|
1 /***************************************************************************/ |
|
2 /* */ |
|
3 /* ttinterp.h */ |
|
4 /* */ |
|
5 /* TrueType bytecode interpreter (specification). */ |
|
6 /* */ |
|
7 /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2010 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 __TTINTERP_H__ |
|
20 #define __TTINTERP_H__ |
|
21 |
|
22 #include <ft2build.h> |
|
23 #include "ttobjs.h" |
|
24 |
|
25 |
|
26 FT_BEGIN_HEADER |
|
27 |
|
28 |
|
29 #ifndef TT_CONFIG_OPTION_STATIC_INTERPRETER /* indirect implementation */ |
|
30 |
|
31 #define EXEC_OP_ TT_ExecContext exc, |
|
32 #define EXEC_OP TT_ExecContext exc |
|
33 #define EXEC_ARG_ exc, |
|
34 #define EXEC_ARG exc |
|
35 |
|
36 #else /* static implementation */ |
|
37 |
|
38 #define EXEC_OP_ /* void */ |
|
39 #define EXEC_OP /* void */ |
|
40 #define EXEC_ARG_ /* void */ |
|
41 #define EXEC_ARG /* void */ |
|
42 |
|
43 #endif /* TT_CONFIG_OPTION_STATIC_INTERPRETER */ |
|
44 |
|
45 |
|
46 /*************************************************************************/ |
|
47 /* */ |
|
48 /* Rounding mode constants. */ |
|
49 /* */ |
|
50 #define TT_Round_Off 5 |
|
51 #define TT_Round_To_Half_Grid 0 |
|
52 #define TT_Round_To_Grid 1 |
|
53 #define TT_Round_To_Double_Grid 2 |
|
54 #define TT_Round_Up_To_Grid 4 |
|
55 #define TT_Round_Down_To_Grid 3 |
|
56 #define TT_Round_Super 6 |
|
57 #define TT_Round_Super_45 7 |
|
58 |
|
59 |
|
60 /*************************************************************************/ |
|
61 /* */ |
|
62 /* Function types used by the interpreter, depending on various modes */ |
|
63 /* (e.g. the rounding mode, whether to render a vertical or horizontal */ |
|
64 /* line etc). */ |
|
65 /* */ |
|
66 /*************************************************************************/ |
|
67 |
|
68 /* Rounding function */ |
|
69 typedef FT_F26Dot6 |
|
70 (*TT_Round_Func)( EXEC_OP_ FT_F26Dot6 distance, |
|
71 FT_F26Dot6 compensation ); |
|
72 |
|
73 /* Point displacement along the freedom vector routine */ |
|
74 typedef void |
|
75 (*TT_Move_Func)( EXEC_OP_ TT_GlyphZone zone, |
|
76 FT_UShort point, |
|
77 FT_F26Dot6 distance ); |
|
78 |
|
79 /* Distance projection along one of the projection vectors */ |
|
80 typedef FT_F26Dot6 |
|
81 (*TT_Project_Func)( EXEC_OP_ FT_Pos dx, |
|
82 FT_Pos dy ); |
|
83 |
|
84 /* reading a cvt value. Take care of non-square pixels if necessary */ |
|
85 typedef FT_F26Dot6 |
|
86 (*TT_Get_CVT_Func)( EXEC_OP_ FT_ULong idx ); |
|
87 |
|
88 /* setting or moving a cvt value. Take care of non-square pixels */ |
|
89 /* if necessary */ |
|
90 typedef void |
|
91 (*TT_Set_CVT_Func)( EXEC_OP_ FT_ULong idx, |
|
92 FT_F26Dot6 value ); |
|
93 |
|
94 |
|
95 /*************************************************************************/ |
|
96 /* */ |
|
97 /* This structure defines a call record, used to manage function calls. */ |
|
98 /* */ |
|
99 typedef struct TT_CallRec_ |
|
100 { |
|
101 FT_Int Caller_Range; |
|
102 FT_Long Caller_IP; |
|
103 FT_Long Cur_Count; |
|
104 FT_Long Cur_Restart; |
|
105 |
|
106 } TT_CallRec, *TT_CallStack; |
|
107 |
|
108 |
|
109 /*************************************************************************/ |
|
110 /* */ |
|
111 /* The main structure for the interpreter which collects all necessary */ |
|
112 /* variables and states. */ |
|
113 /* */ |
|
114 typedef struct TT_ExecContextRec_ |
|
