ttgxvar.h

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/****************************************************************************
 *
 * ttgxvar.h
 *
 *   TrueType GX Font Variation loader (specification)
 *
 * Copyright (C) 2004-2020 by
 * David Turner, Robert Wilhelm, Werner Lemberg and George Williams.
 *
 * 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 TTGXVAR_H_
#define TTGXVAR_H_
 
 
#include "ttobjs.h"
 
 
FT_BEGIN_HEADER
 
 
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
 
  /**************************************************************************
   *
   * @Struct:
   *   GX_AVarCorrespondenceRec
   *
   * @Description:
   *   A data structure representing `shortFracCorrespondence' in `avar'
   *   table according to the specifications from Apple.
   */
  typedef struct  GX_AVarCorrespondenceRec_
  {
    FT_Fixed  fromCoord;
    FT_Fixed  toCoord;
 
  } GX_AVarCorrespondenceRec_, *GX_AVarCorrespondence;
 
 
  /**************************************************************************
   *
   * @Struct:
   *   GX_AVarRec
   *
   * @Description:
   *   Data from the segment field of `avar' table.
   *   There is one of these for each axis.
   */
  typedef struct  GX_AVarSegmentRec_
  {
    FT_UShort              pairCount;
    GX_AVarCorrespondence  correspondence; /* array with pairCount entries */
 
  } GX_AVarSegmentRec, *GX_AVarSegment;
 
 
  typedef struct  GX_ItemVarDataRec_
  {
    FT_UInt    itemCount;      /* number of delta sets per item         */
    FT_UInt    regionIdxCount; /* number of region indices in this data */
    FT_UInt*   regionIndices;  /* array of `regionCount' indices;       */
                               /* these index `varRegionList'           */
    FT_Short*  deltaSet;       /* array of `itemCount' deltas           */
                               /* use `innerIndex' for this array       */
 
  } GX_ItemVarDataRec, *GX_ItemVarData;
 
 
  /* contribution of one axis to a region */
  typedef struct  GX_AxisCoordsRec_
  {
    FT_Fixed  startCoord;
    FT_Fixed  peakCoord;      /* zero means no effect (factor = 1) */
    FT_Fixed  endCoord;
 
  } GX_AxisCoordsRec, *GX_AxisCoords;
 
 
  typedef struct  GX_VarRegionRec_
  {
    GX_AxisCoords  axisList;               /* array of axisCount records */
 
  } GX_VarRegionRec, *GX_VarRegion;
 
 
  /* item variation store */
  typedef struct  GX_ItemVarStoreRec_
  {
    FT_UInt         dataCount;
    GX_ItemVarData  varData;            /* array of dataCount records;     */
                                        /* use `outerIndex' for this array */
    FT_UShort     axisCount;
    FT_UInt       regionCount;          /* total number of regions defined */
    GX_VarRegion  varRegionList;
 
  } GX_ItemVarStoreRec, *GX_ItemVarStore;
 
 
  typedef struct  GX_DeltaSetIdxMapRec_
  {
    FT_UInt   mapCount;
    FT_UInt*  outerIndex;             /* indices to item var data */
    FT_UInt*  innerIndex;             /* indices to delta set     */
 
  } GX_DeltaSetIdxMapRec, *GX_DeltaSetIdxMap;
 
 
  /**************************************************************************
   *
   * @Struct:
   *   GX_HVVarTableRec
   *
   * @Description:
   *   Data from either the `HVAR' or `VVAR' table.
   */
  typedef struct  GX_HVVarTableRec_
  {
    GX_ItemVarStoreRec    itemStore;        /* Item Variation Store  */
    GX_DeltaSetIdxMapRec  widthMap;         /* Advance Width Mapping */
 
#if 0
    GX_DeltaSetIdxMapRec  lsbMap;           /* not implemented */
    GX_DeltaSetIdxMapRec  rsbMap;           /* not implemented */
 
    GX_DeltaSetIdxMapRec  tsbMap;           /* not implemented */
    GX_DeltaSetIdxMapRec  bsbMap;           /* not implemented */
    GX_DeltaSetIdxMapRec  vorgMap;          /* not implemented */
#endif
 
  } GX_HVVarTableRec, *GX_HVVarTable;
 
