aboutsummaryrefslogtreecommitdiff
path: root/xorg-server/glx/glxdri2.c
blob: 45a1903e47b93996f5294e92cbdb97d37b909c64 (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
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
/*
 * Copyright © 2007 Red Hat, Inc
 *
 * 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, and that the name of Red Hat,
 * Inc not be used in advertising or publicity pertaining to
 * distribution of the software without specific, written prior
 * permission.  Red Hat, Inc makes no representations about the
 * suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * RED HAT, INC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
 * NO EVENT SHALL RED HAT, INC BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <dlfcn.h>

#include <drm.h>
#include <GL/gl.h>
#include <GL/internal/dri_interface.h>
#include <GL/glxtokens.h>

#include <windowstr.h>
#include <os.h>

#define _XF86DRI_SERVER_
#include <xf86drm.h>
#include <xf86.h>
#include <dri2.h>

#include "glxserver.h"
#include "glxutil.h"
#include "glxdricommon.h"

#include "g_disptab.h"
#include "glapitable.h"
#include "glapi.h"
#include "glthread.h"
#include "dispatch.h"
#include "extension_string.h"

typedef struct __GLXDRIscreen   __GLXDRIscreen;
typedef struct __GLXDRIcontext  __GLXDRIcontext;
typedef struct __GLXDRIdrawable __GLXDRIdrawable;

struct __GLXDRIscreen {
    __GLXscreen		 base;
    __DRIscreen		*driScreen;
    void		*driver;
    int			 fd;

    xf86EnterVTProc	*enterVT;
    xf86LeaveVTProc	*leaveVT;

    const __DRIcoreExtension *core;
    const __DRIdri2Extension *dri2;
    const __DRI2flushExtension *flush;
    const __DRIcopySubBufferExtension *copySubBuffer;
    const __DRIswapControlExtension *swapControl;
    const __DRItexBufferExtension *texBuffer;

    unsigned char glx_enable_bits[__GLX_EXT_BYTES];
};

struct __GLXDRIcontext {
    __GLXcontext	 base;
    __DRIcontext	*driContext;
};

#define MAX_DRAWABLE_BUFFERS 5

struct __GLXDRIdrawable {
    __GLXdrawable	 base;
    __DRIdrawable	*driDrawable;
    __GLXDRIscreen	*screen;

    /* Dimensions as last reported by DRI2GetBuffers. */
    int width;
    int height;
    __DRIbuffer buffers[MAX_DRAWABLE_BUFFERS];
    int count;
};

static void
__glXDRIdrawableDestroy(__GLXdrawable *drawable)
{
    __GLXDRIdrawable *private = (__GLXDRIdrawable *) drawable;
    const __DRIcoreExtension *core = private->screen->core;
    
    (*core->destroyDrawable)(private->driDrawable);

    __glXDrawableRelease(drawable);

    free(private);
}

static void
__glXDRIdrawableCopySubBuffer(__GLXdrawable *drawable,
			       int x, int y, int w, int h)
{
    __GLXDRIdrawable *private = (__GLXDRIdrawable *) drawable;
    BoxRec box;
    RegionRec region;

    box.x1 = x;
    box.y1 = private->height - y - h;
    box.x2 = x + w;
    box.y2 = private->height - y;
    RegionInit(&region, &box, 0);

    DRI2CopyRegion(drawable->pDraw, &region,
		   DRI2BufferFrontLeft, DRI2BufferBackLeft);
}

static void
__glXDRIdrawableWaitX(__GLXdrawable *drawable)
{
    __GLXDRIdrawable *private = (__GLXDRIdrawable *) drawable;
    BoxRec box;
    RegionRec region;

    box.x1 = 0;
    box.y1 = 0;
    box.x2 = private->width;
    box.y2 = private->height;
    RegionInit(&region, &box, 0);

