Go to most recent revision | Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 3918 | Serge | 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 |
||
| 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 */ |