src/egl/main/egldriver.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 VMware, Inc.
   4  * Copyright 2009-2010 Chia-I Wu <olvaffe@gmail.com>
   5  * Copyright 2010-2011 LunarG, Inc.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the
  10  * "Software"), to deal in the Software without restriction, including
  11  * without limitation the rights to use, copy, modify, merge, publish,
  12  * distribute, sub license, and/or sell copies of the Software, and to
  13  * permit persons to whom the Software is furnished to do so, subject to
  14  * the following conditions:
  15  *
  16  * The above copyright notice and this permission notice (including the
  17  * next paragraph) shall be included in all copies or substantial portions
  18  * of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  25  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  26  * DEALINGS IN THE SOFTWARE.
  27  *
  28  **************************************************************************/
  29
  30
  31 /**
  32  * Functions for choosing and opening/loading device drivers.
  33  */
  34
  35
  36 #include <assert.h>
  37 #include <string.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include "c11/threads.h"
  41
  42 #include "egldefines.h"
  43 #include "egldisplay.h"
  44 #include "egldriver.h"
  45 #include "egllog.h"
  46
  47 #include "util/debug.h"
  48
  49 extern _EGLDriver _eglDriver;
  50
  51 static _EGLDriver *
  52 _eglMatchAndInitialize(_EGLDisplay *disp)
  53 {
  54    if (_eglDriver.Initialize(&_eglDriver, disp))
  55       return &_eglDriver;
  56
  57    return NULL;
  58 }
  59
  60 /**
  61  * Match a display to a driver.  The matching is done by finding the first
  62  * driver that can initialize the display.
  63  */
  64 bool
  65 _eglMatchDriver(_EGLDisplay *disp)
  66 {
  67    _EGLDriver *best_drv;
  68
  69    assert(!disp->Initialized);
  70
  71    /* set options */
  72    disp->Options.ForceSoftware =
  73       env_var_as_boolean("LIBGL_ALWAYS_SOFTWARE", false);
  74    if (disp->Options.ForceSoftware)
  75       _eglLog(_EGL_DEBUG, "Found 'LIBGL_ALWAYS_SOFTWARE' set, will use a CPU renderer");
  76
  77    best_drv = _eglMatchAndInitialize(disp);
  78    if (!best_drv && !disp->Options.ForceSoftware) {
  79       disp->Options.ForceSoftware = EGL_TRUE;
  80       best_drv = _eglMatchAndInitialize(disp);
  81    }
  82
  83    if (best_drv) {
  84       disp->Driver = best_drv;
  85       disp->Initialized = EGL_TRUE;
  86    }
  87
  88    return best_drv != NULL;
  89 }
  90
  91 __eglMustCastToProperFunctionPointerType
  92 _eglGetDriverProc(const char *procname)
  93 {
  94    if (_eglDriver.GetProcAddress)
  95       return _eglDriver.GetProcAddress(&_eglDriver, procname);
  96
  97    return NULL;
  98 }