create_context.c revision 588042a8ec4ea91a952c07a0768516fd590758f4 
1/*
2 * Copyright © 2011 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24#include <limits.h>
25#include "glxclient.h"
26#include "glx_error.h"
27#include <xcb/glx.h>
28#include <X11/Xlib-xcb.h>
29
30#include <assert.h>
31
32#if INT_MAX != 2147483647
33#error This code requires sizeof(uint32_t) == sizeof(int).
34#endif
35
36_X_HIDDEN GLXContext
37glXCreateContextAttribsARB(Display *dpy, GLXFBConfig config,
38			   GLXContext share_context, Bool direct,
39			   const int *attrib_list)
40{
41   xcb_connection_t *const c = XGetXCBConnection(dpy);
42   struct glx_config *const cfg = (struct glx_config *) config;
43   struct glx_context *const share = (struct glx_context *) share_context;
44   struct glx_context *gc = NULL;
45   unsigned num_attribs = 0;
46   struct glx_screen *psc;
47   xcb_generic_error_t *err;
48   xcb_void_cookie_t cookie;
49   unsigned dummy_err = 0;
50
51
52   if (dpy == NULL || cfg == NULL)
53      return NULL;
54
55   /* This means that either the caller passed the wrong display pointer or
56    * one of the internal GLX data structures (probably the fbconfig) has an
57    * error.  There is nothing sensible to do, so return an error.
58    */
59   psc = GetGLXScreenConfigs(dpy, cfg->screen);
60   if (psc == NULL)
61      return NULL;
62
63   assert(cfg->screen == psc->scr);
64
65   /* Count the number of attributes specified by the application.  All
66    * attributes appear in pairs, except the terminating None.
67    */
68   if (attrib_list != NULL) {
69      for (/* empty */; attrib_list[num_attribs * 2] != 0; num_attribs++)
70	 /* empty */ ;
71   }
72
73   if (direct && psc->vtable->create_context_attribs) {
74      /* GLX drops the error returned by the driver.  The expectation is that
75       * an error will also be returned by the server.  The server's error
76       * will be delivered to the application.
77       */
78      gc = psc->vtable->create_context_attribs(psc, cfg, share, num_attribs,
79					       (const uint32_t *) attrib_list,
80					       &dummy_err);
81   }
82
83   if (gc == NULL)
84      gc = indirect_create_context(psc, cfg, share, 0);
85
86   gc->xid = xcb_generate_id(c);
87   gc->share_xid = (share != NULL) ? share->xid : 0;
88
89   /* The manual pages for glXCreateContext and glXCreateNewContext say:
90    *
91    *     "NULL is returned if execution fails on the client side."
92    *
93    * If the server generates an error, the application is supposed to catch
94    * the protocol error and handle it.  Part of handling the error is freeing
95    * the possibly non-NULL value returned by this function.
96    */
97   cookie =
98      xcb_glx_create_context_attribs_arb_checked(c,
99						 gc->xid,
100						 cfg->fbconfigID,
101						 cfg->screen,
102						 gc->share_xid,
103						 gc->isDirect,
104						 num_attribs,
105						 (const uint32_t *)
106						 attrib_list);
107   err = xcb_request_check(c, cookie);
108   if (err != NULL) {
109      gc->vtable->destroy(gc);
110      gc = NULL;
111
112      __glXSendErrorForXcb(dpy, err);
113      free(err);
114   }
115
116   return (GLXContext) gc;
117}
118