    DRI2CopyRegion(drawable->pDraw, &region,
		   DRI2BufferFakeFrontLeft, DRI2BufferFrontLeft);
}

static void
__glXDRIdrawableWaitGL(__GLXdrawable *drawable)
{
    __GLXDRIdrawable *private = (__GLXDRIdrawable *) drawable;
    BoxRec box;
    RegionRec region;

    box.x1 = 0;
    box.y1 = 0;
    box.x2 = private->width;
    box.y2 = private->height;
    RegionInit(&region, &box, 0);

    DRI2CopyRegion(drawable->pDraw, &region,
		   DRI2BufferFrontLeft, DRI2BufferFakeFrontLeft);
}

static void
__glXdriSwapEvent(ClientPtr client, void *data, int type, CARD64 ust,
		  CARD64 msc, CARD64 sbc)
{
    __GLXdrawable *drawable = data;
    xGLXBufferSwapComplete wire;

    if (!(drawable->eventMask & GLX_BUFFER_SWAP_COMPLETE_INTEL_MASK))
	return;

    wire.type = __glXEventBase + GLX_BufferSwapComplete;
    switch (type) {
    case DRI2_EXCHANGE_COMPLETE:
	wire.event_type = GLX_EXCHANGE_COMPLETE_INTEL;
	break;
    case DRI2_BLIT_COMPLETE:
	wire.event_type = GLX_BLIT_COMPLETE_INTEL;
	break;
    case DRI2_FLIP_COMPLETE:
	wire.event_type = GLX_FLIP_COMPLETE_INTEL;
	break;
    default:
	/* unknown swap completion type */
	break;
    }
    wire.drawable = drawable->drawId;
    wire.ust_hi = ust >> 32;
    wire.ust_lo = ust & 0xffffffff;
    wire.msc_hi = msc >> 32;
    wire.msc_lo = msc & 0xffffffff;
    wire.sbc_hi = sbc >> 32;
    wire.sbc_lo = sbc & 0xffffffff;

    WriteEventsToClient(client, 1, (xEvent *) &wire);
}

/*
 * Copy or flip back to front, honoring the swap interval if possible.
 *
 * If the kernel supports it, we request an event for the frame when the
 * swap should happen, then perform the copy when we receive it.
 */
static GLboolean
__glXDRIdrawableSwapBuffers(ClientPtr client, __GLXdrawable *drawable)
{
    __GLXDRIdrawable *priv = (__GLXDRIdrawable *) drawable;
    __GLXDRIscreen *screen = priv->screen;
    CARD64 unused;

#if __DRI2_FLUSH_VERSION >= 3
    if (screen->flush) {
	(*screen->flush->flush)(priv->driDrawable);
	(*screen->flush->invalidate)(priv->driDrawable);
    }
#else
    if (screen->flush)
	(*screen->flush->flushInvalidate)(priv->driDrawable);
#endif

    if (DRI2SwapBuffers(client, drawable->pDraw, 0, 0, 0, &unused,
			__glXdriSwapEvent, drawable->pDraw) != Success)
	return FALSE;

    return TRUE;
}

static int
__glXDRIdrawableSwapInterval(__GLXdrawable *drawable, int interval)
{
    if (interval <= 0) /* || interval > BIGNUM? */
	return GLX_BAD_VALUE;

    DRI2SwapInterval(drawable->pDraw, interval);

    return 0;
}

static void
__glXDRIcontextDestroy(__GLXcontext *baseContext)
{
    __GLXDRIcontext *context = (__GLXDRIcontext *) baseContext;
    __GLXDRIscreen *screen = (__GLXDRIscreen *) context->base.pGlxScreen;

