typedef struct FT_StrokerRec_*  FT_Stroker;

Opaque handler to a path stroker object.

  typedef enum  FT_Stroker_LineJoin_
  {
    FT_STROKER_LINEJOIN_ROUND          = 0,
    FT_STROKER_LINEJOIN_BEVEL          = 1,
    FT_STROKER_LINEJOIN_MITER_VARIABLE = 2,
    FT_STROKER_LINEJOIN_MITER          = FT_STROKER_LINEJOIN_MITER_VARIABLE,
    FT_STROKER_LINEJOIN_MITER_FIXED    = 3

  } FT_Stroker_LineJoin;

These values determine how two joining lines are rendered in a stroker.

  typedef enum  FT_Stroker_LineCap_
  {
    FT_STROKER_LINECAP_BUTT = 0,
    FT_STROKER_LINECAP_ROUND,
    FT_STROKER_LINECAP_SQUARE

  } FT_Stroker_LineCap;

These values determine how the end of opened sub-paths are rendered in a stroke.

  typedef enum  FT_StrokerBorder_
  {
    FT_STROKER_BORDER_LEFT = 0,
    FT_STROKER_BORDER_RIGHT

  } FT_StrokerBorder;

These values are used to select a given stroke border in FT_Stroker_GetBorderCounts and FT_Stroker_ExportBorder.

Applications are generally interested in the ‘inside’ and ‘outside’ borders. However, there is no direct mapping between these and the ‘left’ and ‘right’ ones, since this really depends on the glyph's drawing orientation, which varies between font formats.

You can however use FT_Outline_GetInsideBorder and FT_Outline_GetOutsideBorder to get these.

  FT_EXPORT( FT_StrokerBorder )
  FT_Outline_GetInsideBorder( FT_Outline*  outline );

Retrieve the FT_StrokerBorder value corresponding to the ‘inside’ borders of a given outline.

The border index. FT_STROKER_BORDER_RIGHT for empty or invalid outlines.

  FT_EXPORT( FT_StrokerBorder )
  FT_Outline_GetOutsideBorder( FT_Outline*  outline );

Retrieve the FT_StrokerBorder value corresponding to the ‘outside’ borders of a given outline.

The border index. FT_STROKER_BORDER_LEFT for empty or invalid outlines.

  FT_EXPORT( FT_Error )
  FT_Stroker_New( FT_Library   library,
                  FT_Stroker  *astroker );

Create a new stroker object.

FreeType error code. 0 means success.

  FT_EXPORT( void )
  FT_Stroker_Set( FT_Stroker           stroker,
                  FT_Fixed             radius,
                  FT_Stroker_LineCap   line_cap,
                  FT_Stroker_LineJoin  line_join,
                  FT_Fixed             miter_limit );

Reset a stroker object's attributes.

The radius is expressed in the same units as the outline coordinates.

  FT_EXPORT( void )
  FT_Stroker_Rewind( FT_Stroker  stroker );

Reset a stroker object without changing its attributes. You should call this function before beginning a new series of calls to FT_Stroker_BeginSubPath or FT_Stroker_EndSubPath.

  FT_EXPORT( FT_Error )
  FT_Stroker_ParseOutline( FT_Stroker   stroker,
                           FT_Outline*  outline,
                           FT_Bool      opened );

A convenience function used to parse a whole outline with the stroker. The resulting outline(s) can be retrieved later by functions like FT_Stroker_GetCounts and FT_Stroker_Export.

FreeType error code. 0 means success.

If ‘opened’ is 0 (the default), the outline is treated as a closed path, and the stroker generates two distinct ‘border’ outlines.

If ‘opened’ is 1, the outline is processed as an open path, and the stroker generates a single ‘stroke’ outline.

This function calls FT_Stroker_Rewind automatically.

  FT_EXPORT( FT_Error )
  FT_Stroker_BeginSubPath( FT_Stroker  stroker,
                           FT_Vector*  to,
                           FT_Bool     open );

Start a new sub-path in the stroker.

FreeType error code. 0 means success.

This function is useful when you need to stroke a path that is not stored as an FT_Outline object.

  FT_EXPORT( FT_Error )
  FT_Stroker_EndSubPath( FT_Stroker  stroker );

Close the current sub-path in the stroker.

FreeType error code. 0 means success.

You should call this function after FT_Stroker_BeginSubPath. If the subpath was not ‘opened’, this function ‘draws’ a single line segment to the start position when needed.

  FT_EXPORT( FT_Error )
  FT_Stroker_LineTo( FT_Stroker  stroker,
                     FT_Vector*  to );

‘Draw’ a single line segment in the stroker's current sub-path, from the last position.

