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ttobjs.h
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00001 /***************************************************************************/ 00002 /* */ 00003 /* ttobjs.h */ 00004 /* */ 00005 /* Objects manager (specification). */ 00006 /* */ 00007 /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by */ 00008 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ 00009 /* */ 00010 /* This file is part of the FreeType project, and may only be used, */ 00011 /* modified, and distributed under the terms of the FreeType project */ 00012 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ 00013 /* this file you indicate that you have read the license and */ 00014 /* understand and accept it fully. */ 00015 /* */ 00016 /***************************************************************************/ 00017 00018 00019 #ifndef __TTOBJS_H__ 00020 #define __TTOBJS_H__ 00021 00022 00023 #include <ft2build.h> 00024 #include FT_INTERNAL_OBJECTS_H 00025 #include FT_INTERNAL_TRUETYPE_TYPES_H 00026 00027 00028 FT_BEGIN_HEADER 00029 00030 00031 /*************************************************************************/ 00032 /* */ 00033 /* <Type> */ 00034 /* TT_Driver */ 00035 /* */ 00036 /* <Description> */ 00037 /* A handle to a TrueType driver object. */ 00038 /* */ 00039 typedef struct TT_DriverRec_* TT_Driver; 00040 00041 00042 /*************************************************************************/ 00043 /* */ 00044 /* <Type> */ 00045 /* TT_Instance */ 00046 /* */ 00047 /* <Description> */ 00048 /* A handle to a TrueType size object. */ 00049 /* */ 00050 typedef struct TT_SizeRec_* TT_Size; 00051 00052 00053 /*************************************************************************/ 00054 /* */ 00055 /* <Type> */ 00056 /* TT_GlyphSlot */ 00057 /* */ 00058 /* <Description> */ 00059 /* A handle to a TrueType glyph slot object. */ 00060 /* */ 00061 /* <Note> */ 00062 /* This is a direct typedef of FT_GlyphSlot, as there is nothing */ 00063 /* specific about the TrueType glyph slot. */ 00064 /* */ 00065 typedef FT_GlyphSlot TT_GlyphSlot; 00066 00067 00068 /*************************************************************************/ 00069 /* */ 00070 /* <Struct> */ 00071 /* TT_GraphicsState */ 00072 /* */ 00073 /* <Description> */ 00074 /* The TrueType graphics state used during bytecode interpretation. */ 00075 /* */ 00076 typedef struct TT_GraphicsState_ 00077 { 00078 FT_UShort rp0; 00079 FT_UShort rp1; 00080 FT_UShort rp2; 00081 00082 FT_UnitVector dualVector; 00083 FT_UnitVector projVector; 00084 FT_UnitVector freeVector; 00085 00086 #ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING 00087 FT_Bool both_x_axis; 00088 #endif 00089 00090 FT_Long loop; 00091 FT_F26Dot6 minimum_distance; 00092 FT_Int round_state; 00093 00094 FT_Bool auto_flip; 00095 FT_F26Dot6 control_value_cutin; 00096 FT_F26Dot6 single_width_cutin; 00097 FT_F26Dot6 single_width_value; 00098 FT_Short delta_base; 00099 FT_Short delta_shift; 00100 00101 FT_Byte instruct_control; 00102 /* According to Greg Hitchcock from Microsoft, the `scan_control' */ 00103 /* variable as documented in the TrueType specification is a 32-bit */ 00104 /* integer; the high-word part holds the SCANTYPE value, the low-word */ 00105 /* part the SCANCTRL value. We separate it into two fields. */ 00106 FT_Bool scan_control; 00107 FT_Int scan_type; 00108 00109 FT_UShort gep0; 00110 FT_UShort gep1; 00111 FT_UShort gep2; 00112 00113 } TT_GraphicsState; 00114 00115 00116 #ifdef TT_USE_BYTECODE_INTERPRETER 00117 00118 FT_LOCAL( void ) 00119 tt_glyphzone_done( TT_GlyphZone zone ); 00120 00121 FT_LOCAL( FT_Error ) 00122 tt_glyphzone_new( FT_Memory memory, 00123 FT_UShort maxPoints, 00124 FT_Short maxContours, 00125 TT_GlyphZone zone ); 00126 00127 #endif /* TT_USE_BYTECODE_INTERPRETER */ 00128 00129 00130 00131 /*************************************************************************/ 00132 /* */ 00133 /* EXECUTION SUBTABLES */ 00134 /* */ 00135 /* These sub-tables relate to instruction execution. */ 00136 /* */ 00137 /*************************************************************************/ 00138 00139 00140 #define TT_MAX_CODE_RANGES 3 00141 00142 00143 /*************************************************************************/ 00144 /* */ 00145 /* There can only be 3 active code ranges at once: */ 00146 /* - the Font Program */ 00147 /* - the CVT Program */ 00148 /* - a glyph's instructions set */ 00149 /* */ 00150 typedef enum TT_CodeRange_Tag_ 00151 { 00152 tt_coderange_none = 0, 00153 tt_coderange_font, 00154 tt_coderange_cvt, 00155 tt_coderange_glyph 00156 00157 } TT_CodeRange_Tag; 00158 00159 00160 typedef struct TT_CodeRange_ 00161 { 00162 FT_Byte* base; 00163 FT_ULong size; 00164 00165 } TT_CodeRange; 00166 00167 typedef TT_CodeRange TT_CodeRangeTable[TT_MAX_CODE_RANGES]; 00168 00169 00170 /*************************************************************************/ 00171 /* */ 00172 /* Defines a function/instruction definition record. */ 00173 /* */ 00174 typedef struct TT_DefRecord_ 00175 { 00176 FT_Int range; /* in which code range is it located? */ 00177 FT_Long start; /* where does it start? */ 00178 FT_UInt opc; /* function #, or instruction code */ 00179 FT_Bool active; /* is it active? */ 00180 00181 } TT_DefRecord, *TT_DefArray; 00182 00183 00184 /*************************************************************************/ 00185 /* */ 00186 /* Subglyph transformation record. */ 00187 /* */ 00188 typedef struct TT_Transform_ 00189 { 00190 FT_Fixed xx, xy; /* transformation matrix coefficients */ 00191 FT_Fixed yx, yy; 00192 FT_F26Dot6 ox, oy; /* offsets */ 00193 00194 } TT_Transform; 00195 00196 00197 /*************************************************************************/ 00198 /* */ 00199 /* A note regarding non-squared pixels: */ 00200 /* */ 00201 /* (This text will probably go into some docs at some time; for now, it */ 00202 /* is kept here to explain some definitions in the TT_Size_Metrics */ 00203 /* record). */ 00204 /* */ 00205 /* The CVT is a one-dimensional array containing values that control */ 00206 /* certain important characteristics in a font, like the height of all */ 00207 /* capitals, all lowercase letter, default spacing or stem width/height. */ 00208 /* */ 00209 /* These values are found in FUnits in the font file, and must be scaled */ 00210 /* to pixel coordinates before being used by the CVT and glyph programs. */ 00211 /* Unfortunately, when using distinct x and y resolutions (or distinct x */ 00212 /* and y pointsizes), there are two possible scalings. */ 00213 /* */ 00214 /* A first try was to implement a `lazy' scheme where all values were */ 00215 /* scaled when first used. However, while some values are always used */ 00216 /* in the same direction, some others are used under many different */ 00217 /* circumstances and orientations. */ 00218 /* */ 00219 /* I have found a simpler way to do the same, and it even seems to work */ 00220 /* in most of the cases: */ 00221 /* */ 00222 /* - All CVT values are scaled to the maximum ppem size. */ 00223 /* */ 00224 /* - When performing a read or write in the CVT, a ratio factor is used */ 00225 /* to perform adequate scaling. Example: */ 00226 /* */ 00227 /* x_ppem = 14 */ 00228 /* y_ppem = 10 */ 00229 /* */ 00230 /* We choose ppem = x_ppem = 14 as the CVT scaling size. All cvt */ 00231 /* entries are scaled to it. */ 00232 /* */ 00233 /* x_ratio = 1.0 */ 00234 /* y_ratio = y_ppem/ppem (< 1.0) */ 00235 /* */ 00236 /* We compute the current ratio like: */ 00237 /* */ 00238 /* - If projVector is horizontal, */ 00239 /* ratio = x_ratio = 1.0 */ 00240 /* */ 00241 /* - if projVector is vertical, */ 00242 /* ratio = y_ratio */ 00243 /* */ 00244 /* - else, */ 00245 /* ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */ 00246 /* */ 00247 /* Reading a cvt value returns */ 00248 /* ratio * cvt[index] */ 00249 /* */ 00250 /* Writing a cvt value in pixels: */ 00251 /* cvt[index] / ratio */ 00252 /* */ 00253 /* The current ppem is simply */ 00254 /* ratio * ppem */ 00255 /* */ 00256 /*************************************************************************/ 00257 00258 00259 /*************************************************************************/ 00260 /* */ 00261 /* Metrics used by the TrueType size and context objects. */ 00262 /* */ 00263 typedef struct TT_Size_Metrics_ 00264 { 00265 /* for non-square pixels */ 00266 FT_Long x_ratio; 00267 FT_Long y_ratio; 00268 00269 FT_UShort ppem; /* maximum ppem size */ 00270 FT_Long ratio; /* current ratio */ 00271 FT_Fixed scale; 00272 00273 FT_F26Dot6 compensations[4]; /* device-specific compensations */ 00274 00275 FT_Bool valid; 00276 00277 FT_Bool rotated; /* `is the glyph rotated?'-flag */ 00278 FT_Bool stretched; /* `is the glyph stretched?'