1 /** 2 * @file lv_font_fmt_txt.h 3 * 4 */ 5 6 #ifndef LV_FONT_FMT_TXT_H 7 #define LV_FONT_FMT_TXT_H 8 9 #ifdef __cplusplus 10 extern "C" { 11 #endif 12 13 /********************* 14 * INCLUDES 15 *********************/ 16 #include "lv_font.h" 17 #include "../misc/lv_types.h" 18 19 /********************* 20 * DEFINES 21 *********************/ 22 23 /********************** 24 * TYPEDEFS 25 **********************/ 26 27 /** This describes a glyph.*/ 28 typedef struct { 29 #if LV_FONT_FMT_TXT_LARGE == 0 30 uint32_t bitmap_index : 20; /**< Start index of the bitmap. A font can be max 1 MB.*/ 31 uint32_t adv_w : 12; /**< Draw the next glyph after this width. 8.4 format (real_value * 16 is stored).*/ 32 uint8_t box_w; /**< Width of the glyph's bounding box*/ 33 uint8_t box_h; /**< Height of the glyph's bounding box*/ 34 int8_t ofs_x; /**< x offset of the bounding box*/ 35 int8_t ofs_y; /**< y offset of the bounding box. Measured from the top of the line*/ 36 #else 37 uint32_t bitmap_index; /**< Start index of the bitmap. A font can be max 4 GB.*/ 38 uint32_t adv_w; /**< Draw the next glyph after this width. 28.4 format (real_value * 16 is stored).*/ 39 uint16_t box_w; /**< Width of the glyph's bounding box*/ 40 uint16_t box_h; /**< Height of the glyph's bounding box*/ 41 int16_t ofs_x; /**< x offset of the bounding box*/ 42 int16_t ofs_y; /**< y offset of the bounding box. Measured from the top of the line*/ 43 #endif 44 } lv_font_fmt_txt_glyph_dsc_t; 45 46 /** Format of font character map.*/ 47 typedef enum { 48 LV_FONT_FMT_TXT_CMAP_FORMAT0_FULL, 49 LV_FONT_FMT_TXT_CMAP_SPARSE_FULL, 50 LV_FONT_FMT_TXT_CMAP_FORMAT0_TINY, 51 LV_FONT_FMT_TXT_CMAP_SPARSE_TINY, 52 } lv_font_fmt_txt_cmap_type_t; 53 54 /** 55 * Map codepoints to a `glyph_dsc`s 56 * Several formats are supported to optimize memory usage 57 * See https://github.com/lvgl/lv_font_conv/blob/master/doc/font_spec.md 58 */ 59 typedef struct { 60 /** First Unicode character for this range*/ 61 uint32_t range_start; 62 63 /** Number of Unicode characters related to this range. 64 * Last Unicode character = range_start + range_length - 1*/ 65 uint16_t range_length; 66 67 /** First glyph ID (array index of `glyph_dsc`) for this range*/ 68 uint16_t glyph_id_start; 69 70 /* 71 According the specification there are 4 formats: 72 https://github.com/lvgl/lv_font_conv/blob/master/doc/font_spec.md 73 74 For simplicity introduce "relative code point": 75 rcp = codepoint - range_start 76 77 and a search function: 78 search a "value" in an "array" and returns the index of "value". 79 80 Format 0 tiny 81 unicode_list == NULL && glyph_id_ofs_list == NULL 82 glyph_id = glyph_id_start + rcp 83 84 Format 0 full 85 unicode_list == NULL && glyph_id_ofs_list != NULL 86 glyph_id = glyph_id_start + glyph_id_ofs_list[rcp] 87 88 Sparse tiny 89 unicode_list != NULL && glyph_id_ofs_list == NULL 90 glyph_id = glyph_id_start + search(unicode_list, rcp) 91 92 Sparse full 93 unicode_list != NULL && glyph_id_ofs_list != NULL 94 glyph_id = glyph_id_start + glyph_id_ofs_list[search(unicode_list, rcp)] 95 */ 96 97 const uint16_t * unicode_list; 98 99 /** if(type == LV_FONT_FMT_TXT_CMAP_FORMAT0_...) it's `uint8_t *` 100 * if(type == LV_FONT_FMT_TXT_CMAP_SPARSE_...) it's `uint16_t *` 101 */ 102 const void * glyph_id_ofs_list; 103 104 /** Length of `unicode_list` and/or `glyph_id_ofs_list`*/ 105 uint16_t list_length; 106 107 /** Type of this character map*/ 108 lv_font_fmt_txt_cmap_type_t type; 109 } lv_font_fmt_txt_cmap_t; 110 111 /** A simple mapping of kern values from pairs*/ 112 typedef struct { 113 /*To get a kern value of two code points: 114 1. Get the `glyph_id_left` and `glyph_id_right` from `lv_font_fmt_txt_cmap_t 115 2. for(i = 0; i < pair_cnt * 2; i += 2) 116 if(glyph_ids[i] == glyph_id_left && 117 glyph_ids[i+1] == glyph_id_right) 118 return values[i / 2]; 119 */ 120 const