1 | /* |
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2 | ----------------------------------------------------------------------------- |
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3 | This source file is part of OGRE |
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4 | (Object-oriented Graphics Rendering Engine) |
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5 | For the latest info, see http://www.ogre3d.org/ |
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6 | |
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7 | Copyright (c) 2000-2013 Torus Knot Software Ltd |
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8 | |
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9 | Permission is hereby granted, free of charge, to any person obtaining a copy |
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10 | of this software and associated documentation files (the "Software"), to deal |
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11 | in the Software without restriction, including without limitation the rights |
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12 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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13 | copies of the Software, and to permit persons to whom the Software is |
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14 | furnished to do so, subject to the following conditions: |
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15 | |
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16 | The above copyright notice and this permission notice shall be included in |
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17 | all copies or substantial portions of the Software. |
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18 | |
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19 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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20 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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21 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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22 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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23 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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24 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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25 | THE SOFTWARE. |
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26 | ----------------------------------------------------------------------------- |
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27 | */ |
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28 | #ifndef __StreamSerialiser_H__ |
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29 | #define __StreamSerialiser_H__ |
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30 | |
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31 | #include "OgrePrerequisites.h" |
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32 | #include "OgreDataStream.h" |
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33 | #include "OgreHeaderPrefix.h" |
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34 | |
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35 | namespace Ogre |
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36 | { |
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37 | /** \addtogroup Core |
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38 | * @{ |
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39 | */ |
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40 | /** \addtogroup Resources |
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41 | * @{ |
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42 | */ |
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43 | |
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44 | /** Utility class providing helper methods for reading / writing |
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45 | structured data held in a DataStream. |
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46 | @remarks |
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47 | The structure of a file read / written by this class is a series of |
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48 | 'chunks'. A chunk-based format has the advantage of being extensible later, |
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49 | and it's robust, in that a reader can skip chunks that they are not |
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50 | able (or willing) to process. |
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51 | @par |
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52 | Chunks are contained serially in the file, but they can also be |
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53 | nested in order both to provide context, and to group chunks together for |
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54 | potential skipping. |
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55 | @par |
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56 | The data format of a chunk is as follows: |
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57 | -# Chunk ID (32-bit uint). This can be any number unique in a context, except the numbers 0x0000, 0x0001 and 0x1000, which are reserved for Ogre's use |
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58 | -# Chunk version (16-bit uint). Chunks can change over time so this version number reflects that |
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59 | -# Length (32-bit uint). The length of the chunk data section, including nested chunks. Note that |
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60 | this length excludes this header, but includes the header of any nested chunks. |
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61 | -# Checksum (32-bit uint). Checksum value generated from the above - basically lets us check this is a valid chunk. |
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62 | -# Chunk data |
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63 | The 'Chunk data' section will contain chunk-specific data, which may include |
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64 | other nested chunks. |
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65 | */ |
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66 | class _OgreExport StreamSerialiser : public StreamAlloc |
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67 | { |
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68 | public: |
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69 | /// The endianness of files |
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70 | enum Endian |
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71 | { |
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72 | /// Automatically determine endianness |
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73 | ENDIAN_AUTO, |
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74 | /// Use big endian (0x1000 is serialised as 0x10 0x00) |
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75 | ENDIAN_BIG, |
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76 | /// Use little endian (0x1000 is serialised as 0x00 0x10) |
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77 | ENDIAN_LITTLE |
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78 | }; |
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79 | |
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80 | /// The storage format of Real values |
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81 | enum RealStorageFormat |
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82 | { |
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83 | /// Real is stored as float, reducing precision if you're using OGRE_DOUBLE_PRECISION |
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84 | REAL_FLOAT, |
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85 | /// Real as stored as double, not useful unless you're using OGRE_DOUBLE_PRECISION |
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86 | REAL_DOUBLE |
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87 | }; |
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88 | |
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89 | |
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90 | /// Definition of a chunk of data in a file |
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91 | struct Chunk : public StreamAlloc |
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92 | { |
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93 | /// Identifier of the chunk (for example from makeIdentifier) (stored) |
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94 | uint32 id; |
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95 | /// Version of the chunk (stored) |
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96 | uint16 version; |
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97 | /// Length of the chunk data in bytes, excluding the header of this chunk (stored) |
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98 | uint32 length; |
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99 | /// Location of the chunk (header) in bytes from the start of a stream (derived) |
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100 | uint32 offset; |
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101 | |
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102 | Chunk() : id(0), version(1), length(0), offset(0) {} |
