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Diffstat (limited to 'modules/freetype2/src/truetype/ttobjs.h')
| -rw-r--r-- | modules/freetype2/src/truetype/ttobjs.h | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/modules/freetype2/src/truetype/ttobjs.h b/modules/freetype2/src/truetype/ttobjs.h new file mode 100644 index 0000000000..bc6fbe7f19 --- /dev/null +++ b/modules/freetype2/src/truetype/ttobjs.h @@ -0,0 +1,426 @@ +/**************************************************************************** + * + * ttobjs.h + * + * Objects manager (specification). + * + * Copyright (C) 1996-2023 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 TTOBJS_H_ +#define TTOBJS_H_ + + +#include <freetype/internal/ftobjs.h> +#include <freetype/internal/tttypes.h> + + +FT_BEGIN_HEADER + + + /************************************************************************** + * + * @Type: + * TT_Driver + * + * @Description: + * A handle to a TrueType driver object. + */ + typedef struct TT_DriverRec_* TT_Driver; + + + /************************************************************************** + * + * @Type: + * TT_GlyphSlot + * + * @Description: + * A handle to a TrueType glyph slot object. + * + * @Note: + * This is a direct typedef of FT_GlyphSlot, as there is nothing + * specific about the TrueType glyph slot. + */ + typedef FT_GlyphSlot TT_GlyphSlot; + + + /************************************************************************** + * + * @Struct: + * TT_GraphicsState + * + * @Description: + * The TrueType graphics state used during bytecode interpretation. + */ + typedef struct TT_GraphicsState_ + { + FT_UShort rp0; + FT_UShort rp1; + FT_UShort rp2; + + FT_UnitVector dualVector; + FT_UnitVector projVector; + FT_UnitVector freeVector; + + FT_Long loop; + FT_F26Dot6 minimum_distance; + FT_Int round_state; + + FT_Bool auto_flip; + FT_F26Dot6 control_value_cutin; + FT_F26Dot6 single_width_cutin; + FT_F26Dot6 single_width_value; + FT_UShort delta_base; + FT_UShort delta_shift; + + FT_Byte instruct_control; + /* According to Greg Hitchcock from Microsoft, the `scan_control' */ + /* variable as documented in the TrueType specification is a 32-bit */ + /* integer; the high-word part holds the SCANTYPE value, the low-word */ + /* part the SCANCTRL value. We separate it into two fields. */ + FT_Bool scan_control; + FT_Int scan_type; + + FT_UShort gep0; + FT_UShort gep1; + FT_UShort gep2; + + } TT_GraphicsState; + + +#ifdef TT_USE_BYTECODE_INTERPRETER + + FT_LOCAL( void ) + tt_glyphzone_done( TT_GlyphZone zone ); + + FT_LOCAL( FT_Error ) + tt_glyphzone_new( FT_Memory memory, + FT_UShort maxPoints, + FT_Short maxContours, + TT_GlyphZone zone ); + +#endif /* TT_USE_BYTECODE_INTERPRETER */ + + + + /************************************************************************** + * + * EXECUTION SUBTABLES + * + * These sub-tables relate to instruction execution. + * + */ + + +#define TT_MAX_CODE_RANGES 3 + + + /************************************************************************** + * + * There can only be 3 active code ranges at once: + * - the Font Program + * - the CVT Program + * - a glyph's instructions set + */ + typedef enum TT_CodeRange_Tag_ + { + tt_coderange_none = 0, + tt_coderange_font, + tt_coderange_cvt, + tt_coderange_glyph + + } TT_CodeRange_Tag; + + + typedef struct TT_CodeRange_ + { + FT_Byte* base; + FT_Long size; + + } TT_CodeRange; + + typedef TT_CodeRange TT_CodeRangeTable[TT_MAX_CODE_RANGES]; + + + /************************************************************************** + * + * Defines a function/instruction definition record. + */ + typedef struct TT_DefRecord_ + { + FT_Int range; /* in which code range is it located? */ + FT_Long start; /* where does it start? */ + FT_Long end; /* where does it end? */ + FT_UInt opc; /* function #, or instruction code */ + FT_Bool active; /* is it active? */ + FT_Bool inline_delta; /* is function that defines inline delta? */ + FT_ULong sph_fdef_flags; /* flags to identify special functions */ + + } TT_DefRecord, *TT_DefArray; + + + /************************************************************************** + * + * Subglyph transformation record. + */ + typedef struct TT_Transform_ + { + FT_Fixed xx, xy; /* transformation matrix coefficients */ + FT_Fixed yx, yy; + FT_F26Dot6 ox, oy; /* offsets */ + + } TT_Transform; + + + /************************************************************************** + * + * A note regarding non-squared pixels: + * + * (This text will probably go into some docs at some time; for now, it + * is kept here to explain some definitions in the TT_Size_Metrics + * record). + * + * The CVT is a one-dimensional array containing values that control + * certain important characteristics in a font, like the height of all + * capitals, all lowercase letter, default spacing or stem width/height. + * + * These values are found in FUnits in the font file, and must be scaled + * to pixel coordinates before being used by the CVT and glyph programs. + * Unfortunately, when using distinct x and y resolutions (or distinct x + * and y pointsizes), there are two possible scalings. + * + * A first try was to implement a `lazy' scheme where all values were + * scaled when first used. However, while some values are always used + * in the same direction, some others are used under many different + * circumstances and orientations. + * + * I have found a simpler way to do the