-flag */ 00279 00280 } TT_Size_Metrics; 00281 00282 00283 /*************************************************************************/ 00284 /* */ 00285 /* TrueType size class. */ 00286 /* */ 00287 typedef struct TT_SizeRec_ 00288 { 00289 FT_SizeRec root; 00290 00291 /* we have our own copy of metrics so that we can modify */ 00292 /* it without affecting auto-hinting (when used) */ 00293 FT_Size_Metrics metrics; 00294 00295 TT_Size_Metrics ttmetrics; 00296 00297 FT_ULong strike_index; /* 0xFFFFFFFF to indicate invalid */ 00298 00299 #ifdef TT_USE_BYTECODE_INTERPRETER 00300 00301 FT_UInt num_function_defs; /* number of function definitions */ 00302 FT_UInt max_function_defs; 00303 TT_DefArray function_defs; /* table of function definitions */ 00304 00305 FT_UInt num_instruction_defs; /* number of ins. definitions */ 00306 FT_UInt max_instruction_defs; 00307 TT_DefArray instruction_defs; /* table of ins. definitions */ 00308 00309 FT_UInt max_func; 00310 FT_UInt max_ins; 00311 00312 TT_CodeRangeTable codeRangeTable; 00313 00314 TT_GraphicsState GS; 00315 00316 FT_ULong cvt_size; /* the scaled control value table */ 00317 FT_Long* cvt; 00318 00319 FT_UShort storage_size; /* The storage area is now part of */ 00320 FT_Long* storage; /* the instance */ 00321 00322 TT_GlyphZoneRec twilight; /* The instance's twilight zone */ 00323 00324 /* debugging variables */ 00325 00326 /* When using the debugger, we must keep the */ 00327 /* execution context tied to the instance */ 00328 /* object rather than asking it on demand. */ 00329 00330 FT_Bool debug; 00331 TT_ExecContext context; 00332 00333 FT_Bool bytecode_ready; 00334 FT_Bool cvt_ready; 00335 00336 #endif /* TT_USE_BYTECODE_INTERPRETER */ 00337 00338 } TT_SizeRec; 00339 00340 00341 /*************************************************************************/ 00342 /* */ 00343 /* TrueType driver class. */ 00344 /* */ 00345 typedef struct TT_DriverRec_ 00346 { 00347 FT_DriverRec root; 00348 TT_ExecContext context; /* execution context */ 00349 TT_GlyphZoneRec zone; /* glyph loader points zone */ 00350 00351 void* extension_component; 00352 00353 } TT_DriverRec; 00354 00355 00356 /* Note: All of the functions below (except tt_size_reset()) are used */ 00357 /* as function pointers in a FT_Driver_ClassRec. Therefore their */ 00358 /* parameters are of types FT_Face, FT_Size, etc., rather than TT_Face, */ 00359 /* TT_Size, etc., so that the compiler can confirm that the types and */ 00360 /* number of parameters are correct. In all cases the FT_xxx types are */ 00361 /* cast to their TT_xxx counterparts inside the functions since FreeType */ 00362 /* will always use the TT driver to create them. */ 00363 00364 00365 /*************************************************************************/ 00366 /* */ 00367 /* Face functions */ 00368 /* */ 00369 FT_LOCAL( FT_Error ) 00370 tt_face_init( FT_Stream stream, 00371 FT_Face ttface, /* TT_Face */ 00372 FT_Int face_index, 00373 FT_Int num_params, 00374 FT_Parameter* params ); 00375 00376 FT_LOCAL( void ) 00377 tt_face_done( FT_Face ttface ); /* TT_Face */ 00378 00379 00380 /*************************************************************************/ 00381 /* */ 00382 /* Size functions */ 00383 /* */ 00384 FT_LOCAL( FT_Error ) 00385 tt_size_init( FT_Size ttsize ); /* TT_Size */ 00386 00387 FT_LOCAL( void ) 00388 tt_size_done( FT_Size ttsize ); /* TT_Size */ 00389 00390 #ifdef TT_USE_BYTECODE_INTERPRETER 00391 00392 FT_LOCAL( FT_Error ) 00393 tt_size_run_fpgm( TT_Size size ); 00394 00395 FT_LOCAL( FT_Error ) 00396 tt_size_run_prep( TT_Size size ); 00397 00398 FT_LOCAL( FT_Error ) 00399 tt_size_ready_bytecode( TT_Size size ); 00400 00401 #endif /* TT_USE_BYTECODE_INTERPRETER */ 00402 00403 FT_LOCAL( FT_Error ) 00404 tt_size_reset( TT_Size size ); 00405 00406 00407 /*************************************************************************/ 00408 /* */ 00409 /* Driver functions */ 00410 /* */ 00411 FT_LOCAL( FT_Error ) 00412 tt_driver_init( FT_Module ttdriver ); /* TT_Driver */ 00413 00414 FT_LOCAL( void ) 00415 tt_driver_done( FT_Module ttdriver ); /* TT_Driver */ 00416 00417 00418 /*************************************************************************/ 00419 /* */ 00420 /* Slot functions */ 00421 /* */ 00422 FT_LOCAL( FT_Error ) 00423 tt_slot_init( FT_GlyphSlot slot ); 00424 00425 00426 FT_END_HEADER 00427 00428 #endif /* __TTOBJS_H__ */ 00429 00430 00431 /* END */
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