summaryrefslogtreecommitdiffstats
path: root/uisimulator/x11/visual.c
blob: 57b73151c53f6a4cd7a7c3611c08f389520bb573 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
/* xscreensaver, Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998, 1999
 *  by Jamie Zawinski <jwz@jwz.org>
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation.  No representations are made about the suitability of this
 * software for any purpose.  It is provided "as is" without express or 
 * implied warranty.
 */

/* This file contains some code for intelligently picking the best visual
   (where "best" is biased in the direction of either: high color counts;
   or: having writable color cells...)
 */

#include "utils.h"
#include "resources.h"  /* for get_string_resource() */
#include "visual.h"

#include <X11/Xutil.h>

extern char *progname;


#ifndef isupper
# define isupper(c)  ((c) >= 'A' && (c) <= 'Z')
#endif
#ifndef _tolower
# define _tolower(c)  ((c) - 'A' + 'a')
#endif


static Visual *pick_best_visual (Screen *, Bool, Bool);
static Visual *pick_mono_visual (Screen *);
static Visual *pick_best_visual_of_class (Screen *, int);
static Visual *pick_best_gl_visual (Screen *);
static Visual *id_to_visual (Screen *, int);
static Visual *id_to_visual (Screen *screen, int id);


#define DEFAULT_VISUAL	-1
#define BEST_VISUAL	-2
#define MONO_VISUAL	-3
#define GRAY_VISUAL	-4
#define COLOR_VISUAL	-5
#define GL_VISUAL	-6
#define SPECIFIC_VISUAL	-7

Visual *
get_visual (Screen *screen, const char *string, Bool prefer_writable_cells,
	    Bool verbose_p)
{
  char *v = (string ? strdup(string) : 0);
  char c, *tmp;
  int vclass;
  unsigned long id;
  Visual *result = 0;

  if (v)
    for (tmp = v; *tmp; tmp++)
      if (isupper (*tmp)) *tmp = _tolower (*tmp);

  if (!v || !*v)				  vclass = BEST_VISUAL;
  else if (!strcmp (v, "default"))		  vclass = DEFAULT_VISUAL;
  else if (!strcmp (v, "best")) 		  vclass = BEST_VISUAL;
  else if (!strcmp (v, "mono")) 		  vclass = MONO_VISUAL;
  else if (!strcmp (v, "monochrome")) 		  vclass = MONO_VISUAL;
  else if (!strcmp (v, "gray")) 		  vclass = GRAY_VISUAL;
  else if (!strcmp (v, "grey")) 		  vclass = GRAY_VISUAL;
  else if (!strcmp (v, "color")) 		  vclass = COLOR_VISUAL;
  else if (!strcmp (v, "gl"))	 		  vclass = GL_VISUAL;
  else if (!strcmp (v, "staticgray"))	 	  vclass = StaticGray;
  else if (!strcmp (v, "staticcolor"))		  vclass = StaticColor;
  else if (!strcmp (v, "truecolor"))		  vclass = TrueColor;
  else if (!strcmp (v, "grayscale"))		  vclass = GrayScale;
  else if (!strcmp (v, "greyscale"))		  vclass = GrayScale;
  else if (!strcmp (v, "pseudocolor"))		  vclass = PseudoColor;
  else if (!strcmp (v, "directcolor"))		  vclass = DirectColor;
  else if (1 == sscanf (v, " %ld %c", &id, &c))	  vclass = SPECIFIC_VISUAL;
  else if (1 == sscanf (v, " 0x%lx %c", &id, &c)) vclass = SPECIFIC_VISUAL;
  else
    {
      fprintf (stderr, "%s: unrecognized visual \"%s\".\n", progname, v);
      vclass = DEFAULT_VISUAL;
    }

  if (vclass == DEFAULT_VISUAL)
    result = DefaultVisualOfScreen (screen);
  else if (vclass == BEST_VISUAL)
    result = pick_best_visual (screen, prefer_writable_cells, False);
  else if (vclass == MONO_VISUAL)
    {
      result = pick_mono_visual (screen);
      if (!result && verbose_p)
	fprintf (stderr, "%s: no monochrome visuals.\n", progname);
    }
  else if (vclass == GRAY_VISUAL)
    {
      if (prefer_writable_cells)
	result = pick_best_visual_of_class (screen, GrayScale);
      if (!result)
	result = pick_best_visual_of_class (screen, StaticGray);
      if (!result)
	result = pick_best_visual_of_class (screen, GrayScale);
      if (!result && verbose_p)
	fprintf (stderr, "%s: no GrayScale or StaticGray visuals.\n",
		 progname);
    }
  else if (vclass == COLOR_VISUAL)
    {
      int class;
      /* First see if the default visual will do. */
      result = DefaultVisualOfScreen (screen);
      class = visual_class(screen, result);
      if (class != TrueColor &&
	  class != PseudoColor &&
	  class != DirectColor &&
	  class != StaticColor)
	result = 0;
      if (result && visual_depth(screen, result) <= 1)
	result = 0;