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103 | }; |
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104 | |
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105 | /** Constructor. |
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106 | @param stream The stream on which you will read / write data. |
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107 | @param endianMode The endian mode in which to read / writedata. If left at |
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108 | the default, when writing the endian mode will be the native platform mode, |
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109 | and when reading it's expected that the first chunk encountered will be |
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110 | the header chunk, which will determine the endian mode. |
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111 | @param autoHeader If true, the first write or read to this stream will |
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112 | automatically read / write the header too. This is required if you |
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113 | set endianMode to ENDIAN_AUTO, but if you manually set the endian mode, |
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114 | then you can skip writing / reading the header if you wish, if for example |
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115 | this stream is midway through a file which has already included header |
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116 | information. |
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117 | @param realFormat Set the format you want to write reals in. Only useful for files that |
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118 | you're writing (since when reading this is picked up from the file), |
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119 | and can only be changed if autoHeader is true, since real format is stored in the header. |
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120 | Defaults to float unless you're using OGRE_DOUBLE_PRECISION. |
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121 | */ |
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122 | StreamSerialiser(const DataStreamPtr& stream, Endian endianMode = ENDIAN_AUTO, |
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123 | bool autoHeader = true, |
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124 | #if OGRE_DOUBLE_PRECISION |
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125 | RealStorageFormat realFormat = REAL_DOUBLE |
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126 | #else |
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127 | RealStorageFormat realFormat = REAL_FLOAT |
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128 | #endif |
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129 | ); |
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130 | virtual ~StreamSerialiser(); |
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131 | |
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132 | /** Get the endian mode. |
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133 | @remarks |
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134 | If the result is ENDIAN_AUTO, this mode will change when the first piece of |
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135 | data is read / written. |
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136 | */ |
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137 | virtual Endian getEndian() const { return mEndian; } |
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138 | |
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139 | /** Pack a 4-character code into a 32-bit identifier. |
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140 | @remarks |
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141 | You can use this to generate id's for your chunks based on friendlier |
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142 | 4-character codes rather than assigning numerical IDs, if you like. |
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143 | @param code String to pack - must be 4 characters. |
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144 | */ |
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145 | static uint32 makeIdentifier(const String& code); |
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146 | |
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147 | /** Report the current depth of the chunk nesting, whether reading or writing. |
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148 | @remarks |
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149 | Returns how many levels of nested chunks are currently being processed, |
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150 | either writing or reading. In order to tidily finish, you must call |
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151 | read/writeChunkEnd this many times. |
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152 | */ |
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153 | size_t getCurrentChunkDepth() const { return mChunkStack.size(); } |
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154 | |
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155 | /** Get the ID of the chunk that's currently being read/written, if any. |
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156 | @return The id of the current chunk being read / written (at the tightest |
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157 | level of nesting), or zero if no chunk is being processed. |
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158 | */ |
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159 | uint32 getCurrentChunkID() const; |
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160 | |
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161 | /** Get the current byte position relative to the start of the data section |
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162 | of the last chunk that was read or written. |
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163 | @return the offset. Note that a return value of 0 means that either the |
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164 | position is at the start of the chunk data section (ie right after the |
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165 | header), or that no chunk is currently active. Use getCurrentChunkID |
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166 | or getCurrentChunkDepth to determine if a chunk is active. |
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167 | */ |
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168 | size_t getOffsetFromChunkStart() const; |
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169 | |
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170 | /** Reads the start of the next chunk in the file. |
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171 | @remarks |
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172 | Files are serialised in a chunk-based manner, meaning that each section |
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173 | of data is prepended by a chunk header. After reading this chunk header, |
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174 | the next set of data is available directly afterwards. |
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175 | @note |
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176 | When you have finished with this chunk, you should call readChunkEnd. |
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177 | This will perform a bit of validation and clear the chunk from |
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178 | the stack. |
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179 | @return The Chunk that comes next |
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180 | */ |
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181 | virtual const Chunk* readChunkBegin(); |
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182 | |
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183 | /** Reads the start of the next chunk so long as it's of a given ID and version. |
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184 | @remarks |
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185 | This method operates like readChunkBegin, except it checks the ID and |
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186 | version. |
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187 | @param id The ID you're expecting. If the next chunk isn't of this ID, then |
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188 | the chunk read is undone and the method returns null. |
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189 | @param maxVersion The maximum version you're able to process. If the ID is correct |
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190 | but the version exceeds what is passed in here, the chunk is skipped over, |
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191 | the problem logged and null is returned. |
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192 | @param msg Descriptive text added to the log if versions are not compatible |
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193 | @return The chunk if it passes the validation. |
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194 | */ |
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195 | virtual const Chunk* readChunkBegin(uint32 id, uint16 maxVersion, const String& msg = StringUtil::BLANK); |
