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1 /***************************************************************************/
2 /*                                                                         */
3 /*  ttobjs.h                                                               */
4 /*                                                                         */
5 /*    Objects manager (specification).                                     */
6 /*                                                                         */
7 /*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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_Instance                                                        */
46   /*                                                                       */
47   /* <Description>                                                         */
48   /*    A handle to a TrueType size object.                                */
49   /*                                                                       */
50   typedef struct TT_SizeRec_*  TT_Size;
51 
52 
53   /*************************************************************************/
54   /*                                                                       */
55   /* <Type>                                                                */
56   /*    TT_GlyphSlot                                                       */
57   /*                                                                       */
58   /* <Description>                                                         */
59   /*    A handle to a TrueType glyph slot object.                          */
60   /*                                                                       */
61   /* <Note>                                                                */
62   /*    This is a direct typedef of FT_GlyphSlot, as there is nothing      */
63   /*    specific about the TrueType glyph slot.                            */
64   /*                                                                       */
65   typedef FT_GlyphSlot  TT_GlyphSlot;
66 
67 
68   /*************************************************************************/
69   /*                                                                       */
70   /* <Struct>                                                              */
71   /*    TT_GraphicsState                                                   */
72   /*                                                                       */
73   /* <Description>                                                         */
74   /*    The TrueType graphics state used during bytecode interpretation.   */
75   /*                                                                       */
76   typedef struct  TT_GraphicsState_
77   {
78     FT_UShort      rp0;
79     FT_UShort      rp1;
80     FT_UShort      rp2;
81 
82     FT_UnitVector  dualVector;
83     FT_UnitVector  projVector;
84     FT_UnitVector  freeVector;
85 
86 #ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
87     FT_Bool        both_x_axis;
88 #endif
89 
90     FT_Long        loop;
91     FT_F26Dot6     minimum_distance;
92     FT_Int         round_state;
93 
94     FT_Bool        auto_flip;
95     FT_F26Dot6     control_value_cutin;
96     FT_F26Dot6     single_width_cutin;
97     FT_F26Dot6     single_width_value;
98     FT_Short       delta_base;
99     FT_Short       delta_shift;
100 
101     FT_Byte        instruct_control;
102     /* According to Greg Hitchcock from Microsoft, the `scan_control'     */
103     /* variable as documented in the TrueType specification is a 32-bit   */
104     /* integer; the high-word part holds the SCANTYPE value, the low-word */
105     /* part the SCANCTRL value.  We separate it into two fields.          */
106     FT_Bool        scan_control;
107     FT_Int         scan_type;
108 
109     FT_UShort      gep0;
110     FT_UShort      gep1;
111     FT_UShort      gep2;
112 
113   } TT_GraphicsState;
114 
115 
116 #ifdef TT_USE_BYTECODE_INTERPRETER
117 
118   FT_LOCAL( void )
119   tt_glyphzone_done( TT_GlyphZone  zone );
120 
121   FT_LOCAL( FT_Error )
122   tt_glyphzone_new( FT_Memory     memory,
123                     FT_UShort     maxPoints,
124                     FT_Short      maxContours,
125                     TT_GlyphZone  zone );
126 
127 #endif /* TT_USE_BYTECODE_INTERPRETER */
128 
129 
130 
131   /*************************************************************************/
132   /*                                                                       */
133   /*  EXECUTION SUBTABLES                                                  */
134   /*                                                                       */
135   /*  These sub-tables relate to instruction execution.                    */
136   /*                                                                       */
137   /*************************************************************************/
138 
139 
140 #define TT_MAX_CODE_RANGES  3
141 
142 
143   /*************************************************************************/
144   /*                                                                       */
145   /* There can only be 3 active code ranges at once:                       */
146   /*   - the Font Program                                                  */
147   /*   - the CVT Program                                                   */
148   /*   - a glyph's instructions set                                        */
149   /*                                                                       */
150   typedef enum  TT_CodeRange_Tag_
151   {
152     tt_coderange_none = 0,
153     tt_coderange_font,
154     tt_coderange_cvt,
155     tt_coderange_glyph
156 
157   } TT_CodeRange_Tag;
158 
159 
160   typedef struct  TT_CodeRange_
161   {
162     FT_Byte*  base;
163     FT_ULong  size;
164 
165   } TT_CodeRange;
166 
167   typedef TT_CodeRange  TT_CodeRangeTable[TT_MAX_CODE_RANGES];
168 
169 
170   /*************************************************************************/
171   /*                                                                       */
172   /* Defines a function/instruction definition record.                     */
173   /*                                                                       */
174   typedef struct  TT_DefRecord_
175   {
