1 /***************************************************************************/
5 /* Objects manager (specification). */
7 /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by */
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
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. */
16 /***************************************************************************/
24 #include FT_INTERNAL_OBJECTS_H
25 #include FT_INTERNAL_TRUETYPE_TYPES_H
31 /*************************************************************************/
37 /* A handle to a TrueType driver object. */
39 typedef struct TT_DriverRec_
* TT_Driver
;
42 /*************************************************************************/
48 /* A handle to a TrueType size object. */
50 typedef struct TT_SizeRec_
* TT_Size
;
53 /*************************************************************************/
59 /* A handle to a TrueType glyph slot object. */
62 /* This is a direct typedef of FT_GlyphSlot, as there is nothing */
63 /* specific about the TrueType glyph slot. */
65 typedef FT_GlyphSlot TT_GlyphSlot
;
68 /*************************************************************************/
71 /* TT_GraphicsState */
74 /* The TrueType graphics state used during bytecode interpretation. */
76 typedef struct TT_GraphicsState_
82 FT_UnitVector dualVector
;
83 FT_UnitVector projVector
;
84 FT_UnitVector freeVector
;
86 #ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
91 FT_F26Dot6 minimum_distance
;
95 FT_F26Dot6 control_value_cutin
;
96 FT_F26Dot6 single_width_cutin
;
97 FT_F26Dot6 single_width_value
;
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
;
116 #ifdef TT_USE_BYTECODE_INTERPRETER
119 tt_glyphzone_done( TT_GlyphZone zone
);
122 tt_glyphzone_new( FT_Memory memory
,
124 FT_Short maxContours
,
127 #endif /* TT_USE_BYTECODE_INTERPRETER */
131 /*************************************************************************/
133 /* EXECUTION SUBTABLES */
135 /* These sub-tables relate to instruction execution. */
137 /*************************************************************************/
140 #define TT_MAX_CODE_RANGES 3
143 /*************************************************************************/
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 */
150 typedef enum TT_CodeRange_Tag_
152 tt_coderange_none
= 0,
160 typedef struct TT_CodeRange_
167 typedef TT_CodeRange TT_CodeRangeTable
[TT_MAX_CODE_RANGES
];
170 /*************************************************************************/
172 /* Defines a function/instruction definition record. */
174 typedef struct TT_DefRecord_
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? */
181 } TT_DefRecord
, *TT_DefArray
;
184 /*************************************************************************/
186 /* Subglyph transformation record. */
188 typedef struct TT_Transform_
190 FT_Fixed xx
, xy
; /* transformation matrix coefficients */
192 FT_F26Dot6 ox
, oy
; /* offsets */
197 /*************************************************************************/
199 /* A note regarding non-squared pixels: */
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 */
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. */
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. */
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. */
219 /* I have found a simpler way to do the same, and it even seems to work */
220 /* in most of the cases: */
222 /* - All CVT values are scaled to the maximum ppem size. */
224 /* - When performing a read or write in the CVT, a ratio factor is used */
225 /* to perform adequate scaling. Example: */
230 /* We choose ppem = x_ppem = 14 as the CVT scaling size. All cvt */
231 /* entries are scaled to it. */
234 /* y_ratio = y_ppem/ppem (< 1.0) */
236 /* We compute the current ratio like: */
238 /* - If projVector is horizontal, */
239 /* ratio = x_ratio = 1.0 */
241 /* - if projVector is vertical, */
242 /* ratio = y_ratio */
245 /* ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */
247 /* Reading a cvt value returns */
248 /* ratio * cvt[index] */
250 /* Writing a cvt value in pixels: */
251 /* cvt[index] / ratio */
253 /* The current ppem is simply */
256 /*************************************************************************/
259 /*************************************************************************/
261 /* Metrics used by the TrueType size and context objects. */
263 typedef struct TT_Size_Metrics_
265 /* for non-square pixels */
269 FT_UShort ppem
; /* maximum ppem size */
270 FT_Long ratio
; /* current ratio */
273 FT_F26Dot6 compensations
[4]; /* device-specific compensations */
277 FT_Bool rotated
; /* `is the glyph rotated?'-flag */
278 FT_Bool stretched
; /* `is the glyph stretched?'-flag */
283 /*************************************************************************/
285 /* TrueType size class. */
287 typedef struct TT_SizeRec_
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
;
295 TT_Size_Metrics ttmetrics
;
297 FT_ULong strike_index
; /* 0xFFFFFFFF to indicate invalid */
299 #ifdef TT_USE_BYTECODE_INTERPRETER
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 */
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 */
312 TT_CodeRangeTable codeRangeTable
;
316 FT_ULong cvt_size
; /* the scaled control value table */
319 FT_UShort storage_size
; /* The storage area is now part of */
320 FT_Long
* storage
; /* the instance */
322 TT_GlyphZoneRec twilight
; /* The instance's twilight zone */
324 /* debugging variables */
326 /* When using the debugger, we must keep the */
327 /* execution context tied to the instance */
328 /* object rather than asking it on demand. */
331 TT_ExecContext context
;
333 FT_Bool bytecode_ready
;
336 #endif /* TT_USE_BYTECODE_INTERPRETER */
341 /*************************************************************************/
343 /* TrueType driver class. */
345 typedef struct TT_DriverRec_
348 TT_ExecContext context
; /* execution context */
349 TT_GlyphZoneRec zone
; /* glyph loader points zone */
351 void* extension_component
;
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. */
365 /*************************************************************************/
370 tt_face_init( FT_Stream stream
,
371 FT_Face ttface
, /* TT_Face */
374 FT_Parameter
* params
);
377 tt_face_done( FT_Face ttface
); /* TT_Face */
380 /*************************************************************************/
385 tt_size_init( FT_Size ttsize
); /* TT_Size */
388 tt_size_done( FT_Size ttsize
); /* TT_Size */
390 #ifdef TT_USE_BYTECODE_INTERPRETER
393 tt_size_run_fpgm( TT_Size size
);
396 tt_size_run_prep( TT_Size size
);
399 tt_size_ready_bytecode( TT_Size size
);
401 #endif /* TT_USE_BYTECODE_INTERPRETER */
404 tt_size_reset( TT_Size size
);
407 /*************************************************************************/
409 /* Driver functions */
412 tt_driver_init( FT_Module ttdriver
); /* TT_Driver */
415 tt_driver_done( FT_Module ttdriver
); /* TT_Driver */
418 /*************************************************************************/
423 tt_slot_init( FT_GlyphSlot slot
);
428 #endif /* __TTOBJS_H__ */