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196 | |
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197 | /** Call this to 'rewind' the stream to just before the start of the current |
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198 | chunk. |
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199 | @remarks |
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200 | The most common case of wanting to use this is if you'd calledReadChunkBegin(), |
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201 | but the chunk you read wasn't one you wanted to process, and rather than |
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202 | skipping over it (which readChunkEnd() would do), you want to backtrack |
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203 | and give something else an opportunity to read it. |
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204 | @param id The id of the chunk that you were reading (for validation purposes) |
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205 | */ |
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206 | virtual void undoReadChunk(uint32 id); |
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207 | |
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208 | /** Call this to 'peek' at the next chunk ID without permanently moving the stream pointer. */ |
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209 | virtual uint32 peekNextChunkID(); |
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210 | |
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211 | /** Finish the reading of a chunk. |
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212 | @remarks |
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213 | You can call this method at any point after calling readChunkBegin, even |
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214 | if you didn't read all the rest of the data in the chunk. If you did |
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215 | not read to the end of a chunk, this method will automatically skip |
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216 | over the remainder of the chunk and position the stream just after it. |
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217 | @param id The id of the chunk that you were reading (for validation purposes) |
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218 | */ |
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219 | virtual void readChunkEnd(uint32 id); |
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220 | |
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221 | /** Return whether the current data pointer is at the end of the current chunk. |
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222 | @param id The id of the chunk that you were reading (for validation purposes) |
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223 | */ |
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224 | virtual bool isEndOfChunk(uint32 id); |
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225 | |
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226 | /// Reports whether the stream is at the end of file |
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227 | virtual bool eof() const; |
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228 | |
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229 | /** Get the definition of the current chunk being read (if any). */ |
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230 | virtual const Chunk* getCurrentChunk() const; |
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231 | |
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232 | /** Begin writing a new chunk. |
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233 | @remarks |
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234 | This starts the process of writing a new chunk to the stream. This will |
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235 | write the chunk header for you, and store a pointer so that the |
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236 | class can automatically go back and fill in the size for you later |
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237 | should you need it to. If you have already begun a chunk without ending |
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238 | it, then this method will start a nested chunk within it. Once written, |
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239 | you can then start writing chunk-specific data into your stream. |
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240 | @note If this is the first chunk in the file |
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241 | @param id The identifier of the new chunk. Any value that's unique in the |
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242 | file context is valid, except for the numbers 0x0001 and 0x1000 which are reserved |
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243 | for internal header identification use. |
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244 | @param version The version of the chunk you're writing |
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245 | */ |
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246 | virtual void writeChunkBegin(uint32 id, uint16 version = 1); |
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247 | /** End writing a chunk. |
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248 | @param id The identifier of the chunk - this is really just a safety check, |
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249 | since you can only end the chunk you most recently started. |
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250 | */ |
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251 | virtual void writeChunkEnd(uint32 id); |
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252 | |
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253 | /** Write arbitrary data to a stream. |
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254 | @param buf Pointer to bytes |
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255 | @param size The size of each element to write; each will be endian-flipped if |
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256 | necessary |
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257 | @param count The number of elements to write |
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258 | */ |
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259 | virtual void writeData(const void* buf, size_t size, size_t count); |
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260 | |
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261 | /** Catch-all method to write primitive types. */ |
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262 | template <typename T> |
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263 | void write(const T* pT, size_t count = 1) |
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264 | { |
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265 | writeData(pT, sizeof(T), count); |
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266 | } |
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267 | |
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268 | // Special-case Real since we need to deal with single/double precision |
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269 | virtual void write(const Real* val, size_t count = 1); |
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270 | |
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271 | virtual void write(const Vector2* vec, size_t count = 1); |
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272 | virtual void write(const Vector3* vec, size_t count = 1); |
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273 | virtual void write(const Vector4* vec, size_t count = 1); |
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274 | virtual void write(const Quaternion* q, size_t count = 1); |
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275 | virtual void write(const Matrix3* m, size_t count = 1); |
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276 | virtual void write(const Matrix4* m, size_t count = 1); |
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277 | virtual void write(const String* string); |
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278 | virtual void write(const AxisAlignedBox* aabb, size_t count = 1); |
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279 | virtual void write(const Sphere* sphere, size_t count = 1); |
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280 | virtual void write(const Plane* plane, size_t count = 1); |
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281 | virtual void write(const Ray* ray, size_t count = 1); |
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282 | virtual void write(const Radian* angle, size_t count = 1); |
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283 | virtual void write(const Node* node, size_t count = 1); |
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284 | virtual void write(const bool* boolean, size_t count = 1); |
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285 | |
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286 | |
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287 | /** Read arbitrary data from a stream. |
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288 | @param buf Pointer to bytes |
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289 | @param size The size of each element to read; each will be endian-flipped if |