176     FT_Int   range;      /* in which code range is it located? */
177     FT_Long  start;      /* where does it start?               */
178     FT_UInt  opc;        /* function #, or instruction code    */
179     FT_Bool  active;     /* is it active?                      */
180 
181   } TT_DefRecord, *TT_DefArray;
182 
183 
184   /*************************************************************************/
185   /*                                                                       */
186   /* Subglyph transformation record.                                       */
187   /*                                                                       */
188   typedef struct  TT_Transform_
189   {
190     FT_Fixed    xx, xy;     /* transformation matrix coefficients */
191     FT_Fixed    yx, yy;
192     FT_F26Dot6  ox, oy;     /* offsets        */
193 
194   } TT_Transform;
195 
196 
197   /*************************************************************************/
198   /*                                                                       */
199   /* A note regarding non-squared pixels:                                  */
200   /*                                                                       */
201   /* (This text will probably go into some docs at some time; for now, it  */
202   /* is kept here to explain some definitions in the TT_Size_Metrics       */
203   /* record).                                                              */
204   /*                                                                       */
205   /* The CVT is a one-dimensional array containing values that control     */
206   /* certain important characteristics in a font, like the height of all   */
207   /* capitals, all lowercase letter, default spacing or stem width/height. */
208   /*                                                                       */
209   /* These values are found in FUnits in the font file, and must be scaled */
210   /* to pixel coordinates before being used by the CVT and glyph programs. */
211   /* Unfortunately, when using distinct x and y resolutions (or distinct x */
212   /* and y pointsizes), there are two possible scalings.                   */
213   /*                                                                       */
214   /* A first try was to implement a `lazy' scheme where all values were    */
215   /* scaled when first used.  However, while some values are always used   */
216   /* in the same direction, some others are used under many different      */
217   /* circumstances and orientations.                                       */
218   /*                                                                       */
219   /* I have found a simpler way to do the same, and it even seems to work  */
220   /* in most of the cases:                                                 */
221   /*                                                                       */
222   /* - All CVT values are scaled to the maximum ppem size.                 */
223   /*                                                                       */
224   /* - When performing a read or write in the CVT, a ratio factor is used  */
225   /*   to perform adequate scaling.  Example:                              */
226   /*                                                                       */
227   /*     x_ppem = 14                                                       */
228   /*     y_ppem = 10                                                       */
229   /*                                                                       */
230   /*   We choose ppem = x_ppem = 14 as the CVT scaling size.  All cvt      */
231   /*   entries are scaled to it.                                           */
232   /*                                                                       */
233   /*     x_ratio = 1.0                                                     */
234   /*     y_ratio = y_ppem/ppem (< 1.0)                                     */
235   /*                                                                       */
236   /*   We compute the current ratio like:                                  */
237   /*                                                                       */
238   /*   - If projVector is horizontal,                                      */
239   /*       ratio = x_ratio = 1.0                                           */
240   /*                                                                       */
241   /*   - if projVector is vertical,                                        */
242   /*       ratio = y_ratio                                                 */
243   /*                                                                       */
244   /*   - else,                                                             */
245   /*       ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */
246   /*                                                                       */
247   /*   Reading a cvt value returns                                         */
248   /*     ratio * cvt[index]                                                */
249   /*                                                                       */
250   /*   Writing a cvt value in pixels:                                      */
251   /*     cvt[index] / ratio                                                */
252   /*                                                                       */
253   /*   The current ppem is simply                                          */
254   /*     ratio * ppem                                                      */
255   /*                                                                       */
256   /*************************************************************************/
257 
258 
259   /*************************************************************************/
260   /*                                                                       */
261   /* Metrics used by the TrueType size and context objects.                */
262   /*                                                                       */
263   typedef struct  TT_Size_Metrics_
264   {
265     /* for non-square pixels */
266     FT_Long     x_ratio;
267     FT_Long     y_ratio;
268 
269     FT_UShort   ppem;               /* maximum ppem size              */
