1 /***************************************************************************/
2 /* */
3 /* ttobjs.h */
4 /* */
5 /* Objects manager (specification). */
6 /* */
7 /* Copyright 1996-2018 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 TTOBJS_H_
20 #define TTOBJS_H_
21
22
23 #include <ft2build.h>
24 #include FT_INTERNAL_OBJECTS_H
25 #include FT_INTERNAL_TRUETYPE_TYPES_H
26
27
28 FT_BEGIN_HEADER
29
30
31 /*************************************************************************/
32 /* */
33 /* <Type> */
34 /* TT_Driver */
35 /* */
36 /* <Description> */
37 /* A handle to a TrueType driver object. */
38 /* */
39 typedef struct TT_DriverRec_* TT_Driver;
40
41
42 /*************************************************************************/
43 /* */
44 /* <Type> */
45 /* TT_GlyphSlot */
46 /* */
47 /* <Description> */
48 /* A handle to a TrueType glyph slot object. */
49 /* */
50 /* <Note> */
51 /* This is a direct typedef of FT_GlyphSlot, as there is nothing */
52 /* specific about the TrueType glyph slot. */
53 /* */
54 typedef FT_GlyphSlot TT_GlyphSlot;
55
56
57 /*************************************************************************/
58 /* */
59 /* <Struct> */
60 /* TT_GraphicsState */
61 /* */
62 /* <Description> */
63 /* The TrueType graphics state used during bytecode interpretation. */
64 /* */
65 typedef struct TT_GraphicsState_
66 {
67 FT_UShort rp0;
68 FT_UShort rp1;
69 FT_UShort rp2;
70
71 FT_UnitVector dualVector;
72 FT_UnitVector projVector;
73 FT_UnitVector freeVector;
74
75 FT_Long loop;
76 FT_F26Dot6 minimum_distance;
77 FT_Int round_state;
78
79 FT_Bool auto_flip;
80 FT_F26Dot6 control_value_cutin;
81 FT_F26Dot6 single_width_cutin;
82 FT_F26Dot6 single_width_value;
83 FT_UShort delta_base;
84 FT_UShort delta_shift;
85
86 FT_Byte instruct_control;
87 /* According to Greg Hitchcock from Microsoft, the `scan_control' */
88 /* variable as documented in the TrueType specification is a 32-bit */
89 /* integer; the high-word part holds the SCANTYPE value, the low-word */
90 /* part the SCANCTRL value. We separate it into two fields. */
91 FT_Bool scan_control;
92 FT_Int scan_type;
93
94 FT_UShort gep0;
95 FT_UShort gep1;
96 FT_UShort gep2;
97
98 } TT_GraphicsState;
99
100
101 #ifdef TT_USE_BYTECODE_INTERPRETER
102
103 FT_LOCAL( void )
104 tt_glyphzone_done( TT_GlyphZone zone );
105
106 FT_LOCAL( FT_Error )
107 tt_glyphzone_new( FT_Memory memory,
108 FT_UShort maxPoints,
109 FT_Short maxContours,
110 TT_GlyphZone zone );
111
112 #endif /* TT_USE_BYTECODE_INTERPRETER */
113
114
115
116 /*************************************************************************/
117 /* */
118 /* EXECUTION SUBTABLES */
119 /* */
120 /* These sub-tables relate to instruction execution. */
121 /* */
122 /*************************************************************************/
123
124
125 #define TT_MAX_CODE_RANGES 3
126
127
128 /*************************************************************************/
129 /* */
130 /* There can only be 3 active code ranges at once: */
131 /* - the Font Program */
132 /* - the CVT Program */
133 /* - a glyph's instructions set */
134 /* */
135 typedef enum TT_CodeRange_Tag_
136 {
137 tt_coderange_none = 0,
138 tt_coderange_font,
139 tt_coderange_cvt,
140 tt_coderange_glyph
141
142 } TT_CodeRange_Tag;
143
144
145 typedef struct TT_CodeRange_
146 {
147 FT_Byte* base;
148 FT_Long size;
149
150 } TT_CodeRange;
151
152 typedef TT_CodeRange TT_CodeRangeTable[TT_MAX_CODE_RANGES];
153
154
155 /*************************************************************************/
156 /* */
157 /* Defines a function/instruction definition record. */
158 /* */
159 typedef struct TT_DefRecord_
160 {
161 FT_Int range; /* in which code range is it located? */
162 FT_Long start; /* where does it start? */
163 FT_Long end; /* where does it end? */
164 FT_UInt opc; /* function #, or instruction code */
165 FT_Bool active; /* is it active? */
