src/glx/glx_query.c

   1 /*
   2  * (C) Copyright IBM Corporation 2004
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * the Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  19  * IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file glx_query.c
  27  * Generic utility functions to query internal data from the server.
  28  *
  29  * \author Ian Romanick <idr@us.ibm.com>
  30  */
  31
  32 #include "glxclient.h"
  33
  34 #if defined(USE_XCB)
  35 # include <X11/Xlib-xcb.h>
  36 # include <xcb/xcb.h>
  37 # include <xcb/glx.h>
  38 #endif
  39
  40 #ifdef USE_XCB
  41
  42 /**
  43  * Exchange a protocol request for glXQueryServerString.
  44  */
  45 char *
  46 __glXQueryServerString(Display * dpy, int opcode, CARD32 screen, CARD32 name)
  47 {
  48    xcb_connection_t *c = XGetXCBConnection(dpy);
  49    xcb_glx_query_server_string_reply_t *reply =
  50       xcb_glx_query_server_string_reply(c,
  51                                         xcb_glx_query_server_string(c,
  52                                                                     screen,
  53                                                                     name),
  54                                         NULL);
  55
  56    /* The spec doesn't mention this, but the Xorg server replies with
  57     * a string already terminated with '\0'. */
  58    uint32_t len = xcb_glx_query_server_string_string_length(reply);
  59    char *buf = Xmalloc(len);
  60    memcpy(buf, xcb_glx_query_server_string_string(reply), len);
  61    free(reply);
  62
  63    return buf;
  64 }
  65
  66 /**
  67  * Exchange a protocol request for glGetString.
  68  */
  69 char *
  70 __glXGetString(Display * dpy, int opcode, CARD32 contextTag, CARD32 name)
  71 {
  72    xcb_connection_t *c = XGetXCBConnection(dpy);
  73    xcb_glx_get_string_reply_t *reply = xcb_glx_get_string_reply(c,
  74                                                                 xcb_glx_get_string
  75                                                                 (c,
  76                                                                  contextTag,
  77                                                                  name),
  78                                                                 NULL);
  79
  80    /* The spec doesn't mention this, but the Xorg server replies with
  81     * a string already terminated with '\0'. */
  82    uint32_t len = xcb_glx_get_string_string_length(reply);
  83    char *buf = Xmalloc(len);
  84    memcpy(buf, xcb_glx_get_string_string(reply), len);
  85    free(reply);
  86
  87    return buf;
  88 }
  89
  90 #else
  91
  92 /**
  93  * GLX protocol structure for the ficticious "GXLGenericGetString" request.
  94  *
  95  * This is a non-existant protocol packet.  It just so happens that all of
  96  * the real protocol packets used to request a string from the server have
  97  * an identical binary layout.  The only difference between them is the
  98  * meaning of the \c for_whom field and the value of the \c glxCode.
  99  */
 100 typedef struct GLXGenericGetString
 101 {
 102    CARD8 reqType;
 103    CARD8 glxCode;
 104    CARD16 length B16;
 105    CARD32 for_whom B32;
 106    CARD32 name B32;
 107 } xGLXGenericGetStringReq;
 108
 109 /* These defines are only needed to make the GetReq macro happy.
 110  */
 111 #define sz_xGLXGenericGetStringReq 12
 112 #define X_GLXGenericGetString 0
 113
 114 /**
 115  * Query the Server GLX string.
 116  * This routine will allocate the necessay space for the string.
 117  */
 118 static char *
 119 __glXGetStringFromServer(Display * dpy, int opcode, CARD32 glxCode,
 120                          CARD32 for_whom, CARD32 name)
 121 {
 122    xGLXGenericGetStringReq *req;
 123    xGLXSingleReply reply;
 124    int length;
 125    int numbytes;
 126    char *buf;
 127
 128
 129    LockDisplay(dpy);
 130
 131
 132    /* All of the GLX protocol requests for getting a string from the server
 133     * look the same.  The exact meaning of the for_whom field is usually
 134     * either the screen number (for glXQueryServerString) or the context tag
 135     * (for GLXSingle).
 136     */
 137
 138    GetReq(GLXGenericGetString, req);
 139    req->reqType = opcode;
 140    req->glxCode = glxCode;
 141    req->for_whom = for_whom;
 142    req->name = name;
 143
 144    _XReply(dpy, (xReply *) & reply, 0, False);
 145
 146    length = reply.length * 4;
 147    numbytes = reply.size;
 148
 149    buf = (char *) Xmalloc(numbytes);
 150    if (buf != NULL) {
 151       _XRead(dpy, buf, numbytes);
 152       length -= numbytes;
 153    }
 154
 155    _XEatData(dpy, length);
 156
 157    UnlockDisplay(dpy);
 158    SyncHandle();
 159
 160    return buf;
 161 }
 162
 163 char *
 164 __glXQueryServerString(Display * dpy, int opcode, CARD32 screen, CARD32 name)
 165 {
 166    return __glXGetStringFromServer(dpy, opcode,
 167                                    X_GLXQueryServerString, screen, name);
 168 }
 169
 170 char *
 171 __glXGetString(Display * dpy, int opcode, CARD32 contextTag, CARD32 name)
 172 {
 173    return __glXGetStringFromServer(dpy, opcode, X_GLsop_GetString,
 174                                    contextTag, name);
 175 }
 176
 177 #endif /* USE_XCB */