1 /* |
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2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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3 * |
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4 * This code is free software; you can redistribute it and/or modify it |
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5 * under the terms of the GNU General Public License version 2 only, as |
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6 * published by the Free Software Foundation. Oracle designates this |
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7 * particular file as subject to the "Classpath" exception as provided |
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8 * by Oracle in the LICENSE file that accompanied this code. |
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9 * |
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10 * This code is distributed in the hope that it will be useful, but WITHOUT |
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11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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13 * version 2 for more details (a copy is included in the LICENSE file that |
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14 * accompanied this code). |
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15 * |
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16 * You should have received a copy of the GNU General Public License version |
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17 * 2 along with this work; if not, write to the Free Software Foundation, |
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18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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19 * |
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20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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21 * or visit www.oracle.com if you need additional information or have any |
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22 * questions. |
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23 */ |
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24 |
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25 /* pngwtran.c - transforms the data in a row for PNG writers |
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26 * |
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27 * This file is available under and governed by the GNU General Public |
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28 * License version 2 only, as published by the Free Software Foundation. |
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29 * However, the following notice accompanied the original version of this |
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30 * file and, per its terms, should not be removed: |
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31 * |
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32 * Last changed in libpng 1.6.18 [July 23, 2015] |
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33 * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson |
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34 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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35 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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36 * |
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37 * This code is released under the libpng license. |
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38 * For conditions of distribution and use, see the disclaimer |
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39 * and license in png.h |
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40 */ |
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41 |
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42 #include "pngpriv.h" |
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43 |
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44 #ifdef PNG_WRITE_SUPPORTED |
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45 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED |
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46 |
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47 #ifdef PNG_WRITE_PACK_SUPPORTED |
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48 /* Pack pixels into bytes. Pass the true bit depth in bit_depth. The |
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49 * row_info bit depth should be 8 (one pixel per byte). The channels |
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50 * should be 1 (this only happens on grayscale and paletted images). |
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51 */ |
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52 static void |
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53 png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) |
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54 { |
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55 png_debug(1, "in png_do_pack"); |
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56 |
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57 if (row_info->bit_depth == 8 && |
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58 row_info->channels == 1) |
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59 { |
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60 switch ((int)bit_depth) |
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61 { |
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62 case 1: |
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63 { |
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64 png_bytep sp, dp; |
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65 int mask, v; |
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66 png_uint_32 i; |
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67 png_uint_32 row_width = row_info->width; |
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68 |
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69 sp = row; |
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70 dp = row; |
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71 mask = 0x80; |
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72 v = 0; |
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73 |
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74 for (i = 0; i < row_width; i++) |
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75 { |
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76 if (*sp != 0) |
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77 v |= mask; |
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78 |
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79 sp++; |
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80 |
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81 if (mask > 1) |
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82 mask >>= 1; |
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83 |
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84 else |
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85 { |
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86 mask = 0x80; |
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87 *dp = (png_byte)v; |
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88 dp++; |
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89 v = 0; |
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90 } |
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91 } |
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92 |
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93 if (mask != 0x80) |
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94 *dp = (png_byte)v; |
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95 |
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96 break; |
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97 } |
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98 |
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99 case 2: |
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100 { |
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101 png_bytep sp, dp; |
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102 unsigned int shift; |
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103 int v; |
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104 png_uint_32 i; |
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105 png_uint_32 row_width = row_info->width; |
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106 |
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107 sp = row; |
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108 dp = row; |
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109 shift = 6; |
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110 v = 0; |
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111 |
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112 for (i = 0; i < row_width; i++) |
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113 { |
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114 png_byte value; |
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115 |
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116 value = (png_byte)(*sp & 0x03); |
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117 v |= (value << shift); |