    (*screen->core->destroyContext)(context->driContext);
    __glXContextDestroy(&context->base);
    free(context);
}

static int
__glXDRIcontextMakeCurrent(__GLXcontext *baseContext)
{
    __GLXDRIcontext *context = (__GLXDRIcontext *) baseContext;
    __GLXDRIdrawable *draw = (__GLXDRIdrawable *) baseContext->drawPriv;
    __GLXDRIdrawable *read = (__GLXDRIdrawable *) baseContext->readPriv;
    __GLXDRIscreen *screen = (__GLXDRIscreen *) context->base.pGlxScreen;

    return (*screen->core->bindContext)(context->driContext,
					draw->driDrawable,
					read->driDrawable);
}					      

static int
__glXDRIcontextLoseCurrent(__GLXcontext *baseContext)
{
    __GLXDRIcontext *context = (__GLXDRIcontext *) baseContext;
    __GLXDRIscreen *screen = (__GLXDRIscreen *) context->base.pGlxScreen;

    return (*screen->core->unbindContext)(context->driContext);
}

static int
__glXDRIcontextCopy(__GLXcontext *baseDst, __GLXcontext *baseSrc,
		    unsigned long mask)
{
    __GLXDRIcontext *dst = (__GLXDRIcontext *) baseDst;
    __GLXDRIcontext *src = (__GLXDRIcontext *) baseSrc;
    __GLXDRIscreen *screen = (__GLXDRIscreen *) dst->base.pGlxScreen;

    return (*screen->core->copyContext)(dst->driContext,
					src->driContext, mask);
}

static int
__glXDRIcontextForceCurrent(__GLXcontext *baseContext)
{
    __GLXDRIcontext *context = (__GLXDRIcontext *) baseContext;
    __GLXDRIdrawable *draw = (__GLXDRIdrawable *) baseContext->drawPriv;
    __GLXDRIdrawable *read = (__GLXDRIdrawable *) baseContext->readPriv;
    __GLXDRIscreen *screen = (__GLXDRIscreen *) context->base.pGlxScreen;

    return (*screen->core->bindContext)(context->driContext,
					draw->driDrawable,
					read->driDrawable);
}

static Bool
__glXDRIcontextWait(__GLXcontext *baseContext,
		    __GLXclientState *cl, int *error)
{
    if (DRI2WaitSwap(cl->client, baseContext->drawPriv->pDraw)) {
	*error = cl->client->noClientException;
	return TRUE;
    }

    return FALSE;
}

#ifdef __DRI_TEX_BUFFER

static int
__glXDRIbindTexImage(__GLXcontext *baseContext,
		     int buffer,
		     __GLXdrawable *glxPixmap)
{
    __GLXDRIdrawable *drawable = (__GLXDRIdrawable *) glxPixmap;
    const __DRItexBufferExtension *texBuffer = drawable->screen->texBuffer;
    __GLXDRIcontext *context = (__GLXDRIcontext *) baseContext;

    if (texBuffer == NULL)
        return Success;

#if __DRI_TEX_BUFFER_VERSION >= 2
    if (texBuffer->base.version >= 2 && texBuffer->setTexBuffer2 != NULL) {
	(*texBuffer->setTexBuffer2)(context->driContext,
				    glxPixmap->target,
				    glxPixmap->format,
				    drawable->driDrawable);
    } else
#endif
    {
	texBuffer->setTexBuffer(context->driContext,
				glxPixmap->target,
				drawable->driDrawable);
    }

    return Success;
}

static int
__glXDRIreleaseTexImage(__GLXcontext *baseContext,
			int buffer,
			__GLXdrawable *pixmap)
{
    /* FIXME: Just unbind the texture? */
    return Success;
}

#else

static int
__glXDRIbindTexImage(__GLXcontext *baseContext,
		     int buffer,
		     __GLXdrawable *glxPixmap)
{
    return Success;
}

static int
__glXDRIreleaseTexImage(__GLXcontext *baseContext,
			int buffer,
			__GLXdrawable *pixmap)
{
    return Success;
}

#endif

static __GLXtextureFromPixmap __glXDRItextureFromPixmap = {
    __glXDRIbindTexImage,
    __glXDRIreleaseTexImage
};

static void
__glXDRIscreenDestroy(__GLXscreen *baseScreen)
{
    __GLXDRIscreen *screen = (__GLXDRIscreen *) baseScreen;