      /* Else, find the best non-default color visual */
      if (!result)
	result = pick_best_visual (screen, prefer_writable_cells, True);

      if (!result && verbose_p)
	fprintf (stderr, "%s: no color visuals.\n", progname);
    }
  else if (vclass == GL_VISUAL)
    {
      Visual *visual = pick_best_gl_visual (screen);
      if (visual)
	result = visual;
      else if (verbose_p)
	fprintf (stderr, "%s: no visual suitable for GL.\n", progname);
    }
  else if (vclass == SPECIFIC_VISUAL)
    {
      result = id_to_visual (screen, id);
      if (!result && verbose_p)
	fprintf (stderr, "%s: no visual with id 0x%x.\n", progname,
		 (unsigned int) id);
    }
  else
    {
      Visual *visual = pick_best_visual_of_class (screen, vclass);
      if (visual)
	result = visual;
      else if (verbose_p)
	fprintf (stderr, "%s: no visual of class %s.\n", progname, v);
    }

  if (v) free (v);
  return result;
}

Visual *
get_visual_resource (Screen *screen, char *name, char *class,
		     Bool prefer_writable_cells)
{
  char *string = get_string_resource (name, class);
  Visual *v = get_visual (screen, string, prefer_writable_cells, True);
  if (string)
    free(string);
  if (v)
    return v;
  else
    return DefaultVisualOfScreen (screen);
}


static Visual *
pick_best_visual (Screen *screen, Bool prefer_writable_cells, Bool color_only)
{
  Visual *visual;

  if (!prefer_writable_cells)
    {
      /* If we don't prefer writable cells, then the "best" visual is the one
	 on which we can allocate the largest range and number of colors.

	 Therefore, a TrueColor visual which is at least 16 bits deep is best.
	 (The assumption here being that a TrueColor of less than 16 bits is
	 really just a PseudoColor visual with a pre-allocated color cube.)

	 The next best thing is a PseudoColor visual of any type.  After that
	 come the non-colormappable visuals, and non-color visuals.
       */
      if ((visual = pick_best_visual_of_class (screen, TrueColor)) &&
	  visual_depth (screen, visual) >= 16)
	return visual;
    }

#define TRY_CLASS(CLASS) \
  if ((visual = pick_best_visual_of_class (screen, CLASS)) && \
      (!color_only || visual_depth(screen, visual) > 1)) \
    return visual
  TRY_CLASS(PseudoColor);
  TRY_CLASS(TrueColor);
  TRY_CLASS(DirectColor);
  TRY_CLASS(StaticColor);
  if (!color_only)
    {
      TRY_CLASS(GrayScale);
      TRY_CLASS(StaticGray);
    }
#undef TRY_CLASS

  visual = DefaultVisualOfScreen (screen);
  if (!color_only || visual_depth(screen, visual) > 1)
    return visual;
  else
    return 0;
}

static Visual *
pick_mono_visual (Screen *screen)
{
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  int out_count;

  vi_in.depth = 1;
  vi_in.screen = screen_number (screen);
  vi_out = XGetVisualInfo (dpy, (VisualDepthMask | VisualScreenMask),
			   &vi_in, &out_count);
  if (vi_out)
    {
      Visual *v = (out_count > 0 ? vi_out [0].visual : 0);
      if (v && vi_out[0].depth != 1)
	v = 0;
      XFree ((char *) vi_out);
      return v;
    }
  else
    return 0;
}


static Visual *
pick_best_visual_of_class (Screen *screen, int visual_class)
{
  /* The best visual of a class is the one which on which we can allocate
     the largest range and number of colors, which means the one with the
     greatest depth and number of cells.

