1 /*
2 * Copyright © 2012 Google, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27 #ifndef ANSI_PRINT_HH
28 #define ANSI_PRINT_HH
29
30 #include "hb.hh"
31
32 #include <cairo.h>
33
34 #include <assert.h>
35 #include <stdlib.h>
36 #include <stddef.h>
37 #include <string.h>
38 #include <math.h>
39
40 #if defined (_MSC_VER) && (_MSC_VER < 1800)
41 static inline long int
lround(double x)42 lround (double x)
43 {
44 if (x >= 0)
45 return floor (x + 0.5);
46 else
47 return ceil (x - 0.5);
48 }
49 #endif
50
51 #define CELL_W 8
52 #define CELL_H (2 * CELL_W)
53
54 struct color_diff_t
55 {
dotcolor_diff_t56 int dot (const color_diff_t &o)
57 { return v[0]*o.v[0] + v[1]*o.v[1] + v[2]*o.v[2] + v[3]*o.v[3]; }
58
59 int v[4];
60 };
61
62 struct color_t
63 {
from_ansicolor_t64 static color_t from_ansi (unsigned int x)
65 {
66 color_t c = {(0xFFu<<24) | ((0xFFu*(x&1))<<16) | ((0xFFu*((x >> 1)&1))<<8) | (0xFFu*((x >> 2)&1))};
67 return c;
68 }
to_ansicolor_t69 unsigned int to_ansi ()
70 {
71 return ((v >> 23) & 1) | ((v >> 14)&2) | ((v >> 5)&4);
72 }
73
diffcolor_t74 color_diff_t diff (const color_t &o)
75 {
76 color_diff_t d;
77 for (unsigned int i = 0; i < 4; i++)
78 d.v[i] = (int) ((v >> (i*8))&0xFF) - (int) ((o.v >> (i*8))&0xFF);
79 return d;
80 }
81
82 uint32_t v;
83 };
84
85 struct image_t
86 {
87 public:
88
image_timage_t89 image_t (unsigned int width_,
90 unsigned int height_,
91 const uint32_t *data_,
92 unsigned int stride_) :
93 width (width_),
94 height (height_),
95 own_data (false),
96 data ((color_t *) data_),
97 stride (stride_) {}
image_timage_t98 image_t (unsigned int width_,
99 unsigned int height_) :
100 width (width_),
101 height (height_),
102 own_data (true),
103 data ((color_t *) malloc (sizeof (data[0]) * width * height)),
104 stride (width) {}
~image_timage_t105 ~image_t ()
106 { if (own_data) free (data); }
107
operator ()image_t108 color_t &operator () (unsigned int x, unsigned int y)
109 { return data[x + y * stride]; }
110
operator ()image_t111 color_t operator () (unsigned int x, unsigned int y) const
112 { return data[x + y * stride]; }
113
114 void
copy_sub_imageimage_t115 copy_sub_image (const image_t &s,
116 unsigned int x, unsigned int y,
117 unsigned int w, unsigned int h)
118 {
119 assert (x < width);
120 assert (y < height);
121 for (unsigned int row = 0; row < h; row++) {
122 color_t *p = data + x + hb_min (y + row, height - 1) * stride;
123 color_t *q = s.data + row * s.stride;
124 if (x + w <= width)
125 for (unsigned int col = 0; col < w; col++)
126 *q++ = *p++;
127 else {
128 unsigned int limit = width - x;
129 for (unsigned int col = 0; col < limit; col++)
130 *q++ = *p++;
131 p--;
132 for (unsigned int col = limit; col < w; col++)
133 *q++ = *p;
134 }
135 }
136 }
137
138 const unsigned int width;
139 const unsigned int height;
140
141 private:
142 bool own_data;
143 color_t * const data;
144 const unsigned int stride;
145 };
146
147 struct biimage_t
148 {
149 public:
150
biimage_tbiimage_t151 biimage_t (unsigned int width, unsigned int height) :
152 width (width),
153 height (height),
154 bg (0), fg (0), unicolor (true),
155 data ((uint8_t *) malloc (sizeof (data[0]) * width * height)) {}
~biimage_tbiimage_t156 ~biimage_t ()
157 { free (data); }
158
setbiimage_t159 void set (const image_t &image)
160 {
161 assert (image.width == width);
162 assert (image.height == height);
163 int freq[8] = {0};
164 for (unsigned int y = 0; y < height; y++)
165 for (unsigned int x = 0; x < width; x++) {
166 color_t c = image (x, y);
167 freq[c.to_ansi ()]++;
168 }
169 bg = 0;
