reactos/lib/3rdparty/freetype/src/base/ftadvanc.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftadvanc.c                                                             */
   4 /*                                                                         */
   5 /*    Quick computation of advance widths (body).                          */
   6 /*                                                                         */
   7 /*  Copyright 2008, 2009, 2011, 2013 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 #include <ft2build.h>
  20 #include FT_INTERNAL_DEBUG_H
  21
  22 #include FT_ADVANCES_H
  23 #include FT_INTERNAL_OBJECTS_H
  24
  25
  26   static FT_Error
  27   _ft_face_scale_advances( FT_Face    face,
  28                            FT_Fixed*  advances,
  29                            FT_UInt    count,
  30                            FT_Int32   flags )
  31   {
  32     FT_Fixed  scale;
  33     FT_UInt   nn;
  34
  35
  36     if ( flags & FT_LOAD_NO_SCALE )
  37       return FT_Err_Ok;
  38
  39     if ( face->size == NULL )
  40       return FT_THROW( Invalid_Size_Handle );
  41
  42     if ( flags & FT_LOAD_VERTICAL_LAYOUT )
  43       scale = face->size->metrics.y_scale;
  44     else
  45       scale = face->size->metrics.x_scale;
  46
  47     /* this must be the same scaling as to get linear{Hori,Vert}Advance */
  48     /* (see `FT_Load_Glyph' implementation in src/base/ftobjs.c)        */
  49
  50     for ( nn = 0; nn < count; nn++ )
  51       advances[nn] = FT_MulDiv( advances[nn], scale, 64 );
  52
  53     return FT_Err_Ok;
  54   }
  55
  56
  57    /* at the moment, we can perform fast advance retrieval only in */
  58    /* the following cases:                                         */
  59    /*                                                              */
  60    /*  - unscaled load                                             */
  61    /*  - unhinted load                                             */
  62    /*  - light-hinted load                                         */
  63
  64 #define LOAD_ADVANCE_FAST_CHECK( flags )                            \
  65           ( flags & ( FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING )    || \
  66             FT_LOAD_TARGET_MODE( flags ) == FT_RENDER_MODE_LIGHT )
  67
  68
  69   /* documentation is in ftadvanc.h */
  70
  71   FT_EXPORT_DEF( FT_Error )
  72   FT_Get_Advance( FT_Face    face,
  73                   FT_UInt    gindex,
  74                   FT_Int32   flags,
  75                   FT_Fixed  *padvance )
  76   {
  77     FT_Face_GetAdvancesFunc  func;
  78
  79
  80     if ( !face )
  81       return FT_THROW( Invalid_Face_Handle );
  82
  83     if ( gindex >= (FT_UInt)face->num_glyphs )
  84       return FT_THROW( Invalid_Glyph_Index );
  85
  86     func = face->driver->clazz->get_advances;
  87     if ( func && LOAD_ADVANCE_FAST_CHECK( flags ) )
  88     {
  89       FT_Error  error;
  90
  91
  92       error = func( face, gindex, 1, flags, padvance );
  93       if ( !error )
  94         return _ft_face_scale_advances( face, padvance, 1, flags );
  95
  96       if ( FT_ERR_NEQ( error, Unimplemented_Feature ) )
  97         return error;
  98     }
  99
 100     return FT_Get_Advances( face, gindex, 1, flags, padvance );
 101   }
 102
 103
 104   /* documentation is in ftadvanc.h */
 105
 106   FT_EXPORT_DEF( FT_Error )
 107   FT_Get_Advances( FT_Face    face,
 108                    FT_UInt    start,
 109                    FT_UInt    count,
 110                    FT_Int32   flags,
 111                    FT_Fixed  *padvances )
 112   {
 113     FT_Face_GetAdvancesFunc  func;
 114     FT_UInt                  num, end, nn;
 115     FT_Error                 error = FT_Err_Ok;
 116
 117
 118     if ( !face )
 119       return FT_THROW( Invalid_Face_Handle );
 120
 121     num = (FT_UInt)face->num_glyphs;
 122     end = start + count;
 123     if ( start >= num || end < start || end > num )
 124       return FT_THROW( Invalid_Glyph_Index );
 125
 126     if ( count == 0 )
 127       return FT_Err_Ok;
 128
 129     func = face->driver->clazz->get_advances;
 130     if ( func && LOAD_ADVANCE_FAST_CHECK( flags ) )
 131     {
 132       error = func( face, start, count, flags, padvances );
 133       if ( !error )
 134         return _ft_face_scale_advances( face, padvances, count, flags );
 135
 136       if ( FT_ERR_NEQ( error, Unimplemented_Feature ) )
 137         return error;
 138     }
 139
 140     error = FT_Err_Ok;
 141
 142     if ( flags & FT_ADVANCE_FLAG_FAST_ONLY )
 143       return FT_THROW( Unimplemented_Feature );
 144
 145     flags |= (FT_UInt32)FT_LOAD_ADVANCE_ONLY;
 146     for ( nn = 0; nn < count; nn++ )
 147     {
 148       error = FT_Load_Glyph( face, start + nn, flags );
 149       if ( error )
 150         break;
 151
 152       /* scale from 26.6 to 16.16 */
 153       padvances[nn] = ( flags & FT_LOAD_VERTICAL_LAYOUT )
 154                       ? face->glyph->advance.y << 10
 155                       : face->glyph->advance.x << 10;
 156     }
 157
 158     return error;
 159   }
 160
 161
 162 /* END */