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118 |
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119 if (shift == 0) |
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120 { |
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121 shift = 6; |
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122 *dp = (png_byte)v; |
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123 dp++; |
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124 v = 0; |
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125 } |
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126 |
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127 else |
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128 shift -= 2; |
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129 |
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130 sp++; |
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131 } |
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132 |
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133 if (shift != 6) |
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134 *dp = (png_byte)v; |
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135 |
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136 break; |
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137 } |
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138 |
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139 case 4: |
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140 { |
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141 png_bytep sp, dp; |
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142 unsigned int shift; |
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143 int v; |
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144 png_uint_32 i; |
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145 png_uint_32 row_width = row_info->width; |
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146 |
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147 sp = row; |
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148 dp = row; |
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149 shift = 4; |
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150 v = 0; |
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151 |
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152 for (i = 0; i < row_width; i++) |
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153 { |
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154 png_byte value; |
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155 |
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156 value = (png_byte)(*sp & 0x0f); |
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157 v |= (value << shift); |
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158 |
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159 if (shift == 0) |
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160 { |
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161 shift = 4; |
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162 *dp = (png_byte)v; |
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163 dp++; |
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164 v = 0; |
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165 } |
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166 |
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167 else |
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168 shift -= 4; |
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169 |
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170 sp++; |
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171 } |
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172 |
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173 if (shift != 4) |
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174 *dp = (png_byte)v; |
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175 |
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176 break; |
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177 } |
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178 |
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179 default: |
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180 break; |
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181 } |
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182 |
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183 row_info->bit_depth = (png_byte)bit_depth; |
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184 row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); |
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185 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
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186 row_info->width); |
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187 } |
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188 } |
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189 #endif |
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190 |
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191 #ifdef PNG_WRITE_SHIFT_SUPPORTED |
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192 /* Shift pixel values to take advantage of whole range. Pass the |
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193 * true number of bits in bit_depth. The row should be packed |
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194 * according to row_info->bit_depth. Thus, if you had a row of |
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195 * bit depth 4, but the pixels only had values from 0 to 7, you |
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196 * would pass 3 as bit_depth, and this routine would translate the |
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197 * data to 0 to 15. |
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198 */ |
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199 static void |
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200 png_do_shift(png_row_infop row_info, png_bytep row, |
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201 png_const_color_8p bit_depth) |
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202 { |
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203 png_debug(1, "in png_do_shift"); |
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204 |
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205 if (row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
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206 { |
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207 int shift_start[4], shift_dec[4]; |
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208 int channels = 0; |
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209 |
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210 if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) |
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211 { |
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212 shift_start[channels] = row_info->bit_depth - bit_depth->red; |
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213 shift_dec[channels] = bit_depth->red; |
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214 channels++; |
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215 |
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216 shift_start[channels] = row_info->bit_depth - bit_depth->green; |
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217 shift_dec[channels] = bit_depth->green; |
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218 channels++; |
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219 |
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220 shift_start[channels] = row_info->bit_depth - bit_depth->blue; |
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221 shift_dec[channels] = bit_depth->blue; |
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222 channels++; |
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223 } |
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224 |
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225 else |
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226 { |
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227 shift_start[channels] = row_info->bit_depth - bit_depth->gray; |
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228 shift_dec[channels] = bit_depth->gray; |
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229 channels++; |
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230 } |
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231 |
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232 if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) |
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233 { |
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234 shift_start[channels] = row_info->bit_depth - bit_depth->alpha; |
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235 shift_dec[channels] = bit_depth->alpha; |
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236 channels++; |
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237 } |
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238 |
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239 /* With low row depths, could only be grayscale, so one channel */ |
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240 if (row_info->bit_depth < 8) |