     (But actually, for XDaliClock, all visuals of the same class are
     probably equivalent - either we have writable cells or we don't.)
   */
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  int out_count;

  vi_in.class = visual_class;
  vi_in.screen = screen_number (screen);
  vi_out = XGetVisualInfo (dpy, (VisualClassMask | VisualScreenMask),
			   &vi_in, &out_count);
  if (vi_out)
    {
      /* choose the 'best' one, if multiple */
      int i, best;
      Visual *visual;
/*      for (i = 0, best = 0; i < out_count; i++) */
      for (i = out_count-1, best = i; i >= 0; i--) /* go backwards */
	/* It's better if it's deeper, or if it's the same depth with
	   more cells (does that ever happen?  Well, it could...) */
	if ((vi_out [i].depth > vi_out [best].depth) ||
	    ((vi_out [i].depth == vi_out [best].depth) &&
	     (vi_out [i].colormap_size > vi_out [best].colormap_size)))
	  best = i;
      visual = (best < out_count ? vi_out [best].visual : 0);
      XFree ((char *) vi_out);
      return visual;
    }
  else
    return 0;
}

static Visual *
pick_best_gl_visual (Screen *screen)
{
  /* The best visual for GL is a TrueColor visual that is half as deep as
     the screen.  If such a thing doesn't exist, then TrueColor is best.
     Failing that, the deepest available color visual is best.

     Compare this function to get_gl_visual() in visual-gl.c.
     This function tries to find the best GL visual using Xlib calls,
     whereas that function does the same thing using GLX calls.
   */
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  int out_count;
  Visual *result = 0;

  int ndepths = 0;
  int *depths = XListDepths (dpy, screen_number (screen), &ndepths);
  int screen_depth = depths[ndepths];
  XFree (depths);

  vi_in.class = TrueColor;
  vi_in.screen = screen_number (screen);
  vi_in.depth = screen_depth / 2;
  vi_out = XGetVisualInfo (dpy, (VisualClassMask | VisualScreenMask |
                                 VisualDepthMask),
			   &vi_in, &out_count);
  if (out_count > 0)
    result = vi_out[0].visual;

  if (vi_out)
    XFree ((char *) vi_out);

  if (!result && screen_depth > 24)
    {
      /* If it's a 32-deep screen and we didn't find a depth-16 visual,
         see if there's a depth-12 visual. */
      vi_in.class = TrueColor;
      vi_in.screen = screen_number (screen);
      vi_in.depth = 12;
      vi_out = XGetVisualInfo (dpy, (VisualClassMask | VisualScreenMask |
                                     VisualDepthMask),
                               &vi_in, &out_count);
      if (out_count > 0)
        result = vi_out[0].visual;
    }

  if (!result)
    /* No half-depth TrueColor?  Ok, try for any TrueColor (the deepest.) */
    result = pick_best_visual_of_class (screen, TrueColor);

  if (!result)
    /* No TrueColor?  Ok, try for anything. */
    result = pick_best_visual (screen, False, False);

  return result;
}


static Visual *
id_to_visual (Screen *screen, int id)
{
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  int out_count;
  vi_in.screen = screen_number (screen);
  vi_in.visualid = id;
  vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualIDMask),
			   &vi_in, &out_count);
  if (vi_out)
    {
      Visual *v = vi_out[0].visual;
      XFree ((char *) vi_out);
      return v;
    }
  return 0;
}

int
visual_depth (Screen *screen, Visual *visual)
{
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  int out_count, d;
  vi_in.screen = screen_number (screen);
  vi_in.visualid = XVisualIDFromVisual (visual);
  vi_out = XGetVisualInfo (dpy, VisualScreenMask|VisualIDMask,
			   &vi_in, &out_count);
  if (! vi_out) abort ();
  d = vi_out [0].depth;
  XFree ((char *) vi_out);
  return d;
}


#if 0
/* You very probably don't want to be using this.
   Pixmap depth doesn't refer to the depths of pixmaps, but rather, to
   the depth of protocol-level on-the-wire pixmap data, that is, XImages.
   To get this info, you should be looking at XImage->bits_per_pixel
   instead.  (And allocating the data for your XImage structures by
   multiplying ximage->bytes_per_line by ximage->height.)
 */
int
visual_pixmap_depth (Screen *screen, Visual *visual)
{
  Display *dpy = DisplayOfScreen (screen);
  int vdepth = visual_depth (screen, visual);
  int pdepth = vdepth;
  int i, pfvc = 0;
  XPixmapFormatValues *pfv = XListPixmapFormats (dpy, &pfvc);

