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/***************************************************************************/
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/* TrueType bytecode interpreter (specification). */
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/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2010 by */
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */
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/* This file is part of the FreeType project, and may only be used, */
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/* modified, and distributed under the terms of the FreeType project */
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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/* this file you indicate that you have read the license and */
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/* understand and accept it fully. */
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/***************************************************************************/
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#ifndef __TTINTERP_H__
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#define __TTINTERP_H__
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#ifndef TT_CONFIG_OPTION_STATIC_INTERPRETER /* indirect implementation */
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#define EXEC_OP_ TT_ExecContext exc,
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#define EXEC_OP TT_ExecContext exc
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#define EXEC_ARG_ exc,
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#else /* static implementation */
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#define EXEC_OP_ /* void */
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#define EXEC_OP /* void */
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#define EXEC_ARG_ /* void */
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#define EXEC_ARG /* void */
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#endif /* TT_CONFIG_OPTION_STATIC_INTERPRETER */
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/*************************************************************************/
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/* Rounding mode constants. */
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#define TT_Round_Off 5
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#define TT_Round_To_Half_Grid 0
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#define TT_Round_To_Grid 1
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#define TT_Round_To_Double_Grid 2
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#define TT_Round_Up_To_Grid 4
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#define TT_Round_Down_To_Grid 3
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#define TT_Round_Super 6
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#define TT_Round_Super_45 7
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/*************************************************************************/
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/* Function types used by the interpreter, depending on various modes */
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/* (e.g. the rounding mode, whether to render a vertical or horizontal */
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/*************************************************************************/
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/* Rounding function */
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(*TT_Round_Func)( EXEC_OP_ FT_F26Dot6 distance,
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FT_F26Dot6 compensation );
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/* Point displacement along the freedom vector routine */
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(*TT_Move_Func)( EXEC_OP_ TT_GlyphZone zone,
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FT_F26Dot6 distance );
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/* Distance projection along one of the projection vectors */
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(*TT_Project_Func)( EXEC_OP_ FT_Pos dx,
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/* reading a cvt value. Take care of non-square pixels if necessary */
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(*TT_Get_CVT_Func)( EXEC_OP_ FT_ULong idx );
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/* setting or moving a cvt value. Take care of non-square pixels */
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(*TT_Set_CVT_Func)( EXEC_OP_ FT_ULong idx,
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/*************************************************************************/
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/* This structure defines a call record, used to manage function calls. */
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typedef struct TT_CallRec_
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} TT_CallRec, *TT_CallStack;
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/*************************************************************************/
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/* The main structure for the interpreter which collects all necessary */
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/* variables and states. */
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typedef struct TT_ExecContextRec_
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/* instructions state */
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FT_Error error; /* last execution error */
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FT_Long top; /* top of exec. stack */
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FT_UInt stackSize; /* size of exec. stack */
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FT_Long* stack; /* current exec. stack */
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FT_UInt new_top; /* new top after exec. */
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TT_GlyphZoneRec zp0, /* zone records */
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FT_Size_Metrics metrics;
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TT_Size_Metrics tt_metrics; /* size metrics */
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TT_GraphicsState GS; /* current graphics state */
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FT_Int curRange; /* current code range number */
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FT_Byte* code; /* current code range */
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FT_Long IP; /* current instruction pointer */
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FT_Long codeSize; /* size of current range */
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FT_Byte opcode; /* current opcode */
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FT_Int length; /* length of current opcode */
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FT_Bool step_ins; /* true if the interpreter must */
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/* increment IP after ins. exec */
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FT_UInt glyphSize; /* glyph instructions buffer size */
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FT_Byte* glyphIns; /* glyph instructions buffer */
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FT_UInt numFDefs; /* number of function defs */
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FT_UInt maxFDefs; /* maximum number of function defs */
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TT_DefArray FDefs; /* table of FDefs entries */
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FT_UInt numIDefs; /* number of instruction defs */
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FT_UInt maxIDefs; /* maximum number of ins defs */
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TT_DefArray IDefs; /* table of IDefs entries */
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FT_UInt maxFunc; /* maximum function index */
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FT_UInt maxIns; /* maximum instruction index */
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FT_Int callTop, /* top of call stack during execution */
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callSize; /* size of call stack */
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TT_CallStack callStack; /* call stack */
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FT_UShort maxPoints; /* capacity of this context's `pts' */
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FT_Short maxContours; /* record, expressed in points and */
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TT_CodeRangeTable codeRangeTable; /* table of valid code ranges */
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/* useful for the debugger */
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FT_UShort storeSize; /* size of current storage */
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FT_Long* storage; /* storage area */
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FT_F26Dot6 period; /* values used for the */
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FT_F26Dot6 phase; /* `SuperRounding' */
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FT_F26Dot6 threshold;
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/* this seems to be unused */
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FT_Int cur_ppem; /* ppem along the current proj vector */
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FT_Bool instruction_trap; /* If `True', the interpreter will */
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/* exit after each instruction */
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TT_GraphicsState default_GS; /* graphics state resulting from */
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/* the prep program */
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FT_Bool is_composite; /* true if the glyph is composite */
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FT_Bool pedantic_hinting; /* true if pedantic interpretation */
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/* latest interpreter additions */
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FT_Long F_dot_P; /* dot product of freedom and projection */
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TT_Round_Func func_round; /* current rounding function */
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TT_Project_Func func_project, /* current projection function */
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func_dualproj, /* current dual proj. function */
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func_freeProj; /* current freedom proj. func */
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TT_Move_Func func_move; /* current point move function */
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TT_Move_Func func_move_orig; /* move original position function */
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TT_Get_CVT_Func func_read_cvt; /* read a cvt entry */
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TT_Set_CVT_Func func_write_cvt; /* write a cvt entry (in pixels) */
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TT_Set_CVT_Func func_move_cvt; /* incr a cvt entry (in pixels) */
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FT_Bool grayscale; /* are we hinting for grayscale? */
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extern const TT_GraphicsState tt_default_graphics_state;
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TT_Goto_CodeRange( TT_ExecContext exec,
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TT_Set_CodeRange( TT_ExecContext exec,
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TT_Clear_CodeRange( TT_ExecContext exec,
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Update_Max( FT_Memory memory,
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/*************************************************************************/
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/* Queries the face context for a given font. Note that there is */
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/* now a _single_ execution context in the TrueType driver which is */
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/* shared among faces. */
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/* face :: A handle to the source face object. */
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/* A handle to the execution context. Initialized for `face'. */
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/* Only the glyph loader and debugger should call this function. */
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FT_EXPORT( TT_ExecContext )
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TT_New_Context( TT_Driver driver );
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TT_Done_Context( TT_ExecContext exec );
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TT_Load_Context( TT_ExecContext exec,
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TT_Save_Context( TT_ExecContext exec,
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TT_Run_Context( TT_ExecContext exec,
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/*************************************************************************/
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/* Executes one or more instruction in the execution context. This */
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/* is the main function of the TrueType opcode interpreter. */
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/* exec :: A handle to the target execution context. */
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/* FreeType error code. 0 means success. */
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/* Only the object manager and debugger should call this function. */
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/* This function is publicly exported because it is directly */
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/* invoked by the TrueType debugger. */
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FT_EXPORT( FT_Error )
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TT_RunIns( TT_ExecContext exec );
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#endif /* __TTINTERP_H__ */