xref: /netbsd-src/sys/dev/wscons/wsdisplay_glyphcache.c (revision 08eb92781f914973e4424deeaa66f9f4b384e0c9)
1 /*	$NetBSD: wsdisplay_glyphcache.c,v 1.14 2024/12/06 11:46:11 macallan Exp $	*/
2 
3 /*
4  * Copyright (c) 2012 Michael Lorenz
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 /*
29  * a simple glyph cache in offscreen memory
30  */
31 
32 #ifdef _KERNEL_OPT
33 #include "opt_glyphcache.h"
34 #endif
35 
36 #include <sys/systm.h>
37 #include <sys/atomic.h>
38 #include <sys/errno.h>
39 #include <sys/kmem.h>
40 #include <dev/wscons/wsdisplayvar.h>
41 #include <dev/rasops/rasops.h>
42 #include <dev/wscons/wsdisplay_vconsvar.h>
43 #include <dev/wscons/wsdisplay_glyphcachevar.h>
44 
45 #ifdef GLYPHCACHE_DEBUG
46 #define DPRINTF aprint_normal
47 #else
48 #define DPRINTF while (0) printf
49 #endif
50 
51 #define NBUCKETS 32
52 
53 static inline int
54 attr2idx(long attr)
55 {
56 	return (((attr >> 16) & 0x0f) | ((attr >> 20) & 0xf0));
57 }
58 
59 int
60 glyphcache_init(glyphcache *gc, int first, int lines, int width,
61     int cellwidth, int cellheight, long attr)
62 {
63 	return glyphcache_init_align(gc, first, lines, width, cellwidth, cellheight,
64 	    attr, 0);
65 }
66 
67 int
68 glyphcache_init_align(glyphcache *gc, int first, int lines, int width,
69     int cellwidth, int cellheight, long attr, int alignment)
70 {
71 
72 	/* first the geometry stuff */
73 	if (lines < 0) lines = 0;
74 	gc->gc_width = width;
75 	gc->gc_cellwidth = -1;
76 	gc->gc_cellheight = -1;
77 	gc->gc_firstline = first;
78 	gc->gc_firstcol = 0;
79 	gc->gc_lines = lines;
80 	gc->gc_cellalign = alignment;
81 	gc->gc_buckets = NULL;
82 	gc->gc_numbuckets = 0;
83 	// XXX: Never free?
84 	gc->gc_buckets = kmem_alloc(sizeof(*gc->gc_buckets) * NBUCKETS,
85 	    KM_SLEEP);
86 	gc->gc_nbuckets = NBUCKETS;
87 	return glyphcache_reconfig(gc, cellwidth, cellheight, attr);
88 
89 }
90 
91 int
92 glyphcache_init_x(glyphcache *gc, int x, int y, int lines, int width,
93     int cellwidth, int cellheight, long attr)
94 {
95 
96 	/* first the geometry stuff */
97 	if (lines < 0) lines = 0;
98 	gc->gc_width = width;
99 	gc->gc_cellwidth = -1;
100 	gc->gc_cellheight = -1;
101 	gc->gc_firstline = y;
102 	gc->gc_firstcol = x;
103 	gc->gc_lines = lines;
104 	gc->gc_cellalign = 0;
105 	gc->gc_buckets = NULL;
106 	gc->gc_numbuckets = 0;
107 	// XXX: Never free?
