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1 /****************************************************************************
2  *
3  * ttgxvar.h
4  *
5  *   TrueType GX Font Variation loader (specification)
6  *
7  * Copyright (C) 2004-2021 by
8  * David Turner, Robert Wilhelm, Werner Lemberg and George Williams.
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 TTGXVAR_H_
20 #define TTGXVAR_H_
21 
22 
23 #include "ttobjs.h"
24 
25 
26 FT_BEGIN_HEADER
27 
28 
29 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
30 
31   /**************************************************************************
32    *
33    * @Struct:
34    *   GX_AVarCorrespondenceRec
35    *
36    * @Description:
37    *   A data structure representing `shortFracCorrespondence' in `avar'
38    *   table according to the specifications from Apple.
39    */
40   typedef struct  GX_AVarCorrespondenceRec_
41   {
42     FT_Fixed  fromCoord;
43     FT_Fixed  toCoord;
44 
45   } GX_AVarCorrespondenceRec_, *GX_AVarCorrespondence;
46 
47 
48   /**************************************************************************
49    *
50    * @Struct:
51    *   GX_AVarRec
52    *
53    * @Description:
54    *   Data from the segment field of `avar' table.
55    *   There is one of these for each axis.
56    */
57   typedef struct  GX_AVarSegmentRec_
58   {
59     FT_UShort              pairCount;
60     GX_AVarCorrespondence  correspondence; /* array with pairCount entries */
61 
62   } GX_AVarSegmentRec, *GX_AVarSegment;
63 
64 
65   typedef struct  GX_ItemVarDataRec_
66   {
67     FT_UInt    itemCount;      /* number of delta sets per item         */
68     FT_UInt    regionIdxCount; /* number of region indices in this data */
69     FT_UInt*   regionIndices;  /* array of `regionCount' indices;       */
70                                /* these index `varRegionList'           */
71     FT_Short*  deltaSet;       /* array of `itemCount' deltas           */
72                                /* use `innerIndex' for this array       */
73 
74   } GX_ItemVarDataRec, *GX_ItemVarData;
75 
76 
77   /* contribution of one axis to a region */
78   typedef struct  GX_AxisCoordsRec_
79   {
80     FT_Fixed  startCoord;
81     FT_Fixed  peakCoord;      /* zero means no effect (factor = 1) */
82     FT_Fixed  endCoord;
83 
84   } GX_AxisCoordsRec, *GX_AxisCoords;
85 
86 
87   typedef struct  GX_VarRegionRec_
88   {
89     GX_AxisCoords  axisList;               /* array of axisCount records */
90 
91   } GX_VarRegionRec, *GX_VarRegion;
92 
93 
94   /* item variation store */
95   typedef struct  GX_ItemVarStoreRec_
96   {
97     FT_UInt         dataCount;
98     GX_ItemVarData  varData;            /* array of dataCount records;     */
99                                         /* use `outerIndex' for this array */
100     FT_UShort     axisCount;
101     FT_UInt       regionCount;          /* total number of regions defined */
102     GX_VarRegion  varRegionList;
103 
104   } GX_ItemVarStoreRec, *GX_ItemVarStore;
105 
106 
107   typedef struct  GX_DeltaSetIdxMapRec_
108   {
109     FT_ULong  mapCount;
110     FT_UInt*  outerIndex;               /* indices to item var data */
111     FT_UInt*  innerIndex;               /* indices to delta set     */
112 
113   } GX_DeltaSetIdxMapRec, *GX_DeltaSetIdxMap;
114 
115 
116   /**************************************************************************
117    *
118    * @Struct:
119    *   GX_HVVarTableRec
120    *
121    * @Description:
122    *   Data from either the `HVAR' or `VVAR' table.
