xref: /aosp_15_r20/external/mesa3d/src/glx/glxext.c (revision 6104692788411f58d303aa86923a9ff6ecaded22)
1 /*
2  * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3  * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
4  *
5  * SPDX-License-Identifier: SGI-B-2.0
6  */
7 
8 /**
9  * \file glxext.c
10  * GLX protocol interface boot-strap code.
11  *
12  * Direct rendering support added by Precision Insight, Inc.
13  *
14  * \author Kevin E. Martin <[email protected]>
15  */
16 
17 #include <assert.h>
18 #include <stdbool.h>
19 #include <stdarg.h>
20 
21 #include "glxclient.h"
22 #include <X11/extensions/Xext.h>
23 #include <X11/extensions/extutil.h>
24 #ifdef GLX_USE_APPLEGL
25 #include "apple/apple_glx.h"
26 #include "apple/apple_visual.h"
27 #endif
28 #include "glxextensions.h"
29 
30 #include "util/u_debug.h"
31 #ifndef GLX_USE_APPLEGL
32 #include "dri_common.h"
33 #endif
34 
35 #include "loader_x11.h"
36 #ifdef HAVE_LIBDRM
37 #include "loader_dri3_helper.h"
38 #endif
39 
40 #include <X11/Xlib-xcb.h>
41 #include <xcb/xcb.h>
42 #include <xcb/glx.h>
43 #include "dri_util.h"
44 #if defined(GLX_DIRECT_RENDERING) && (!defined(GLX_USE_APPLEGL) || defined(GLX_USE_APPLE))
45 #include <dlfcn.h>
46 #endif
47 
48 #define __GLX_MIN_CONFIG_PROPS	18
49 #define __GLX_EXT_CONFIG_PROPS	32
50 
51 /*
52 ** Since we send all non-core visual properties as token, value pairs,
53 ** we require 2 words across the wire. In order to maintain backwards
54 ** compatibility, we need to send the total number of words that the
55 ** VisualConfigs are sent back in so old libraries can simply "ignore"
56 ** the new properties.
57 */
58 #define __GLX_TOTAL_CONFIG \
59    (__GLX_MIN_CONFIG_PROPS + 2 * __GLX_EXT_CONFIG_PROPS)
60 
61 _X_HIDDEN void
glx_message(int level,const char * f,...)62 glx_message(int level, const char *f, ...)
63 {
64    va_list args;
65    int threshold = _LOADER_WARNING;
66    const char *libgl_debug;
67 
68    libgl_debug = getenv("LIBGL_DEBUG");
69    if (libgl_debug) {
70       if (strstr(libgl_debug, "quiet"))
71          threshold = _LOADER_FATAL;
72       else if (strstr(libgl_debug, "verbose"))
73          threshold = _LOADER_DEBUG;
74    }
75 
76    /* Note that the _LOADER_* levels are lower numbers for more severe. */
77    if (level <= threshold) {
78       va_start(args, f);
79       vfprintf(stderr, f, args);
80       va_end(args);
81    }
82 }
83 
84 /*
85 ** You can set this cell to 1 to force the gl drawing stuff to be
86 ** one command per packet
87 */
88 _X_HIDDEN int __glXDebug = 0;
89 
90 /* Extension required boiler plate */
91 
92 static const char __glXExtensionName[] = GLX_EXTENSION_NAME;
93 static struct glx_display *glx_displays;
94 
95 static /* const */ char *error_list[] = {
96    "GLXBadContext",
97    "GLXBadContextState",
98    "GLXBadDrawable",
99    "GLXBadPixmap",
100    "GLXBadContextTag",
101    "GLXBadCurrentWindow",
102    "GLXBadRenderRequest",
103    "GLXBadLargeRequest",
104    "GLXUnsupportedPrivateRequest",
105    "GLXBadFBConfig",
106    "GLXBadPbuffer",
107    "GLXBadCurrentDrawable",
108    "GLXBadWindow",
109    "GLXBadProfileARB",
110 };
111 
112 #ifdef GLX_USE_APPLEGL
113 static char *__glXErrorString(Display *dpy, int code, XExtCodes *codes,
114                               char *buf, int n);
115 #endif
116 
117 static
XEXT_GENERATE_ERROR_STRING(__glXErrorString,__glXExtensionName,__GLX_NUMBER_ERRORS,error_list)118 XEXT_GENERATE_ERROR_STRING(__glXErrorString, __glXExtensionName,
119                            __GLX_NUMBER_ERRORS, error_list)
120 
121 /*
122  * GLX events are a bit funky.  We don't stuff the X event code into
123  * our user exposed (via XNextEvent) structure.  Instead we use the GLX
124  * private event code namespace (and hope it doesn't conflict).  Clients
125  * have to know that bit 15 in the event type field means they're getting
126  * a GLX event, and then handle the various sub-event types there, rather
127  * than simply checking the event code and handling it directly.
128  */
129 
130 static Bool
131 __glXWireToEvent(Display *dpy, XEvent *event, xEvent *wire)
132 {
133      struct glx_display *glx_dpy = __glXInitialize(dpy);
134 
135    if (glx_dpy == NULL)
136       return False;
137 
138    switch ((wire->u.u.type & 0x7f) - glx_dpy->codes.first_event) {
139    case GLX_PbufferClobber:
140    {
141       GLXPbufferClobberEvent *aevent = (GLXPbufferClobberEvent *)event;
142       xGLXPbufferClobberEvent *awire = (xGLXPbufferClobberEvent *)wire;
143       aevent->event_type = awire->event_type;
144       aevent->serial = awire->sequenceNumber;
145       aevent->draw_type = awire->draw_type;
146       aevent->drawable = awire->drawable;
147       aevent->buffer_mask = awire->buffer_mask;
148       aevent->aux_buffer = awire->aux_buffer;
149       aevent->x = awire->x;
150       aevent->y = awire->y;
151       aevent->width = awire->width;
152       aevent->height = awire->height;
153       aevent->count = awire->count;
154       return True;
155    }
156    case GLX_BufferSwapComplete:
157    {
158       GLXBufferSwapComplete *aevent = (GLXBufferSwapComplete *)event;
159       xGLXBufferSwapComplete2 *awire = (xGLXBufferSwapComplete2 *)wire;
160       struct glx_drawable *glxDraw = GetGLXDrawable(dpy, awire->drawable);
161 
162       if (!glxDraw)
163 	 return False;
164 
165       aevent->serial = _XSetLastRequestRead(dpy, (xGenericReply *) wire);
166       aevent->send_event = (awire->type & 0x80) != 0;
167       aevent->display = dpy;
168       aevent->event_type = awire->event_type;
169       aevent->drawable = glxDraw->xDrawable;
170       aevent->ust = ((CARD64)awire->ust_hi << 32) | awire->ust_lo;
171       aevent->msc = ((CARD64)awire->msc_hi << 32) | awire->msc_lo;
172 
173       /* Handle 32-Bit wire sbc wraparound in both directions to cope with out
174        * of sequence 64-Bit sbc's
175        */
176       if ((int64_t) awire->sbc < ((int64_t) glxDraw->lastEventSbc - 0x40000000))
177          glxDraw->eventSbcWrap += 0x100000000;
178       if ((int64_t) awire->sbc > ((int64_t) glxDraw->lastEventSbc + 0x40000000))
179          glxDraw->eventSbcWrap -= 0x100000000;
180       glxDraw->lastEventSbc = awire->sbc;
181       aevent->sbc = awire->sbc + glxDraw->eventSbcWrap;
182       return True;
183    }
184    default:
185       /* client doesn't support server event */
186       break;
187    }
188 
189    return False;
190 }
191 
192 /* We don't actually support this.  It doesn't make sense for clients to
193  * send each other GLX events.
