1 /**************************************************************************** 2 * 3 * ftdrv.h 4 * 5 * FreeType internal font driver interface (specification). 6 * 7 * Copyright (C) 1996-2020 by 8 * David Turner, Robert Wilhelm, and Werner Lemberg. 9 * 10 * This file is part of the FreeType project, and may only be used, 11 * modified, and distributed under the terms of the FreeType project 12 * license, LICENSE.TXT. By continuing to use, modify, or distribute 13 * this file you indicate that you have read the license and 14 * understand and accept it fully. 15 * 16 */ 17 18 19 #ifndef FTDRV_H_ 20 #define FTDRV_H_ 21 22 23 #include <freetype/ftmodapi.h> 24 25 #include "compiler-macros.h" 26 27 FT_BEGIN_HEADER 28 29 30 typedef FT_Error 31 (*FT_Face_InitFunc)( FT_Stream stream, 32 FT_Face face, 33 FT_Int typeface_index, 34 FT_Int num_params, 35 FT_Parameter* parameters ); 36 37 typedef void 38 (*FT_Face_DoneFunc)( FT_Face face ); 39 40 41 typedef FT_Error 42 (*FT_Size_InitFunc)( FT_Size size ); 43 44 typedef void 45 (*FT_Size_DoneFunc)( FT_Size size ); 46 47 48 typedef FT_Error 49 (*FT_Slot_InitFunc)( FT_GlyphSlot slot ); 50 51 typedef void 52 (*FT_Slot_DoneFunc)( FT_GlyphSlot slot ); 53 54 55 typedef FT_Error 56 (*FT_Size_RequestFunc)( FT_Size size, 57 FT_Size_Request req ); 58 59 typedef FT_Error 60 (*FT_Size_SelectFunc)( FT_Size size, 61 FT_ULong size_index ); 62 63 typedef FT_Error 64 (*FT_Slot_LoadFunc)( FT_GlyphSlot slot, 65 FT_Size size, 66 FT_UInt glyph_index, 67 FT_Int32 load_flags ); 68 69 70 typedef FT_Error 71 (*FT_Face_GetKerningFunc)( FT_Face face, 72 FT_UInt left_glyph, 73 FT_UInt right_glyph, 74 FT_Vector* kerning ); 75 76 77 typedef FT_Error 78 (*FT_Face_AttachFunc)( FT_Face face, 79 FT_Stream stream ); 80 81 82 typedef FT_Error 83 (*FT_Face_GetAdvancesFunc)( FT_Face face, 84 FT_UInt first, 85 FT_UInt count, 86 FT_Int32 flags, 87 FT_Fixed* advances ); 88 89 90 /************************************************************************** 91 * 92 * @struct: 93 * FT_Driver_ClassRec 94 * 95 * @description: 96 * The font driver class. This structure mostly contains pointers to 97 * driver methods. 98 * 99 * @fields: 100 * root :: 101 * The parent module. 102 * 103 * face_object_size :: 104 * The size of a face object in bytes. 105 * 106 * size_object_size :: 107 * The size of a size object in bytes. 108 * 109 * slot_object_size :: 110 * The size of a glyph object in bytes. 111 * 112 * init_face :: 113 * The format-specific face constructor. 114 * 115 * done_face :: 116 * The format-specific face destructor. 117 * 118 * init_size :: 119 * The format-specific size constructor. 120 * 121 * done_size :: 122 * The format-specific size destructor. 123 * 124 * init_slot :: 125 * The format-specific slot constructor. 126 * 127 * done_slot :: 128 * The format-specific slot destructor. 129 * 130 * 131 * load_glyph :: 132 * A function handle to load a glyph to a slot. This field is 133 * mandatory! 134 * 135 * get_kerning :: 136 * A function handle to return the unscaled kerning for a given pair of 137 * glyphs. Can be set to 0 if the format doesn't support kerning. 138 * 139 * attach_file :: 140 * This function handle is used to read additional data for a face from 141 * another file/stream. For example, this can be used to add data from 142 * AFM or PFM files on a Type 1 face, or a CIDMap on a CID-keyed face. 143 * 144 * get_advances :: 145 * A function handle used to return advance widths of 'count' glyphs 146 * (in font units), starting at 'first'. The 'vertical' flag must be 147 * set to get vertical advance heights. The 'advances' buffer is 148 * caller-allocated. The idea of this function is to be able to 149 * perform device-independent text layout without loading a single 150 * glyph image. 