123    */
124   typedef struct  GX_HVVarTableRec_
125   {
126     GX_ItemVarStoreRec    itemStore;        /* Item Variation Store  */
127     GX_DeltaSetIdxMapRec  widthMap;         /* Advance Width Mapping */
128 
129 #if 0
130     GX_DeltaSetIdxMapRec  lsbMap;           /* not implemented */
131     GX_DeltaSetIdxMapRec  rsbMap;           /* not implemented */
132 
133     GX_DeltaSetIdxMapRec  tsbMap;           /* not implemented */
134     GX_DeltaSetIdxMapRec  bsbMap;           /* not implemented */
135     GX_DeltaSetIdxMapRec  vorgMap;          /* not implemented */
136 #endif
137 
138   } GX_HVVarTableRec, *GX_HVVarTable;
139 
140 
141 #define MVAR_TAG_GASP_0  FT_MAKE_TAG( 'g', 's', 'p', '0' )
142 #define MVAR_TAG_GASP_1  FT_MAKE_TAG( 'g', 's', 'p', '1' )
143 #define MVAR_TAG_GASP_2  FT_MAKE_TAG( 'g', 's', 'p', '2' )
144 #define MVAR_TAG_GASP_3  FT_MAKE_TAG( 'g', 's', 'p', '3' )
145 #define MVAR_TAG_GASP_4  FT_MAKE_TAG( 'g', 's', 'p', '4' )
146 #define MVAR_TAG_GASP_5  FT_MAKE_TAG( 'g', 's', 'p', '5' )
147 #define MVAR_TAG_GASP_6  FT_MAKE_TAG( 'g', 's', 'p', '6' )
148 #define MVAR_TAG_GASP_7  FT_MAKE_TAG( 'g', 's', 'p', '7' )
149 #define MVAR_TAG_GASP_8  FT_MAKE_TAG( 'g', 's', 'p', '8' )
150 #define MVAR_TAG_GASP_9  FT_MAKE_TAG( 'g', 's', 'p', '9' )
151 
152 #define MVAR_TAG_CPHT  FT_MAKE_TAG( 'c', 'p', 'h', 't' )
153 #define MVAR_TAG_HASC  FT_MAKE_TAG( 'h', 'a', 's', 'c' )
154 #define MVAR_TAG_HCLA  FT_MAKE_TAG( 'h', 'c', 'l', 'a' )
155 #define MVAR_TAG_HCLD  FT_MAKE_TAG( 'h', 'c', 'l', 'd' )
156 #define MVAR_TAG_HCOF  FT_MAKE_TAG( 'h', 'c', 'o', 'f' )
157 #define MVAR_TAG_HCRN  FT_MAKE_TAG( 'h', 'c', 'r', 'n' )
158 #define MVAR_TAG_HCRS  FT_MAKE_TAG( 'h', 'c', 'r', 's' )
159 #define MVAR_TAG_HDSC  FT_MAKE_TAG( 'h', 'd', 's', 'c' )
160 #define MVAR_TAG_HLGP  FT_MAKE_TAG( 'h', 'l', 'g', 'p' )
161 #define MVAR_TAG_SBXO  FT_MAKE_TAG( 's', 'b', 'x', 'o' )
162 #define MVAR_TAG_SBXS  FT_MAKE_TAG( 's', 'b', 'x', 's' )
163 #define MVAR_TAG_SBYO  FT_MAKE_TAG( 's', 'b', 'y', 'o' )
164 #define MVAR_TAG_SBYS  FT_MAKE_TAG( 's', 'b', 'y', 's' )
165 #define MVAR_TAG_SPXO  FT_MAKE_TAG( 's', 'p', 'x', 'o' )
166 #define MVAR_TAG_SPXS  FT_MAKE_TAG( 's', 'p', 'x', 's' )
167 #define MVAR_TAG_SPYO  FT_MAKE_TAG( 's', 'p', 'y', 'o' )
168 #define MVAR_TAG_SPYS  FT_MAKE_TAG( 's', 'p', 'y', 's' )
169 #define MVAR_TAG_STRO  FT_MAKE_TAG( 's', 't', 'r', 'o' )
170 #define MVAR_TAG_STRS  FT_MAKE_TAG( 's', 't', 'r', 's' )
171 #define MVAR_TAG_UNDO  FT_MAKE_TAG( 'u', 'n', 'd', 'o' )
172 #define MVAR_TAG_UNDS  FT_MAKE_TAG( 'u', 'n', 'd', 's' )
173 #define MVAR_TAG_VASC  FT_MAKE_TAG( 'v', 'a', 's', 'c' )
174 #define MVAR_TAG_VCOF  FT_MAKE_TAG( 'v', 'c', 'o', 'f' )
175 #define MVAR_TAG_VCRN  FT_MAKE_TAG( 'v', 'c', 'r', 'n' )
176 #define MVAR_TAG_VCRS  FT_MAKE_TAG( 'v', 'c', 'r', 's' )
177 #define MVAR_TAG_VDSC  FT_MAKE_TAG( 'v', 'd', 's', 'c' )
178 #define MVAR_TAG_VLGP  FT_MAKE_TAG( 'v', 'l', 'g', 'p' )
179 #define MVAR_TAG_XHGT  FT_MAKE_TAG( 'x', 'h', 'g', 't' )
180 
181 
182   typedef struct  GX_ValueRec_
183   {
184     FT_ULong   tag;
185     FT_UShort  outerIndex;
186     FT_UShort  innerIndex;
187 
188     FT_Short  unmodified;  /* values are either FT_Short or FT_UShort */
189 
190   } GX_ValueRec, *GX_Value;
191 
192 
193   /**************************************************************************
194    *
195    * @Struct:
196    *   GX_MVarTableRec
197    *
198    * @Description:
199    *   Data from the `MVAR' table.