194  */
195 static Status
__glXEventToWire(Display * dpy,XEvent * event,xEvent * wire)196 __glXEventToWire(Display *dpy, XEvent *event, xEvent *wire)
197 {
198      struct glx_display *glx_dpy = __glXInitialize(dpy);
199 
200    if (glx_dpy == NULL)
201       return False;
202 
203    switch (event->type) {
204    case GLX_DAMAGED:
205       break;
206    case GLX_SAVED:
207       break;
208    case GLX_EXCHANGE_COMPLETE_INTEL:
209       break;
210    case GLX_COPY_COMPLETE_INTEL:
211       break;
212    case GLX_FLIP_COMPLETE_INTEL:
213       break;
214    default:
215       /* client doesn't support server event */
216       break;
217    }
218 
219    return Success;
220 }
221 
222 /************************************************************************/
223 /*
224 ** Free the per screen configs data as well as the array of
225 ** __glXScreenConfigs.
226 */
227 static void
FreeScreenConfigs(struct glx_display * priv)228 FreeScreenConfigs(struct glx_display * priv)
229 {
230    struct glx_screen *psc;
231    GLint i, screens;
232 
233    /* Free screen configuration information */
234    screens = ScreenCount(priv->dpy);
235    for (i = 0; i < screens; i++) {
236       psc = priv->screens[i];
237       if (!psc)
238          continue;
239       glx_screen_cleanup(psc);
240 
241 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
242       if (psc->driScreen.deinitScreen)
243          psc->driScreen.deinitScreen(psc);
244       /* Free the direct rendering per screen data */
245       driDestroyScreen(psc->frontend_screen);
246 #endif
247       free(psc);
248    }
249    free((char *) priv->screens);
250    priv->screens = NULL;
251 }
252 
253 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
254 static void
free_zombie_glx_drawable(struct set_entry * entry)255 free_zombie_glx_drawable(struct set_entry *entry)
256 {
257    __GLXDRIdrawable *pdraw = (__GLXDRIdrawable *)entry->key;
258 
259    pdraw->destroyDrawable(pdraw);
260 }
261 #endif
262 
263 static void
glx_display_free(struct glx_display * priv)264 glx_display_free(struct glx_display *priv)
265 {
266    struct glx_context *gc;
267 
268    gc = __glXGetCurrentContext();
269    if (priv->dpy == gc->currentDpy) {
270       if (gc != &dummyContext)
271          gc->vtable->unbind(gc);
272 
273       gc->vtable->destroy(gc);
274       __glXSetCurrentContextNull();
275    }
276 
277    /* Needs to be done before free screen. */
278 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
279    _mesa_set_destroy(priv->zombieGLXDrawable, free_zombie_glx_drawable);
280 #endif
281 
282    FreeScreenConfigs(priv);
283 
284    __glxHashDestroy(priv->glXDrawHash);
285 
286 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
287    __glxHashDestroy(priv->drawHash);
288    if (priv->dri2Hash)
289       __glxHashDestroy(priv->dri2Hash);
290 
291 #endif /* GLX_DIRECT_RENDERING && !GLX_USE_APPLEGL */
292 
293    free((char *) priv);
294 }
295 
296 static int
__glXCloseDisplay(Display * dpy,XExtCodes * codes)297 __glXCloseDisplay(Display * dpy, XExtCodes * codes)
298 {
299    struct glx_display *priv, **prev;
300 
301    _XLockMutex(_Xglobal_lock);
302    prev = &glx_displays;
303    for (priv = glx_displays; priv; prev = &priv->next, priv = priv->next) {
304       if (priv->dpy == dpy) {
305          *prev = priv->next;
306 	 break;
307       }
308    }
309    _XUnlockMutex(_Xglobal_lock);
310 
311    if (priv != NULL)
312       glx_display_free(priv);
313 
314    return 1;
315 }
316 
317 /*
318 ** Query the version of the GLX extension.  This procedure works even if
319 ** the client extension is not completely set up.
320 */
321 static Bool
QueryVersion(Display * dpy,int opcode,int * major,int * minor)322 QueryVersion(Display * dpy, int opcode, int *major, int *minor)
323 {
324    xcb_connection_t *c = XGetXCBConnection(dpy);
325    xcb_glx_query_version_reply_t *reply = xcb_glx_query_version_reply(c,
326                                                                       xcb_glx_query_version
327                                                                       (c,
328                                                                        GLX_MAJOR_VERSION,
329                                                                        GLX_MINOR_VERSION),
330                                                                       NULL);
331 
332    if (!reply)
333      return GL_FALSE;
334 
335    if (reply->major_version != GLX_MAJOR_VERSION) {
336       free(reply);
337       return GL_FALSE;
338    }
339    *major = reply->major_version;
340    *minor = min(reply->minor_version, GLX_MINOR_VERSION);
341    free(reply);
342    return GL_TRUE;
343 }
344 
345 /*
346  * We don't want to enable this GLX_OML_swap_method in glxext.h,
347  * because we can't support it.  The X server writes it out though,
348  * so we should handle it somehow, to avoid false warnings.