151 * 152 * request_size :: 153 * A handle to a function used to request the new character size. Can 154 * be set to 0 if the scaling done in the base layer suffices. 155 * 156 * select_size :: 157 * A handle to a function used to select a new fixed size. It is used 158 * only if @FT_FACE_FLAG_FIXED_SIZES is set. Can be set to 0 if the 159 * scaling done in the base layer suffices. 160 * @note: 161 * Most function pointers, with the exception of `load_glyph`, can be set 162 * to 0 to indicate a default behaviour. 163 */ 164 typedef struct FT_Driver_ClassRec_ 165 { 166 FT_Module_Class root; 167 168 FT_Long face_object_size; 169 FT_Long size_object_size; 170 FT_Long slot_object_size; 171 172 FT_Face_InitFunc init_face; 173 FT_Face_DoneFunc done_face; 174 175 FT_Size_InitFunc init_size; 176 FT_Size_DoneFunc done_size; 177 178 FT_Slot_InitFunc init_slot; 179 FT_Slot_DoneFunc done_slot; 180 181 FT_Slot_LoadFunc load_glyph; 182 183 FT_Face_GetKerningFunc get_kerning; 184 FT_Face_AttachFunc attach_file; 185 FT_Face_GetAdvancesFunc get_advances; 186 187 /* since version 2.2 */ 188 FT_Size_RequestFunc request_size; 189 FT_Size_SelectFunc select_size; 190 191 } FT_Driver_ClassRec, *FT_Driver_Class; 192 193 194 /************************************************************************** 195 * 196 * @macro: 197 * FT_DECLARE_DRIVER 198 * 199 * @description: 200 * Used to create a forward declaration of an FT_Driver_ClassRec struct 201 * instance. 202 * 203 * @macro: 204 * FT_DEFINE_DRIVER 205 * 206 * @description: 207 * Used to initialize an instance of FT_Driver_ClassRec struct. 208 * 209 * `ftinit.c` (ft_create_default_module_classes) already contains a 210 * mechanism to call these functions for the default modules described in 211 * `ftmodule.h`. 212 * 213 * The struct will be allocated in the global scope (or the scope where 214 * the macro is used). 215 */ 216 #define FT_DECLARE_DRIVER( class_ ) \ 217 FT_CALLBACK_TABLE \ 218 const FT_Driver_ClassRec class_; 219 220 #define FT_DEFINE_DRIVER( \ 221 class_, \ 222 flags_, \ 223 size_, \ 224 name_, \ 225 version_, \ 226 requires_, \ 227 interface_, \ 228 init_, \ 229 done_, \ 230 get_interface_, \ 231 face_object_size_, \ 232 size_object_size_, \ 233 slot_object_size_, \ 234 init_face_, \ 235 done_face_, \ 236 init_size_, \ 237 done_size_, \ 238 init_slot_, \ 239 done_slot_, \ 240 load_glyph_, \ 241 get_kerning_, \ 242 attach_file_, \ 243 get_advances_, \ 244 request_size_, \ 245 select_size_ ) \ 246 FT_CALLBACK_TABLE_DEF \ 247 const FT_Driver_ClassRec class_ = \ 248 { \ 249 FT_DEFINE_ROOT_MODULE( flags_, \ 250 size_, \ 251 name_, \ 252 version_, \ 253 requires_, \ 254 interface_, \ 255 init_, \ 256 done_, \ 257 get_interface_ ) \ 258 \ 259 face_object_size_, \ 260 size_object_size_, \ 261 slot_object_size_, \ 262 \ 263 init_face_, \ 264 done_face_, \ 265 \ 266 init_size_, \ 267 done_size_, \ 268 \ 269 init_slot_, \ 270 done_slot_, \ 271 \ 272 load_glyph_, \ 273 \ 274 get_kerning_, \ 275 attach_file_, \ 276 get_advances_, \ 277 \ 278 request_size_, \ 279 select_size_ \ 280 }; 281 282 283 FT_END_HEADER 284 285 #endif /* FTDRV_H_ */ 286 287 288 /* END */ 289
Indexes created Fri Jul 03 00:25:33 UTC 2026