void * glyph_ids; 121 const int8_t * values; 122 uint32_t pair_cnt : 30; 123 uint32_t glyph_ids_size : 2; /**< 0: `glyph_ids` is stored as `uint8_t`; 1: as `uint16_t` */ 124 } lv_font_fmt_txt_kern_pair_t; 125 126 /** More complex but more optimal class based kern value storage*/ 127 typedef struct { 128 /*To get a kern value of two code points: 129 1. Get the `glyph_id_left` and `glyph_id_right` from `lv_font_fmt_txt_cmap_t 130 2. Get the class of the left and right glyphs as `left_class` and `right_class` 131 left_class = left_class_mapping[glyph_id_left]; 132 right_class = right_class_mapping[glyph_id_right]; 133 3. value = class_pair_values[(left_class-1)*right_class_cnt + (right_class-1)] 134 */ 135 136 const int8_t * class_pair_values; /**< left_class_cnt * right_class_cnt value */ 137 const uint8_t * left_class_mapping; /**< Map the glyph_ids to classes: index -> glyph_id -> class_id */ 138 const uint8_t * right_class_mapping; /**< Map the glyph_ids to classes: index -> glyph_id -> class_id */ 139 uint8_t left_class_cnt; 140 uint8_t right_class_cnt; 141 } lv_font_fmt_txt_kern_classes_t; 142 143 /** Bitmap formats*/ 144 typedef enum { 145 LV_FONT_FMT_TXT_PLAIN = 0, 146 LV_FONT_FMT_TXT_COMPRESSED = 1, 147 LV_FONT_FMT_TXT_COMPRESSED_NO_PREFILTER = 2, 148 LV_FONT_FMT_PLAIN_ALIGNED = 3, 149 } lv_font_fmt_txt_bitmap_format_t; 150 151 /** Describe store for additional data for fonts */ 152 typedef struct { 153 /** The bitmaps of all glyphs */ 154 const uint8_t * glyph_bitmap; 155 156 /** Describe the glyphs */ 157 const lv_font_fmt_txt_glyph_dsc_t * glyph_dsc; 158 159 /** Map the glyphs to Unicode characters. 160 *Array of `lv_font_cmap_fmt_txt_t` variables */ 161 const lv_font_fmt_txt_cmap_t * cmaps; 162 163 /** 164 * Store kerning values. 165 * Can be `lv_font_fmt_txt_kern_pair_t * or `lv_font_kern_classes_fmt_txt_t *` 166 * depending on `kern_classes` 167 */ 168 const void * kern_dsc; 169 170 /** Scale kern values in 12.4 format */ 171 uint16_t kern_scale; 172 173 /** Number of cmap tables */ 174 uint16_t cmap_num : 9; 175 176 /** Bit per pixel: 1, 2, 3, 4, 8 */ 177 uint16_t bpp : 4; 178 179 /** Type of `kern_dsc` */ 180 uint16_t kern_classes : 1; 181 182 /** 183 * storage format of the bitmap 184 * from `lv_font_fmt_txt_bitmap_format_t` 185 */ 186 uint16_t bitmap_format : 2; 187 } lv_font_fmt_txt_dsc_t; 188 189 /********************** 190 * GLOBAL PROTOTYPES 191 **********************/ 192 193 /** 194 * Used as `get_glyph_bitmap` callback in lvgl's native font format if the font is uncompressed. 195 * @param g_dsc the glyph descriptor including which font to use, which supply the glyph_index and format. 196 * @param draw_buf a draw buffer that can be used to store the bitmap of the glyph, it's OK not to use it. 197 * @return pointer to an A8 bitmap (not necessarily bitmap_out) or NULL if `unicode_letter` not found 198 */ 199 const void * lv_font_get_bitmap_fmt_txt(lv_font_glyph_dsc_t * g_dsc, lv_draw_buf_t * draw_buf); 200 201 /** 202 * Used as `get_glyph_dsc` callback in lvgl's native font format if the font is uncompressed. 203 * @param font pointer to font 204 * @param dsc_out store the result descriptor here 205 * @param unicode_letter a UNICODE letter code 206 * @param unicode_letter_next the unicode letter succeeding the letter under test 207 * @return true: descriptor is successfully loaded into `dsc_out`. 208 * false: the letter was not found, no data is loaded to `dsc_out` 209 */ 210 bool lv_font_get_glyph_dsc_fmt_txt(const lv_font_t * font, lv_font_glyph_dsc_t * dsc_out, uint32_t unicode_letter, 211 uint32_t unicode_letter_next); 212 213 /********************** 214 * MACROS 215 **********************/ 216 217 /********************** 218 * ADD BUILT IN FONTS 219 **********************/ 220 221 #ifdef __cplusplus 222 } /*extern "C"*/ 223 #endif 224 225 #endif /*LV_FONT_FMT_TXT_H*/ 226
