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Diffstat (limited to 'third_party/freetype/src/truetype/ttinterp.h')
| -rw-r--r-- | third_party/freetype/src/truetype/ttinterp.h | 523 |
1 files changed, 0 insertions, 523 deletions
diff --git a/third_party/freetype/src/truetype/ttinterp.h b/third_party/freetype/src/truetype/ttinterp.h deleted file mode 100644 index 6625e16c76..0000000000 --- a/third_party/freetype/src/truetype/ttinterp.h +++ /dev/null @@ -1,523 +0,0 @@ -/***************************************************************************/ -/* */ -/* ttinterp.h */ -/* */ -/* TrueType bytecode interpreter (specification). */ -/* */ -/* Copyright 1996-2017 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 - - - /*************************************************************************/ - /* */ - /* 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)( TT_ExecContext exc, - FT_F26Dot6 distance, - FT_F26Dot6 compensation ); - - /* Point displacement along the freedom vector routine */ - typedef void - (*TT_Move_Func)( TT_ExecContext exc, - TT_GlyphZone zone, - FT_UShort point, - FT_F26Dot6 distance ); - - /* Distance projection along one of the projection vectors */ - typedef FT_F26Dot6 - (*TT_Project_Func)( TT_ExecContext exc, - FT_Pos dx, - FT_Pos dy ); - - /* getting current ppem. Take care of non-square pixels if necessary */ - typedef FT_Long - (*TT_Cur_Ppem_Func)( TT_ExecContext exc ); - - /* reading a cvt value. Take care of non-square pixels if necessary */ - typedef FT_F26Dot6 - (*TT_Get_CVT_Func)( TT_ExecContext exc, - FT_ULong idx ); - - /* setting or moving a cvt value. Take care of non-square pixels */ - /* if necessary */ - typedef void - (*TT_Set_CVT_Func)( TT_ExecContext exc, - 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; - - TT_DefRecord *Def; /* either FDEF or IDEF */ - - } TT_CallRec, *TT_CallStack; - - -#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY - - /*************************************************************************/ - /* */ - /* These structures define rules used to tweak subpixel hinting for */ - /* various fonts. "", 0, "", NULL value indicates to match any value. */ - /* */ - -#define SPH_MAX_NAME_SIZE 32 -#define SPH_MAX_CLASS_MEMBERS 100 - - typedef struct SPH_TweakRule_ - { - const char family[SPH_MAX_NAME_SIZE]; - const FT_UInt ppem; - const char style[SPH_MAX_NAME_SIZE]; - const FT_ULong glyph; - - } SPH_TweakRule; - - - typedef struct SPH_ScaleRule_ - { - const char family[SPH_MAX_NAME_SIZE]; - const FT_UInt ppem; - const char style[SPH_MAX_NAME_SIZE]; - const FT_ULong glyph; - const FT_ULong scale; - - } SPH_ScaleRule; - - - typedef struct SPH_Font_Class_ - { - const char name[SPH_MAX_NAME_SIZE]; - const char member[SPH_MAX_CLASS_MEMBERS][SPH_MAX_NAME_SIZE]; - - } SPH_Font_Class; - -#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */ - - - /*************************************************************************/ - /* */ - /* 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_Long stackSize; /* size of exec. stack */ - FT_Long* stack; /* current exec. stack */ - - FT_Long args; - FT_Long new_top; /* new top after exec. */ - - TT_GlyphZoneRec zp0, /* zone records */ - zp1, - zp2, - pts, - twilight; - - FT_Long pointSize; /* in 26.6 format */ - 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_ULong 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; - - 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_Cur_Ppem_Func func_cur_ppem; /* get current proj. ppem value */ - - 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; /* bi-level hinting and */ - /* grayscale rendering */ - -#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL - /* - * Modern TrueType fonts are usually rendered through Microsoft's - * collection of rendering techniques called ClearType (e.g., subpixel - * rendering and subpixel hinting). When ClearType was introduced, most - * fonts were not ready. Microsoft decided to implement a backwards - * compatibility mode that employed several simple to complicated - * assumptions and tricks that modified the interpretation of the - * bytecode contained in these fonts to