200    */
201   typedef struct  GX_MVarTableRec_
202   {
203     FT_UShort  valueCount;
204 
205     GX_ItemVarStoreRec  itemStore;        /* Item Variation Store  */
206     GX_Value            values;           /* Value Records         */
207 
208   } GX_MVarTableRec, *GX_MVarTable;
209 
210 
211   /**************************************************************************
212    *
213    * @Struct:
214    *   GX_BlendRec
215    *
216    * @Description:
217    *   Data for interpolating a font from a distortable font specified
218    *   by the GX *var tables ([fgcahvm]var).
219    *
220    * @Fields:
221    *   num_axis ::
222    *     The number of axes along which interpolation may happen.
223    *
224    *   coords ::
225    *     An array of design coordinates (in user space) indicating the
226    *     contribution along each axis to the final interpolated font.
227    *     `normalizedcoords' holds the same values.
228    *
229    *   normalizedcoords ::
230    *     An array of normalized values (between [-1,1]) indicating the
231    *     contribution along each axis to the final interpolated font.
232    *     `coords' holds the same values.
233    *
234    *   mmvar ::
235    *     Data from the `fvar' table.
236    *
237    *   mmvar_len ::
238    *     The length of the `mmvar' structure.
239    *
240    *   normalized_stylecoords ::
241    *     A two-dimensional array that holds the named instance data from
242    *     `mmvar' as normalized values.
243    *
244    *   avar_loaded ::
245    *     A Boolean; if set, FreeType tried to load (and parse) the `avar'
246    *     table.
247    *
248    *   avar_segment ::
249    *     Data from the `avar' table.
250    *
251    *   hvar_loaded ::
252    *     A Boolean; if set, FreeType tried to load (and parse) the `hvar'
253    *     table.
254    *
255    *   hvar_checked ::
256    *     A Boolean; if set, FreeType successfully loaded and parsed the
257    *     `hvar' table.
258    *
259    *   hvar_error ::
260    *     If loading and parsing of the `hvar' table failed, this field
261    *     holds the corresponding error code.
262    *
263    *   hvar_table ::
264    *     Data from the `hvar' table.
265    *
266    *   vvar_loaded ::
267    *     A Boolean; if set, FreeType tried to load (and parse) the `vvar'
268    *     table.
269    *
270    *   vvar_checked ::
271    *     A Boolean; if set, FreeType successfully loaded and parsed the
272    *     `vvar' table.
273    *
274    *   vvar_error ::
275    *     If loading and parsing of the `vvar' table failed, this field
276    *     holds the corresponding error code.
277    *
278    *   vvar_table ::
279    *     Data from the `vvar' table.
280    *
281    *   mvar_table ::
282    *     Data from the `mvar' table.
283    *
284    *   tuplecount ::
285    *     The number of shared tuples in the `gvar' table.
286    *
287    *   tuplecoords ::
288    *     A two-dimensional array that holds the shared tuple coordinates
289    *     in the `gvar' table.
290    *
291    *   gv_glyphcnt ::
292    *     The number of glyphs handled in the `gvar' table.
293    *
294    *   glyphoffsets ::
295    *     Offsets into the glyph variation data array.
296    *
297    *   gvar_size ::
298    *     The size of the `gvar' table.
299    */
300   typedef struct  GX_BlendRec_
301   {
302     FT_UInt         num_axis;
303     FT_Fixed*       coords;
304     FT_Fixed*       normalizedcoords;
305 
306     FT_MM_Var*      mmvar;
307     FT_Offset       mmvar_len;
308 
309     FT_Fixed*       normalized_stylecoords;
310                       /* normalized_stylecoords[num_namedstyles][num_axis] */
311 
312     FT_Bool         avar_loaded;
313     GX_AVarSegment  avar_segment;                /* avar_segment[num_axis] */
314 
315     FT_Bool         hvar_loaded;
316     FT_Bool         hvar_checked;
317     FT_Error        hvar_error;
318     GX_HVVarTable   hvar_table;
319 
320     FT_Bool         vvar_loaded;
321     FT_Bool         vvar_checked;
322     FT_Error        vvar_error;
323     GX_HVVarTable   vvar_table;
324 
325     GX_MVarTable    mvar_table;
326 
327     FT_UInt         tuplecount;
328     FT_Fixed*       tuplecoords;      /* tuplecoords[tuplecount][num_axis] */
329 
330     FT_UInt         gv_glyphcnt;
331     FT_ULong*       glyphoffsets;         /* glyphoffsets[gv_glyphcnt + 1] */
332 
333     FT_ULong        gvar_size;
334 
335   } GX_BlendRec;
336 
337 
338   /**************************************************************************
339    *
340    * @enum:
341    *   GX_TupleCountFlags
342    *
343    * @Description:
344    *   Flags used within the `TupleCount' field of the `gvar' table.