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241 { |
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242 png_bytep bp = row; |
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243 png_size_t i; |
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244 unsigned int mask; |
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245 png_size_t row_bytes = row_info->rowbytes; |
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246 |
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247 if (bit_depth->gray == 1 && row_info->bit_depth == 2) |
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248 mask = 0x55; |
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249 |
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250 else if (row_info->bit_depth == 4 && bit_depth->gray == 3) |
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251 mask = 0x11; |
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252 |
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253 else |
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254 mask = 0xff; |
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255 |
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256 for (i = 0; i < row_bytes; i++, bp++) |
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257 { |
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258 int j; |
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259 unsigned int v, out; |
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260 |
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261 v = *bp; |
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262 out = 0; |
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263 |
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264 for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0]) |
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265 { |
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266 if (j > 0) |
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267 out |= v << j; |
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268 |
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269 else |
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270 out |= (v >> (-j)) & mask; |
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271 } |
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272 |
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273 *bp = (png_byte)(out & 0xff); |
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274 } |
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275 } |
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276 |
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277 else if (row_info->bit_depth == 8) |
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278 { |
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279 png_bytep bp = row; |
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280 png_uint_32 i; |
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281 png_uint_32 istop = channels * row_info->width; |
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282 |
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283 for (i = 0; i < istop; i++, bp++) |
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284 { |
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285 |
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286 const unsigned int c = i%channels; |
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287 int j; |
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288 unsigned int v, out; |
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289 |
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290 v = *bp; |
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291 out = 0; |
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292 |
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293 for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) |
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294 { |
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295 if (j > 0) |
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296 out |= v << j; |
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297 |
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298 else |
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299 out |= v >> (-j); |
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300 } |
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301 |
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302 *bp = (png_byte)(out & 0xff); |
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303 } |
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304 } |
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305 |
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306 else |
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307 { |
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308 png_bytep bp; |
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309 png_uint_32 i; |
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310 png_uint_32 istop = channels * row_info->width; |
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311 |
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312 for (bp = row, i = 0; i < istop; i++) |
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313 { |
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314 const unsigned int c = i%channels; |
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315 int j; |
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316 unsigned int value, v; |
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317 |
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318 v = png_get_uint_16(bp); |
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319 value = 0; |
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320 |
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321 for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) |
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322 { |
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323 if (j > 0) |
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324 value |= v << j; |
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325 |
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326 else |
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327 value |= v >> (-j); |
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328 } |
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329 *bp++ = (png_byte)((value >> 8) & 0xff); |
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330 *bp++ = (png_byte)(value & 0xff); |
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331 } |
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332 } |
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333 } |
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334 } |
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335 #endif |
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336 |
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337 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED |
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338 static void |
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339 png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) |
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340 { |
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341 png_debug(1, "in png_do_write_swap_alpha"); |
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342 |
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343 { |
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344 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
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345 { |
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346 if (row_info->bit_depth == 8) |
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347 { |
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348 /* This converts from ARGB to RGBA */ |
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349 png_bytep sp, dp; |
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350 png_uint_32 i; |
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351 png_uint_32 row_width = row_info->width; |
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352 |
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353 for (i = 0, sp = dp = row; i < row_width; i++) |
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354 { |
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355 png_byte save = *(sp++); |
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356 *(dp++) = *(sp++); |
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357 *(dp++) = *(sp++); |
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358 *(dp++) = *(sp++); |
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359 *(dp++) = save; |
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360 } |
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361 } |
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362 |
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363 #ifdef PNG_WRITE_16BIT_SUPPORTED |
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364 else |
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365 { |
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366 /* This converts from AARRGGBB to RRGGBBAA */ |
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367 png_bytep sp, dp; |