349  */
350 enum {
351     IGNORE_GLX_SWAP_METHOD_OML = 0x8060
352 };
353 
354 
355 static GLint
convert_from_x_visual_type(int visualType)356 convert_from_x_visual_type(int visualType)
357 {
358    static const int glx_visual_types[] = {
359       [StaticGray]  = GLX_STATIC_GRAY,
360       [GrayScale]   = GLX_GRAY_SCALE,
361       [StaticColor] = GLX_STATIC_COLOR,
362       [PseudoColor] = GLX_PSEUDO_COLOR,
363       [TrueColor]   = GLX_TRUE_COLOR,
364       [DirectColor] = GLX_DIRECT_COLOR,
365    };
366 
367    if (visualType < ARRAY_SIZE(glx_visual_types))
368       return glx_visual_types[visualType];
369 
370    return GLX_NONE;
371 }
372 
373 /*
374  * getVisualConfigs uses the !tagged_only path.
375  * getFBConfigs uses the tagged_only path.
376  */
377 _X_HIDDEN void
__glXInitializeVisualConfigFromTags(struct glx_config * config,int count,const INT32 * bp,Bool tagged_only,Bool fbconfig_style_tags)378 __glXInitializeVisualConfigFromTags(struct glx_config * config, int count,
379                                     const INT32 * bp, Bool tagged_only,
380                                     Bool fbconfig_style_tags)
381 {
382    int i;
383 
384    if (!tagged_only) {
385       /* Copy in the first set of properties */
386       config->visualID = *bp++;
387 
388       config->visualType = convert_from_x_visual_type(*bp++);
389 
390       config->renderType = *bp++ ? GLX_RGBA_BIT : GLX_COLOR_INDEX_BIT;
391 
392       config->redBits = *bp++;
393       config->greenBits = *bp++;
394       config->blueBits = *bp++;
395       config->alphaBits = *bp++;
396       config->accumRedBits = *bp++;
397       config->accumGreenBits = *bp++;
398       config->accumBlueBits = *bp++;
399       config->accumAlphaBits = *bp++;
400 
401       config->doubleBufferMode = *bp++;
402       config->stereoMode = *bp++;
403 
404       config->rgbBits = *bp++;
405       config->depthBits = *bp++;
406       config->stencilBits = *bp++;
407       config->numAuxBuffers = *bp++;
408       config->level = *bp++;
409 
410 #ifdef GLX_USE_APPLEGL
411        /* AppleSGLX supports pixmap and pbuffers with all config. */
412        config->drawableType = GLX_WINDOW_BIT | GLX_PIXMAP_BIT | GLX_PBUFFER_BIT;
413        /* Unfortunately this can create an ABI compatibility problem. */
414        count -= 18;
415 #else
416       count -= __GLX_MIN_CONFIG_PROPS;
417 #endif
418    }
419 
420    /*
421     ** Additional properties may be in a list at the end
422     ** of the reply.  They are in pairs of property type
423     ** and property value.
424     */
425 
426 #define FETCH_OR_SET(tag) \
427     config-> tag = ( fbconfig_style_tags ) ? *bp++ : 1
428 
429    for (i = 0; i < count; i += 2) {
430       long int tag = *bp++;
431 
432       switch (tag) {
433       case GLX_RGBA:
434          if (fbconfig_style_tags)
435             config->renderType = *bp++ ? GLX_RGBA_BIT : GLX_COLOR_INDEX_BIT;
436          else
437             config->renderType = GLX_RGBA_BIT;
438          break;
439       case GLX_BUFFER_SIZE:
440          config->rgbBits = *bp++;
441          break;
442       case GLX_LEVEL:
443          config->level = *bp++;
444          break;
445       case GLX_DOUBLEBUFFER:
446          FETCH_OR_SET(doubleBufferMode);
447          break;
448       case GLX_STEREO:
449          FETCH_OR_SET(stereoMode);
450          break;
451       case GLX_AUX_BUFFERS:
452          config->numAuxBuffers = *bp++;
453          break;
454       case GLX_RED_SIZE:
455          config->redBits = *bp++;
456          break;
457       case GLX_GREEN_SIZE:
458          config->greenBits = *bp++;
459          break;
460       case GLX_BLUE_SIZE:
461          config->blueBits = *bp++;
462          break;
463       case GLX_ALPHA_SIZE:
464          config->alphaBits = *bp++;
465          break;
466       case GLX_DEPTH_SIZE:
467          config->depthBits = *bp++;
468          break;
469       case GLX_STENCIL_SIZE:
470          config->stencilBits = *bp++;
471          break;
472       case GLX_ACCUM_RED_SIZE:
473          config->accumRedBits = *bp++;
474          break;
475       case GLX_ACCUM_GREEN_SIZE:
476          config->accumGreenBits = *bp++;
477          break;
478       case GLX_ACCUM_BLUE_SIZE:
479          config->accumBlueBits = *bp++;
480          break;
481       case GLX_ACCUM_ALPHA_SIZE:
482          config->accumAlphaBits = *bp++;
483          break;
484       case GLX_VISUAL_CAVEAT_EXT:
485          config->visualRating = *bp++;
486          break;
487       case GLX_X_VISUAL_TYPE:
488          config->visualType = *bp++;
489          break;
490       case GLX_TRANSPARENT_TYPE:
491          config->transparentPixel = *bp++;
492          break;
493       case GLX_TRANSPARENT_INDEX_VALUE:
494          config->transparentIndex = *bp++;
495          break;
496       case GLX_TRANSPARENT_RED_VALUE:
