| /***************************************************************************/ |
| /* */ |
| /* ttinterp.h */ |
| /* */ |
| /* TrueType bytecode intepreter (specification). */ |
| /* */ |
| /* Copyright 1996-1999 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 <ttobjs.h> |
| |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| |
| #ifndef TT_STATIC_INTEPRETER /* 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_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 TT_F26Dot6 (*TT_Round_Func)( EXEC_OP_ TT_F26Dot6 distance, |
| TT_F26Dot6 compensation ); |
| |
| /* Point displacement along the freedom vector routine */ |
| typedef void (*TT_Move_Func)( EXEC_OP_ FT_GlyphZone* zone, |
| TT_UInt point, |
| TT_F26Dot6 distance ); |
| |
| /* Distance projection along one of the projection vectors */ |
| typedef TT_F26Dot6 (*TT_Project_Func)( EXEC_OP_ TT_Vector* v1, |
| TT_Vector* v2 ); |
| |
| /* reading a cvt value. Take care of non-square pixels if necessary */ |
| typedef TT_F26Dot6 (*TT_Get_CVT_Func)( EXEC_OP_ TT_ULong index ); |
| |
| /* setting or moving a cvt value. Take care of non-square pixels */ |
| /* if necessary */ |
| typedef void (*TT_Set_CVT_Func)( EXEC_OP_ TT_ULong index, |
| TT_F26Dot6 value ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* This structure defines a call record, used to manage function calls. */ |
| /* */ |
| typedef struct TT_CallRec_ |
| { |
| TT_Int Caller_Range; |
| TT_Long Caller_IP; |
| TT_Long Cur_Count; |
| TT_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 */ |
| |
| TT_Error error; /* last execution error */ |
| |
| TT_Long top; /* top of exec. stack */ |
| |
| TT_UInt stackSize; /* size of exec. stack */ |
| TT_Long* stack; /* current exec. stack */ |
| |
| TT_Long args; |
| TT_UInt new_top; /* new top after exec. */ |
| |
| FT_GlyphZone zp0, /* zone records */ |
| zp1, |
| zp2, |
| pts, |
| twilight; |
| |
| FT_Size_Metrics metrics; |
| TT_Size_Metrics tt_metrics; /* size metrics */ |
| |
| TT_GraphicsState GS; /* current graphics state */ |
| |
| TT_Int curRange; /* current code range number */ |
| TT_Byte* code; /* current code range */ |
| TT_Long IP; /* current instruction pointer */ |
| TT_Long codeSize; /* size of current range */ |
| |
| TT_Byte opcode; /* current opcode */ |
| TT_Int length; /* length of current opcode */ |
| |
| TT_Bool step_ins; /* true if the interpreter must */ |
| /* increment IP after ins. exec */ |
| TT_Long cvtSize; |
| TT_Long* cvt; |
| |
| TT_UInt glyphSize; /* glyph instructions buffer size */ |
| TT_Byte* glyphIns; /* glyph instructions buffer */ |
| |
| TT_UInt numFDefs; /* number of function defs */ |
| TT_UInt maxFDefs; /* maximum number of function defs */ |
| TT_DefArray FDefs; /* table of FDefs entries */ |
| |
| TT_UInt numIDefs; /* number of instruction defs */ |
| TT_UInt maxIDefs; /* maximum number of ins defs */ |
| TT_DefArray IDefs; /* table of IDefs entries */ |
| |
| TT_UInt maxFunc; /* maximum function index */ |
| TT_UInt maxIns; /* maximum instruction index */ |
| |
| TT_Int callTop, /* top of call stack during execution */ |
| callSize; /* size of call stack */ |
| TT_CallStack callStack; /* call stack */ |
| |
| TT_UShort maxPoints; /* capacity of this context's `pts' */ |
| TT_Short maxContours; /* record, expressed in points and */ |
| /* contours. */ |
| |
| TT_CodeRangeTable codeRangeTable; /* table of valid code ranges */ |
| /* useful for the debugger */ |
| |
| TT_UShort storeSize; /* size of current storage */ |
| TT_Long* storage; /* storage area */ |
| |
| TT_F26Dot6 period; /* values used for the */ |
| TT_F26Dot6 phase; /* `SuperRounding' */ |
| TT_F26Dot6 threshold; |
| |
| /* this seems to be unused */ |
| #if 0 |
| TT_Int cur_ppem; /* ppem along the current proj vector */ |
| #endif |
| TT_Bool instruction_trap; /* If `True', the interpreter will */ |
| /* exit after each instruction */ |
| |
| TT_GraphicsState default_GS; /* graphics state resulting from */ |
| /* the prep program */ |
| TT_Bool is_composite; /* true if the glyph is composite */ |
| TT_Bool pedantic_hinting; /* true for pedantic interpretation */ |
| |
| /* latest interpreter additions */ |
| |
| TT_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_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) */ |
| |
| TT_ULong loadSize; |
| TT_SubGlyph_Stack loadStack; /* loading subglyph stack */ |
| |
| } TT_ExecContextRec; |
| |
| |
| |
| LOCAL_DEF |
| const TT_GraphicsState tt_default_graphics_state; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* TT_Goto_CodeRange */ |
| /* */ |
| /* <Description> */ |
| /* Switches to a new code range (updates the code related elements in */ |
| /* `exec', and `IP'). */ |
| /* */ |
| /* <Input> */ |
| /* range :: The new execution code range. */ |
| /* IP :: The new IP in the new code range. */ |
