ref: 026bd17b4138fda38885db9c3986b560072c6c02
dir: /src/truetype/ttinterp.h/
/***************************************************************************/ /* */ /* 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. */ /* */ /* This function is publicly exported because it is directly */ /* invoked by the TrueType debugger.. */ /* */ FT_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. */ /* */ LOCAL_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. */ /* */ LOCAL_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. */ /* */ /* This function is publicly exported because it is directly */ /* invoked by the TrueType debugger.. */ /* */ FT_EXPORT_DEF(TT_Error) TT_RunIns( TT_ExecContext exec ); #ifdef __cplusplus } #endif #endif /* TTINTERP_H */ /* END */