108 	gc->gc_buckets = kmem_alloc(sizeof(*gc->gc_buckets) * NBUCKETS,
109 	    KM_SLEEP);
110 	gc->gc_nbuckets = NBUCKETS;
111 	return glyphcache_reconfig(gc, cellwidth, cellheight, attr);
112 
113 }
114 
115 int
116 glyphcache_reconfig(glyphcache *gc, int cellwidth, int cellheight, long attr)
117 {
118 	int cache_lines, buckets, i, usedcells = 0, idx;
119 	gc_bucket *b;
120 
121 	/* see if we actually need to reconfigure anything */
122 	if ((gc->gc_cellwidth == cellwidth) &&
123 	    (gc->gc_cellheight == cellheight) &&
124 	    ((gc->gc_buckets != NULL) &&
125 	     (gc->gc_buckets[0].gb_index == attr2idx(attr)))) {
126 		return 0;
127 	}
128 
129 	gc->gc_cellwidth = cellwidth;
130 	if (gc->gc_cellalign != 0) {
131 		/* alignment in bytes */
132 		gc->gc_cellstride =
133 		    (gc->gc_cellwidth + gc->gc_cellalign - 1) &
134 		    ~(gc->gc_cellalign - 1);
135 	} else
136 		gc->gc_cellstride = cellwidth;
137 	gc->gc_cellheight = cellheight;
138 
139 	gc->gc_cellsperline = gc->gc_width / gc->gc_cellstride;
140 
141 	cache_lines = gc->gc_lines / cellheight;
142 	gc->gc_numcells = cache_lines * gc->gc_cellsperline;
143 
144 	/* now allocate buckets */
145 	buckets = (gc->gc_numcells / 223);
146 	if ((buckets * 223) < gc->gc_numcells)
147 		buckets++;
148 
149 	/*
150 	 * if we don't have enough video memory to cache at least a few glyphs
151 	 * we stop right here
152 	 */
153 	if (buckets < 1)
154 		return ENOMEM;
155 
156 	buckets = uimin(buckets, gc->gc_nbuckets);
157 	gc->gc_numbuckets = buckets;
158 
159 	DPRINTF("%s: using %d buckets\n", __func__, buckets);
160 	for (i = 0; i < buckets; i++) {
161 		b = &gc->gc_buckets[i];
162 		b->gb_firstcell = usedcells;
163 		b->gb_numcells = uimin(223, gc->gc_numcells - usedcells);
164 		usedcells += 223;
165 		b->gb_usedcells = 0;
166 		b->gb_index = -1;
167 	}
168 
169 	/* initialize the attribute map... */
170 	for (i = 0; i < 256; i++) {
171 		gc->gc_attrmap[i] = -1;
172 	}
173 
174 	/* first bucket goes to default attr */
175 	idx = attr2idx(attr);
176 	if (idx >= 0) {
177 		gc->gc_attrmap[idx] = 0;
178 		gc->gc_buckets[0].gb_index = idx;
179 	}
180 
181 	glyphcache_wipe(gc);
182 	DPRINTF("%s: using %d cells total, from %d width %d\n", __func__,
183 	    gc->gc_numcells, gc->gc_firstline, gc->gc_cellsperline);
184 	DPRINTF("%s: cell size %d x %d, stride %d\n", __func__,
185 	    gc->gc_cellwidth, gc->gc_cellheight, gc->gc_cellstride);
186 	return 0;
187 }
188 
189 void
190 glyphcache_adapt(struct vcons_screen *scr, void *cookie)
191 {
192 	glyphcache *gc = cookie;
193 	struct rasops_info *ri = &scr->scr_ri;
194 
195 	if (ri->ri_wsfcookie != gc->gc_fontcookie) {
196 		glyphcache_wipe(gc);
197 		gc->gc_fontcookie = ri->ri_wsfcookie;
198 	}
199 
200 	glyphcache_reconfig(gc, ri->ri_font->fontwidth,
201 			        ri->ri_font->fontheight, scr->scr_defattr);
202 }
203 
204 void
205 glyphcache_wipe(glyphcache *gc)
206 {
207 	gc_bucket *b;
208 	int i, j, idx;
209 
210 	if ((gc->gc_buckets == NULL) || (gc->gc_numbuckets < 1))
211 		return;
212 
213 	idx = gc->gc_buckets[0].gb_index;
214 
215 	/* empty all the buckets */
216 	for (i = 0; i < gc->gc_numbuckets; i++) {
217 		b = &gc->gc_buckets[i];
218 		b->gb_usedcells = 0;
219 		b->gb_index = -1;
220 		for (j = 0; j < b->gb_numcells; j++)
221 			b->gb_map[j] = -1;
222 	}
223 
224 	for (i = 0; i < 256; i++) {
225 		gc->gc_attrmap[i] = -1;
226 	}
227 
228 	/* now put the first bucket back where it was */
229 	gc->gc_attrmap[idx] = 0;
230 	gc->gc_buckets[0].gb_index = idx;
231 }
232 
233 /*
234  * add a glyph drawn at (x,y) to the cache as (c)
235  * call this only if glyphcache_try() returned GC_ADD
