1 /***************************************************************************/ |
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2 /* */ |
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3 /* ftcmanag.h */ |
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4 /* */ |
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5 /* FreeType Cache Manager (specification). */ |
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6 /* */ |
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7 /* Copyright 2000-2001, 2003, 2004, 2006, 2010 by */ |
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8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
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9 /* */ |
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10 /* This file is part of the FreeType project, and may only be used, */ |
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11 /* modified, and distributed under the terms of the FreeType project */ |
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12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
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13 /* this file you indicate that you have read the license and */ |
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14 /* understand and accept it fully. */ |
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15 /* */ |
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16 /***************************************************************************/ |
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17 |
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18 |
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19 /*************************************************************************/ |
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20 /* */ |
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21 /* A cache manager is in charge of the following: */ |
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22 /* */ |
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23 /* - Maintain a mapping between generic FTC_FaceIDs and live FT_Face */ |
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24 /* objects. The mapping itself is performed through a user-provided */ |
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25 /* callback. However, the manager maintains a small cache of FT_Face */ |
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26 /* and FT_Size objects in order to speed up things considerably. */ |
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27 /* */ |
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28 /* - Manage one or more cache objects. Each cache is in charge of */ |
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29 /* holding a varying number of `cache nodes'. Each cache node */ |
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30 /* represents a minimal amount of individually accessible cached */ |
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31 /* data. For example, a cache node can be an FT_Glyph image */ |
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32 /* containing a vector outline, or some glyph metrics, or anything */ |
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33 /* else. */ |
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34 /* */ |
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35 /* Each cache node has a certain size in bytes that is added to the */ |
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36 /* total amount of `cache memory' within the manager. */ |
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37 /* */ |
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38 /* All cache nodes are located in a global LRU list, where the oldest */ |
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39 /* node is at the tail of the list. */ |
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40 /* */ |
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41 /* Each node belongs to a single cache, and includes a reference */ |
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42 /* count to avoid destroying it (due to caching). */ |
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43 /* */ |
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44 /*************************************************************************/ |
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45 |
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46 |
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47 /*************************************************************************/ |
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48 /*************************************************************************/ |
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49 /*************************************************************************/ |
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50 /*************************************************************************/ |
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51 /*************************************************************************/ |
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52 /********* *********/ |
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53 /********* WARNING, THIS IS BETA CODE. *********/ |
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54 /********* *********/ |
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55 /*************************************************************************/ |
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56 /*************************************************************************/ |
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57 /*************************************************************************/ |
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58 /*************************************************************************/ |
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59 /*************************************************************************/ |
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60 |
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61 |
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62 #ifndef __FTCMANAG_H__ |
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63 #define __FTCMANAG_H__ |
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64 |
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65 |
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66 #include <ft2build.h> |
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67 #include FT_CACHE_H |
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68 #include "ftcmru.h" |
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69 #include "ftccache.h" |
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70 |
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71 |
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72 FT_BEGIN_HEADER |
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73 |
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74 |
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75 /*************************************************************************/ |
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76 /* */ |
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77 /* <Section> */ |
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78 /* cache_subsystem */ |
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79 /* */ |
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80 /*************************************************************************/ |
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81 |
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82 |
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83 #define FTC_MAX_FACES_DEFAULT 2 |
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84 #define FTC_MAX_SIZES_DEFAULT 4 |
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85 #define FTC_MAX_BYTES_DEFAULT 200000L /* ~200kByte by default */ |
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86 |
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87 /* maximum number of caches registered in a single manager */ |
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88 #define FTC_MAX_CACHES 16 |
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89 |
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90 |
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91 typedef struct FTC_ManagerRec_ |
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92 { |
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93 FT_Library library; |
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94 FT_Memory memory; |
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95 |
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96 FTC_Node nodes_list; |
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97 FT_ULong max_weight; |
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98 FT_ULong cur_weight; |
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99 FT_UInt num_nodes; |
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100 |
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101 FTC_Cache caches[FTC_MAX_CACHES]; |
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102 FT_UInt num_caches; |
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103 |
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104 FTC_MruListRec faces; |
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105 FTC_MruListRec sizes; |
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106 |
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107 FT_Pointer request_data; |
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108 FTC_Face_Requester request_face; |
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109 |
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110 } FTC_ManagerRec; |
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111 |
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112 |
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113 /*************************************************************************/ |
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114 /* */ |
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115 /* <Function> */ |
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116 /* FTC_Manager_Compress */ |
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117 /* */ |
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118 /* <Description> */ |
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119 /* This function is used to check the state of the cache manager if */ |
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120 /* its `num_bytes' field is greater than its `max_bytes' field. It */ |
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121 /* will flush as many old cache nodes as possible (ignoring cache */ |
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122 /* nodes with a non-zero reference count). */ |
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123 /* */ |
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124 /* <InOut> */ |
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125 /* manager :: A handle to the cache manager. */ |
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126 /* */ |
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127 /* <Note> */ |
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128 /* Client applications should not call this function directly. It is */ |
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129 /* normally invoked by specific cache implementations. */ |
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130 /* */ |
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131 /* The reason this function is exported is to allow client-specific */ |
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132 /* cache classes. */ |
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133 /* */ |
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134 FT_LOCAL( void ) |
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135 FTC_Manager_Compress( FTC_Manager manager ); |
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136 |
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137 |
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138 /* try to flush `count' old nodes from the cache; return the number |
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139 * of really flushed nodes |
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140 */ |
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141 FT_LOCAL( FT_UInt ) |
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142 FTC_Manager_FlushN( FTC_Manager manager, |
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143 FT_UInt count ); |
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144 |
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145 |
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146 /* this must be used internally for the moment */ |
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147 FT_LOCAL( FT_Error ) |
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148 FTC_Manager_RegisterCache( FTC_Manager manager, |
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149 FTC_CacheClass clazz, |
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150 FTC_Cache *acache ); |
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151 |
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152 /* */ |
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153 |
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154 #define FTC_SCALER_COMPARE( a, b ) \ |
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155 ( (a)->face_id == (b)->face_id && \ |
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156 (a)->width == (b)->width && \ |
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157 (a)->height == (b)->height && \ |
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158 ((a)->pixel != 0) == ((b)->pixel != 0) && \ |
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159 ( (a)->pixel || \ |
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160 ( (a)->x_res == (b)->x_res && \ |
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161 (a)->y_res == (b)->y_res ) ) ) |
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162 |
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163 #define FTC_SCALER_HASH( q ) \ |
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164 ( _FTC_FACE_ID_HASH( (q)->face_id ) + \ |
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165 (q)->width + (q)->height*7 + \ |
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166 ( (q)->pixel ? 0 : ( (q)->x_res*33 ^ (q)->y_res*61 ) ) ) |
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167 |
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168 /* */ |
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169 |
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170 FT_END_HEADER |
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171 |
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172 #endif /* __FTCMANAG_H__ */ |
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173 |
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174 |
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175 /* END */ |
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