270     FT_Long     ratio;              /* current ratio                  */
271     FT_Fixed    scale;
272 
273     FT_F26Dot6  compensations[4];   /* device-specific compensations  */
274 
275     FT_Bool     valid;
276 
277     FT_Bool     rotated;            /* `is the glyph rotated?'-flag   */
278     FT_Bool     stretched;          /* `is the glyph stretched?'-flag */
279 
280   } TT_Size_Metrics;
281 
282 
283   /*************************************************************************/
284   /*                                                                       */
285   /* TrueType size class.                                                  */
286   /*                                                                       */
287   typedef struct  TT_SizeRec_
288   {
289     FT_SizeRec         root;
290 
291     /* we have our own copy of metrics so that we can modify */
292     /* it without affecting auto-hinting (when used)         */
293     FT_Size_Metrics    metrics;
294 
295     TT_Size_Metrics    ttmetrics;
296 
297     FT_ULong           strike_index;      /* 0xFFFFFFFF to indicate invalid */
298 
299 #ifdef TT_USE_BYTECODE_INTERPRETER
300 
301     FT_UInt            num_function_defs; /* number of function definitions */
302     FT_UInt            max_function_defs;
303     TT_DefArray        function_defs;     /* table of function definitions  */
304 
305     FT_UInt            num_instruction_defs;  /* number of ins. definitions */
306     FT_UInt            max_instruction_defs;
307     TT_DefArray        instruction_defs;      /* table of ins. definitions  */
308 
309     FT_UInt            max_func;
310     FT_UInt            max_ins;
311 
312     TT_CodeRangeTable  codeRangeTable;
313 
314     TT_GraphicsState   GS;
315 
316     FT_ULong           cvt_size;      /* the scaled control value table */
317     FT_Long*           cvt;
318 
319     FT_UShort          storage_size; /* The storage area is now part of */
320     FT_Long*           storage;      /* the instance                    */
321 
322     TT_GlyphZoneRec    twilight;     /* The instance's twilight zone    */
323 
324     /* debugging variables */
325 
326     /* When using the debugger, we must keep the */
327     /* execution context tied to the instance    */
328     /* object rather than asking it on demand.   */
329 
330     FT_Bool            debug;
331     TT_ExecContext     context;
332 
333     FT_Bool            bytecode_ready;
334     FT_Bool            cvt_ready;
335 
336 #endif /* TT_USE_BYTECODE_INTERPRETER */
337 
338   } TT_SizeRec;
339 
340 
341   /*************************************************************************/
342   /*                                                                       */
343   /* TrueType driver class.                                                */
344   /*                                                                       */
345   typedef struct  TT_DriverRec_
346   {
347     FT_DriverRec     root;
348     TT_ExecContext   context;  /* execution context        */
349     TT_GlyphZoneRec  zone;     /* glyph loader points zone */
350 
351     void*            extension_component;
352 
353   } TT_DriverRec;
354 
355 
356   /* Note: All of the functions below (except tt_size_reset()) are used    */
357   /* as function pointers in a FT_Driver_ClassRec.  Therefore their        */
358   /* parameters are of types FT_Face, FT_Size, etc., rather than TT_Face,  */
359   /* TT_Size, etc., so that the compiler can confirm that the types and    */
360   /* number of parameters are correct.  In all cases the FT_xxx types are  */
361   /* cast to their TT_xxx counterparts inside the functions since FreeType */
362   /* will always use the TT driver to create them.                         */
363 
364 
365   /*************************************************************************/
366   /*                                                                       */
367   /* Face functions                                                        */
368   /*                                                                       */
369   FT_LOCAL( FT_Error )
370   tt_face_init( FT_Stream      stream,
371                 FT_Face        ttface,      /* TT_Face */
372                 FT_Int         face_index,
373                 FT_Int         num_params,
374                 FT_Parameter*  params );
375 
376   FT_LOCAL( void )
377   tt_face_done( FT_Face  ttface );          /* TT_Face */
378 
379 
380   /*************************************************************************/
381   /*                                                                       */
382   /* Size functions                                                        */
383   /*                                                                       */
384   FT_LOCAL( FT_Error )
385   tt_size_init( FT_Size  ttsize );          /* TT_Size */
386 
387   FT_LOCAL( void )
388   tt_size_done( FT_Size  ttsize );          /* TT_Size */
389 
390 #ifdef TT_USE_BYTECODE_INTERPRETER
391 
392   FT_LOCAL( FT_Error )
393   tt_size_run_fpgm( TT_Size  size );
394 
395   FT_LOCAL( FT_Error )
396   tt_size_run_prep( TT_Size  size );
397 
398   FT_LOCAL( FT_Error )
399   tt_size_ready_bytecode( TT_Size  size );
400 
401 #endif /* TT_USE_BYTECODE_INTERPRETER */
402 
403   FT_LOCAL( FT_Error )
404   tt_size_reset( TT_Size  size );
405 
406 
407   /*************************************************************************/
408   /*                                                                       */
409   /* Driver functions                                                      */
410   /*                                                                       */
411   FT_LOCAL( FT_Error )
412   tt_driver_init( FT_Module  ttdriver );    /* TT_Driver */
413 
414   FT_LOCAL( void )
415   tt_driver_done( FT_Module  ttdriver );    /* TT_Driver */
416 
417 
418   /*************************************************************************/
419   /*                                                                       */
420   /* Slot functions                                                        */
421   /*                                                                       */
422   FT_LOCAL( FT_Error )
423   tt_slot_init( FT_GlyphSlot  slot );
424 
425 
426 FT_END_HEADER
427 
428 #endif /* __TTOBJS_H__ */
429 
430 
431 /* END */
432