166 FT_Bool inline_delta; /* is function that defines inline delta? */
167 FT_ULong sph_fdef_flags; /* flags to identify special functions */
168
169 } TT_DefRecord, *TT_DefArray;
170
171
172 /*************************************************************************/
173 /* */
174 /* Subglyph transformation record. */
175 /* */
176 typedef struct TT_Transform_
177 {
178 FT_Fixed xx, xy; /* transformation matrix coefficients */
179 FT_Fixed yx, yy;
180 FT_F26Dot6 ox, oy; /* offsets */
181
182 } TT_Transform;
183
184
185 /*************************************************************************/
186 /* */
187 /* A note regarding non-squared pixels: */
188 /* */
189 /* (This text will probably go into some docs at some time; for now, it */
190 /* is kept here to explain some definitions in the TT_Size_Metrics */
191 /* record). */
192 /* */
193 /* The CVT is a one-dimensional array containing values that control */
194 /* certain important characteristics in a font, like the height of all */
195 /* capitals, all lowercase letter, default spacing or stem width/height. */
196 /* */
197 /* These values are found in FUnits in the font file, and must be scaled */
198 /* to pixel coordinates before being used by the CVT and glyph programs. */
199 /* Unfortunately, when using distinct x and y resolutions (or distinct x */
200 /* and y pointsizes), there are two possible scalings. */
201 /* */
202 /* A first try was to implement a `lazy' scheme where all values were */
203 /* scaled when first used. However, while some values are always used */
204 /* in the same direction, some others are used under many different */
205 /* circumstances and orientations. */
206 /* */
207 /* I have found a simpler way to do the same, and it even seems to work */
208 /* in most of the cases: */
209 /* */
210 /* - All CVT values are scaled to the maximum ppem size. */
211 /* */
212 /* - When performing a read or write in the CVT, a ratio factor is used */
213 /* to perform adequate scaling. Example: */
214 /* */
215 /* x_ppem = 14 */
216 /* y_ppem = 10 */
217 /* */
218 /* We choose ppem = x_ppem = 14 as the CVT scaling size. All cvt */
219 /* entries are scaled to it. */
220 /* */
221 /* x_ratio = 1.0 */
222 /* y_ratio = y_ppem/ppem (< 1.0) */
223 /* */
224 /* We compute the current ratio like: */
225 /* */
226 /* - If projVector is horizontal, */
227 /* ratio = x_ratio = 1.0 */
228 /* */
229 /* - if projVector is vertical, */
230 /* ratio = y_ratio */
231 /* */
232 /* - else, */
233 /* ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */
234 /* */
235 /* Reading a cvt value returns */
236 /* ratio * cvt[index] */
237 /* */
238 /* Writing a cvt value in pixels: */
239 /* cvt[index] / ratio */
240 /* */
241 /* The current ppem is simply */
242 /* ratio * ppem */
243 /* */
244 /*************************************************************************/
245
246
247 /*************************************************************************/
248 /* */
249 /* Metrics used by the TrueType size and context objects. */
250 /* */
251 typedef struct TT_Size_Metrics_
252 {
253 /* for non-square pixels */
254 FT_Long x_ratio;
255 FT_Long y_ratio;
256
257 FT_UShort ppem; /* maximum ppem size */
258 FT_Long ratio; /* current ratio */
259 FT_Fixed scale;
260
261 FT_F26Dot6 compensations[4]; /* device-specific compensations */
262
263 FT_Bool valid;
264
265 FT_Bool rotated; /* `is the glyph rotated?'-flag */
266 FT_Bool stretched; /* `is the glyph stretched?'-flag */
267
268 } TT_Size_Metrics;
269
270
271 /*************************************************************************/
272 /* */
273 /* TrueType size class. */
274 /* */
275 typedef struct TT_SizeRec_
276 {
277 FT_SizeRec root;
278
279 /* we have our own copy of metrics so that we can modify */
280 /* it without affecting auto-hinting (when used) */
281 FT_Size_Metrics* metrics; /* for the current rendering mode */