115 { |
|
116 TT_Face face; |
|
117 TT_Size size; |
|
118 FT_Memory memory; |
|
119 |
|
120 /* instructions state */ |
|
121 |
|
122 FT_Error error; /* last execution error */ |
|
123 |
|
124 FT_Long top; /* top of exec. stack */ |
|
125 |
|
126 FT_UInt stackSize; /* size of exec. stack */ |
|
127 FT_Long* stack; /* current exec. stack */ |
|
128 |
|
129 FT_Long args; |
|
130 FT_UInt new_top; /* new top after exec. */ |
|
131 |
|
132 TT_GlyphZoneRec zp0, /* zone records */ |
|
133 zp1, |
|
134 zp2, |
|
135 pts, |
|
136 twilight; |
|
137 |
|
138 FT_Size_Metrics metrics; |
|
139 TT_Size_Metrics tt_metrics; /* size metrics */ |
|
140 |
|
141 TT_GraphicsState GS; /* current graphics state */ |
|
142 |
|
143 FT_Int curRange; /* current code range number */ |
|
144 FT_Byte* code; /* current code range */ |
|
145 FT_Long IP; /* current instruction pointer */ |
|
146 FT_Long codeSize; /* size of current range */ |
|
147 |
|
148 FT_Byte opcode; /* current opcode */ |
|
149 FT_Int length; /* length of current opcode */ |
|
150 |
|
151 FT_Bool step_ins; /* true if the interpreter must */ |
|
152 /* increment IP after ins. exec */ |
|
153 FT_ULong cvtSize; |
|
154 FT_Long* cvt; |
|
155 |
|
156 FT_UInt glyphSize; /* glyph instructions buffer size */ |
|
157 FT_Byte* glyphIns; /* glyph instructions buffer */ |
|
158 |
|
159 FT_UInt numFDefs; /* number of function defs */ |
|
160 FT_UInt maxFDefs; /* maximum number of function defs */ |
|
161 TT_DefArray FDefs; /* table of FDefs entries */ |
|
162 |
|
163 FT_UInt numIDefs; /* number of instruction defs */ |
|
164 FT_UInt maxIDefs; /* maximum number of ins defs */ |
|
165 TT_DefArray IDefs; /* table of IDefs entries */ |
|
166 |
|
167 FT_UInt maxFunc; /* maximum function index */ |
|
168 FT_UInt maxIns; /* maximum instruction index */ |
|
169 |
|
170 FT_Int callTop, /* top of call stack during execution */ |
|
171 callSize; /* size of call stack */ |
|
172 TT_CallStack callStack; /* call stack */ |
|
173 |
|
174 FT_UShort maxPoints; /* capacity of this context's `pts' */ |
|
175 FT_Short maxContours; /* record, expressed in points and */ |
|
176 /* contours. */ |
|
177 |
|
178 TT_CodeRangeTable codeRangeTable; /* table of valid code ranges */ |
|
179 /* useful for the debugger */ |
|
180 |
|
181 FT_UShort storeSize; /* size of current storage */ |
|
182 FT_Long* storage; /* storage area */ |
|
183 |
|
184 FT_F26Dot6 period; /* values used for the */ |
|
185 FT_F26Dot6 phase; /* `SuperRounding' */ |
|
186 FT_F26Dot6 threshold; |
|
187 |
|
188 #if 0 |
|
189 /* this seems to be unused */ |
|
190 FT_Int cur_ppem; /* ppem along the current proj vector */ |
|
191 #endif |
|
192 |
|
193 FT_Bool instruction_trap; /* If `True', the interpreter will */ |
|
194 /* exit after each instruction */ |
|
195 |
|
196 TT_GraphicsState default_GS; /* graphics state resulting from */ |
|
197 /* the prep program */ |
|
198 FT_Bool is_composite; /* true if the glyph is composite */ |
|
199 FT_Bool pedantic_hinting; /* true if pedantic interpretation */ |
|
200 |
|
201 /* latest interpreter additions */ |
|
202 |
|
203 FT_Long F_dot_P; /* dot product of freedom and projection */ |
|
204 /* vectors */ |
|
205 TT_Round_Func func_round; /* current rounding function */ |
|
206 |
|
207 TT_Project_Func func_project, /* current projection function */ |
|
208 func_dualproj, /* current dual proj. function */ |
|