497          config->transparentRed = *bp++;
498          break;
499       case GLX_TRANSPARENT_GREEN_VALUE:
500          config->transparentGreen = *bp++;
501          break;
502       case GLX_TRANSPARENT_BLUE_VALUE:
503          config->transparentBlue = *bp++;
504          break;
505       case GLX_TRANSPARENT_ALPHA_VALUE:
506          config->transparentAlpha = *bp++;
507          break;
508       case GLX_VISUAL_ID:
509          config->visualID = *bp++;
510          break;
511       case GLX_DRAWABLE_TYPE:
512          config->drawableType = *bp++;
513 #ifdef GLX_USE_APPLEGL
514          /* AppleSGLX supports pixmap and pbuffers with all config. */
515          config->drawableType |= GLX_WINDOW_BIT | GLX_PIXMAP_BIT | GLX_PBUFFER_BIT;
516 #endif
517          break;
518       case GLX_RENDER_TYPE: /* fbconfig render type bits */
519          config->renderType = *bp++;
520          break;
521       case GLX_X_RENDERABLE:
522          config->xRenderable = *bp++;
523          break;
524       case GLX_FBCONFIG_ID:
525          config->fbconfigID = *bp++;
526          break;
527       case GLX_MAX_PBUFFER_WIDTH:
528          config->maxPbufferWidth = *bp++;
529          break;
530       case GLX_MAX_PBUFFER_HEIGHT:
531          config->maxPbufferHeight = *bp++;
532          break;
533       case GLX_MAX_PBUFFER_PIXELS:
534          config->maxPbufferPixels = *bp++;
535          break;
536 #ifndef GLX_USE_APPLEGL
537       case GLX_OPTIMAL_PBUFFER_WIDTH_SGIX:
538          config->optimalPbufferWidth = *bp++;
539          break;
540       case GLX_OPTIMAL_PBUFFER_HEIGHT_SGIX:
541          config->optimalPbufferHeight = *bp++;
542          break;
543       case GLX_VISUAL_SELECT_GROUP_SGIX:
544          config->visualSelectGroup = *bp++;
545          break;
546 #endif
547       case GLX_SAMPLE_BUFFERS_SGIS:
548          config->sampleBuffers = *bp++;
549          break;
550       case GLX_SAMPLES_SGIS:
551          config->samples = *bp++;
552          break;
553       case IGNORE_GLX_SWAP_METHOD_OML:
554          /* We ignore this tag.  See the comment above this function. */
555          ++bp;
556          break;
557 #ifndef GLX_USE_APPLEGL
558       case GLX_BIND_TO_TEXTURE_RGB_EXT:
559          config->bindToTextureRgb = *bp++;
560          break;
561       case GLX_BIND_TO_TEXTURE_RGBA_EXT:
562          config->bindToTextureRgba = *bp++;
563          break;
564       case GLX_BIND_TO_MIPMAP_TEXTURE_EXT:
565          config->bindToMipmapTexture = *bp++;
566          break;
567       case GLX_BIND_TO_TEXTURE_TARGETS_EXT:
568          config->bindToTextureTargets = *bp++;
569          break;
570       case GLX_Y_INVERTED_EXT:
571          config->yInverted = *bp++;
572          break;
573 #endif
574       case GLX_FRAMEBUFFER_SRGB_CAPABLE_EXT:
575          config->sRGBCapable = *bp++;
576          break;
577 
578       case GLX_USE_GL:
579          if (fbconfig_style_tags)
580             bp++;
581          break;
582       case GLX_FLOAT_COMPONENTS_NV:
583          config->floatComponentsNV = *bp++;
584          break;
585       case None:
586          i = count;
587          break;
588       default: {
589             long int tagvalue = *bp++;
590             DebugMessageF("WARNING: unknown fbconfig attribute from server: "
591                           "tag 0x%lx value 0x%lx\n", tag, tagvalue);
592             break;
593          }
594       }
595    }
596 }
597 
598 static struct glx_config *
createConfigsFromProperties(Display * dpy,int nvisuals,int nprops,int screen,GLboolean tagged_only)599 createConfigsFromProperties(Display * dpy, int nvisuals, int nprops,
600                             int screen, GLboolean tagged_only)
601 {
602    INT32 buf[__GLX_TOTAL_CONFIG], *props;
603    unsigned prop_size;
604    struct glx_config *modes, *m;
605    int i;
606 
607    if (nprops == 0)
608       return NULL;
609 
610    /* Check number of properties */
611    if (nprops < __GLX_MIN_CONFIG_PROPS)
612       return NULL;
613 
614    /* Allocate memory for our config structure */
615    modes = glx_config_create_list(nvisuals);
616    if (!modes)
617       return NULL;
618 
619    prop_size = nprops * __GLX_SIZE_INT32;
620    if (prop_size <= sizeof(buf))
621       props = buf;
622    else
623       props = malloc(prop_size);
624 
625    /* Read each config structure and convert it into our format */
626    m = modes;
627    for (i = 0; i < nvisuals; i++) {
628       _XRead(dpy, (char *) props, prop_size);
629       /* If this is GLXGetVisualConfigs then the reply will not include
630        * any drawable type info, but window support is implied because
631        * that's what a Visual describes, and pixmap support is implied
632        * because you almost certainly have a pixmap format corresponding
633        * to your visual format.
