Home | History | Annotate | Download | only in freetype
      1 /****************************************************************************
      2  *
      3  * ftrender.h
      4  *
      5  *   FreeType renderer modules public interface (specification).
      6  *
      7  * Copyright 1996-2018 by
      8  * David Turner, Robert Wilhelm, and Werner Lemberg.
      9  *
     10  * This file is part of the FreeType project, and may only be used,
     11  * modified, and distributed under the terms of the FreeType project
     12  * license, LICENSE.TXT.  By continuing to use, modify, or distribute
     13  * this file you indicate that you have read the license and
     14  * understand and accept it fully.
     15  *
     16  */
     17 
     18 
     19 #ifndef FTRENDER_H_
     20 #define FTRENDER_H_
     21 
     22 
     23 #include <ft2build.h>
     24 #include FT_MODULE_H
     25 #include FT_GLYPH_H
     26 
     27 
     28 FT_BEGIN_HEADER
     29 
     30 
     31   /**************************************************************************
     32    *
     33    * @section:
     34    *   module_management
     35    *
     36    */
     37 
     38 
     39   /* create a new glyph object */
     40   typedef FT_Error
     41   (*FT_Glyph_InitFunc)( FT_Glyph      glyph,
     42                         FT_GlyphSlot  slot );
     43 
     44   /* destroys a given glyph object */
     45   typedef void
     46   (*FT_Glyph_DoneFunc)( FT_Glyph  glyph );
     47 
     48   typedef void
     49   (*FT_Glyph_TransformFunc)( FT_Glyph          glyph,
     50                              const FT_Matrix*  matrix,
     51                              const FT_Vector*  delta );
     52 
     53   typedef void
     54   (*FT_Glyph_GetBBoxFunc)( FT_Glyph  glyph,
     55                            FT_BBox*  abbox );
     56 
     57   typedef FT_Error
     58   (*FT_Glyph_CopyFunc)( FT_Glyph   source,
     59                         FT_Glyph   target );
     60 
     61   typedef FT_Error
     62   (*FT_Glyph_PrepareFunc)( FT_Glyph      glyph,
     63                            FT_GlyphSlot  slot );
     64 
     65 /* deprecated */
     66 #define FT_Glyph_Init_Func       FT_Glyph_InitFunc
     67 #define FT_Glyph_Done_Func       FT_Glyph_DoneFunc
     68 #define FT_Glyph_Transform_Func  FT_Glyph_TransformFunc
     69 #define FT_Glyph_BBox_Func       FT_Glyph_GetBBoxFunc
     70 #define FT_Glyph_Copy_Func       FT_Glyph_CopyFunc
     71 #define FT_Glyph_Prepare_Func    FT_Glyph_PrepareFunc
     72 
     73 
     74   struct  FT_Glyph_Class_
     75   {
     76     FT_Long                 glyph_size;
     77     FT_Glyph_Format         glyph_format;
     78 
     79     FT_Glyph_InitFunc       glyph_init;
     80     FT_Glyph_DoneFunc       glyph_done;
     81     FT_Glyph_CopyFunc       glyph_copy;
     82     FT_Glyph_TransformFunc  glyph_transform;
     83     FT_Glyph_GetBBoxFunc    glyph_bbox;
     84     FT_Glyph_PrepareFunc    glyph_prepare;
     85   };
     86 
     87 
     88   typedef FT_Error
     89   (*FT_Renderer_RenderFunc)( FT_Renderer       renderer,
     90                              FT_GlyphSlot      slot,
     91                              FT_Render_Mode    mode,
     92                              const FT_Vector*  origin );
     93 
     94   typedef FT_Error
     95   (*FT_Renderer_TransformFunc)( FT_Renderer       renderer,
     96                                 FT_GlyphSlot      slot,
     97                                 const FT_Matrix*  matrix,
     98                                 const FT_Vector*  delta );
     99 
    100 
    101   typedef void
    102   (*FT_Renderer_GetCBoxFunc)( FT_Renderer   renderer,
    103                               FT_GlyphSlot  slot,
    104                               FT_BBox*      cbox );
    105 
    106 
    107   typedef FT_Error
    108   (*FT_Renderer_SetModeFunc)( FT_Renderer  renderer,
    109                               FT_ULong     mode_tag,
    110                               FT_Pointer   mode_ptr );
    111 
    112 /* deprecated identifiers */
    113 #define FTRenderer_render  FT_Renderer_RenderFunc
    114 #define FTRenderer_transform  FT_Renderer_TransformFunc
    115 #define FTRenderer_getCBox  FT_Renderer_GetCBoxFunc
    116 #define FTRenderer_setMode  FT_Renderer_SetModeFunc
    117 
    118 
    119   /**************************************************************************
    120    *
    121    * @struct:
    122    *   FT_Renderer_Class
    123    *
    124    * @description:
    125    *   The renderer module class descriptor.
