src/glx/create_context.c

   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
  37 glXCreateContextAttribsARB(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 #ifdef GLX_USE_APPLEGL
  85       gc = applegl_create_context(psc, cfg, share, 0);
  86 #else
  87       gc = indirect_create_context_attribs(psc, cfg, share, num_attribs,
  88               (const uint32_t *) attrib_list,
  89               &dummy_err);
  90 #endif
  91    }
  92
  93    gc->xid = xcb_generate_id(c);
  94    gc->share_xid = (share != NULL) ? share->xid : 0;
  95
  96    /* The manual pages for glXCreateContext and glXCreateNewContext say:
  97     *
  98     *     "NULL is returned if execution fails on the client side."
  99     *
 100     * If the server generates an error, the application is supposed to catch
 101     * the protocol error and handle it.  Part of handling the error is freeing
 102     * the possibly non-NULL value returned by this function.
 103     */
 104    cookie =
 105       xcb_glx_create_context_attribs_arb_checked(c,
 106                                                  gc->xid,
 107                                                  cfg->fbconfigID,
 108                                                  cfg->screen,
 109                                                  gc->share_xid,
 110                                                  gc->isDirect,
 111                                                  num_attribs,
 112                                                  (const uint32_t *)
 113                                                  attrib_list);
 114    err = xcb_request_check(c, cookie);
 115    if (err != NULL) {
 116       gc->vtable->destroy(gc);
 117       gc = NULL;
 118
 119       __glXSendErrorForXcb(dpy, err);
 120       free(err);
 121    }
 122
 123    return (GLXContext) gc;
 124 }