aflatin.h (7408B)
1 /**************************************************************************** 2 * 3 * aflatin.h 4 * 5 * Auto-fitter hinting routines for latin writing system 6 * (specification). 7 * 8 * Copyright (C) 2003-2025 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 #define AF_LATIN_IS_CAPITAL_BOTTOM_BLUE( b ) \ 65 ( (b)->properties & AF_BLUE_PROPERTY_LATIN_CAPITAL_BOTTOM ) 66 #define AF_LATIN_IS_SMALL_BOTTOM_BLUE( b ) \ 67 ( (b)->properties & AF_BLUE_PROPERTY_LATIN_SMALL_BOTTOM ) 68 69 #define AF_LATIN_MAX_WIDTHS 16 70 71 72 #define AF_LATIN_BLUE_ACTIVE ( 1U << 0 ) /* zone height is <= 3/4px */ 73 #define AF_LATIN_BLUE_TOP ( 1U << 1 ) /* we have a top blue zone */ 74 #define AF_LATIN_BLUE_SUB_TOP ( 1U << 2 ) /* we have a subscript */ 75 /* top blue zone */ 76 #define AF_LATIN_BLUE_NEUTRAL ( 1U << 3 ) /* we have a neutral blue */ 77 /* zone */ 78 #define AF_LATIN_BLUE_ADJUSTMENT ( 1U << 4 ) /* used for scale adjustm. */ 79 /* optimization */ 80 #define AF_LATIN_BLUE_BOTTOM ( 1U << 5 ) /* we have a capital */ 81 /* letter bottom blue zone */ 82 #define AF_LATIN_BLUE_BOTTOM_SMALL ( 1U << 6 ) /* we have a small letter */ 83 /* bottom blue zone */ 84 85 86 typedef struct AF_LatinBlueRec_ 87 { 88 AF_WidthRec ref; 89 AF_WidthRec shoot; 90 FT_Pos ascender; 91 FT_Pos descender; 92 FT_UInt flags; 93 94 } AF_LatinBlueRec, *AF_LatinBlue; 95 96 97 typedef struct AF_LatinAxisRec_ 98 { 99 FT_Fixed scale; 100 FT_Pos delta; 101 102 FT_UInt width_count; /* number of used widths */ 103 AF_WidthRec widths[AF_LATIN_MAX_WIDTHS]; /* widths array */ 104 FT_Pos edge_distance_threshold; /* used for creating edges */ 105 FT_Pos standard_width; /* the default stem thickness */ 106 FT_Bool extra_light; /* is standard width very light? */ 107 108 /* ignored for horizontal metrics */ 109 FT_UInt blue_count; 110 AF_LatinBlueRec blues[AF_BLUE_STRINGSET_MAX_LEN]; 111 112 FT_Fixed org_scale; 113 FT_Pos org_delta; 114 115 } AF_LatinAxisRec, *AF_LatinAxis; 116 117 118 typedef struct AF_LatinMetricsRec_ 119 { 120 AF_StyleMetricsRec root; 121 FT_UInt units_per_em; 122 AF_LatinAxisRec axis[AF_DIMENSION_MAX]; 123 124 } AF_LatinMetricsRec, *AF_LatinMetrics; 125 126 127 FT_LOCAL( FT_Error ) 128 af_latin_metrics_init( AF_StyleMetrics metrics, 129 FT_Face face ); 130 131 FT_LOCAL( void ) 132 af_latin_metrics_scale( AF_StyleMetrics metrics, 133 AF_Scaler scaler ); 134 135 FT_LOCAL( void ) 136 af_latin_metrics_init_widths( AF_LatinMetrics metrics, 137 FT_Face face ); 138 139 FT_LOCAL( void ) 140 af_latin_metrics_check_digits( AF_LatinMetrics metrics, 141 FT_Face face ); 142 143 144 /*************************************************************************/ 145 /*************************************************************************/ 146 /***** *****/ 147 /***** L A T I N G L Y P H A N A L Y S I S *****/ 148 /***** *****/ 149 /*************************************************************************/ 150 /*************************************************************************/ 151 152 #define AF_LATIN_HINTS_HORZ_SNAP ( 1U << 0 ) /* stem width snapping */ 153 #define AF_LATIN_HINTS_VERT_SNAP ( 1U << 1 ) /* stem height snapping */ 154 #define AF_LATIN_HINTS_STEM_ADJUST ( 1U << 2 ) /* stem width/height */ 155 /* adjustment */ 156 #define AF_LATIN_HINTS_MONO ( 1U << 3 ) /* monochrome rendering */ 157 158 159 #define AF_LATIN_HINTS_DO_HORZ_SNAP( h ) \ 160 AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_HORZ_SNAP ) 161 162 #define AF_LATIN_HINTS_DO_VERT_SNAP( h ) \ 163 AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_VERT_SNAP ) 164 165 #define AF_LATIN_HINTS_DO_STEM_ADJUST( h ) \ 166 AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_STEM_ADJUST ) 167 168 #define AF_LATIN_HINTS_DO_MONO( h ) \ 169 AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_MONO ) 170 171 172 /* 173 * The next functions shouldn't normally be exported. However, other 174 * writing systems might like to use these functions as-is. 175 */ 176 FT_LOCAL( FT_Error ) 177 af_latin_hints_compute_segments( AF_GlyphHints hints, 178 AF_Dimension dim ); 179 180 FT_LOCAL( void ) 181 af_latin_hints_link_segments( AF_GlyphHints hints, 182 FT_UInt width_count, 183 AF_WidthRec* widths, 184 AF_Dimension dim ); 185 186 FT_LOCAL( FT_Error ) 187 af_latin_hints_compute_edges( AF_GlyphHints hints, 188 AF_Dimension dim ); 189 190 FT_LOCAL( FT_Error ) 191 af_latin_hints_detect_features( AF_GlyphHints hints, 192 FT_UInt width_count, 193 AF_WidthRec* widths, 194 AF_Dimension dim ); 195 196 /* */ 197 198 FT_END_HEADER 199 200 #endif /* AFLATIN_H_ */ 201 202 203 /* END */