    126    *
    127    * @fields:
    128    *   root ::
    129    *     The root @FT_Module_Class fields.
    130    *
    131    *   glyph_format ::
    132    *     The glyph image format this renderer handles.
    133    *
    134    *   render_glyph ::
    135    *     A method used to render the image that is in a
    136    *     given glyph slot into a bitmap.
    137    *
    138    *   transform_glyph ::
    139    *     A method used to transform the image that is in
    140    *     a given glyph slot.
    141    *
    142    *   get_glyph_cbox ::
    143    *     A method used to access the glyph's cbox.
    144    *
    145    *   set_mode ::
    146    *     A method used to pass additional parameters.
    147    *
    148    *   raster_class ::
    149    *     For @FT_GLYPH_FORMAT_OUTLINE renderers only.
    150    *     This is a pointer to its raster's class.
    151    */
    152   typedef struct  FT_Renderer_Class_
    153   {
    154     FT_Module_Class            root;
    155 
    156     FT_Glyph_Format            glyph_format;
    157 
    158     FT_Renderer_RenderFunc     render_glyph;
    159     FT_Renderer_TransformFunc  transform_glyph;
    160     FT_Renderer_GetCBoxFunc    get_glyph_cbox;
    161     FT_Renderer_SetModeFunc    set_mode;
    162 
    163     FT_Raster_Funcs*           raster_class;
    164 
    165   } FT_Renderer_Class;
    166 
    167 
    168   /**************************************************************************
    169    *
    170    * @function:
    171    *   FT_Get_Renderer
    172    *
    173    * @description:
    174    *   Retrieve the current renderer for a given glyph format.
    175    *
    176    * @input:
    177    *   library ::
    178    *     A handle to the library object.
    179    *
    180    *   format ::
    181    *     The glyph format.
    182    *
    183    * @return:
    184    *   A renderer handle.  0~if none found.
    185    *
    186    * @note:
    187    *   An error will be returned if a module already exists by that name,
    188    *   or if the module requires a version of FreeType that is too great.
    189    *
    190    *   To add a new renderer, simply use @FT_Add_Module.  To retrieve a
    191    *   renderer by its name, use @FT_Get_Module.
    192    */
    193   FT_EXPORT( FT_Renderer )
    194   FT_Get_Renderer( FT_Library       library,
    195                    FT_Glyph_Format  format );
    196 
    197 
    198   /**************************************************************************
    199    *
    200    * @function:
    201    *   FT_Set_Renderer
    202    *
    203    * @description:
    204    *   Set the current renderer to use, and set additional mode.
    205    *
    206    * @inout:
    207    *   library ::
    208    *     A handle to the library object.
    209    *
    210    * @input:
    211    *   renderer ::
    212    *     A handle to the renderer object.
    213    *
    214    *   num_params ::
    215    *     The number of additional parameters.
    216    *
    217    *   parameters ::
    218    *     Additional parameters.
    219    *
    220    * @return:
    221    *   FreeType error code.  0~means success.
    222    *
    223    * @note:
    224    *   In case of success, the renderer will be used to convert glyph
    225    *   images in the renderer's known format into bitmaps.
    226    *
    227    *   This doesn't change the current renderer for other formats.
    228    *
    229    *   Currently, no FreeType renderer module uses `parameters'; you
    230    *   should thus always pass NULL as the value.
    231    */
    232   FT_EXPORT( FT_Error )
    233   FT_Set_Renderer( FT_Library     library,
    234                    FT_Renderer    renderer,
    235                    FT_UInt        num_params,
    236                    FT_Parameter*  parameters );
    237 
    238   /* */
    239 
    240 
    241 FT_END_HEADER
    242 
    243 #endif /* FTRENDER_H_ */
    244 
    245 
    246 /* END */
    247