236  * caller or gc_bitblt must make sure the glyph is actually completely drawn
237  */
238 int
239 glyphcache_add(glyphcache *gc, int c, int x, int y)
240 {
241 	gc_bucket *b = gc->gc_next;
242 	int cell;
243 	int cx, cy;
244 
245 	if (b->gb_usedcells >= b->gb_numcells)
246 		return ENOMEM;
247 	cell = atomic_add_int_nv(&b->gb_usedcells, 1) - 1;
248 	cell += b->gb_firstcell;
249 	cy = gc->gc_firstline +
250 	    (cell / gc->gc_cellsperline) * gc->gc_cellheight;
251 	cx = gc->gc_firstcol +
252 	    (cell % gc->gc_cellsperline) * gc->gc_cellstride;
253 	b->gb_map[c - 33] = (cx << 16) | cy;
254 	gc->gc_bitblt(gc->gc_blitcookie, x, y, cx, cy,
255 	    gc->gc_cellwidth, gc->gc_cellheight, gc->gc_rop);
256 	if (gc->gc_underline & 1) {
257 		glyphcache_underline(gc, x, y, gc->gc_underline);
258 	}
259 	return 0;
260 }
261 
262 void
263 glyphcache_underline(glyphcache *gc, int x, int y, long attr)
264 {
265 	if (gc->gc_rectfill == NULL)
266 		return;
267 
268 	gc->gc_rectfill(gc->gc_blitcookie, x, y + gc->gc_cellheight - 2,
269 	    gc->gc_cellwidth, 1, attr);
270 }
271 /*
272  * check if (c) is in the cache, if so draw it at (x,y)
273  * return:
274  * - GC_OK when the glyph was found
275  * - GC_ADD when the glyph wasn't found but can be added
276  * - GC_NOPE when the glyph can't be cached
277  */
278 int
279 glyphcache_try(glyphcache *gc, int c, int x, int y, long attr)
280 {
281 	int cell, cx, cy, idx, bi;
282 	gc_bucket *b;
283 
284 	idx = attr2idx(attr);
285 	/* see if we're in range */
286 	if ((c < 33) || (c > 255) || (idx < 0))
287 		return GC_NOPE;
288 	/* see if there's already a bucket for this attribute */
289 	bi = gc->gc_attrmap[idx];
290 	if (bi == -1) {
291 		/* nope, see if there's an empty one left */
292 		bi = 1;
293 		while ((bi < gc->gc_numbuckets) &&
294 		       (gc->gc_buckets[bi].gb_index != -1)) {
295 			bi++;
296 		}
297 		if (bi < gc->gc_numbuckets) {
298 			/* found one -> grab it */
299 			gc->gc_attrmap[idx] = bi;
300 			b = &gc->gc_buckets[bi];
301 			b->gb_index = idx;
302 			b->gb_usedcells = 0;
303 			/* make sure this doesn't get evicted right away */
304 			b->gb_lastread = time_uptime;
305 		} else {
306 			/*
307 			 * still nothing
308 			 * steal the least recently read bucket
309 			 */
310 			time_t moo = time_uptime;
311 			int i, oldest = 1;
312 
313 			for (i = 1; i < gc->gc_numbuckets; i++) {
314 				if (gc->gc_buckets[i].gb_lastread < moo) {
315 					oldest = i;
316 					moo = gc->gc_buckets[i].gb_lastread;
317 				}
318 			}
319 
320 			/* if we end up here all buckets must be in use */
321 			b = &gc->gc_buckets[oldest];
322 			gc->gc_attrmap[b->gb_index] = -1;
323 			b->gb_index = idx;
324 			b->gb_usedcells = 0;
325 			gc->gc_attrmap[idx] = oldest;
326 			/* now scrub it */
327 			for (i = 0; i < b->gb_numcells; i++)
328 				b->gb_map[i] = -1;
329 			/* and set the time stamp */
330 			b->gb_lastread = time_uptime;
331 		}
332 	} else {
333 		/* found one */
334 		b = &gc->gc_buckets[bi];
335 	}
336 
337 	/* see if there's room in the bucket */
338 	if (b->gb_usedcells >= b->gb_numcells)
339 		return GC_NOPE;
340 
341 	cell = b->gb_map[c - 33];
342 	if (cell == -1) {
343 		gc->gc_next = b;
344 		gc->gc_underline = attr;
345 		return GC_ADD;
346 	}
347 
348 	/* it's in the cache - draw it */
349 	cy = cell & 0xffff;
350 	cx = (cell >> 16) & 0xffff;
351 	gc->gc_bitblt(gc->gc_blitcookie, cx, cy, x, y,
352 	    gc->gc_cellwidth, gc->gc_cellheight, gc->gc_rop);
353 	/* and underline it if needed */
354 	if (attr & 1)
355 		glyphcache_underline(gc, x, y, attr);
356 	/* update bucket's time stamp */
357 	b->gb_lastread = time_uptime;
358 	return GC_OK;
359 }
360