| /* */ |
| /* <InOut> */ |
| /* exec :: The target execution context. */ |
| /* */ |
| /* <Return> */ |
| /* TrueType error code. 0 means success. */ |
| /* */ |
| LOCAL_DEF |
| TT_Error TT_Goto_CodeRange( TT_ExecContext exec, |
| TT_Int range, |
| TT_Long IP ); |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* TT_Set_CodeRange */ |
| /* */ |
| /* <Description> */ |
| /* Sets a code range. */ |
| /* */ |
| /* <Input> */ |
| /* range :: The code range index. */ |
| /* base :: The new code base. */ |
| /* length :: The range size in bytes. */ |
| /* */ |
| /* <InOut> */ |
| /* exec :: The target execution context. */ |
| /* */ |
| /* <Return> */ |
| /* TrueType error code. 0 means success. */ |
| /* */ |
| LOCAL_DEF |
| TT_Error TT_Set_CodeRange( TT_ExecContext exec, |
| TT_Int range, |
| void* base, |
| TT_Long length ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* TT_Clear_CodeRange */ |
| /* */ |
| /* <Description> */ |
| /* Clears a code range. */ |
| /* */ |
| /* <Input> */ |
| /* range :: The code range index. */ |
| /* */ |
| /* <InOut> */ |
| /* exec :: The target execution context. */ |
| /* */ |
| /* <Return> */ |
| /* TrueType error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* Does not set the Error variable. */ |
| /* */ |
| LOCAL_DEF |
| TT_Error TT_Clear_CodeRange( TT_ExecContext exec, |
| TT_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. */ |
| /* */ |
| EXPORT_DEF |
| TT_ExecContext TT_New_Context( TT_Face face ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* TT_Done_Context */ |
| /* */ |
| /* <Description> */ |
| /* Discards an execution context. */ |
| /* */ |
| /* <Input> */ |
| /* exec :: A handle to the target execution context. */ |
| /* */ |
| /* <Return> */ |
| /* TrueType error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* Only the glyph loader and debugger should call this function. */ |
| /* */ |
| EXPORT_DEF |
| TT_Error TT_Done_Context( TT_ExecContext exec ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* TT_Destroy_Context */ |
| /* */ |
| /* <Description> */ |
| /* Destroys a given context. */ |
| /* */ |
| /* <Input> */ |
| /* exec :: A handle to the target execution context. */ |
| /* memory :: A handle to the parent memory object. */ |
| /* */ |
| /* <Return> */ |
| /* TrueType error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* Only the glyph loader and debugger should call this function. */ |
| /* */ |
| LOCAL_DEF |
| TT_Error TT_Destroy_Context( TT_ExecContext exec, |
| FT_Memory memory ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* TT_Load_Context */ |
| /* */ |
| /* <Description> */ |
| /* Prepare an execution context for glyph hinting. */ |
| /* */ |
| /* <Input> */ |
| /* exec :: A handle to the target execution context. */ |
| /* face :: A handle to the source face object. */ |
| /* size :: A handle to the source size object. */ |
| /* */ |
| /* <Return> */ |
| /* TrueType error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* Only the glyph loader and debugger should call this function. */ |
| /* */ |
| EXPORT_DEF |
| TT_Error TT_Load_Context( TT_ExecContext exec, |
| TT_Face face, |
| TT_Size size ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* TT_Save_Context */ |
| /* */ |
| /* <Description> */ |
| /* Saves the code ranges in a `size' object. */ |
| /* */ |
| /* <Input> */ |
| /* exec :: A handle to the source execution context. */ |
| /* */ |
| /* <Output> */ |
| /* ins :: A handle to the target size object. */ |
| /* */ |
| /* <Return> */ |
| /* TrueType error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* Only the glyph loader and debugger should call this function. */ |
| /* */ |
| LOCAL_DEF |
| TT_Error TT_Save_Context( TT_ExecContext exec, |
| TT_Size ins ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* TT_Run_Context */ |
| /* */ |
| /* <Description> */ |
| /* Executes one or more instructions in the execution context. */ |
| /* */ |
| /* <Input> */ |
| /* exec :: A handle to the target execution context. */ |
| /* */ |
| /* debug :: A Boolean flag. If set, the function sets some internal */ |
| /* variables and returns immediately, otherwise TT_RunIns() */ |
| /* is called. */ |
| /* */ |
| /* <Return> */ |
| /* TrueTyoe error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* Only the glyph loader and debugger should call this function. */ |
| /* */ |
| LOCAL_DEF |
| TT_Error TT_Run_Context( TT_ExecContext exec, |
| TT_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> */ |
| /* TrueType error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* Only object manager and debugger should call this function. */ |
| /* */ |
| EXPORT_DEF |
| TT_Error TT_RunIns( TT_ExecContext exec ); |
| |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* TTINTERP_H */ |
| |
| |
| /* END */ |