170 for (unsigned int i = 1; i < 8; i++)
171 if (freq[bg] < freq[i])
172 bg = i;
173 fg = 8;
174 for (unsigned int i = 0; i < 8; i++)
175 if (i != bg && (fg == 8 || freq[fg] < freq[i]))
176 fg = i;
177 if (freq[fg] == 0) {
178 fg = bg;
179 unicolor = true;
180 }
181 else
182 unicolor = false;
183
184 /* Set the data... */
185
186 if (unicolor) {
187 memset (data, 0, sizeof (data[0]) * width * height);
188 return;
189 }
190
191 color_t bgc = color_t::from_ansi (bg);
192 color_t fgc = color_t::from_ansi (fg);
193 color_diff_t diff = fgc.diff (bgc);
194 double dd = sqrt (diff.dot (diff));
195 for (unsigned int y = 0; y < height; y++)
196 for (unsigned int x = 0; x < width; x++) {
197 double d = sqrt (diff.dot (image (x, y).diff (bgc)));
198 (*this)(x, y) = d <= 0 ? 0 : d >= dd ? 255 : lround (d / dd * 255.);
199 }
200 }
201
operator ()biimage_t202 uint8_t &operator () (unsigned int x, unsigned int y)
203 { return data[x + y * width]; }
204
operator ()biimage_t205 uint8_t operator () (unsigned int x, unsigned int y) const
206 { return data[x + y * width]; }
207
208 const unsigned int width;
209 const unsigned int height;
210 unsigned int bg;
211 unsigned int fg;
212 bool unicolor;
213
214 private:
215 uint8_t * const data;
216 };
217
218 static const char *
block_best(const biimage_t & bi,bool * inverse)219 block_best (const biimage_t &bi, bool *inverse)
220 {
221 assert (bi.width <= CELL_W);
222 assert (bi.height <= CELL_H);
223
224 unsigned int score = UINT_MAX;
225 unsigned int row_sum[CELL_H] = {0};
226 unsigned int col_sum[CELL_W] = {0};
227 unsigned int row_sum_i[CELL_H] = {0};
228 unsigned int col_sum_i[CELL_W] = {0};
229 unsigned int quad[2][2] = {{0}};
230 unsigned int quad_i[2][2] = {{0}};
231 unsigned int total = 0;
232 unsigned int total_i = 0;
233 for (unsigned int y = 0; y < bi.height; y++)
234 for (unsigned int x = 0; x < bi.width; x++) {
235 unsigned int c = bi (x, y);
236 unsigned int c_i = 255 - c;
237 row_sum[y] += c;
238 row_sum_i[y] += c_i;
239 col_sum[x] += c;
240 col_sum_i[x] += c_i;
241 quad[2 * y / bi.height][2 * x / bi.width] += c;
242 quad_i[2 * y / bi.height][2 * x / bi.width] += c_i;
243 total += c;
244 total_i += c_i;
245 }
246
247 /* Make the sums cumulative */
248 for (unsigned int i = 1; i < bi.height; i++) {
249 row_sum[i] += row_sum[i - 1];
250 row_sum_i[i] += row_sum_i[i - 1];
251 }
252 for (unsigned int i = 1; i < bi.width; i++) {
253 col_sum[i] += col_sum[i - 1];
254 col_sum_i[i] += col_sum_i[i - 1];
255 }
256
257 const char *best_c = " ";
258
259 /* Maybe empty is better! */
260 if (total < score) {
261 score = total;
262 *inverse = false;
263 best_c = " ";
264 }
265 /* Maybe full is better! */
266 if (total_i < score) {
267 score = total_i;
268 *inverse = true;
269 best_c = " ";
270 }
271
272 /* Find best lower line */
273 if (1) {
274 unsigned int best_s = UINT_MAX;
275 bool best_inv = false;
276 int best_i = 0;
277 for (unsigned int i = 0; i < bi.height - 1; i++)
278 {
279 unsigned int s;
280 s = row_sum[i] + total_i - row_sum_i[i];
281 if (s < best_s) {
282 best_s = s;
283 best_i = i;
284 best_inv = false;
285 }
286 s = row_sum_i[i] + total - row_sum[i];
287 if (s < best_s) {
288 best_s = s;
289 best_i = i;
290 best_inv = true;
291 }
292 }
293 if (best_s < score) {
294 static const char *lower[7] = {"▁", "▂", "▃", "▄", "▅", "▆", "▇"};
295 unsigned int which = lround ((double) ((best_i + 1) * 8) / bi.height);
296 if (1 <= which && which <= 7) {
297 score = best_s;
298 *inverse = best_inv;
299 best_c = lower[7 - which];
300 }
301 }
302 }
303
304 /* Find best left line */
305 if (1) {