 
#define MVAR_TAG_GASP_0  FT_MAKE_TAG( 'g', 's', 'p', '0' )
#define MVAR_TAG_GASP_1  FT_MAKE_TAG( 'g', 's', 'p', '1' )
#define MVAR_TAG_GASP_2  FT_MAKE_TAG( 'g', 's', 'p', '2' )
#define MVAR_TAG_GASP_3  FT_MAKE_TAG( 'g', 's', 'p', '3' )
#define MVAR_TAG_GASP_4  FT_MAKE_TAG( 'g', 's', 'p', '4' )
#define MVAR_TAG_GASP_5  FT_MAKE_TAG( 'g', 's', 'p', '5' )
#define MVAR_TAG_GASP_6  FT_MAKE_TAG( 'g', 's', 'p', '6' )
#define MVAR_TAG_GASP_7  FT_MAKE_TAG( 'g', 's', 'p', '7' )
#define MVAR_TAG_GASP_8  FT_MAKE_TAG( 'g', 's', 'p', '8' )
#define MVAR_TAG_GASP_9  FT_MAKE_TAG( 'g', 's', 'p', '9' )
 
#define MVAR_TAG_CPHT  FT_MAKE_TAG( 'c', 'p', 'h', 't' )
#define MVAR_TAG_HASC  FT_MAKE_TAG( 'h', 'a', 's', 'c' )
#define MVAR_TAG_HCLA  FT_MAKE_TAG( 'h', 'c', 'l', 'a' )
#define MVAR_TAG_HCLD  FT_MAKE_TAG( 'h', 'c', 'l', 'd' )
#define MVAR_TAG_HCOF  FT_MAKE_TAG( 'h', 'c', 'o', 'f' )
#define MVAR_TAG_HCRN  FT_MAKE_TAG( 'h', 'c', 'r', 'n' )
#define MVAR_TAG_HCRS  FT_MAKE_TAG( 'h', 'c', 'r', 's' )
#define MVAR_TAG_HDSC  FT_MAKE_TAG( 'h', 'd', 's', 'c' )
#define MVAR_TAG_HLGP  FT_MAKE_TAG( 'h', 'l', 'g', 'p' )
#define MVAR_TAG_SBXO  FT_MAKE_TAG( 's', 'b', 'x', 'o' )
#define MVAR_TAG_SBXS  FT_MAKE_TAG( 's', 'b', 'x', 's' )
#define MVAR_TAG_SBYO  FT_MAKE_TAG( 's', 'b', 'y', 'o' )
#define MVAR_TAG_SBYS  FT_MAKE_TAG( 's', 'b', 'y', 's' )
#define MVAR_TAG_SPXO  FT_MAKE_TAG( 's', 'p', 'x', 'o' )
#define MVAR_TAG_SPXS  FT_MAKE_TAG( 's', 'p', 'x', 's' )
#define MVAR_TAG_SPYO  FT_MAKE_TAG( 's', 'p', 'y', 'o' )
#define MVAR_TAG_SPYS  FT_MAKE_TAG( 's', 'p', 'y', 's' )
#define MVAR_TAG_STRO  FT_MAKE_TAG( 's', 't', 'r', 'o' )
#define MVAR_TAG_STRS  FT_MAKE_TAG( 's', 't', 'r', 's' )
#define MVAR_TAG_UNDO  FT_MAKE_TAG( 'u', 'n', 'd', 'o' )
#define MVAR_TAG_UNDS  FT_MAKE_TAG( 'u', 'n', 'd', 's' )
#define MVAR_TAG_VASC  FT_MAKE_TAG( 'v', 'a', 's', 'c' )
#define MVAR_TAG_VCOF  FT_MAKE_TAG( 'v', 'c', 'o', 'f' )
#define MVAR_TAG_VCRN  FT_MAKE_TAG( 'v', 'c', 'r', 'n' )
#define MVAR_TAG_VCRS  FT_MAKE_TAG( 'v', 'c', 'r', 's' )
#define MVAR_TAG_VDSC  FT_MAKE_TAG( 'v', 'd', 's', 'c' )
#define MVAR_TAG_VLGP  FT_MAKE_TAG( 'v', 'l', 'g', 'p' )
#define MVAR_TAG_XHGT  FT_MAKE_TAG( 'x', 'h', 'g', 't' )
 
 
  typedef struct  GX_ValueRec_
  {
    FT_ULong   tag;
    FT_UShort  outerIndex;
    FT_UShort  innerIndex;
 
