GNU Unifont: src/unifont-support.c Source File

GNU Unifont 15.1.05 Pan-Unicode font with complete Unicode Plane 0 coverage and partial coverage of higher planes

unifont-support.c
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1/**
2 @file: unifont-support.c
3
4 @brief: Support functions for Unifont .hex files.
5
6 @author Paul Hardy
7
8 @copyright Copyright © 2023 Paul Hardy
9*/
10/*
11 LICENSE:
12
13 This program is free software: you can redistribute it and/or modify
14 it under the terms of the GNU General Public License as published by
15 the Free Software Foundation, either version 2 of the License, or
16 (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful,
19 but WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 GNU General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program. If not, see <http://www.gnu.org/licenses/>.
25*/
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29
30
31/**
32 @brief Decode a Unifont .hex file into Uniocde code point and glyph.
33
34 This function takes one line from a Unifont .hex file and decodes
35 it into a code point followed by a 16-row glyph array. The glyph
36 array can be one byte (8 columns) or two bytes (16 columns).
37
38 @param[in] hexstring The Unicode .hex string for one code point.
39 @param[out] width The number of columns in a glyph with 16 rows.
40 @param[out] codept The code point, contained in the first .hex file field.
41 @param[out] glyph The Unifont glyph, as 16 rows by 1 or 2 bytes wide.
42*/
43void
44parse_hex (char *hexstring,
45 int *width,
46 unsigned *codept,
47 unsigned char glyph[16][2]) {
48
49 int i;
50 int row;
51 int length;
52
53 sscanf (hexstring, "%X", codept);
54 length = strlen (hexstring);
55 for (i = length - 1; i > 0 && hexstring[i] != '\n'; i--);
56 hexstring[i] = '\0';
57 for (i = 0; i < 9 && hexstring[i] != ':'; i++);
58 i++; /* Skip over ':' */
59 *width = (length - i) * 4 / 16; /* 16 rows per glyphbits */
60
61 for (row = 0; row < 16; row++) {
62 sscanf (&hexstring[i], "%2hhX", &glyph [row][0]);
63 i += 2;
64 if (*width > 8) {
65 sscanf (&hexstring[i], "%2hhX", &glyph [row][1]);
66 i += 2;
67 }
68 else {
69 glyph [row][1] = 0x00;
70 }
71 }
72
73
74 return;
75}
76
77
78/**
79 @brief Convert a Unifont binary glyph into a binary glyph array of bits.
80
81 This function takes a Unifont 16-row by 1- or 2-byte wide binary glyph
82 and returns an array of 16 rows by 16 columns. For each output array
83 element, a 1 indicates the corresponding bit was set in the binary
84 glyph, and a 0 indicates the corresponding bit was not set.
85
86 @param[in] width The number of columns in the glyph.
87 @param[in] glyph The binary glyph, as a 16-row by 2-byte array.
88 @param[out] glyphbits The converted glyph, as a 16-row, 16-column array.
89*/
90void
91glyph2bits (int width,
92 unsigned char glyph[16][2],
93 unsigned char glyphbits [16][16]) {
94
95 unsigned char tmp_byte;
96 unsigned char mask;
97 int row, column;
98
99 for (row = 0; row < 16; row++) {
100 tmp_byte = glyph [row][0];
101 mask = 0x80;
102 for (column = 0; column < 8; column++) {
103 glyphbits [row][column] = tmp_byte & mask ? 1 : 0;
104 mask >>= 1;
105 }
106
107 if (width > 8)
108 tmp_byte = glyph [row][1];
109 else
110 tmp_byte = 0x00;
111
112 mask = 0x80;
113 for (column = 8; column < 16; column++) {
114 glyphbits [row][column] = tmp_byte & mask ? 1 : 0;
115 mask >>= 1;
116 }
117 }
118
119
120 return;
121}
122
123
124/**
125 @brief Transpose a Unifont .hex format glyph into 2 column-major sub-arrays.
126
127 This function takes a 16-by-16 cell bit array made from a Unifont
128 glyph (as created by the glyph2bits function) and outputs a transposed
129 array of 2 sets of 8 or 16 columns, depending on the glyph width.
130 This format simplifies outputting these bit patterns on a graphics
131 display with a controller chip designed to output a column of 8 pixels
132 at a time.
133
134 For a line of text with Unifont output, first all glyphs can have
135 their first 8 rows of pixels displayed on a line. Then the second
136 8 rows of all glyphs on the line can be displayed. This simplifies
137 code for such controller chips that are designed to automatically
138 increment input bytes of column data by one column at a time for
139 each successive byte.
140
141 The glyphbits array contains a '1' in each cell where the corresponding
142 non-transposed glyph has a pixel set, and 0 in each cell where a pixel
143 is not set.
144
145 @param[in] width The number of columns in the glyph.
146 @param[in] glyphbits The 16-by-16 pixel glyph bits.
147 @param[out] transpose The array of 2 sets of 8 ot 16 columns of 8 pixels.