345    */
346   typedef enum  GX_TupleCountFlags_
347   {
348     GX_TC_TUPLES_SHARE_POINT_NUMBERS = 0x8000,
349     GX_TC_RESERVED_TUPLE_FLAGS       = 0x7000,
350     GX_TC_TUPLE_COUNT_MASK           = 0x0FFF
351 
352   } GX_TupleCountFlags;
353 
354 
355   /**************************************************************************
356    *
357    * @enum:
358    *   GX_TupleIndexFlags
359    *
360    * @Description:
361    *   Flags used within the `TupleIndex' field of the `gvar' and `cvar'
362    *   tables.
363    */
364   typedef enum  GX_TupleIndexFlags_
365   {
366     GX_TI_EMBEDDED_TUPLE_COORD  = 0x8000,
367     GX_TI_INTERMEDIATE_TUPLE    = 0x4000,
368     GX_TI_PRIVATE_POINT_NUMBERS = 0x2000,
369     GX_TI_RESERVED_TUPLE_FLAG   = 0x1000,
370     GX_TI_TUPLE_INDEX_MASK      = 0x0FFF
371 
372   } GX_TupleIndexFlags;
373 
374 
375 #define TTAG_wght  FT_MAKE_TAG( 'w', 'g', 'h', 't' )
376 #define TTAG_wdth  FT_MAKE_TAG( 'w', 'd', 't', 'h' )
377 #define TTAG_opsz  FT_MAKE_TAG( 'o', 'p', 's', 'z' )
378 #define TTAG_slnt  FT_MAKE_TAG( 's', 'l', 'n', 't' )
379 
380 
381   FT_LOCAL( FT_Error )
382   TT_Set_MM_Blend( TT_Face    face,
383                    FT_UInt    num_coords,
384                    FT_Fixed*  coords );
385 
386   FT_LOCAL( FT_Error )
387   TT_Get_MM_Blend( TT_Face    face,
388                    FT_UInt    num_coords,
389                    FT_Fixed*  coords );
390 
391   FT_LOCAL( FT_Error )
392   TT_Set_Var_Design( TT_Face    face,
393                      FT_UInt    num_coords,
394                      FT_Fixed*  coords );
395 
396   FT_LOCAL( FT_Error )
397   TT_Get_MM_Var( TT_Face      face,
398                  FT_MM_Var*  *master );
399 
400   FT_LOCAL( FT_Error )
401   TT_Get_Var_Design( TT_Face    face,
402                      FT_UInt    num_coords,
403                      FT_Fixed*  coords );
404 
405   FT_LOCAL( FT_Error )
406   TT_Set_Named_Instance( TT_Face  face,
407                          FT_UInt  instance_index );
408 
409   FT_LOCAL( FT_Error )
410   tt_face_vary_cvt( TT_Face    face,
411                     FT_Stream  stream );
412 
413 
414   FT_LOCAL( FT_Error )
415   TT_Vary_Apply_Glyph_Deltas( TT_Face      face,
416                               FT_UInt      glyph_index,
417                               FT_Outline*  outline,
418                               FT_Vector*   unrounded,
419                               FT_UInt      n_points );
420 
421   FT_LOCAL( FT_Error )
422   tt_hadvance_adjust( TT_Face  face,
423                       FT_UInt  gindex,
424                       FT_Int  *adelta );
425 
426   FT_LOCAL( FT_Error )
427   tt_vadvance_adjust( TT_Face  face,
428                       FT_UInt  gindex,
429                       FT_Int  *adelta );
430 
431   FT_LOCAL( void )
432   tt_apply_mvar( TT_Face  face );
433 
434   FT_LOCAL( FT_Error )
435   tt_get_var_blend( TT_Face      face,
436                     FT_UInt     *num_coords,
437                     FT_Fixed*   *coords,
438                     FT_Fixed*   *normalizedcoords,
439                     FT_MM_Var*  *mm_var );
440 
441   FT_LOCAL( void )
442   tt_done_blend( TT_Face  face );
443 
444 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
445 
446 
447 FT_END_HEADER
448 
449 
450 #endif /* TTGXVAR_H_ */
451 
452 
453 /* END */
454