    (*screen->core->destroyScreen)(screen->driScreen);

    dlclose(screen->driver);

    __glXScreenDestroy(baseScreen);

    free(screen);
}

static __GLXcontext *
__glXDRIscreenCreateContext(__GLXscreen *baseScreen,
			    __GLXconfig *glxConfig,
			    __GLXcontext *baseShareContext)
{
    __GLXDRIscreen *screen = (__GLXDRIscreen *) baseScreen;
    __GLXDRIcontext *context, *shareContext;
    __GLXDRIconfig *config = (__GLXDRIconfig *) glxConfig;
    __DRIcontext *driShare;

    shareContext = (__GLXDRIcontext *) baseShareContext;
    if (shareContext)
	driShare = shareContext->driContext;
    else
	driShare = NULL;

    context = calloc(1, sizeof *context);
    if (context == NULL)
	return NULL;

    context->base.destroy           = __glXDRIcontextDestroy;
    context->base.makeCurrent       = __glXDRIcontextMakeCurrent;
    context->base.loseCurrent       = __glXDRIcontextLoseCurrent;
    context->base.copy              = __glXDRIcontextCopy;
    context->base.forceCurrent      = __glXDRIcontextForceCurrent;
    context->base.textureFromPixmap = &__glXDRItextureFromPixmap;
    context->base.wait              = __glXDRIcontextWait;

    context->driContext =
	(*screen->dri2->createNewContext)(screen->driScreen,
					  config->driConfig,
					  driShare, context);
    if (context->driContext == NULL) {
	    free(context);
        return NULL;
    }

    return &context->base;
}

static void
__glXDRIinvalidateBuffers(DrawablePtr pDraw, void *priv)
{
#if __DRI2_FLUSH_VERSION >= 3
    __GLXDRIdrawable *private = priv;
    __GLXDRIscreen *screen = private->screen;

    if (screen->flush)
	(*screen->flush->invalidate)(private->driDrawable);
#endif
}

static __GLXdrawable *
__glXDRIscreenCreateDrawable(ClientPtr client,
			     __GLXscreen *screen,
			     DrawablePtr pDraw,
			     XID drawId,
			     int type,
			     XID glxDrawId,
			     __GLXconfig *glxConfig)
{
    __GLXDRIscreen *driScreen = (__GLXDRIscreen *) screen;
    __GLXDRIconfig *config = (__GLXDRIconfig *) glxConfig;
    __GLXDRIdrawable *private;

    private = calloc(1, sizeof *private);
    if (private == NULL)
	return NULL;

    private->screen = driScreen;
    if (!__glXDrawableInit(&private->base, screen,
			   pDraw, type, glxDrawId, glxConfig)) {
        free(private);
	return NULL;
    }

    private->base.destroy       = __glXDRIdrawableDestroy;
    private->base.swapBuffers   = __glXDRIdrawableSwapBuffers;
    private->base.copySubBuffer = __glXDRIdrawableCopySubBuffer;
    private->base.waitGL	= __glXDRIdrawableWaitGL;
    private->base.waitX		= __glXDRIdrawableWaitX;

    if (DRI2CreateDrawable(client, pDraw, drawId,
			   __glXDRIinvalidateBuffers, private)) {
	    free(private);
	    return NULL;
    }

    private->driDrawable =
	(*driScreen->dri2->createNewDrawable)(driScreen->driScreen,
					      config->driConfig, private);

    return &private->base;
}

static __DRIbuffer *
dri2GetBuffers(__DRIdrawable *driDrawable,
	       int *width, int *height,
	       unsigned int *attachments, int count,
	       int *out_count, void *loaderPrivate)
{
    __GLXDRIdrawable *private = loaderPrivate;
    DRI2BufferPtr *buffers;
    int i;
    int j;

    buffers = DRI2GetBuffers(private->base.pDraw,
			     width, height, attachments, count, out_count);
    if (*out_count > MAX_DRAWABLE_BUFFERS) {
	*out_count = 0;
	return NULL;
    }
	
    private->width = *width;
    private->height = *height;