306 unsigned int best_s = UINT_MAX;
307 bool best_inv = false;
308 int best_i = 0;
309 for (unsigned int i = 0; i < bi.width - 1; i++)
310 {
311 unsigned int s;
312 s = col_sum[i] + total_i - col_sum_i[i];
313 if (s < best_s) {
314 best_s = s;
315 best_i = i;
316 best_inv = true;
317 }
318 s = col_sum_i[i] + total - col_sum[i];
319 if (s < best_s) {
320 best_s = s;
321 best_i = i;
322 best_inv = false;
323 }
324 }
325 if (best_s < score) {
326 static const char *left [7] = {"▏", "▎", "▍", "▌", "▋", "▊", "▉"};
327 unsigned int which = lround ((double) ((best_i + 1) * 8) / bi.width);
328 if (1 <= which && which <= 7) {
329 score = best_s;
330 *inverse = best_inv;
331 best_c = left[which - 1];
332 }
333 }
334 }
335
336 /* Find best quadrant */
337 if (1) {
338 unsigned int q = 0;
339 unsigned int qs = 0;
340 for (unsigned int i = 0; i < 2; i++)
341 for (unsigned int j = 0; j < 2; j++)
342 if (quad[i][j] > quad_i[i][j]) {
343 q += 1 << (2 * i + j);
344 qs += quad_i[i][j];
345 } else
346 qs += quad[i][j];
347 if (qs < score) {
348 const char *c = nullptr;
349 bool inv = false;
350 switch (q) {
351 case 1: c = "▟"; inv = true; break;
352 case 2: c = "▙"; inv = true; break;
353 case 4: c = "▖"; inv = false; break;
354 case 6: c = "▞"; inv = false; break;
355 case 7: c = "▛"; inv = false; break;
356 case 8: c = "▗"; inv = false; break;
357 case 9: c = "▚"; inv = false; break;
358 case 11: c = "▜"; inv = false; break;
359 case 13: c = "▙"; inv = false; break;
360 case 14: c = "▟"; inv = false; break;
361 }
362 if (c) {
363 score = qs;
364 *inverse = inv;
365 best_c = c;
366 }
367 }
368 }
369
370 return best_c;
371 }
372
373 static inline void
ansi_print_image_rgb24(const uint32_t * data,unsigned int width,unsigned int height,unsigned int stride,cairo_write_func_t write_func,void * closure)374 ansi_print_image_rgb24 (const uint32_t *data,
375 unsigned int width,
376 unsigned int height,
377 unsigned int stride,
378 cairo_write_func_t write_func,
379 void *closure)
380 {
381 image_t image (width, height, data, stride);
382
383 unsigned int rows = (height + CELL_H - 1) / CELL_H;
384 unsigned int cols = (width + CELL_W - 1) / CELL_W;
385 image_t cell (CELL_W, CELL_H);
386 biimage_t bi (CELL_W, CELL_H);
387 unsigned int last_bg = -1, last_fg = -1;
388 for (unsigned int row = 0; row < rows; row++)
389 {
390 for (unsigned int col = 0; col < cols; col++)
391 {
392 image.copy_sub_image (cell, col * CELL_W, row * CELL_H, CELL_W, CELL_H);
393 bi.set (cell);
394 if (bi.unicolor)
395 {
396 if (last_bg != bi.bg)
397 {
398 char buf[] = "\033[40m";
399 buf[3] += bi.bg;
400 write_func (closure, (unsigned char *) buf, 5);
401 last_bg = bi.bg;
402 }
403 write_func (closure, (unsigned char *) " ", 1);
404 }
405 else
406 {
407 /* Figure out the closest character to the biimage */
408 bool inverse = false;
409 const char *c = block_best (bi, &inverse);
410 if (inverse)
411 {
412 if (last_bg != bi.fg || last_fg != bi.bg)
413 {
414 char buf[] = "\033[30;40m";
415 buf[3] += bi.bg;
416 buf[6] += bi.fg;
417 write_func (closure, (unsigned char *) buf, 8);
418 last_bg = bi.fg;
419 last_fg = bi.bg;
420 }
421 }
422 else
423 {
424 if (last_bg != bi.bg || last_fg != bi.fg)
425 {
426 char buf[] = "\033[40;30m";
427 buf[3] += bi.bg;
428 buf[6] += bi.fg;
429 write_func (closure, (unsigned char *) buf, 8);
430 last_bg = bi.bg;
431 last_fg = bi.fg;
432 }
433 }
434 write_func (closure, (unsigned char *) c, strlen (c));
435 }
436 }
437 write_func (closure, (unsigned char *) "\033[0m\n", 5); /* Reset */
438 last_bg = last_fg = -1;
439 }
440 }
441
442 #endif
443