    FT_Short  unmodified;  /* values are either FT_Short or FT_UShort */
 
  } GX_ValueRec, *GX_Value;
 
 
  /**************************************************************************
   *
   * @Struct:
   *   GX_MVarTableRec
   *
   * @Description:
   *   Data from the `MVAR' table.
   */
  typedef struct  GX_MVarTableRec_
  {
    FT_UShort  valueCount;
 
    GX_ItemVarStoreRec  itemStore;        /* Item Variation Store  */
    GX_Value            values;           /* Value Records         */
 
  } GX_MVarTableRec, *GX_MVarTable;
 
 
  /**************************************************************************
   *
   * @Struct:
   *   GX_BlendRec
   *
   * @Description:
   *   Data for interpolating a font from a distortable font specified
   *   by the GX *var tables ([fgcahvm]var).
   *
   * @Fields:
   *   num_axis ::
   *     The number of axes along which interpolation may happen.
   *
   *   coords ::
   *     An array of design coordinates (in user space) indicating the
   *     contribution along each axis to the final interpolated font.
   *     `normalizedcoords' holds the same values.
   *
   *   normalizedcoords ::
   *     An array of normalized values (between [-1,1]) indicating the
   *     contribution along each axis to the final interpolated font.
   *     `coords' holds the same values.
   *
   *   mmvar ::
   *     Data from the `fvar' table.
   *
   *   mmvar_len ::
   *     The length of the `mmvar' structure.
   *
   *   normalized_stylecoords ::
   *     A two-dimensional array that holds the named instance data from
   *     `mmvar' as normalized values.
   *
   *   avar_loaded ::
   *     A Boolean; if set, FreeType tried to load (and parse) the `avar'
   *     table.
   *
   *   avar_segment ::
   *     Data from the `avar' table.
   *
   *   hvar_loaded ::
   *     A Boolean; if set, FreeType tried to load (and parse) the `hvar'
   *     table.
   *
   *   hvar_checked ::
   *     A Boolean; if set, FreeType successfully loaded and parsed the
   *     `hvar' table.
   *
   *   hvar_error ::
   *     If loading and parsing of the `hvar' table failed, this field
   *     holds the corresponding error code.
   *
   *   hvar_table ::
   *     Data from the `hvar' table.
   *
   *   vvar_loaded ::
   *     A Boolean; if set, FreeType tried to load (and parse) the `vvar'
   *     table.
   *
   *   vvar_checked ::
   *     A Boolean; if set, FreeType successfully loaded and parsed the
   *     `vvar' table.
   *
   *   vvar_error ::
   *     If loading and parsing of the `vvar' table failed, this field
   *     holds the corresponding error code.
   *
   *   vvar_table ::
   *     Data from the `vvar' table.
   *
   *   mvar_table ::
   *     Data from the `mvar' table.
   *
   *   tuplecount ::
   *     The number of shared tuples in the `gvar' table.
   *
   *   tuplecoords ::
   *     A two-dimensional array that holds the shared tuple coordinates
   *     in the `gvar' table.
   *
   *   gv_glyphcnt ::
   *     The number of glyphs handled in the `gvar' table.
   *
   *   glyphoffsets ::
   *     Offsets into the glyph variation data array.
   *
   *   gvar_size ::
   *     The size of the `gvar' table.
   */
  typedef struct  GX_BlendRec_
  {
    FT_UInt         num_axis;
    FT_Fixed*       coords;
    FT_Fixed*       normalizedcoords;
 
    FT_MM_Var*      mmvar;
    FT_Offset       mmvar_len;
 
    FT_Fixed*       normalized_stylecoords;
                      /* normalized_stylecoords[num_namedstyles][num_axis] */
 
    FT_Bool         avar_loaded;
    GX_AVarSegment  avar_segment;                /* avar_segment[num_axis] */
 
    FT_Bool         hvar_loaded;
    FT_Bool         hvar_checked;
    FT_Error        hvar_error;
    GX_HVVarTable   hvar_table;
 
    FT_Bool         vvar_loaded;
    FT_Bool         vvar_checked;
    FT_Error        vvar_error;
    GX_HVVarTable   vvar_table;
 
    GX_MVarTable    mvar_table;
 
    FT_UInt         tuplecount;
    FT_Fixed*       tuplecoords;      /* tuplecoords[tuplecount][num_axis] */
 