    /* This assumes the DRI2 buffer attachment tokens matches the
     * __DRIbuffer tokens. */
    j = 0;
    for (i = 0; i < *out_count; i++) {
	/* Do not send the real front buffer of a window to the client.
	 */
	if ((private->base.pDraw->type == DRAWABLE_WINDOW)
	    && (buffers[i]->attachment == DRI2BufferFrontLeft)) {
	    continue;
	}

	private->buffers[j].attachment = buffers[i]->attachment;
	private->buffers[j].name = buffers[i]->name;
	private->buffers[j].pitch = buffers[i]->pitch;
	private->buffers[j].cpp = buffers[i]->cpp;
	private->buffers[j].flags = buffers[i]->flags;
	j++;
    }

    *out_count = j;
    return private->buffers;
}

static __DRIbuffer *
dri2GetBuffersWithFormat(__DRIdrawable *driDrawable,
			 int *width, int *height,
			 unsigned int *attachments, int count,
			 int *out_count, void *loaderPrivate)
{
    __GLXDRIdrawable *private = loaderPrivate;
    DRI2BufferPtr *buffers;
    int i;
    int j = 0;

    buffers = DRI2GetBuffersWithFormat(private->base.pDraw,
				       width, height, attachments, count,
				       out_count);
    if (*out_count > MAX_DRAWABLE_BUFFERS) {
	*out_count = 0;
	return NULL;
    }

    private->width = *width;
    private->height = *height;

    /* This assumes the DRI2 buffer attachment tokens matches the
     * __DRIbuffer tokens. */
    for (i = 0; i < *out_count; i++) {
	/* Do not send the real front buffer of a window to the client.
	 */
	if ((private->base.pDraw->type == DRAWABLE_WINDOW)
	    && (buffers[i]->attachment == DRI2BufferFrontLeft)) {
	    continue;
	}

	private->buffers[j].attachment = buffers[i]->attachment;
	private->buffers[j].name = buffers[i]->name;
	private->buffers[j].pitch = buffers[i]->pitch;
	private->buffers[j].cpp = buffers[i]->cpp;
	private->buffers[j].flags = buffers[i]->flags;
	j++;
    }

    *out_count = j;
    return private->buffers;
}

static void 
dri2FlushFrontBuffer(__DRIdrawable *driDrawable, void *loaderPrivate)
{
    (void) driDrawable;
    __glXDRIdrawableWaitGL((__GLXdrawable *) loaderPrivate);
}

static const __DRIdri2LoaderExtension loaderExtension = {
    { __DRI_DRI2_LOADER, __DRI_DRI2_LOADER_VERSION },
    dri2GetBuffers,
    dri2FlushFrontBuffer,
    dri2GetBuffersWithFormat,
};

#ifdef __DRI_USE_INVALIDATE
static const __DRIuseInvalidateExtension dri2UseInvalidate = {
   { __DRI_USE_INVALIDATE, __DRI_USE_INVALIDATE_VERSION }
};
#endif

static const __DRIextension *loader_extensions[] = {
    &systemTimeExtension.base,
    &loaderExtension.base,
#ifdef __DRI_USE_INVALIDATE
    &dri2UseInvalidate,
#endif
    NULL
};

static const char dri_driver_path[] = DRI_DRIVER_PATH;

static Bool
glxDRIEnterVT (int index, int flags)
{
    ScrnInfoPtr scrn = xf86Screens[index];
    Bool	ret;
    __GLXDRIscreen *screen = (__GLXDRIscreen *) 
	glxGetScreen(screenInfo.screens[index]);