148*/
149void
150hexpose (int width,
151 unsigned char glyphbits [16][16],
152 unsigned char transpose [2][16]) {
153
154 int column;
155
156
157 for (column = 0; column < 8; column++) {
158 transpose [0][column] =
159 (glyphbits [ 0][column] << 7) |
160 (glyphbits [ 1][column] << 6) |
161 (glyphbits [ 2][column] << 5) |
162 (glyphbits [ 3][column] << 4) |
163 (glyphbits [ 4][column] << 3) |
164 (glyphbits [ 5][column] << 2) |
165 (glyphbits [ 6][column] << 1) |
166 (glyphbits [ 7][column] );
167 transpose [1][column] =
168 (glyphbits [ 8][column] << 7) |
169 (glyphbits [ 9][column] << 6) |
170 (glyphbits [10][column] << 5) |
171 (glyphbits [11][column] << 4) |
172 (glyphbits [12][column] << 3) |
173 (glyphbits [13][column] << 2) |
174 (glyphbits [14][column] << 1) |
175 (glyphbits [15][column] );
176 }
177 if (width > 8) {
178 for (column = 8; column < width; column++) {
179 transpose [0][column] =
180 (glyphbits [0][column] << 7) |
181 (glyphbits [1][column] << 6) |
182 (glyphbits [2][column] << 5) |
183 (glyphbits [3][column] << 4) |
184 (glyphbits [4][column] << 3) |
185 (glyphbits [5][column] << 2) |
186 (glyphbits [6][column] << 1) |
187 (glyphbits [7][column] );
188 transpose [1][column] =
189 (glyphbits [ 8][column] << 7) |
190 (glyphbits [ 9][column] << 6) |
191 (glyphbits [10][column] << 5) |
192 (glyphbits [11][column] << 4) |
193 (glyphbits [12][column] << 3) |
194 (glyphbits [13][column] << 2) |
195 (glyphbits [14][column] << 1) |
196 (glyphbits [15][column] );
197 }
198 }
199 else {
200 for (column = 8; column < width; column++)
201 transpose [0][column] = transpose [1][column] = 0x00;
202 }
203
204
205 return;
206}
207
208
209/**
210 @brief Convert a glyph code point and byte array into a Unifont .hex string.
211
212 This function takes a code point and a 16-row by 1- or 2-byte binary
213 glyph, and converts it into a Unifont .hex format character array.
214
215 @param[in] width The number of columns in the glyph.
216 @param[in] codept The code point to appear in the output .hex string.
217 @param[in] glyph The glyph, with each of 16 rows 1 or 2 bytes wide.
218 @param[out] outstring The output string, in Unifont .hex format.
219*/
220void
221glyph2string (int width, unsigned codept,
222 unsigned char glyph [16][2],
223 char *outstring) {
224
225 int i; /* index into outstring array */
226 int row;
227
228 if (codept <= 0xFFFF) {
229 sprintf (outstring, "%04X:", codept);
230 i = 5;
231 }
232 else {
233 sprintf (outstring, "%06X:", codept);
234 i = 7;
235 }
236
237 for (row = 0; row < 16; row++) {
238 sprintf (&outstring[i], "%02X", glyph [row][0]);
239 i += 2;
240
241 if (width > 8) {
242 sprintf (&outstring[i], "%02X", glyph [row][1]);
243 i += 2;
244 }
245 }
246
247 outstring[i] = '\0'; /* terminate output string */
248
249
250 return;
251}
252
253
254/**
255 @brief Convert a code point and transposed glyph into a Unifont .hex string.
256
257 This function takes a code point and a transposed Unifont glyph
258 of 2 rows of 8 pixels in a column, and converts it into a Unifont
259 .hex format character array.
260
261 @param[in] width The number of columns in the glyph.
262 @param[in] codept The code point to appear in the output .hex string.
263 @param[in] transpose The transposed glyph, with 2 sets of 8-row data.
264 @param[out] outstring The output string, in Unifont .hex format.
265*/
266void
267xglyph2string (int width, unsigned codept,
268 unsigned char transpose [2][16],
269 char *outstring) {
270
271 int i; /* index into outstring array */
272 int column;
273
274 if (codept <= 0xFFFF) {
275 sprintf (outstring, "%04X:", codept);
276 i = 5;
277 }
278 else {
279 sprintf (outstring, "%06X:", codept);
280 i = 7;
281 }
282
283 for (column = 0; column < 8; column++) {
284 sprintf (&outstring[i], "%02X", transpose [0][column]);
285 i += 2;
286 }
287 if (width > 8) {
288 for (column = 8; column < 16; column++) {
289 sprintf (&outstring[i], "%02X", transpose [0][column]);
290 i += 2;
291 }
292 }
293 for (column = 0; column < 8; column++) {
294 sprintf (&outstring[i], "%02X", transpose [1][column]);
295 i += 2;
296 }
297 if (width > 8) {
298 for (column = 8; column < 16; column++) {
299 sprintf (&outstring[i], "%02X", transpose [1][column]);
300 i += 2;
301 }
302 }
303
304 outstring[i] = '\0'; /* terminate output string */
305
306
307 return;
308}
309
hexpose
void hexpose(int width, unsigned char glyphbits[16][16], unsigned char transpose[2][16])
Transpose a Unifont .hex format glyph into 2 column-major sub-arrays.
Definition: unifont-support.c:150
glyph2bits
void glyph2bits(int width, unsigned char glyph[16][2], unsigned char glyphbits[16][16])
Convert a Unifont binary glyph into a binary glyph array of bits.
Definition: unifont-support.c:91
xglyph2string
void xglyph2string(int width, unsigned codept, unsigned char transpose[2][16], char *outstring)
Convert a code point and transposed glyph into a Unifont .hex string.
Definition: unifont-support.c:267
parse_hex
void parse_hex(char *hexstring, int *width, unsigned *codept, unsigned char glyph[16][2])
Decode a Unifont .hex file into Uniocde code point and glyph.
Definition: unifont-support.c:44
glyph2string
void glyph2string(int width, unsigned codept, unsigned char glyph[16][2], char *outstring)
Convert a glyph code point and byte array into a Unifont .hex string.
Definition: unifont-support.c:221