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      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 }
    125