FreeType error code. 0 means success.

You should call this function between FT_Stroker_BeginSubPath and FT_Stroker_EndSubPath.

  FT_EXPORT( FT_Error )
  FT_Stroker_ConicTo( FT_Stroker  stroker,
                      FT_Vector*  control,
                      FT_Vector*  to );

‘Draw’ a single quadratic Bézier in the stroker's current sub-path, from the last position.

FreeType error code. 0 means success.

You should call this function between FT_Stroker_BeginSubPath and FT_Stroker_EndSubPath.

  FT_EXPORT( FT_Error )
  FT_Stroker_CubicTo( FT_Stroker  stroker,
                      FT_Vector*  control1,
                      FT_Vector*  control2,
                      FT_Vector*  to );

‘Draw’ a single cubic Bézier in the stroker's current sub-path, from the last position.

FreeType error code. 0 means success.

You should call this function between FT_Stroker_BeginSubPath and FT_Stroker_EndSubPath.

  FT_EXPORT( FT_Error )
  FT_Stroker_GetBorderCounts( FT_Stroker        stroker,
                              FT_StrokerBorder  border,
                              FT_UInt          *anum_points,
                              FT_UInt          *anum_contours );

Call this function once you have finished parsing your paths with the stroker. It returns the number of points and contours necessary to export one of the ‘border’ or ‘stroke’ outlines generated by the stroker.

FreeType error code. 0 means success.

When an outline, or a sub-path, is ‘closed’, the stroker generates two independent ‘border’ outlines, named ‘left’ and ‘right’.

When the outline, or a sub-path, is ‘opened’, the stroker merges the ‘border’ outlines with caps. The ‘left’ border receives all points, while the ‘right’ border becomes empty.

Use the function FT_Stroker_GetCounts instead if you want to retrieve the counts associated to both borders.

  FT_EXPORT( void )
  FT_Stroker_ExportBorder( FT_Stroker        stroker,
                           FT_StrokerBorder  border,
                           FT_Outline*       outline );

Call this function after FT_Stroker_GetBorderCounts to export the corresponding border to your own FT_Outline structure.

Note that this function appends the border points and contours to your outline, but does not try to resize its arrays.

Always call this function after FT_Stroker_GetBorderCounts to get sure that there is enough room in your FT_Outline object to receive all new data.

When an outline, or a sub-path, is ‘closed’, the stroker generates two independent ‘border’ outlines, named ‘left’ and ‘right’

When the outline, or a sub-path, is ‘opened’, the stroker merges the ‘border’ outlines with caps. The ‘left’ border receives all points, while the ‘right’ border becomes empty.

Use the function FT_Stroker_Export instead if you want to retrieve all borders at once.

  FT_EXPORT( FT_Error )
  FT_Stroker_GetCounts( FT_Stroker  stroker,
                        FT_UInt    *anum_points,
                        FT_UInt    *anum_contours );

Call this function once you have finished parsing your paths with the stroker. It returns the number of points and contours necessary to export all points/borders from the stroked outline/path.

FreeType error code. 0 means success.

  FT_EXPORT( void )
  FT_Stroker_Export( FT_Stroker   stroker,
                     FT_Outline*  outline );

Call this function after FT_Stroker_GetBorderCounts to export all borders to your own FT_Outline structure.

Note that this function appends the border points and contours to your outline, but does not try to resize its arrays.

  FT_EXPORT( void )
  FT_Stroker_Done( FT_Stroker  stroker );

Destroy a stroker object.

  FT_EXPORT( FT_Error )
  FT_Glyph_Stroke( FT_Glyph    *pglyph,
                   FT_Stroker   stroker,
                   FT_Bool      destroy );

Stroke a given outline glyph object with a given stroker.

FreeType error code. 0 means success.

The source glyph is untouched in case of error.

Adding stroke may yield a significantly wider and taller glyph depending on how large of a radius was used to stroke the glyph. You may need to manually adjust horizontal and vertical advance amounts to account for this added size.

  FT_EXPORT( FT_Error )
  FT_Glyph_StrokeBorder( FT_Glyph    *pglyph,
                         FT_Stroker   stroker,
                         FT_Bool      inside,
                         FT_Bool      destroy );

Stroke a given outline glyph object with a given stroker, but only return either its inside or outside border.

FreeType error code. 0 means success.

The source glyph is untouched in case of error.

Adding stroke may yield a significantly wider and taller glyph depending on how large of a radius was used to stroke the glyph. You may need to manually adjust horizontal and vertical advance amounts to account for this added size.