src/glx/x11/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,
  47                        int opcode,
  48                        CARD32 screen,
  49                        CARD32 name)
  50 {
  51    xcb_connection_t *c = XGetXCBConnection(dpy);
  52    xcb_glx_query_server_string_reply_t* reply =
  53       xcb_glx_query_server_string_reply(c,
  54                                         xcb_glx_query_server_string(c,
  55                                                                     screen,
  56                                                                     name),
  57                                         NULL);
  58
  59    /* The spec doesn't mention this, but the Xorg server replies with
  60     * a string already terminated with '\0'. */
  61    uint32_t len = xcb_glx_query_server_string_string_length(reply);
  62    char* buf = Xmalloc(len);
  63    memcpy(buf, xcb_glx_query_server_string_string(reply), len);
  64    free(reply);
  65
  66    return buf;
  67 }
  68
  69 /**
  70  * Exchange a protocol request for glGetString.
  71  */
  72 char *
  73 __glXGetString(Display* dpy,
  74                int opcode,
  75                CARD32 contextTag,
  76                CARD32 name)
  77 {
  78    xcb_connection_t *c = XGetXCBConnection(dpy);
  79    xcb_glx_get_string_reply_t* reply =
  80       xcb_glx_get_string_reply(c,
  81                                xcb_glx_get_string(c,
  82                                                   contextTag,
  83                                                   name),
  84                                NULL);
  85
  86    /* The spec doesn't mention this, but the Xorg server replies with
  87     * a string already terminated with '\0'. */
  88    uint32_t len = xcb_glx_get_string_string_length(reply);
  89    char* buf = Xmalloc(len);
  90    memcpy(buf, xcb_glx_get_string_string(reply), len);
  91    free(reply);
  92
  93    return buf;
  94 }
  95
  96 #else
  97
  98 /**
  99  * GLX protocol structure for the ficticious "GXLGenericGetString" request.
 100  *
 101  * This is a non-existant protocol packet.  It just so happens that all of
 102  * the real protocol packets used to request a string from the server have
 103  * an identical binary layout.  The only difference between them is the
 104  * meaning of the \c for_whom field and the value of the \c glxCode.
 105  */
 106 typedef struct GLXGenericGetString
 107 {
 108    CARD8 reqType;
 109    CARD8 glxCode;
 110    CARD16 length B16;
 111    CARD32 for_whom B32;
 112    CARD32 name B32;
 113 } xGLXGenericGetStringReq;
 114
 115 /* These defines are only needed to make the GetReq macro happy.
 116  */
 117 #define sz_xGLXGenericGetStringReq 12
 118 #define X_GLXGenericGetString 0
 119
 120 /**
 121  * Query the Server GLX string.
 122  * This routine will allocate the necessay space for the string.
 123  */
 124 static char *
 125 __glXGetStringFromServer(Display * dpy, int opcode, CARD32 glxCode,
 126                          CARD32 for_whom, CARD32 name)
 127 {
 128    xGLXGenericGetStringReq *req;
 129    xGLXSingleReply reply;
 130    int length;
 131    int numbytes;
 132    char *buf;
 133
 134
 135    LockDisplay(dpy);
 136
 137
 138    /* All of the GLX protocol requests for getting a string from the server
 139     * look the same.  The exact meaning of the for_whom field is usually
 140     * either the screen number (for glXQueryServerString) or the context tag
 141     * (for GLXSingle).
 142     */
 143
 144    GetReq(GLXGenericGetString, req);
 145    req->reqType = opcode;
 146    req->glxCode = glxCode;
 147    req->for_whom = for_whom;
 148    req->name = name;
 149
 150    _XReply(dpy, (xReply *) & reply, 0, False);
 151
 152    length = reply.length * 4;
 153    numbytes = reply.size;
 154
 155    buf = (char *) Xmalloc(numbytes);
 156    if (buf != NULL) {
 157       _XRead(dpy, buf, numbytes);
 158       length -= numbytes;
 159    }
 160
 161    _XEatData(dpy, length);
 162
 163    UnlockDisplay(dpy);
 164    SyncHandle();
 165
 166    return buf;
 167 }
 168
 169 char *
 170 __glXQueryServerString(Display* dpy,
 171                        int opcode,
 172                        CARD32 screen,
 173                        CARD32 name)
 174 {
 175    return __glXGetStringFromServer(dpy, opcode,
 176                                    X_GLXQueryServerString,
 177                                    screen, name);
 178 }
 179
 180 char *
 181 __glXGetString(Display* dpy,
 182                int opcode,
 183                CARD32 contextTag,
 184                CARD32 name)
 185 {
 186    return __glXGetStringFromServer(dpy, opcode, X_GLsop_GetString,
 187                                    contextTag, name);
 188 }
 189
 190 #endif /* USE_XCB */
 191