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

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftadvanc.c                                                             */
   4 /*                                                                         */
   5 /*    Quick computation of advance widths (body).                          */
   6 /*                                                                         */
   7 /*  Copyright 2008-2016 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    /*  - neither a MM nor a GX font                                */
  64
  65 #define LOAD_ADVANCE_FAST_CHECK( face, flags )                          \
  66           ( ( flags & ( FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING )    ||   \
  67               FT_LOAD_TARGET_MODE( flags ) == FT_RENDER_MODE_LIGHT ) && \
  68             !FT_HAS_MULTIPLE_MASTERS( face )                         )
  69
  70
  71   /* documentation is in ftadvanc.h */
  72
  73   FT_EXPORT_DEF( FT_Error )
  74   FT_Get_Advance( FT_Face    face,
  75                   FT_UInt    gindex,
  76                   FT_Int32   flags,
  77                   FT_Fixed  *padvance )
  78   {
  79     FT_Face_GetAdvancesFunc  func;
  80
  81
  82     if ( !face )
  83       return FT_THROW( Invalid_Face_Handle );
  84
  85     if ( !padvance )
  86       return FT_THROW( Invalid_Argument );
  87
  88     if ( gindex >= (FT_UInt)face->num_glyphs )
  89       return FT_THROW( Invalid_Glyph_Index );
  90
  91     func = face->driver->clazz->get_advances;
  92     if ( func && LOAD_ADVANCE_FAST_CHECK( face, flags ) )
  93     {
  94       FT_Error  error;
  95
  96
  97       error = func( face, gindex, 1, flags, padvance );
  98       if ( !error )
  99         return _ft_face_scale_advances( face, padvance, 1, flags );
 100
 101       if ( FT_ERR_NEQ( error, Unimplemented_Feature ) )
 102         return error;
 103     }
 104
 105     return FT_Get_Advances( face, gindex, 1, flags, padvance );
 106   }
 107
 108
 109   /* documentation is in ftadvanc.h */
 110
 111   FT_EXPORT_DEF( FT_Error )
 112   FT_Get_Advances( FT_Face    face,
 113                    FT_UInt    start,
 114                    FT_UInt    count,
 115                    FT_Int32   flags,
 116                    FT_Fixed  *padvances )
 117   {
 118     FT_Face_GetAdvancesFunc  func;
 119     FT_UInt                  num, end, nn;
 120     FT_Error                 error = FT_Err_Ok;
 121
 122
 123     if ( !face )
 124       return FT_THROW( Invalid_Face_Handle );
 125
 126     if ( !padvances )
 127       return FT_THROW( Invalid_Argument );
 128
 129     num = (FT_UInt)face->num_glyphs;
 130     end = start + count;
 131     if ( start >= num || end < start || end > num )
 132       return FT_THROW( Invalid_Glyph_Index );
 133
 134     if ( count == 0 )
 135       return FT_Err_Ok;
 136
 137     func = face->driver->clazz->get_advances;
 138     if ( func && LOAD_ADVANCE_FAST_CHECK( face, flags ) )
 139     {
 140       error = func( face, start, count, flags, padvances );
 141       if ( !error )
 142         return _ft_face_scale_advances( face, padvances, count, flags );
 143
 144       if ( FT_ERR_NEQ( error, Unimplemented_Feature ) )
 145         return error;
 146     }
 147
 148     error = FT_Err_Ok;
 149
 150     if ( flags & FT_ADVANCE_FLAG_FAST_ONLY )
 151       return FT_THROW( Unimplemented_Feature );
 152
 153     flags |= (FT_UInt32)FT_LOAD_ADVANCE_ONLY;
 154     for ( nn = 0; nn < count; nn++ )
 155     {
 156       error = FT_Load_Glyph( face, start + nn, flags );
 157       if ( error )
 158         break;
 159
 160       /* scale from 26.6 to 16.16 */
 161       padvances[nn] = ( flags & FT_LOAD_VERTICAL_LAYOUT )
 162                       ? face->glyph->advance.y << 10
 163                       : face->glyph->advance.x << 10;
 164     }
 165
 166     return error;
 167   }
 168
 169
 170 /* END */