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368 png_uint_32 i; |
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369 png_uint_32 row_width = row_info->width; |
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370 |
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371 for (i = 0, sp = dp = row; i < row_width; i++) |
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372 { |
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373 png_byte save[2]; |
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374 save[0] = *(sp++); |
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375 save[1] = *(sp++); |
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376 *(dp++) = *(sp++); |
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377 *(dp++) = *(sp++); |
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378 *(dp++) = *(sp++); |
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379 *(dp++) = *(sp++); |
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380 *(dp++) = *(sp++); |
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381 *(dp++) = *(sp++); |
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382 *(dp++) = save[0]; |
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383 *(dp++) = save[1]; |
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384 } |
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385 } |
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386 #endif /* WRITE_16BIT */ |
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387 } |
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388 |
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389 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_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 AG to GA */ |
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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 |
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398 for (i = 0, sp = dp = row; i < row_width; i++) |
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399 { |
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400 png_byte save = *(sp++); |
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401 *(dp++) = *(sp++); |
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402 *(dp++) = save; |
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403 } |
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404 } |
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405 |
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406 #ifdef PNG_WRITE_16BIT_SUPPORTED |
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407 else |
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408 { |
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409 /* This converts from AAGG to GGAA */ |
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410 png_bytep sp, dp; |
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411 png_uint_32 i; |
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412 png_uint_32 row_width = row_info->width; |
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413 |
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414 for (i = 0, sp = dp = row; i < row_width; i++) |
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415 { |
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416 png_byte save[2]; |
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417 save[0] = *(sp++); |
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418 save[1] = *(sp++); |
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419 *(dp++) = *(sp++); |
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420 *(dp++) = *(sp++); |
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421 *(dp++) = save[0]; |
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422 *(dp++) = save[1]; |
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423 } |
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424 } |
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425 #endif /* WRITE_16BIT */ |
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426 } |
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427 } |
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428 } |
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429 #endif |
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430 |
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431 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED |
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432 static void |
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433 png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) |
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434 { |
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435 png_debug(1, "in png_do_write_invert_alpha"); |
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436 |
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437 { |
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438 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
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439 { |
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440 if (row_info->bit_depth == 8) |
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441 { |
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442 /* This inverts the alpha channel in RGBA */ |
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443 png_bytep sp, dp; |
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444 png_uint_32 i; |
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445 png_uint_32 row_width = row_info->width; |
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446 |
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447 for (i = 0, sp = dp = row; i < row_width; i++) |
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448 { |
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449 /* Does nothing |
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450 *(dp++) = *(sp++); |
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451 *(dp++) = *(sp++); |
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452 *(dp++) = *(sp++); |
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453 */ |
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454 sp+=3; dp = sp; |
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455 *dp = (png_byte)(255 - *(sp++)); |
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456 } |
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457 } |
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458 |
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459 #ifdef PNG_WRITE_16BIT_SUPPORTED |
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460 else |
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461 { |
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462 /* This inverts the alpha channel in RRGGBBAA */ |
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463 png_bytep sp, dp; |
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464 png_uint_32 i; |
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465 png_uint_32 row_width = row_info->width; |
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466 |
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467 for (i = 0, sp = dp = row; i < row_width; i++) |
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468 { |
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469 /* Does nothing |
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470 *(dp++) = *(sp++); |
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471 *(dp++) = *(sp++); |
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472 *(dp++) = *(sp++); |
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473 *(dp++) = *(sp++); |
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474 *(dp++) = *(sp++); |
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475 *(dp++) = *(sp++); |
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476 */ |
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477 sp+=6; dp = sp; |
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478 *(dp++) = (png_byte)(255 - *(sp++)); |
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479 *dp = (png_byte)(255 - *(sp++)); |
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480 } |
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481 } |
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482 #endif /* WRITE_16BIT */ |
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483 } |
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484 |
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485 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
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486 { |
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487 if (row_info->bit_depth == 8) |
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488 { |
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489 /* This inverts the alpha channel in GA */ |
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490 png_bytep sp, dp; |
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491 png_uint_32 i; |
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492 png_uint_32 row_width = row_info->width; |
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493 |
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494 for (i = 0, sp = dp = row; i < row_width; i++) |