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290 | necessary |
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291 | @param count The number of elements to read |
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292 | */ |
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293 | virtual void readData(void* buf, size_t size, size_t count); |
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294 | |
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295 | /** Catch-all method to read primitive types. */ |
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296 | template <typename T> |
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297 | void read(T* pT, size_t count = 1) |
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298 | { |
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299 | readData(pT, sizeof(T), count); |
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300 | } |
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301 | |
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302 | // Special case Real, single/double-precision issues |
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303 | virtual void read(Real* val, size_t count = 1); |
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304 | |
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305 | /// read a Vector3 |
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306 | virtual void read(Vector2* vec, size_t count = 1); |
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307 | virtual void read(Vector3* vec, size_t count = 1); |
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308 | virtual void read(Vector4* vec, size_t count = 1); |
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309 | virtual void read(Quaternion* q, size_t count = 1); |
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310 | virtual void read(Matrix3* m, size_t count = 1); |
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311 | virtual void read(Matrix4* m, size_t count = 1); |
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312 | virtual void read(String* string); |
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313 | virtual void read(AxisAlignedBox* aabb, size_t count = 1); |
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314 | virtual void read(Sphere* sphere, size_t count = 1); |
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315 | virtual void read(Plane* plane, size_t count = 1); |
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316 | virtual void read(Ray* ray, size_t count = 1); |
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317 | virtual void read(Radian* angle, size_t count = 1); |
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318 | virtual void read(Node* node, size_t count = 1); |
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319 | virtual void read(bool* val, size_t count = 1); |
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320 | |
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321 | /** Start (un)compressing data |
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322 | @param avail_in Available bytes for uncompressing |
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323 | */ |
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324 | virtual void startDeflate(size_t avail_in = 0); |
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325 | /** Stop (un)compressing data |
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326 | */ |
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327 | virtual void stopDeflate(); |
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328 | protected: |
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329 | DataStreamPtr mStream; |
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330 | DataStreamPtr mOriginalStream; |
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331 | Endian mEndian; |
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332 | bool mFlipEndian; |
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333 | bool mReadWriteHeader; |
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334 | RealStorageFormat mRealFormat; |
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335 | typedef deque<Chunk*>::type ChunkStack; |
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336 | /// Current list of open chunks |
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337 | ChunkStack mChunkStack; |
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338 | |
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339 | static uint32 HEADER_ID; |
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340 | static uint32 REVERSE_HEADER_ID; |
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341 | static uint32 CHUNK_HEADER_SIZE; |
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342 | |
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343 | virtual Chunk* readChunkImpl(); |
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344 | virtual void writeChunkImpl(uint32 id, uint16 version); |
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345 | virtual void readHeader(); |
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346 | virtual void writeHeader(); |
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347 | virtual uint32 calculateChecksum(Chunk* c); |
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348 | virtual void checkStream(bool failOnEof = false, |
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349 | bool validateReadable = false, bool validateWriteable = false) const; |
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350 | |
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351 | virtual void flipEndian(void * pData, size_t size, size_t count); |
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352 | virtual void flipEndian(void * pData, size_t size); |
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353 | virtual void determineEndianness(); |
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354 | virtual Chunk* popChunk(uint id); |
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355 | |
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356 | virtual void writeFloatsAsDoubles(const float* val, size_t count); |
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357 | virtual void writeDoublesAsFloats(const double* val, size_t count); |
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358 | virtual void readFloatsAsDoubles(double* val, size_t count); |
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359 | virtual void readDoublesAsFloats(float* val, size_t count); |
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360 | template <typename T, typename U> |
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361 | void writeConverted(const T* src, U typeToWrite, size_t count) |
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362 | { |
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363 | U* tmp = OGRE_ALLOC_T(U, count, MEMCATEGORY_GENERAL); |
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364 | U* pDst = tmp; |
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365 | const T* pSrc = src; |
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366 | for (size_t i = 0; i < count; ++i) |
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367 | *pDst++ = static_cast<U>(*pSrc++); |
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368 | |
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369 | writeData(tmp, sizeof(U), count); |
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370 | |
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371 | OGRE_FREE(tmp, MEMCATEGORY_GENERAL); |
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372 | } |
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373 | template <typename T, typename U> |
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374 | void readConverted(T* dst, U typeToRead, size_t count) |
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375 | { |
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376 | U* tmp = OGRE_ALLOC_T(U, count, MEMCATEGORY_GENERAL); |
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377 | readData(tmp, sizeof(U), count); |
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378 | |
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379 | T* pDst = dst; |
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380 | const U* pSrc = tmp; |
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381 | for (size_t i = 0; i < count; ++i) |
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382 | *pDst++ = static_cast<T>(*pSrc++); |
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383 | |
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384 | |
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385 | OGRE_FREE(tmp, MEMCATEGORY_GENERAL); |
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386 | } |
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387 | |
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388 | }; |
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389 | /** @} */ |
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390 | /** @} */ |
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391 | } |
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392 | |
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393 | #include "OgreHeaderSuffix.h" |
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394 | |
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395 | #endif |
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396 | |
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