209 func_freeProj; /* current freedom proj. func */ |
|
210 |
|
211 TT_Move_Func func_move; /* current point move function */ |
|
212 TT_Move_Func func_move_orig; /* move original position function */ |
|
213 |
|
214 TT_Get_CVT_Func func_read_cvt; /* read a cvt entry */ |
|
215 TT_Set_CVT_Func func_write_cvt; /* write a cvt entry (in pixels) */ |
|
216 TT_Set_CVT_Func func_move_cvt; /* incr a cvt entry (in pixels) */ |
|
217 |
|
218 FT_Bool grayscale; /* are we hinting for grayscale? */ |
|
219 |
|
220 } TT_ExecContextRec; |
|
221 |
|
222 |
|
223 extern const TT_GraphicsState tt_default_graphics_state; |
|
224 |
|
225 |
|
226 FT_LOCAL( FT_Error ) |
|
227 TT_Goto_CodeRange( TT_ExecContext exec, |
|
228 FT_Int range, |
|
229 FT_Long IP ); |
|
230 |
|
231 FT_LOCAL( FT_Error ) |
|
232 TT_Set_CodeRange( TT_ExecContext exec, |
|
233 FT_Int range, |
|
234 void* base, |
|
235 FT_Long length ); |
|
236 |
|
237 FT_LOCAL( FT_Error ) |
|
238 TT_Clear_CodeRange( TT_ExecContext exec, |
|
239 FT_Int range ); |
|
240 |
|
241 |
|
242 FT_LOCAL( FT_Error ) |
|
243 Update_Max( FT_Memory memory, |
|
244 FT_ULong* size, |
|
245 FT_Long multiplier, |
|
246 void* _pbuff, |
|
247 FT_ULong new_max ); |
|
248 |
|
249 |
|
250 /*************************************************************************/ |
|
251 /* */ |
|
252 /* <Function> */ |
|
253 /* TT_New_Context */ |
|
254 /* */ |
|
255 /* <Description> */ |
|
256 /* Queries the face context for a given font. Note that there is */ |
|
257 /* now a _single_ execution context in the TrueType driver which is */ |
|
258 /* shared among faces. */ |
|
259 /* */ |
|
260 /* <Input> */ |
|
261 /* face :: A handle to the source face object. */ |
|
262 /* */ |
|
263 /* <Return> */ |
|
264 /* A handle to the execution context. Initialized for `face'. */ |
|
265 /* */ |
|
266 /* <Note> */ |
|
267 /* Only the glyph loader and debugger should call this function. */ |
|
268 /* */ |
|
269 FT_EXPORT( TT_ExecContext ) |
|
270 TT_New_Context( TT_Driver driver ); |
|
271 |
|
272 FT_LOCAL( FT_Error ) |
|
273 TT_Done_Context( TT_ExecContext exec ); |
|
274 |
|
275 FT_LOCAL( FT_Error ) |
|
276 TT_Load_Context( TT_ExecContext exec, |
|
277 TT_Face face, |
|
278 TT_Size size ); |
|
279 |
|
280 FT_LOCAL( FT_Error ) |
|
281 TT_Save_Context( TT_ExecContext exec, |
|
282 TT_Size ins ); |
|
283 |
|
284 FT_LOCAL( FT_Error ) |
|
285 TT_Run_Context( TT_ExecContext exec, |
|
286 FT_Bool debug ); |
|
287 |
|
288 |
|
289 /*************************************************************************/ |
|
290 /* */ |
|
291 /* <Function> */ |
|
292 /* TT_RunIns */ |
|
293 /* */ |
|
294 /* <Description> */ |
|
295 /* Executes one or more instruction in the execution context. This */ |
|
296 /* is the main function of the TrueType opcode interpreter. */ |
|
297 /* */ |
|
298 /* <Input> */ |
|
299 /* exec :: A handle to the target execution context. */ |
|
300 /* */ |
|
301 /* <Return> */ |
|
302 /* FreeType error code. 0 means success. */ |
|
303 /* */ |
|
304 /* <Note> */ |
|
305 /* Only the object manager and debugger should call this function. */ |
|
306 /* */ |
|
307 /* This function is publicly exported because it is directly */ |
|
308 /* invoked by the TrueType debugger. */ |
|
309 /* */ |
|
310 FT_EXPORT( FT_Error ) |
|
311 TT_RunIns( TT_ExecContext exec ); |
|
312 |
|
313 |
|
314 FT_END_HEADER |
|
315 |
|
316 #endif /* __TTINTERP_H__ */ |
|
317 |
|
318 |
|
319 /* END */ |