same, and it even seems to work + * in most of the cases: + * + * - All CVT values are scaled to the maximum ppem size. + * + * - When performing a read or write in the CVT, a ratio factor is used + * to perform adequate scaling. Example: + * + * x_ppem = 14 + * y_ppem = 10 + * + * We choose ppem = x_ppem = 14 as the CVT scaling size. All cvt + * entries are scaled to it. + * + * x_ratio = 1.0 + * y_ratio = y_ppem/ppem (< 1.0) + * + * We compute the current ratio like: + * + * - If projVector is horizontal, + * ratio = x_ratio = 1.0 + * + * - if projVector is vertical, + * ratio = y_ratio + * + * - else, + * ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) + * + * Reading a cvt value returns + * ratio * cvt[index] + * + * Writing a cvt value in pixels: + * cvt[index] / ratio + * + * The current ppem is simply + * ratio * ppem + * + */ + + + /************************************************************************** + * + * Metrics used by the TrueType size and context objects. + */ + typedef struct TT_Size_Metrics_ + { + /* for non-square pixels */ + FT_Long x_ratio; + FT_Long y_ratio; + + FT_UShort ppem; /* maximum ppem size */ + FT_Long ratio; /* current ratio */ + FT_Fixed scale; + + FT_F26Dot6 compensations[4]; /* device-specific compensations */ + + FT_Bool valid; + + FT_Bool rotated; /* `is the glyph rotated?'-flag */ + FT_Bool stretched; /* `is the glyph stretched?'-flag */ + + } TT_Size_Metrics; + + + /************************************************************************** + * + * TrueType size class. + */ + typedef struct TT_SizeRec_ + { + FT_SizeRec root; + + /* we have our own copy of metrics so that we can modify */ + /* it without affecting auto-hinting (when used) */ + FT_Size_Metrics* metrics; /* for the current rendering mode */ + FT_Size_Metrics hinted_metrics; /* for the hinted rendering mode */ + + TT_Size_Metrics ttmetrics; + + FT_Byte* widthp; /* glyph widths from the hdmx table */ + + FT_ULong strike_index; /* 0xFFFFFFFF to indicate invalid */ + +#ifdef TT_USE_BYTECODE_INTERPRETER + + FT_Long point_size; /* for the `MPS' bytecode instruction */ + + FT_UInt num_function_defs; /* number of function definitions */ + FT_UInt max_function_defs; + TT_DefArray function_defs; /* table of function definitions */ + + FT_UInt num_instruction_defs; /* number of ins. definitions */ + FT_UInt max_instruction_defs; + TT_DefArray instruction_defs; /* table of ins. definitions */ + + FT_UInt max_func; + FT_UInt max_ins; + + TT_CodeRangeTable codeRangeTable; + + TT_GraphicsState GS; + + FT_ULong cvt_size; /* the scaled control value table */ + FT_Long* cvt; + + FT_UShort storage_size; /* The storage area is now part of */ + FT_Long* storage; /* the instance */ + + TT_GlyphZoneRec twilight; /* The instance's twilight zone */ + + TT_ExecContext context; + + /* if negative, `fpgm' (resp. `prep'), wasn't executed yet; */ + /* otherwise it is the returned error code */ + FT_Error bytecode_ready; + FT_Error cvt_ready; + +#endif /* TT_USE_BYTECODE_INTERPRETER */ + + } TT_SizeRec; + + + /************************************************************************** + * + * TrueType driver class. + */ + typedef struct TT_DriverRec_ + { + FT_DriverRec root; + + TT_GlyphZoneRec zone; /* glyph loader points zone */ + + FT_UInt interpreter_version; + + } TT_DriverRec; + + + /* Note: All of the functions below (except tt_size_reset()) are used */ + /* as function pointers in a FT_Driver_ClassRec. Therefore their */ + /* parameters are of types FT_Face, FT_Size, etc., rather than TT_Face, */ + /* TT_Size, etc., so that the compiler can confirm that the types and */ + /* number of parameters are correct. In all cases the FT_xxx types are */ + /* cast to their TT_xxx counterparts inside the functions since FreeType */ + /* will always use the TT driver to create them. */ + + + /************************************************************************** + * + * Face functions + */ + FT_LOCAL( FT_Error ) + tt_face_init( FT_Stream stream, + FT_Face ttface, /* TT_Face */ + FT_Int face_index, + FT_Int num_params, + FT_Parameter* params ); + + FT_LOCAL( void ) + tt_face_done( FT_Face ttface ); /* TT_Face */ + + + /************************************************************************** + * + * Size functions + */ + FT_LOCAL( FT_Error ) + tt_size_init( FT_Size ttsize ); /* TT_Size */ + + FT_LOCAL( void ) + tt_size_done( FT_Size ttsize ); /* TT_Size */ + +#ifdef TT_USE_BYTECODE_INTERPRETER + + FT_LOCAL( FT_Error ) + tt_size_run_fpgm( TT_Size size, + FT_Bool pedantic ); + + FT_LOCAL( FT_Error ) + tt_size_run_prep( TT_Size size, + FT_Bool pedantic ); + + FT_LOCAL( FT_Error ) + tt_size_ready_bytecode( TT_Size size, + FT_Bool pedantic ); + +#endif /* TT_USE_BYTECODE_INTERPRETER */ + + FT_LOCAL( FT_Error ) + tt_size_reset( TT_Size size, + FT_Bool only_height ); + + + /************************************************************************** + * + * Driver functions + */ + FT_LOCAL( FT_Error ) + tt_driver_init( FT_Module ttdriver ); /* TT_Driver */ + + FT_LOCAL( void ) + tt_driver_done( FT_Module ttdriver ); /* TT_Driver */ + + + /************************************************************************** + * + * Slot functions + */ + FT_LOCAL( FT_Error ) + tt_slot_init( FT_GlyphSlot slot ); + + + /* auxiliary */ +#define IS_HINTED( flags ) ( ( flags & FT_LOAD_NO_HINTING ) == 0 ) + + +FT_END_HEADER + +#endif /* TTOBJS_H_ */ + + +/* END */ |