  /* Return the first matching depth in the pixmap formats.  If there are no
     matching pixmap formats (which shouldn't be able to happen at all) then
     return the visual depth instead. */
  for (i = 0; i < pfvc; i++)
    if (pfv[i].depth == vdepth)
      {
	pdepth = pfv[i].bits_per_pixel;
	break;
      }
  if (pfv)
    XFree (pfv);
  return pdepth;
}
#endif /* 0 */


int
visual_class (Screen *screen, Visual *visual)
{
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  int out_count, c;
  vi_in.screen = screen_number (screen);
  vi_in.visualid = XVisualIDFromVisual (visual);
  vi_out = XGetVisualInfo (dpy, VisualScreenMask|VisualIDMask,
			   &vi_in, &out_count);
  if (! vi_out) abort ();
  c = vi_out [0].class;
  XFree ((char *) vi_out);
  return c;
}

Bool
has_writable_cells (Screen *screen, Visual *visual)
{
  switch (visual_class (screen, visual))
    {
    case GrayScale:	/* Mappable grays. */
    case PseudoColor:	/* Mappable colors. */
      return True;
    case StaticGray:	/* Fixed grays. */
    case TrueColor:	/* Fixed colors. */
    case StaticColor:	/* (What's the difference again?) */
    case DirectColor:	/* DirectColor visuals are like TrueColor, but have
			   three colormaps - one for each component of RGB.
			   Screw it. */
      return False;
    default:
      abort();
      return False;
    }
}

void
describe_visual (FILE *f, Screen *screen, Visual *visual, Bool private_cmap_p)
{
  char n[10];
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  int out_count;
  vi_in.screen = screen_number (screen);
  vi_in.visualid = XVisualIDFromVisual (visual);
  vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualIDMask),
			   &vi_in, &out_count);
  if (! vi_out) abort ();
  if (private_cmap_p)
    sprintf(n, "%3d", vi_out->colormap_size);
  else
    strcpy(n, "default");

  fprintf (f, "0x%02x (%s depth: %2d, cmap: %s)\n",
	   (unsigned int) vi_out->visualid,
	   (vi_out->class == StaticGray  ? "StaticGray, " :
	    vi_out->class == StaticColor ? "StaticColor," :
	    vi_out->class == TrueColor   ? "TrueColor,  " :
	    vi_out->class == GrayScale   ? "GrayScale,  " :
	    vi_out->class == PseudoColor ? "PseudoColor," :
	    vi_out->class == DirectColor ? "DirectColor," :
					   "UNKNOWN:    "),
	   vi_out->depth, n);
  XFree ((char *) vi_out);
}

int
screen_number (Screen *screen)
{
  Display *dpy = DisplayOfScreen (screen);
  int i;
  for (i = 0; i < ScreenCount (dpy); i++)
    if (ScreenOfDisplay (dpy, i) == screen)
      return i;
  abort ();
  return 0;
}

int
visual_cells (Screen *screen, Visual *visual)
{
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  int out_count, c;
  vi_in.screen = screen_number (screen);
  vi_in.visualid = XVisualIDFromVisual (visual);
  vi_out = XGetVisualInfo (dpy, VisualScreenMask|VisualIDMask,
			   &vi_in, &out_count);
  if (! vi_out) abort ();
  c = vi_out [0].colormap_size;
  XFree ((char *) vi_out);
  return c;
}

Visual *
find_similar_visual(Screen *screen, Visual *old_visual)
{
  Display *dpy = DisplayOfScreen (screen);
  XVisualInfo vi_in, *vi_out;
  Visual *result = 0;
  int out_count;

  vi_in.screen = screen_number (screen);
  vi_in.class  = visual_class (screen, old_visual);
  vi_in.depth  = visual_depth (screen, old_visual);

  /* Look for a visual of the same class and depth.
   */
  vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualClassMask |
				 VisualDepthMask),
			   &vi_in, &out_count);
  if (vi_out && out_count > 0)
    result = vi_out[0].visual;
  if (vi_out) XFree (vi_out);
  vi_out = 0;

  /* Failing that, look for a visual of the same class.
   */
  if (!result)
    {
      vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualClassMask),
			       &vi_in, &out_count);
      if (vi_out && out_count > 0)
	result = vi_out[0].visual;
      if (vi_out) XFree (vi_out);
      vi_out = 0;
    }

  /* Failing that, return the default visual. */
  if (!result)
    result = DefaultVisualOfScreen (screen);

  return result;
}