    FT_UInt         gv_glyphcnt;
    FT_ULong*       glyphoffsets;         /* glyphoffsets[gv_glyphcnt + 1] */
 
    FT_ULong        gvar_size;
 
  } GX_BlendRec;
 
 
  /**************************************************************************
   *
   * @enum:
   *   GX_TupleCountFlags
   *
   * @Description:
   *   Flags used within the `TupleCount' field of the `gvar' table.
   */
  typedef enum  GX_TupleCountFlags_
  {
    GX_TC_TUPLES_SHARE_POINT_NUMBERS = 0x8000,
    GX_TC_RESERVED_TUPLE_FLAGS       = 0x7000,
    GX_TC_TUPLE_COUNT_MASK           = 0x0FFF
 
  } GX_TupleCountFlags;
 
 
  /**************************************************************************
   *
   * @enum:
   *   GX_TupleIndexFlags
   *
   * @Description:
   *   Flags used within the `TupleIndex' field of the `gvar' and `cvar'
   *   tables.
   */
  typedef enum  GX_TupleIndexFlags_
  {
    GX_TI_EMBEDDED_TUPLE_COORD  = 0x8000,
    GX_TI_INTERMEDIATE_TUPLE    = 0x4000,
    GX_TI_PRIVATE_POINT_NUMBERS = 0x2000,
    GX_TI_RESERVED_TUPLE_FLAG   = 0x1000,
    GX_TI_TUPLE_INDEX_MASK      = 0x0FFF
 
  } GX_TupleIndexFlags;
 
 
#define TTAG_wght  FT_MAKE_TAG( 'w', 'g', 'h', 't' )
#define TTAG_wdth  FT_MAKE_TAG( 'w', 'd', 't', 'h' )
#define TTAG_opsz  FT_MAKE_TAG( 'o', 'p', 's', 'z' )
#define TTAG_slnt  FT_MAKE_TAG( 's', 'l', 'n', 't' )
 
 
  FT_LOCAL( FT_Error )
  TT_Set_MM_Blend( TT_Face    face,
                   FT_UInt    num_coords,
                   FT_Fixed*  coords );
 
  FT_LOCAL( FT_Error )
  TT_Get_MM_Blend( TT_Face    face,
                   FT_UInt    num_coords,
                   FT_Fixed*  coords );
 
  FT_LOCAL( FT_Error )
  TT_Set_Var_Design( TT_Face    face,
                     FT_UInt    num_coords,
                     FT_Fixed*  coords );
 
  FT_LOCAL( FT_Error )
  TT_Get_MM_Var( TT_Face      face,
                 FT_MM_Var*  *master );
 
  FT_LOCAL( FT_Error )
  TT_Get_Var_Design( TT_Face    face,
                     FT_UInt    num_coords,
                     FT_Fixed*  coords );
 
  FT_LOCAL( FT_Error )
  TT_Set_Named_Instance( TT_Face  face,
                         FT_UInt  instance_index );
 
  FT_LOCAL( FT_Error )
  tt_face_vary_cvt( TT_Face    face,
                    FT_Stream  stream );
 
 
  FT_LOCAL( FT_Error )
  TT_Vary_Apply_Glyph_Deltas( TT_Face      face,
                              FT_UInt      glyph_index,
                              FT_Outline*  outline,
                              FT_Vector*   unrounded,
                              FT_UInt      n_points );
 
  FT_LOCAL( FT_Error )
  tt_hadvance_adjust( TT_Face  face,
                      FT_UInt  gindex,
                      FT_Int  *adelta );
 
  FT_LOCAL( FT_Error )
  tt_vadvance_adjust( TT_Face  face,
                      FT_UInt  gindex,
                      FT_Int  *adelta );
 
  FT_LOCAL( void )
  tt_apply_mvar( TT_Face  face );
 
  FT_LOCAL( FT_Error )
  tt_get_var_blend( TT_Face      face,
                    FT_UInt     *num_coords,
                    FT_Fixed*   *coords,
                    FT_Fixed*   *normalizedcoords,
                    FT_MM_Var*  *mm_var );
 
  FT_LOCAL( void )
  tt_done_blend( TT_Face  face );
 
#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
 
 
FT_END_HEADER
 
 
#endif /* TTGXVAR_H_ */
 
 
/* END */