    LogMessage(X_INFO, "AIGLX: Resuming AIGLX clients after VT switch\n");

    scrn->EnterVT = screen->enterVT;

    ret = scrn->EnterVT (index, flags);

    screen->enterVT = scrn->EnterVT;
    scrn->EnterVT = glxDRIEnterVT;

    if (!ret)
	return FALSE;
    
    glxResumeClients();

    return TRUE;
}

static void
glxDRILeaveVT (int index, int flags)
{
    ScrnInfoPtr scrn = xf86Screens[index];
    __GLXDRIscreen *screen = (__GLXDRIscreen *)
	glxGetScreen(screenInfo.screens[index]);

    LogMessage(X_INFO, "AIGLX: Suspending AIGLX clients for VT switch\n");

    glxSuspendClients();

    scrn->LeaveVT = screen->leaveVT;
    (*screen->leaveVT) (index, flags);
    screen->leaveVT = scrn->LeaveVT;
    scrn->LeaveVT = glxDRILeaveVT;
}

static void
initializeExtensions(__GLXDRIscreen *screen)
{
    ScreenPtr pScreen = screen->base.pScreen;
    const __DRIextension **extensions;
    int i;

    extensions = screen->core->getExtensions(screen->driScreen);

    __glXEnableExtension(screen->glx_enable_bits,
			 "GLX_MESA_copy_sub_buffer");
    LogMessage(X_INFO, "AIGLX: enabled GLX_MESA_copy_sub_buffer\n");

    __glXEnableExtension(screen->glx_enable_bits, "GLX_INTEL_swap_event");
    LogMessage(X_INFO, "AIGLX: enabled GLX_INTEL_swap_event\n");

    if (DRI2HasSwapControl(pScreen)) {
	__glXEnableExtension(screen->glx_enable_bits,
			     "GLX_SGI_swap_control");
	__glXEnableExtension(screen->glx_enable_bits,
			     "GLX_MESA_swap_control");
	LogMessage(X_INFO, "AIGLX: enabled GLX_SGI_swap_control and GLX_MESA_swap_control\n");
    }

    for (i = 0; extensions[i]; i++) {
#ifdef __DRI_READ_DRAWABLE
	if (strcmp(extensions[i]->name, __DRI_READ_DRAWABLE) == 0) {
	    __glXEnableExtension(screen->glx_enable_bits,
				 "GLX_SGI_make_current_read");

	    LogMessage(X_INFO, "AIGLX: enabled GLX_SGI_make_current_read\n");
	}
#endif

#ifdef __DRI_TEX_BUFFER
	if (strcmp(extensions[i]->name, __DRI_TEX_BUFFER) == 0) {
	    screen->texBuffer =
		(const __DRItexBufferExtension *) extensions[i];
	    /* GLX_EXT_texture_from_pixmap is always enabled. */
	    LogMessage(X_INFO, "AIGLX: GLX_EXT_texture_from_pixmap backed by buffer objects\n");
	}
#endif

#ifdef __DRI2_FLUSH
	if (strcmp(extensions[i]->name, __DRI2_FLUSH) == 0 &&
	    extensions[i]->version >= 3) {
		screen->flush = (__DRI2flushExtension *) extensions[i];
	}
#endif

	/* Ignore unknown extensions */
    }
}

static __GLXscreen *
__glXDRIscreenProbe(ScreenPtr pScreen)
{
    const char *driverName, *deviceName;
    __GLXDRIscreen *screen;
    char filename[128];
    size_t buffer_size;
    ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
    const __DRIextension **extensions;
    const __DRIconfig **driConfigs;
    int i;

    screen = calloc(1, sizeof *screen);
    if (screen == NULL)
	return NULL;

    if (!xf86LoaderCheckSymbol("DRI2Connect") ||
	!DRI2Connect(pScreen, DRI2DriverDRI,
		     &screen->fd, &driverName, &deviceName)) {
	LogMessage(X_INFO,
		   "AIGLX: Screen %d is not DRI2 capable\n", pScreen->myNum);
	return NULL;
    }

    screen->base.destroy        = __glXDRIscreenDestroy;
    screen->base.createContext  = __glXDRIscreenCreateContext;
    screen->base.createDrawable = __glXDRIscreenCreateDrawable;
    screen->base.swapInterval   = __glXDRIdrawableSwapInterval;
    screen->base.pScreen       = pScreen;

