 8) & 0xff); |
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621 | *(rp + 1) = (png_byte)(red & 0xff); |
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622 | *(rp + 4) = (png_byte)((blue >> 8) & 0xff); |
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623 | *(rp + 5) = (png_byte)(blue & 0xff); |
||
624 | } |
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625 | } |
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626 | #endif /* PNG_WRITE_16BIT_SUPPORTED */ |
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627 | } |
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628 | } |
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629 | #endif /* PNG_MNG_FEATURES_SUPPORTED */ |
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630 | #endif /* PNG_WRITE_SUPPORTED */><>><>><>>>>>>>>>>>><>><>>><>>><>>>><>>><>>> |
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631 |