634        */
635       if (!tagged_only)
636          m->drawableType = GLX_WINDOW_BIT | GLX_PIXMAP_BIT;
637       __glXInitializeVisualConfigFromTags(m, nprops, props,
638                                           tagged_only, GL_TRUE);
639       m->screen = screen;
640       m = m->next;
641    }
642 
643    if (props != buf)
644       free(props);
645 
646    return modes;
647 }
648 
649 static GLboolean
getVisualConfigs(struct glx_screen * psc,struct glx_display * priv,int screen)650 getVisualConfigs(struct glx_screen *psc,
651 		  struct glx_display *priv, int screen)
652 {
653    xGLXGetVisualConfigsReq *req;
654    xGLXGetVisualConfigsReply reply;
655    Display *dpy = priv->dpy;
656 
657    LockDisplay(dpy);
658 
659    psc->visuals = NULL;
660    GetReq(GLXGetVisualConfigs, req);
661    req->reqType = priv->codes.major_opcode;
662    req->glxCode = X_GLXGetVisualConfigs;
663    req->screen = screen;
664 
665    if (!_XReply(dpy, (xReply *) & reply, 0, False))
666       goto out;
667 
668    psc->visuals = createConfigsFromProperties(dpy,
669                                               reply.numVisuals,
670                                               reply.numProps,
671                                               screen, GL_FALSE);
672 
673  out:
674    UnlockDisplay(dpy);
675    return psc->visuals != NULL;
676 }
677 
678 static GLboolean
getFBConfigs(struct glx_screen * psc,struct glx_display * priv,int screen)679 getFBConfigs(struct glx_screen *psc, struct glx_display *priv, int screen)
680 {
681    xGLXGetFBConfigsReq *fb_req;
682    xGLXGetFBConfigsReply reply;
683    Display *dpy = priv->dpy;
684 
685    psc->serverGLXexts = __glXQueryServerString(dpy, screen, GLX_EXTENSIONS);
686 
687    if (psc->serverGLXexts == NULL) {
688       return GL_FALSE;
689    }
690 
691    LockDisplay(dpy);
692 
693    psc->configs = NULL;
694    GetReq(GLXGetFBConfigs, fb_req);
695    fb_req->reqType = priv->codes.major_opcode;
696    fb_req->glxCode = X_GLXGetFBConfigs;
697    fb_req->screen = screen;
698 
699    if (!_XReply(dpy, (xReply *) & reply, 0, False))
700       goto out;
701 
702    psc->configs = createConfigsFromProperties(dpy,
703                                               reply.numFBConfigs,
704                                               reply.numAttribs * 2,
705                                               screen, GL_TRUE);
706 
707  out:
708    UnlockDisplay(dpy);
709    return psc->configs != NULL;
710 }
711 
712 _X_HIDDEN Bool
glx_screen_init(struct glx_screen * psc,int screen,struct glx_display * priv)713 glx_screen_init(struct glx_screen *psc,
714 		 int screen, struct glx_display * priv)
715 {
716    /* Initialize per screen dynamic client GLX extensions */
717    psc->ext_list_first_time = GL_TRUE;
718    psc->scr = screen;
719    psc->dpy = priv->dpy;
720    psc->display = priv;
721 
722    if (!getVisualConfigs(psc, priv, screen))
723       return GL_FALSE;
724 
725    if (!getFBConfigs(psc, priv, screen))
726       return GL_FALSE;
727 
728    return GL_TRUE;
729 }
730 
731 _X_HIDDEN void
glx_screen_cleanup(struct glx_screen * psc)732 glx_screen_cleanup(struct glx_screen *psc)
733 {
734    if (psc->configs) {
735       glx_config_destroy_list(psc->configs);
736       free(psc->effectiveGLXexts);
737       psc->configs = NULL;   /* NOTE: just for paranoia */
738    }
739    if (psc->visuals) {
740       glx_config_destroy_list(psc->visuals);
741       psc->visuals = NULL;   /* NOTE: just for paranoia */
742    }
743 #if defined(GLX_DIRECT_RENDERING) && (!defined(GLX_USE_APPLEGL) || defined(GLX_USE_APPLE))
744    if (psc->driver_configs) {
745       driDestroyConfigs(psc->driver_configs);
746       psc->driver_configs = NULL;
747    }
748 #endif
749    free((char *) psc->serverGLXexts);
750    free((char *) psc->serverGLXvendor);
751    free((char *) psc->serverGLXversion);
752    free(psc->driverName);
753 }
754 
755 static void
bind_extensions(struct glx_screen * psc,const char * driverName)756 bind_extensions(struct glx_screen *psc, const char *driverName)
757 {
758    unsigned mask;
759 
760    if (psc->display->driver != GLX_DRIVER_SW) {
761       __glXEnableDirectExtension(psc, "GLX_EXT_buffer_age");
762       __glXEnableDirectExtension(psc, "GLX_EXT_swap_control");
763       __glXEnableDirectExtension(psc, "GLX_SGI_swap_control");
764       __glXEnableDirectExtension(psc, "GLX_MESA_swap_control");
765       __glXEnableDirectExtension(psc, "GLX_OML_sync_control");
766       __glXEnableDirectExtension(psc, "GLX_SGI_video_sync");
767       // for zink this needs to check whether RELAXED is available
768       if (psc->display->driver == GLX_DRIVER_DRI3)
769          __glXEnableDirectExtension(psc, "GLX_EXT_swap_control_tear");
770    }
771    if (psc->display->driver != GLX_DRIVER_ZINK_YES)
772       __glXEnableDirectExtension(psc, "GLX_MESA_copy_sub_buffer");
773    __glXEnableDirectExtension(psc, "GLX_SGI_make_current_read");
774 
775    if (psc->can_EXT_texture_from_pixmap)
776       __glXEnableDirectExtension(psc, "GLX_EXT_texture_from_pixmap");
777 
778    /*
779     * GLX_INTEL_swap_event is broken on the server side, where it's
780     * currently unconditionally enabled. This completely breaks
781     * systems running on drivers which don't support that extension.
782     * There's no way to test for its presence on this side, so instead
783     * of disabling it unconditionally, just disable it for drivers
784     * which are known to not support it.
785     *
786     * This was fixed in xserver 1.15.0 (190b03215), so now we only
787     * disable the broken driver.
788     */
789    if (!driverName || strcmp(driverName, "vmwgfx") != 0) {
790       __glXEnableDirectExtension(psc, "GLX_INTEL_swap_event");
791    }
792 
793    mask = driGetAPIMask(psc->frontend_screen);
794 
795    __glXEnableDirectExtension(psc, "GLX_ARB_create_context");
796    __glXEnableDirectExtension(psc, "GLX_ARB_create_context_profile");
797    __glXEnableDirectExtension(psc, "GLX_ARB_create_context_no_error");
798    __glXEnableDirectExtension(psc, "GLX_EXT_no_config_context");
799 
800    if ((mask & ((1 << __DRI_API_GLES) |
801                 (1 << __DRI_API_GLES2) |
802                 (1 << __DRI_API_GLES3))) != 0) {
803       __glXEnableDirectExtension(psc,
804                                  "GLX_EXT_create_context_es_profile");
805       __glXEnableDirectExtension(psc,
806                                  "GLX_EXT_create_context_es2_profile");
807    }
808 
809    if (dri_get_screen_param(psc->frontend_screen, PIPE_CAP_DEVICE_RESET_STATUS_QUERY))
810       __glXEnableDirectExtension(psc,
811                                  "GLX_ARB_create_context_robustness");
812 
813    __glXEnableDirectExtension(psc, "GLX_ARB_context_flush_control");
814    __glXEnableDirectExtension(psc, "GLX_MESA_query_renderer");
815 
816    __glXEnableDirectExtension(psc, "GLX_MESA_gl_interop");
817 
818    char *tmp;
819    if (dri2GalliumConfigQuerys(psc->frontend_screen, "glx_extension_override",
820                                     &tmp) == 0)
821       __glXParseExtensionOverride(psc, tmp);
822 
823    if (dri2GalliumConfigQuerys(psc->frontend_screen,
824                                     "indirect_gl_extension_override",
825                                     &tmp) == 0)
826       __IndirectGlParseExtensionOverride(psc, tmp);
827 
828    {
829       uint8_t force = false;
830       if (dri2GalliumConfigQueryb(psc->frontend_screen, "force_direct_glx_context",
831                                     &force) == 0) {
832          psc->force_direct_context = force;
833       }
834 
835       uint8_t invalid_glx_destroy_window = false;
836       if (dri2GalliumConfigQueryb(psc->frontend_screen,
837                                     "allow_invalid_glx_destroy_window",
838                                     &invalid_glx_destroy_window) == 0) {
839          psc->allow_invalid_glx_destroy_window = invalid_glx_destroy_window;
840       }
841 
842       uint8_t keep_native_window_glx_drawable = false;
843       if (dri2GalliumConfigQueryb(psc->frontend_screen,
844                                     "keep_native_window_glx_drawable",
845                                     &keep_native_window_glx_drawable) == 0) {
846          psc->keep_native_window_glx_drawable = keep_native_window_glx_drawable;
847       }
848    }
849 }
850 
851 
852 /*
853 ** Allocate the memory for the per screen configs for each screen.