make them look ClearType-y - * somehow. Most (web)fonts that were released since then have come to - * rely on these hacks to render correctly, even some of Microsoft's - * flagship ClearType fonts (Calibri, Cambria, Segoe UI). - * - * The minimal subpixel hinting code (interpreter version 40) employs a - * small list of font-agnostic hacks to bludgeon non-native-ClearType - * fonts (except tricky ones[1]) into submission. It will not try to - * toggle hacks for specific fonts for performance and complexity - * reasons. The focus is on modern (web)fonts rather than legacy fonts - * that were made for black-and-white rendering. - * - * Major hacks - * - * - Any point movement on the x axis is ignored (cf. `Direct_Move' and - * `Direct_Move_X'). This has the smallest code footprint and single - * biggest effect. The ClearType way to increase resolution is - * supersampling the x axis, the FreeType way is ignoring instructions - * on the x axis, which gives the same result in the majority of - * cases. - * - * - Points are not moved post-IUP (neither on the x nor on the y axis), - * except the x component of diagonal moves post-IUP (cf. - * `Direct_Move', `Direct_Move_Y', `Move_Zp2_Point'). Post-IUP - * changes are commonly used to `fix' pixel patterns which has little - * use outside monochrome rendering. - * - * - SHPIX and DELTAP don't execute unless moving a composite on the - * y axis or moving a previously y touched point. SHPIX additionally - * denies movement on the x axis (cf. `Ins_SHPIX' and `Ins_DELTAP'). - * Both instructions are commonly used to `fix' pixel patterns for - * monochrome or Windows's GDI rendering but make little sense for - * FreeType rendering. Both can distort the outline. See [2] for - * details. - * - * - The hdmx table and modifications to phantom points are ignored. - * Bearings and advance widths remain unchanged (except rounding them - * outside the interpreter!), cf. `compute_glyph_metrics' and - * `TT_Hint_Glyph'. Letting non-native-ClearType fonts modify spacing - * might mess up spacing. - * - * Minor hacks - * - * - FLIPRGON, FLIPRGOFF, and FLIPPT don't execute post-IUP. This - * prevents dents in e.g. Arial-Regular's `D' and `G' glyphs at - * various sizes. - * - * (Post-IUP is the state after both IUP[x] and IUP[y] have been - * executed.) - * - * The best results are achieved for fonts that were from the outset - * designed with ClearType in mind, meaning they leave the x axis mostly - * alone and don't mess with the `final' outline to produce more - * pleasing pixel patterns. The harder the designer tried to produce - * very specific patterns (`superhinting') for pre-ClearType-displays, - * the worse the results. - * - * Microsoft defines a way to turn off backwards compatibility and - * interpret instructions as before (called `native ClearType')[2][3]. - * The font designer then regains full control and is responsible for - * making the font work correctly with ClearType without any - * hand-holding by the interpreter or rasterizer[4]. The v40 - * interpreter assumes backwards compatibility by default, which can be - * turned off the same way by executing the following in the control - * program (cf. `Ins_INSTCTRL'). - * - * #PUSH 4,3 - * INSTCTRL[] - * - * [1] Tricky fonts as FreeType defines them rely on the bytecode - * interpreter to display correctly. Hacks can interfere with them, - * so they get treated like native ClearType fonts (v40 with - * backwards compatibility turned off). Cf. `TT_RunIns'. - * - * [2] Proposed by Microsoft's Greg Hitchcock in - * https://www.microsoft.com/typography/cleartype/truetypecleartype.aspx - * - * [3] Beat Stamm describes it in more detail: - * http://www.beatstamm.com/typography/RTRCh4.htm#Sec12 - * - * [4] The list of `native ClearType' fonts is small at the time of this - * writing; I found the following on a Windows 10 Update 1511 - * installation: Constantia, Corbel, Sitka, Malgun Gothic, Microsoft - * JhengHei (Bold and UI Bold), Microsoft YaHei (Bold and UI Bold), - * SimSun, NSimSun, and Yu Gothic. - * - */ - - /* Using v40 implies subpixel hinting. Used to detect interpreter */ - /* version switches. `_lean' to differentiate from the Infinality */ - /* `subpixel_hinting', which is managed differently. */ - FT_Bool subpixel_hinting_lean; - - /* Long side of a LCD subpixel is vertical (e.g., screen is rotated). */ - /* `_lean' to differentiate from the Infinality `vertical_lcd', which */ - /* is managed differently. */ - FT_Bool vertical_lcd_lean; - - /* Default to backwards compatibility mode in v40 interpreter. If */ - /* this is false, it implies the interpreter is in v35 or in native */ - /* ClearType mode. */ - FT_Bool backwards_compatibility; - - /* Useful for detecting and denying post-IUP trickery that is usually */ - /* used to fix pixel patterns (`superhinting'). */ - FT_Bool iupx_called; - FT_Bool iupy_called; - - /* ClearType hinting and grayscale rendering, as used by Universal */ - /* Windows Platform apps (Windows 8 and above). Like the standard */ - /* colorful ClearType mode, it utilizes a vastly increased virtual */ - /* resolution on the x axis. Different from bi-level hinting and */ - /* grayscale rendering, the old mode from Win9x days that roughly */ - /* adheres to the physical pixel grid on both axes. */ - FT_Bool grayscale_cleartype; -#endif /* TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL */ - -#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY - TT_Round_Func func_round_sphn; /* subpixel rounding function */ - - FT_Bool subpixel_hinting; /* Using subpixel hinting? */ - FT_Bool ignore_x_mode; /* Standard rendering mode for */ - /* subpixel hinting. On if gray */ - /* or subpixel hinting is on. */ - - /* The following 6 aren't fully implemented but here for MS rasterizer */ - /* compatibility. */ - FT_Bool compatible_widths; /* compatible widths? */ - FT_Bool symmetrical_smoothing; /* symmetrical_smoothing? */ - FT_Bool bgr; /* bgr instead of rgb? */ - FT_Bool vertical_lcd; /* long side of LCD subpixel */ - /* rectangles is horizontal */ - FT_Bool subpixel_positioned; /* subpixel positioned */ - /* (DirectWrite ClearType)? */ - FT_Bool gray_cleartype; /* ClearType hinting but */ - /* grayscale rendering */ - - FT_Int rasterizer_version; /* MS rasterizer version */ - - FT_Bool iup_called; /* IUP called for glyph? */ - - FT_ULong sph_tweak_flags; /* flags to control */ - /* hint tweaks */ - - FT_ULong sph_in_func_flags; /* flags to indicate if in */ - /* special functions */ - -#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */ - - /* We maintain two counters (in addition to the instruction counter) */ - /* that act as loop detectors for LOOPCALL and jump opcodes with */ - /* negative arguments. */ - FT_ULong loopcall_counter; - FT_ULong loopcall_counter_max; - FT_ULong neg_jump_counter; - FT_ULong neg_jump_counter_max; - - } TT_ExecContextRec; - - - extern const TT_GraphicsState tt_default_graphics_state; - - -#ifdef TT_USE_BYTECODE_INTERPRETER - FT_LOCAL( void ) - TT_Goto_CodeRange( TT_ExecContext exec, - FT_Int range, - FT_Long IP ); - - FT_LOCAL( void ) - TT_Set_CodeRange( TT_ExecContext exec, - FT_Int range, - void* base, - FT_Long length ); - - FT_LOCAL( void ) - TT_Clear_CodeRange( TT_ExecContext exec, - FT_Int range ); - - - FT_LOCAL( FT_Error ) - Update_Max( FT_Memory memory, - FT_ULong* size, - FT_ULong multiplier, - void* _pbuff, - FT_ULong new_max ); -#endif /* TT_USE_BYTECODE_INTERPRETER */ - - - /*************************************************************************/ - /* */ - /* <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. */ - /* (And right now only the glyph loader uses it.) */ - /* */ - FT_EXPORT( TT_ExecContext ) - TT_New_Context( TT_Driver driver ); - - -#ifdef TT_USE_BYTECODE_INTERPRETER - FT_LOCAL( void ) - TT_Done_Context( TT_ExecContext exec ); - - FT_LOCAL( FT_Error ) - TT_Load_Context( TT_ExecContext exec, - TT_Face face, - TT_Size size ); - - FT_LOCAL( void ) - TT_Save_Context( TT_ExecContext exec, - TT_Size ins ); - - FT_LOCAL( FT_Error ) - TT_Run_Context( TT_ExecContext exec ); -#endif /* TT_USE_BYTECODE_INTERPRETER */ - - - /*************************************************************************/ - /* */ - /* <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 */ |