    __glXInitExtensionEnableBits(screen->glx_enable_bits);

    snprintf(filename, sizeof filename,
	     "%s/%s_dri.so", dri_driver_path, driverName);

    screen->driver = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);
    if (screen->driver == NULL) {
	LogMessage(X_ERROR, "AIGLX error: dlopen of %s failed (%s)\n",
		   filename, dlerror());
        goto handle_error;
    }

    extensions = dlsym(screen->driver, __DRI_DRIVER_EXTENSIONS);
    if (extensions == NULL) {
	LogMessage(X_ERROR, "AIGLX error: %s exports no extensions (%s)\n",
		   driverName, dlerror());
	goto handle_error;
    }
    
    for (i = 0; extensions[i]; i++) {
        if (strcmp(extensions[i]->name, __DRI_CORE) == 0 &&
	    extensions[i]->version >= 1) {
		screen->core = (const __DRIcoreExtension *) extensions[i];
	}
        if (strcmp(extensions[i]->name, __DRI_DRI2) == 0 &&
	    extensions[i]->version >= 1) {
		screen->dri2 = (const __DRIdri2Extension *) extensions[i];
	}
    }

    if (screen->core == NULL || screen->dri2 == NULL) {
	LogMessage(X_ERROR, "AIGLX error: %s exports no DRI extension\n",
		   driverName);
	goto handle_error;
    }

    screen->driScreen =
	(*screen->dri2->createNewScreen)(pScreen->myNum,
					 screen->fd,
					 loader_extensions,
					 &driConfigs,
					 screen);

    if (screen->driScreen == NULL) {
	LogMessage(X_ERROR,
		   "AIGLX error: Calling driver entry point failed\n");
	goto handle_error;
    }

    initializeExtensions(screen);

    screen->base.fbconfigs = glxConvertConfigs(screen->core, driConfigs,
					       GLX_WINDOW_BIT |
					       GLX_PIXMAP_BIT |
					       GLX_PBUFFER_BIT);

    __glXScreenInit(&screen->base, pScreen);

    /* The first call simply determines the length of the extension string.
     * This allows us to allocate some memory to hold the extension string,
     * but it requires that we call __glXGetExtensionString a second time.
     */
    buffer_size = __glXGetExtensionString(screen->glx_enable_bits, NULL);
    if (buffer_size > 0) {
	if (screen->base.GLXextensions != NULL) {
	    free(screen->base.GLXextensions);
	}

	screen->base.GLXextensions = xnfalloc(buffer_size);
	(void) __glXGetExtensionString(screen->glx_enable_bits, 
				       screen->base.GLXextensions);
    }

    /* We're going to assume (perhaps incorrectly?) that all DRI2-enabled
     * drivers support the required extensions for GLX 1.4.  The extensions
     * we're assuming are:
     *
     *    - GLX_SGI_make_current_read (1.3)
     *    - GLX_SGIX_fbconfig (1.3)
     *    - GLX_SGIX_pbuffer (1.3)
     *    - GLX_ARB_multisample (1.4)
     */
    screen->base.GLXmajor = 1;
    screen->base.GLXminor = 4;
    
    screen->enterVT = pScrn->EnterVT;
    pScrn->EnterVT = glxDRIEnterVT; 
    screen->leaveVT = pScrn->LeaveVT;
    pScrn->LeaveVT = glxDRILeaveVT;

    LogMessage(X_INFO,
	       "AIGLX: Loaded and initialized %s\n", filename);

    return &screen->base;

 handle_error:
    if (screen->driver)
        dlclose(screen->driver);

    free(screen);

    LogMessage(X_ERROR, "AIGLX: reverting to software rendering\n");

    return NULL;
}

_X_EXPORT __GLXprovider __glXDRI2Provider = {
    __glXDRIscreenProbe,
    "DRI2",
    NULL
};