854 ** If that works then fetch the per screen configs data.
855 */
856 static Bool
AllocAndFetchScreenConfigs(Display * dpy,struct glx_display * priv,enum glx_driver glx_driver,Bool driver_name_is_inferred)857 AllocAndFetchScreenConfigs(Display * dpy, struct glx_display * priv, enum glx_driver glx_driver, Bool driver_name_is_inferred)
858 {
859    struct glx_screen *psc;
860    GLint i, screens;
861    unsigned screen_count = 0;
862    bool zink = (glx_driver & (GLX_DRIVER_ZINK_INFER | GLX_DRIVER_ZINK_YES)) > 0;
863 
864    /*
865     ** First allocate memory for the array of per screen configs.
866     */
867    screens = ScreenCount(dpy);
868    priv->screens = calloc(screens, sizeof *priv->screens);
869    if (!priv->screens)
870       return GL_FALSE;
871 
872    for (i = 0; i < screens; i++) {
873       psc = NULL;
874 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
875 #if defined(GLX_USE_DRM)
876       if (glx_driver & GLX_DRIVER_DRI3) {
877          bool use_zink;
878          psc = dri3_create_screen(i, priv, driver_name_is_inferred, &use_zink);
879          if (use_zink) {
880             glx_driver |= GLX_DRIVER_ZINK_YES;
881             zink = true;
882             driver_name_is_inferred = false;
883          }
884       }
885 #if defined(HAVE_X11_DRI2)
886       if (psc == NULL && glx_driver & GLX_DRIVER_DRI2 && dri2CheckSupport(dpy)) {
887 	      psc = dri2CreateScreen(i, priv, driver_name_is_inferred);
888          if (psc)
889             priv->dri2Hash = __glxHashCreate();
890       }
891 #endif
892 #endif /* GLX_USE_DRM */
893 
894 #ifdef GLX_USE_WINDOWSGL
895       if (psc == NULL && glx_driver & GLX_DRIVER_WINDOWS) {
896 	      psc = driwindowsCreateScreen(i, priv, driver_name_is_inferred);
897       }
898 #endif
899 
900 #endif /* GLX_DIRECT_RENDERING && !GLX_USE_APPLEGL */
901 #if defined(GLX_DIRECT_RENDERING) && (!defined(GLX_USE_APPLEGL) || defined(GLX_USE_APPLE))
902       if (psc == NULL &&
903           (glx_driver & GLX_DRIVER_SW || zink)) {
904 	      psc = driswCreateScreen(i, priv, glx_driver, driver_name_is_inferred);
905       }
906 #endif
907 
908       bool indirect = false;
909 
910 #if defined(GLX_USE_APPLEGL) && !defined(GLX_USE_APPLE)
911       if (psc == NULL)
912          psc = applegl_create_screen(i, priv);
913 #else
914       if (psc == NULL && !zink)
915       {
916          psc = indirect_create_screen(i, priv);
917          indirect = true;
918       }
919 #endif
920       priv->screens[i] = psc;
921       if (psc)
922          screen_count++;
923 
924       if(indirect) /* Load extensions required only for indirect glx */
925          glxSendClientInfo(priv, i);
926       else if (priv->driver != GLX_DRIVER_WINDOWS)
927          bind_extensions(psc, psc->driverName);
928    }
929    if (zink && !screen_count)
930       return GL_FALSE;
931    SyncHandle();
932    return GL_TRUE;
933 }
934 
935 /*
936 ** Initialize the client side extension code.
937 */
938  _X_HIDDEN struct glx_display *
__glXInitialize(Display * dpy)939 __glXInitialize(Display * dpy)
940 {
941    XExtCodes *codes;
942    struct glx_display *dpyPriv, *d;
943    int i, majorVersion = 0;
944 
945    _XLockMutex(_Xglobal_lock);
946 
947    for (dpyPriv = glx_displays; dpyPriv; dpyPriv = dpyPriv->next) {
948       if (dpyPriv->dpy == dpy) {
949 	 _XUnlockMutex(_Xglobal_lock);
950 	 return dpyPriv;
951       }
952    }
953 
954    /* Drop the lock while we create the display private. */
955    _XUnlockMutex(_Xglobal_lock);
956 
957    dpyPriv = calloc(1, sizeof *dpyPriv);
958    if (!dpyPriv)
959       return NULL;
960 
961    codes = XInitExtension(dpy, __glXExtensionName);
962    if (!codes) {
963       free(dpyPriv);
964       return NULL;
965    }
966 
967    dpyPriv->codes = *codes;
968    dpyPriv->dpy = dpy;
969 
970    /* This GLX implementation requires GLX 1.3 */
971    if (!QueryVersion(dpy, dpyPriv->codes.major_opcode,
972 		     &majorVersion, &dpyPriv->minorVersion)
973        || (majorVersion != 1)
974        || (majorVersion == 1 && dpyPriv->minorVersion < 3)) {
975       free(dpyPriv);
976       return NULL;
977    }
978 
979    for (i = 0; i < __GLX_NUMBER_EVENTS; i++) {
980       XESetWireToEvent(dpy, dpyPriv->codes.first_event + i, __glXWireToEvent);
981       XESetEventToWire(dpy, dpyPriv->codes.first_event + i, __glXEventToWire);
982    }
983 
984    XESetCloseDisplay(dpy, dpyPriv->codes.extension, __glXCloseDisplay);
985    XESetErrorString (dpy, dpyPriv->codes.extension, __glXErrorString);
986 
987    dpyPriv->glXDrawHash = __glxHashCreate();
988 
989    enum glx_driver glx_driver = 0;
990    const char *env = getenv("MESA_LOADER_DRIVER_OVERRIDE");
991 
992 #if defined(GLX_DIRECT_RENDERING) && (!defined(GLX_USE_APPLEGL) || defined(GLX_USE_APPLE))
993    Bool glx_direct = !debug_get_bool_option("LIBGL_ALWAYS_INDIRECT", false);
994    Bool glx_accel = !debug_get_bool_option("LIBGL_ALWAYS_SOFTWARE", false);
995    Bool dri3 = !debug_get_bool_option("LIBGL_DRI3_DISABLE", false);
996    Bool kopper = !debug_get_bool_option("LIBGL_KOPPER_DISABLE", false);
997 
998    if (env && !strcmp(env, "zink"))
999       glx_driver |= GLX_DRIVER_ZINK_YES;
1000 
1001    dpyPriv->drawHash = __glxHashCreate();
1002 
1003    dpyPriv->zombieGLXDrawable = _mesa_pointer_set_create(NULL);
1004 
1005    /* Set the logger before the *CreateDisplay functions. */
1006    loader_set_logger(glx_message);
1007 
1008    /*
1009     ** Initialize the direct rendering per display data and functions.