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495 { |
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496 *(dp++) = *(sp++); |
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497 *(dp++) = (png_byte)(255 - *(sp++)); |
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498 } |
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499 } |
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500 |
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501 #ifdef PNG_WRITE_16BIT_SUPPORTED |
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502 else |
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503 { |
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504 /* This inverts the alpha channel in GGAA */ |
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505 png_bytep sp, dp; |
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506 png_uint_32 i; |
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507 png_uint_32 row_width = row_info->width; |
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508 |
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509 for (i = 0, sp = dp = row; i < row_width; i++) |
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510 { |
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511 /* Does nothing |
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512 *(dp++) = *(sp++); |
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513 *(dp++) = *(sp++); |
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514 */ |
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515 sp+=2; dp = sp; |
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516 *(dp++) = (png_byte)(255 - *(sp++)); |
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517 *dp = (png_byte)(255 - *(sp++)); |
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518 } |
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519 } |
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520 #endif /* WRITE_16BIT */ |
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521 } |
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522 } |
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523 } |
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524 #endif |
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525 |
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526 /* Transform the data according to the user's wishes. The order of |
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527 * transformations is significant. |
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528 */ |
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529 void /* PRIVATE */ |
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530 png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info) |
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531 { |
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532 png_debug(1, "in png_do_write_transformations"); |
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533 |
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534 if (png_ptr == NULL) |
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535 return; |
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536 |
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537 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED |
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538 if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) |
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539 if (png_ptr->write_user_transform_fn != NULL) |
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540 (*(png_ptr->write_user_transform_fn)) /* User write transform |
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541 function */ |
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542 (png_ptr, /* png_ptr */ |
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543 row_info, /* row_info: */ |
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544 /* png_uint_32 width; width of row */ |
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545 /* png_size_t rowbytes; number of bytes in row */ |
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546 /* png_byte color_type; color type of pixels */ |
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547 /* png_byte bit_depth; bit depth of samples */ |
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548 /* png_byte channels; number of channels (1-4) */ |
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549 /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
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550 png_ptr->row_buf + 1); /* start of pixel data for row */ |
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551 #endif |
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552 |
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553 #ifdef PNG_WRITE_FILLER_SUPPORTED |
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554 if ((png_ptr->transformations & PNG_FILLER) != 0) |
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555 png_do_strip_channel(row_info, png_ptr->row_buf + 1, |
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556 !(png_ptr->flags & PNG_FLAG_FILLER_AFTER)); |
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557 #endif |
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558 |
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559 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED |
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560 if ((png_ptr->transformations & PNG_PACKSWAP) != 0) |
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561 png_do_packswap(row_info, png_ptr->row_buf + 1); |
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562 #endif |
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563 |
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564 #ifdef PNG_WRITE_PACK_SUPPORTED |
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565 if ((png_ptr->transformations & PNG_PACK) != 0) |
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566 png_do_pack(row_info, png_ptr->row_buf + 1, |
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567 (png_uint_32)png_ptr->bit_depth); |
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568 #endif |
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569 |
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570 #ifdef PNG_WRITE_SWAP_SUPPORTED |
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571 # ifdef PNG_16BIT_SUPPORTED |
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572 if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) |
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573 png_do_swap(row_info, png_ptr->row_buf + 1); |
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574 # endif |
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575 #endif |
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576 |
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577 #ifdef PNG_WRITE_SHIFT_SUPPORTED |
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578 if ((png_ptr->transformations & PNG_SHIFT) != 0) |
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579 png_do_shift(row_info, png_ptr->row_buf + 1, |
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580 &(png_ptr->shift)); |
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581 #endif |
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582 |
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583 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED |
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584 if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0) |
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585 png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1); |
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586 #endif |
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587 |
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588 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED |
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589 if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) |
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590 png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1); |
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591 #endif |
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592 |
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593 #ifdef PNG_WRITE_BGR_SUPPORTED |
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594 if ((png_ptr->transformations & PNG_BGR) != 0) |
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595 png_do_bgr(row_info, png_ptr->row_buf + 1); |
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596 #endif |
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597 |
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598 #ifdef PNG_WRITE_INVERT_SUPPORTED |
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599 if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) |
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600 png_do_invert(row_info, png_ptr->row_buf + 1); |
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601 #endif |
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602 } |
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603 #endif /* WRITE_TRANSFORMS */ |
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604 #endif /* WRITE */ |
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