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Diffstat (limited to 'src/truetype/ttinterp.h')
| -rw-r--r-- | src/truetype/ttinterp.h | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/src/truetype/ttinterp.h b/src/truetype/ttinterp.h new file mode 100644 index 0000000..07a8972 --- /dev/null +++ b/src/truetype/ttinterp.h @@ -0,0 +1,311 @@ +/***************************************************************************/ +/* */ +/* ttinterp.h */ +/* */ +/* TrueType bytecode interpreter (specification). */ +/* */ +/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007 by */ +/* David Turner, Robert Wilhelm, and Werner Lemberg. */ +/* */ +/* This file is part of the FreeType project, and may only be used, */ +/* modified, and distributed under the terms of the FreeType project */ +/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ +/* this file you indicate that you have read the license and */ +/* understand and accept it fully. */ +/* */ +/***************************************************************************/ + + +#ifndef __TTINTERP_H__ +#define __TTINTERP_H__ + +#include <ft2build.h> +#include "ttobjs.h" + + +FT_BEGIN_HEADER + + +#ifndef TT_CONFIG_OPTION_STATIC_INTERPRETER /* indirect implementation */ + +#define EXEC_OP_ TT_ExecContext exc, +#define EXEC_OP TT_ExecContext exc +#define EXEC_ARG_ exc, +#define EXEC_ARG exc + +#else /* static implementation */ + +#define EXEC_OP_ /* void */ +#define EXEC_OP /* void */ +#define EXEC_ARG_ /* void */ +#define EXEC_ARG /* void */ + +#endif /* TT_CONFIG_OPTION_STATIC_INTERPRETER */ + + + /*************************************************************************/ + /* */ + /* Rounding mode constants. */ + /* */ +#define TT_Round_Off 5 +#define TT_Round_To_Half_Grid 0 +#define TT_Round_To_Grid 1 +#define TT_Round_To_Double_Grid 2 +#define TT_Round_Up_To_Grid 4 +#define TT_Round_Down_To_Grid 3 +#define TT_Round_Super 6 +#define TT_Round_Super_45 7 + + + /*************************************************************************/ + /* */ + /* Function types used by the interpreter, depending on various modes */ + /* (e.g. the rounding mode, whether to render a vertical or horizontal */ + /* line etc). */ + /* */ + /*************************************************************************/ + + /* Rounding function */ + typedef FT_F26Dot6 + (*TT_Round_Func)( EXEC_OP_ FT_F26Dot6 distance, + FT_F26Dot6 compensation ); + + /* Point displacement along the freedom vector routine */ + typedef void + (*TT_Move_Func)( EXEC_OP_ TT_GlyphZone zone, + FT_UShort point, + FT_F26Dot6 distance ); + + /* Distance projection along one of the projection vectors */ + typedef FT_F26Dot6 + (*TT_Project_Func)( EXEC_OP_ FT_Pos dx, + FT_Pos dy ); + + /* reading a cvt value. Take care of non-square pixels if necessary */ + typedef FT_F26Dot6 + (*TT_Get_CVT_Func)( EXEC_OP_ FT_ULong idx ); + + /* setting or moving a cvt value. Take care of non-square pixels */ + /* if necessary */ + typedef void + (*TT_Set_CVT_Func)( EXEC_OP_ FT_ULong idx, + FT_F26Dot6 value ); + + + /*************************************************************************/ + /* */ + /* This structure defines a call record, used to manage function calls. */ + /* */ + typedef struct TT_CallRec_ + { + FT_Int Caller_Range; + FT_Long Caller_IP; + FT_Long Cur_Count; + FT_Long Cur_Restart; + + } TT_CallRec, *TT_CallStack; + + + /*************************************************************************/ + /* */ + /* The main structure for the interpreter which collects all necessary */ + /* variables and states. */ + /* */ + typedef struct TT_ExecContextRec_ + { + TT_Face face; + TT_Size size; + FT_Memory memory; + + /* instructions state */ + + FT_Error error; /* last execution error */ + + FT_Long top; /* top of exec. stack */ + + FT_UInt stackSize; /* size of exec. stack */ + FT_Long* stack; /* current exec. stack */ + + FT_Long args; + FT_UInt new_top; /* new top after exec. */ + + TT_GlyphZoneRec zp0, /* zone records */ + zp1, + zp2, + pts, + twilight; + + FT_Size_Metrics metrics; + TT_Size_Metrics tt_metrics; /* size metrics */ + + TT_GraphicsState GS; /* current graphics state */ + + FT_Int curRange; /* current code range number */ + FT_Byte* code; /* current code range */ + FT_Long IP; /* current instruction pointer */ + FT_Long codeSize; /* size of current range */ + + FT_Byte opcode; /* current opcode */ + FT_Int length; /* length of current opcode */ + + FT_Bool step_ins; /* true if the interpreter must */ + /* increment IP after ins. exec */ + FT_Long cvtSize; + FT_Long* cvt; + + FT_UInt glyphSize; /* glyph instructions buffer size */ + FT_Byte* glyphIns; /* glyph instructions buffer */ + + FT_UInt numFDefs; /* number of function defs */ + FT_UInt maxFDefs; /* maximum number of function defs */ + TT_DefArray FDefs; /* table of FDefs entries */ + + FT_UInt numIDefs; /* number of instruction defs */ + FT_UInt maxIDefs; /* maximum number of ins defs */ + TT_DefArray IDefs; /* table of IDefs entries */ + + FT_UInt maxFunc; /* maximum function index */ + FT_UInt maxIns; /* maximum instruction index */ + + FT_Int callTop, /* top of call stack during execution */ + callSize; /* size of call stack */ + TT_CallStack callStack; /* call stack */ + + FT_UShort maxPoints; /* capacity of this context's `pts' */ + FT_Short maxContours; /* record, expressed in points and */ + /* contours. */ + + TT_CodeRangeTable codeRangeTable; /* table of valid code ranges */ + /* useful for the debugger */ + + FT_UShort storeSize; /* size of current storage */ + FT_Long* storage; /* storage area */ + + FT_F26Dot6 period; /* values used for the */ + FT_F26Dot6 phase; /* `SuperRounding' */ + FT_F26Dot6 threshold; + +#if 0 + /* this seems to be unused */ + FT_Int cur_ppem; /* ppem along the current proj vector */ +#endif + + FT_Bool instruction_trap; /* If `True', the interpreter will */ + /* exit after each instruction */ + + TT_GraphicsState default_GS; /* graphics state resulting from */ + /* the prep program */ + FT_Bool is_composite; /* true if the glyph is composite */ + FT_Bool pedantic_hinting; /* true if pedantic interpretation */ + + /* latest interpreter additions */ + + FT_Long F_dot_P; /* dot product of freedom and projection */ + /* vectors */ + TT_Round_Func func_round; /* current rounding function */ + + TT_Project_Func func_project, /* current projection function */ + func_dualproj, /* current dual proj. function */ + func_freeProj; /* current freedom proj. func */ + + TT_Move_Func func_move; /* current point move function */ + TT_Move_Func func_move_orig; /* move original position function */ + + TT_Get_CVT_Func func_read_cvt; /* read a cvt entry */ + TT_Set_CVT_Func func_write_cvt; /* write a cvt entry (in pixels) */ + TT_Set_CVT_Func func_move_cvt; /* incr a cvt entry (in pixels) */ + + FT_Bool grayscale; /* are we hinting for grayscale? */ + + } TT_ExecContextRec; + + + extern const TT_GraphicsState tt_default_graphics_state; + + + FT_LOCAL( FT_Error ) + TT_Goto_CodeRange( TT_ExecContext exec, + FT_Int range, + FT_Long IP ); + + FT_LOCAL( FT_Error ) + TT_Set_CodeRange( TT_ExecContext exec, + FT_Int range, + void* base, + FT_Long length ); + + FT_LOCAL( FT_Error ) + TT_Clear_CodeRange( TT_ExecContext exec, + FT_Int range ); + + + /*************************************************************************/ + /* */ + /* <Function> */ + /* TT_New_Context */ + /* */ + /* <Description> */ + /* Queries the face context for a given font. Note that there is */ + /* now a _single_ execution context in the TrueType driver which is */ + /* shared among faces. */ + /* */ + /* <Input> */ + /* face :: A handle to the source face object. */ + /* */ + /* <Return> */ + /* A handle to the execution context. Initialized for `face'. */ + /* */ + /* <Note> */ + /* Only the glyph loader and debugger should call this function. */ + /* */ + FT_EXPORT( TT_ExecContext ) + TT_New_Context( TT_Driver driver ); + + FT_LOCAL( FT_Error ) + TT_Done_Context( TT_ExecContext exec ); + + FT_LOCAL( FT_Error ) + TT_Load_Context( TT_ExecContext exec, + TT_Face face, + TT_Size size ); + + FT_LOCAL( FT_Error ) + TT_Save_Context( TT_ExecContext exec, + TT_Size ins ); + + FT_LOCAL( FT_Error ) + TT_Run_Context( TT_ExecContext exec, + FT_Bool debug ); + + + /*************************************************************************/ + /* */ + /* <Function> */ + /* TT_RunIns */ + /* */ + /* <Description> */ + /* Executes one or more instruction in the execution context. This */ + /* is the main function of the TrueType opcode interpreter. */ + /* */ + /* <Input> */ + /* exec :: A handle to the target execution context. */ + /* */ + /* <Return> */ + /* FreeType error code. 0 means success. */ + /* */ + /* <Note> */ + /* Only the object manager and debugger should call this function. */ + /* */ + /* This function is publicly exported because it is directly */ + /* invoked by the TrueType debugger. */ + /* */ + FT_EXPORT( FT_Error ) + TT_RunIns( TT_ExecContext exec ); + + +FT_END_HEADER + +#endif /* __TTINTERP_H__ */ + + +/* END */ |