1010     ** Note: This _must_ be done before calling any other DRI routines
1011     ** (e.g., those called in AllocAndFetchScreenConfigs).
1012     */
1013 #if defined(GLX_USE_DRM)
1014    bool dri3_err = false;
1015    if (glx_direct && glx_accel && dri3)
1016       dpyPriv->has_multibuffer = x11_dri3_check_multibuffer(XGetXCBConnection(dpy), &dri3_err, &dpyPriv->has_explicit_modifiers);
1017    if (glx_direct && glx_accel &&
1018        (!(glx_driver & GLX_DRIVER_ZINK_YES) || !kopper)) {
1019       if (dri3) {
1020          /* dri3 is tried as long as this doesn't error; whether modifiers work is not relevant */
1021          if (!dri3_err) {
1022             glx_driver |= GLX_DRIVER_DRI3;
1023             /* nouveau wants to fallback to zink so if we get a screen enable try_zink */
1024             if (!debug_get_bool_option("LIBGL_KOPPER_DISABLE", false))
1025                glx_driver |= GLX_DRIVER_ZINK_INFER;
1026          }
1027       }
1028 #if defined(HAVE_X11_DRI2)
1029       if (!debug_get_bool_option("LIBGL_DRI2_DISABLE", false))
1030          glx_driver |= GLX_DRIVER_DRI2;
1031 #endif
1032 #if defined(HAVE_ZINK)
1033       if (!(glx_driver & (GLX_DRIVER_DRI2 | GLX_DRIVER_DRI3)))
1034          if (kopper && !getenv("GALLIUM_DRIVER"))
1035             glx_driver |= GLX_DRIVER_ZINK_INFER;
1036 #endif /* HAVE_ZINK */
1037    }
1038 #endif /* GLX_USE_DRM */
1039    if (glx_direct)
1040       glx_driver |= GLX_DRIVER_SW;
1041 
1042    if (!dpyPriv->has_explicit_modifiers && glx_accel && !debug_get_bool_option("LIBGL_KOPPER_DRI2", false)) {
1043       if (glx_driver & GLX_DRIVER_ZINK_YES) {
1044          /* only print error if zink was explicitly requested */
1045          CriticalErrorMessageF("DRI3 not available\n");
1046          free(dpyPriv);
1047          return NULL;
1048       }
1049       /* if no dri3 and not using dri2, disable zink */
1050       glx_driver &= ~GLX_DRIVER_ZINK_INFER;
1051    }
1052 
1053 #ifdef GLX_USE_WINDOWSGL
1054    if (glx_direct && glx_accel)
1055       glx_driver |= GLX_DRIVER_WINDOWS;
1056 #else
1057 #ifndef RTLD_NOW
1058 #define RTLD_NOW 0
1059 #endif
1060 #ifndef RTLD_GLOBAL
1061 #define RTLD_GLOBAL 0
1062 #endif
1063 
1064 #ifndef GL_LIB_NAME
1065 #define GL_LIB_NAME "libGL.so.1"
1066 #endif
1067 
1068    void *glhandle = dlopen(GL_LIB_NAME, RTLD_NOW | RTLD_GLOBAL);
1069    if (glhandle)
1070       dlclose(glhandle);
1071 
1072 #endif
1073 #endif /* GLX_DIRECT_RENDERING && !GLX_USE_APPLEGL */
1074 
1075 #if defined(GLX_USE_APPLEGL) && !defined(GLX_USE_APPLE)
1076    glx_driver |= GLX_DRIVER_SW;
1077 #endif
1078 
1079    if (!AllocAndFetchScreenConfigs(dpy, dpyPriv, glx_driver, !env)) {
1080       Bool fail = True;
1081 #if defined(GLX_DIRECT_RENDERING) && (!defined(GLX_USE_APPLEGL) || defined(GLX_USE_APPLE))
1082       if (glx_driver & GLX_DRIVER_ZINK_INFER) {
1083          fail = !AllocAndFetchScreenConfigs(dpy, dpyPriv, GLX_DRIVER_SW, true);
1084       }
1085 #endif
1086       if (fail) {
1087          free(dpyPriv);
1088          return NULL;
1089       }
1090    }
1091 
1092    glxSendClientInfo(dpyPriv, -1);
1093 
1094    /* Grab the lock again and add the display private, unless somebody
1095     * beat us to initializing on this display in the meantime. */
1096    _XLockMutex(_Xglobal_lock);
1097 
1098    for (d = glx_displays; d; d = d->next) {
1099       if (d->dpy == dpy) {
1100 	 _XUnlockMutex(_Xglobal_lock);
1101 	 glx_display_free(dpyPriv);
1102 	 return d;
1103       }
1104    }
1105 
1106    dpyPriv->next = glx_displays;
1107    glx_displays = dpyPriv;
1108 
1109    _XUnlockMutex(_Xglobal_lock);
1110 
1111    return dpyPriv;
1112 }
1113 
1114 /*
1115 ** Setup for sending a GLX command on dpy.  Make sure the extension is
1116 ** initialized.  Try to avoid calling __glXInitialize as its kinda slow.