282 FT_Size_Metrics hinted_metrics; /* for the hinted rendering mode */
283
284 TT_Size_Metrics ttmetrics;
285
286 FT_ULong strike_index; /* 0xFFFFFFFF to indicate invalid */
287
288 #ifdef TT_USE_BYTECODE_INTERPRETER
289
290 FT_Long point_size; /* for the `MPS' bytecode instruction */
291
292 FT_UInt num_function_defs; /* number of function definitions */
293 FT_UInt max_function_defs;
294 TT_DefArray function_defs; /* table of function definitions */
295
296 FT_UInt num_instruction_defs; /* number of ins. definitions */
297 FT_UInt max_instruction_defs;
298 TT_DefArray instruction_defs; /* table of ins. definitions */
299
300 FT_UInt max_func;
301 FT_UInt max_ins;
302
303 TT_CodeRangeTable codeRangeTable;
304
305 TT_GraphicsState GS;
306
307 FT_ULong cvt_size; /* the scaled control value table */
308 FT_Long* cvt;
309
310 FT_UShort storage_size; /* The storage area is now part of */
311 FT_Long* storage; /* the instance */
312
313 TT_GlyphZoneRec twilight; /* The instance's twilight zone */
314
315 TT_ExecContext context;
316
317 /* if negative, `fpgm' (resp. `prep'), wasn't executed yet; */
318 /* otherwise it is the returned error code */
319 FT_Error bytecode_ready;
320 FT_Error cvt_ready;
321
322 #endif /* TT_USE_BYTECODE_INTERPRETER */
323
324 } TT_SizeRec;
325
326
327 /*************************************************************************/
328 /* */
329 /* TrueType driver class. */
330 /* */
331 typedef struct TT_DriverRec_
332 {
333 FT_DriverRec root;
334
335 TT_GlyphZoneRec zone; /* glyph loader points zone */
336
337 FT_UInt interpreter_version;
338
339 } TT_DriverRec;
340
341
342 /* Note: All of the functions below (except tt_size_reset()) are used */
343 /* as function pointers in a FT_Driver_ClassRec. Therefore their */
344 /* parameters are of types FT_Face, FT_Size, etc., rather than TT_Face, */
345 /* TT_Size, etc., so that the compiler can confirm that the types and */
346 /* number of parameters are correct. In all cases the FT_xxx types are */
347 /* cast to their TT_xxx counterparts inside the functions since FreeType */
348 /* will always use the TT driver to create them. */
349
350
351 /*************************************************************************/
352 /* */
353 /* Face functions */
354 /* */
355 FT_LOCAL( FT_Error )
356 tt_face_init( FT_Stream stream,
357 FT_Face ttface, /* TT_Face */
358 FT_Int face_index,
359 FT_Int num_params,
360 FT_Parameter* params );
361
362 FT_LOCAL( void )
363 tt_face_done( FT_Face ttface ); /* TT_Face */
364
365
366 /*************************************************************************/
367 /* */
368 /* Size functions */
369 /* */
370 FT_LOCAL( FT_Error )
371 tt_size_init( FT_Size ttsize ); /* TT_Size */
372
373 FT_LOCAL( void )
374 tt_size_done( FT_Size ttsize ); /* TT_Size */
375
376 #ifdef TT_USE_BYTECODE_INTERPRETER
377
378 FT_LOCAL( FT_Error )
379 tt_size_run_fpgm( TT_Size size,
380 FT_Bool pedantic );
381
382 FT_LOCAL( FT_Error )
383 tt_size_run_prep( TT_Size size,
384 FT_Bool pedantic );
385
386 FT_LOCAL( FT_Error )
387 tt_size_ready_bytecode( TT_Size size,
388 FT_Bool pedantic );
389
390 #endif /* TT_USE_BYTECODE_INTERPRETER */
391
392 FT_LOCAL( FT_Error )
393 tt_size_reset( TT_Size size,
394 FT_Bool only_height );
395
396
397 /*************************************************************************/
398 /* */
399 /* Driver functions */
400 /* */
401 FT_LOCAL( FT_Error )
402 tt_driver_init( FT_Module ttdriver ); /* TT_Driver */
403
404 FT_LOCAL( void )
405 tt_driver_done( FT_Module ttdriver ); /* TT_Driver */
406
407
408 /*************************************************************************/
409 /* */
410 /* Slot functions */
411 /* */
412 FT_LOCAL( FT_Error )
413 tt_slot_init( FT_GlyphSlot slot );
414
415
416 /* auxiliary */
417 #define IS_HINTED( flags ) ( ( flags & FT_LOAD_NO_HINTING ) == 0 )
418
419
420 FT_END_HEADER
421
422 #endif /* TTOBJS_H_ */
423
424
425 /* END */