1 /**************************************************************************** 2 * 3 * aflatin.h 4 * 5 * Auto-fitter hinting routines for latin writing system 6 * (specification). 7 * 8 * Copyright (C) 2003-2023 by 9 * David Turner, Robert Wilhelm, and Werner Lemberg. 10 * 11 * This file is part of the FreeType project, and may only be used, 12 * modified, and distributed under the terms of the FreeType project 13 * license, LICENSE.TXT. By continuing to use, modify, or distribute 14 * this file you indicate that you have read the license and 15 * understand and accept it fully. 16 * 17 */ 18 19 20 #ifndef AFLATIN_H_ 21 #define AFLATIN_H_ 22 23 #include "afhints.h" 24 25 26 FT_BEGIN_HEADER 27 28 /* the `latin' writing system */ 29 30 AF_DECLARE_WRITING_SYSTEM_CLASS( af_latin_writing_system_class ) 31 32 33 /* constants are given with units_per_em == 2048 in mind */ 34 #define AF_LATIN_CONSTANT( metrics, c ) \ 35 ( ( (c) * (FT_Long)( (AF_LatinMetrics)(metrics) )->units_per_em ) / 2048 ) 36 37 38 /*************************************************************************/ 39 /*************************************************************************/ 40 /***** *****/ 41 /***** L A T I N G L O B A L M E T R I C S *****/ 42 /***** *****/ 43 /*************************************************************************/ 44 /*************************************************************************/ 45 46 47 /* 48 * The following declarations could be embedded in the file `aflatin.c'; 49 * they have been made semi-public to allow alternate writing system 50 * hinters to re-use some of them. 51 */ 52 53 54 #define AF_LATIN_IS_TOP_BLUE( b ) \ 55 ( (b)->properties & AF_BLUE_PROPERTY_LATIN_TOP ) 56 #define AF_LATIN_IS_SUB_TOP_BLUE( b ) \ 57 ( (b)->properties & AF_BLUE_PROPERTY_LATIN_SUB_TOP ) 58 #define AF_LATIN_IS_NEUTRAL_BLUE( b ) \ 59 ( (b)->properties & AF_BLUE_PROPERTY_LATIN_NEUTRAL ) 60 #define AF_LATIN_IS_X_HEIGHT_BLUE( b ) \ 61 ( (b)->properties & AF_BLUE_PROPERTY_LATIN_X_HEIGHT ) 62 #define AF_LATIN_IS_LONG_BLUE( b ) \ 63 ( (b)->properties & AF_BLUE_PROPERTY_LATIN_LONG ) 64 65 #define AF_LATIN_MAX_WIDTHS 16 66 67 68 #define AF_LATIN_BLUE_ACTIVE ( 1U << 0 ) /* zone height is <= 3/4px */ 69 #define AF_LATIN_BLUE_TOP ( 1U << 1 ) /* we have a top blue zone */ 70 #define AF_LATIN_BLUE_SUB_TOP ( 1U << 2 ) /* we have a subscript top */ 71 /* blue zone */ 72 #define AF_LATIN_BLUE_NEUTRAL ( 1U << 3 ) /* we have neutral blue zone */ 73 #define AF_LATIN_BLUE_ADJUSTMENT ( 1U << 4 ) /* used for scale adjustment */ 74 /* optimization */ 75 76 77 typedef struct AF_LatinBlueRec_ 78 { 79 AF_WidthRec ref; 80 AF_WidthRec shoot; 81 FT_Pos ascender; 82 FT_Pos descender; 83 FT_UInt flags; 84 85 } AF_LatinBlueRec, *AF_LatinBlue; 86 87 88 typedef struct AF_LatinAxisRec_ 89 { 90 FT_Fixed scale; 91 FT_Pos delta; 92 93 FT_UInt width_count; /* number of used widths */ 94 AF_WidthRec widths[AF_LATIN_MAX_WIDTHS]; /* widths array */ 95 FT_Pos edge_distance_threshold; /* used for creating edges */ 96 FT_Pos standard_width; /* the default stem thickness */ 97 FT_Bool extra_light; /* is standard width very light? */ 98 99 /* ignored for horizontal metrics */ 100 FT_UInt blue_count; 101 AF_LatinBlueRec blues[AF_BLUE_STRINGSET_MAX]; 102 103 FT_Fixed org_scale; 104 FT_Pos org_delta; 105 106 } AF_LatinAxisRec, *AF_LatinAxis; 107 108 109 typedef struct AF_LatinMetricsRec_ 110 { 111 AF_StyleMetricsRec root; 112 FT_UInt units_per_em; 113 AF_LatinAxisRec axis[AF_DIMENSION_MAX]; 114 115 } AF_LatinMetricsRec, *AF_LatinMetrics; 116 117 118 FT_LOCAL( FT_Error ) 119 af_latin_metrics_init( AF_LatinMetrics metrics, 120 FT_Face face ); 121 122 FT_LOCAL( void ) 123 af_latin_metrics_scale( AF_LatinMetrics metrics, 124 AF_Scaler scaler ); 125 126 FT_LOCAL( void ) 127 af_latin_metrics_init_widths( AF_LatinMetrics metrics, 128 FT_Face face ); 129 130 FT_LOCAL( void ) 131 af_latin_metrics_check_digits( AF_LatinMetrics metrics, 132 FT_Face face ); 133 134 135 /*************************************************************************/ 136 /*************************************************************************/ 137 /***** *****/ 138 /***** L A T I N G L Y P H A N A L Y S I S *****/ 139 /***** *****/ 140 /*************************************************************************/ 141 /*************************************************************************/ 142 143 #define AF_LATIN_HINTS_HORZ_SNAP ( 1U << 0 ) /* stem width snapping */ 144 #define AF_LATIN_HINTS_VERT_SNAP ( 1U << 1 ) /* stem height snapping */ 145 #define AF_LATIN_HINTS_STEM_ADJUST ( 1U << 2 ) /* stem width/height */ 146 /* adjustment */ 147 #define AF_LATIN_HINTS_MONO ( 1U << 3 ) /* monochrome rendering */ 148 149 150 #define AF_LATIN_HINTS_DO_HORZ_SNAP( h ) \ 151 AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_HORZ_SNAP ) 152 153 #define AF_LATIN_HINTS_DO_VERT_SNAP( h ) \ 154 AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_VERT_SNAP ) 155 156 #define AF_LATIN_HINTS_DO_STEM_ADJUST( h ) \ 157 AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_STEM_ADJUST ) 158 159 #define AF_LATIN_HINTS_DO_MONO( h ) \ 160 AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_MONO ) 161 162 163 /* 164 * The next functions shouldn't normally be exported. However, other 165 * writing systems might like to use these functions as-is. 166 */ 167 FT_LOCAL( FT_Error ) 168 af_latin_hints_compute_segments( AF_GlyphHints hints, 169 AF_Dimension dim ); 170 171 FT_LOCAL( void ) 172 af_latin_hints_link_segments( AF_GlyphHints hints, 173 FT_UInt width_count, 174 AF_WidthRec* widths, 175 AF_Dimension dim ); 176 177 FT_LOCAL( FT_Error ) 178 af_latin_hints_compute_edges( AF_GlyphHints hints, 179 AF_Dimension dim ); 180 181 FT_LOCAL( FT_Error ) 182 af_latin_hints_detect_features( AF_GlyphHints hints, 183 FT_UInt width_count, 184 AF_WidthRec* widths, 185 AF_Dimension dim ); 186 187 /* */ 188 189 FT_END_HEADER 190 191 #endif /* AFLATIN_H_ */ 192 193 194 /* END */ 195