1117 */
1118 _X_HIDDEN CARD8
__glXSetupForCommand(Display * dpy)1119 __glXSetupForCommand(Display * dpy)
1120 {
1121     struct glx_context *gc;
1122     struct glx_display *priv;
1123 
1124    /* If this thread has a current context, flush its rendering commands */
1125    gc = __glXGetCurrentContext();
1126    if (gc->currentDpy) {
1127       /* Flush rendering buffer of the current context, if any */
1128       (void) __glXFlushRenderBuffer(gc, gc->pc);
1129 
1130       if (gc->currentDpy == dpy) {
1131          /* Use opcode from gc because its right */
1132          return gc->majorOpcode;
1133       }
1134       else {
1135          /*
1136           ** Have to get info about argument dpy because it might be to
1137           ** a different server
1138           */
1139       }
1140    }
1141 
1142    /* Forced to lookup extension via the slow initialize route */
1143    priv = __glXInitialize(dpy);
1144    if (!priv) {
1145       return 0;
1146    }
1147    return priv->codes.major_opcode;
1148 }
1149 
1150 /**
1151  * Flush the drawing command transport buffer.
1152  *
1153  * \param ctx  Context whose transport buffer is to be flushed.
1154  * \param pc   Pointer to first unused buffer location.
1155  *
1156  * \todo
1157  * Modify this function to use \c ctx->pc instead of the explicit
1158  * \c pc parameter.
1159  */
1160 _X_HIDDEN GLubyte *
__glXFlushRenderBuffer(struct glx_context * ctx,GLubyte * pc)1161 __glXFlushRenderBuffer(struct glx_context * ctx, GLubyte * pc)
1162 {
1163    Display *const dpy = ctx->currentDpy;
1164    xcb_connection_t *c = XGetXCBConnection(dpy);
1165    const GLint size = pc - ctx->buf;
1166 
1167    if ((dpy != NULL) && (size > 0)) {
1168       xcb_glx_render(c, ctx->currentContextTag, size,
1169                      (const uint8_t *) ctx->buf);
1170    }
1171 
1172    /* Reset pointer and return it */
1173    ctx->pc = ctx->buf;
1174    return ctx->pc;
1175 }
1176 
1177 
1178 /**
1179  * Send a portion of a GLXRenderLarge command to the server.  The advantage of
1180  * this function over \c __glXSendLargeCommand is that callers can use the
1181  * data buffer in the GLX context and may be able to avoid allocating an
1182  * extra buffer.  The disadvantage is the clients will have to do more
1183  * GLX protocol work (i.e., calculating \c totalRequests, etc.).
1184  *
1185  * \sa __glXSendLargeCommand
1186  *
1187  * \param gc             GLX context
1188  * \param requestNumber  Which part of the whole command is this?  The first
1189  *                       request is 1.
1190  * \param totalRequests  How many requests will there be?
1191  * \param data           Command data.
1192  * \param dataLen        Size, in bytes, of the command data.
1193  */
1194 _X_HIDDEN void
__glXSendLargeChunk(struct glx_context * gc,GLint requestNumber,GLint totalRequests,const GLvoid * data,GLint dataLen)1195 __glXSendLargeChunk(struct glx_context * gc, GLint requestNumber,
1196                     GLint totalRequests, const GLvoid * data, GLint dataLen)
1197 {
1198    Display *dpy = gc->currentDpy;
1199    xcb_connection_t *c = XGetXCBConnection(dpy);
1200    xcb_glx_render_large(c, gc->currentContextTag, requestNumber,
1201                         totalRequests, dataLen, data);
1202 }
1203 
1204 
1205 /**
1206  * Send a command that is too large for the GLXRender protocol request.
1207  *
1208  * Send a large command, one that is too large for some reason to
1209  * send using the GLXRender protocol request.  One reason to send
1210  * a large command is to avoid copying the data.
1211  *
1212  * \param ctx        GLX context
1213  * \param header     Header data.
1214  * \param headerLen  Size, in bytes, of the header data.  It is assumed that
1215  *                   the header data will always be small enough to fit in
1216  *                   a single X protocol packet.
1217  * \param data       Command data.
1218  * \param dataLen    Size, in bytes, of the command data.
1219  */
1220 _X_HIDDEN void
__glXSendLargeCommand(struct glx_context * ctx,const GLvoid * header,GLint headerLen,const GLvoid * data,GLint dataLen)1221 __glXSendLargeCommand(struct glx_context * ctx,
1222                       const GLvoid * header, GLint headerLen,
1223                       const GLvoid * data, GLint dataLen)
1224 {
1225    GLint maxSize;
1226    GLint totalRequests, requestNumber;
1227 
1228    /*
1229     ** Calculate the maximum amount of data can be stuffed into a single
1230     ** packet.  sz_xGLXRenderReq is added because bufSize is the maximum
1231     ** packet size minus sz_xGLXRenderReq.
1232     */
1233    maxSize = (ctx->bufSize + sz_xGLXRenderReq) - sz_xGLXRenderLargeReq;
1234    totalRequests = 1 + (dataLen / maxSize);
1235    if (dataLen % maxSize)
1236       totalRequests++;
1237 
1238    /*
1239     ** Send all of the command, except the large array, as one request.
1240     */
1241    assert(headerLen <= maxSize);
1242    __glXSendLargeChunk(ctx, 1, totalRequests, header, headerLen);
1243 
1244    /*
1245     ** Send enough requests until the whole array is sent.
1246     */
1247    for (requestNumber = 2; requestNumber <= (totalRequests - 1);
1248         requestNumber++) {
1249       __glXSendLargeChunk(ctx, requestNumber, totalRequests, data, maxSize);
1250       data = (const GLvoid *) (((const GLubyte *) data) + maxSize);
1251       dataLen -= maxSize;
1252       assert(dataLen > 0);
1253    }
1254 
1255    assert(dataLen <= maxSize);
1256    __glXSendLargeChunk(ctx, requestNumber, totalRequests, data, dataLen);
1257 }
1258