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 _eglGetDriver(void)
  53 {
  54    return &_eglDriver;
  55 }
  56
  57 static _EGLDriver *
  58 _eglMatchAndInitialize(_EGLDisplay *disp)
  59 {
  60    if (_eglGetDriver())
  61       if (_eglDriver.Initialize(&_eglDriver, disp))
  62          return &_eglDriver;
  63
  64    return NULL;
  65 }
  66
  67 /**
  68  * Match a display to a driver.  The matching is done by finding the first
  69  * driver that can initialize the display.
  70  */
  71 _EGLDriver *
  72 _eglMatchDriver(_EGLDisplay *disp)
  73 {
  74    _EGLDriver *best_drv;
  75
  76    assert(!disp->Initialized);
  77
  78    /* set options */
  79    disp->Options.ForceSoftware =
  80       env_var_as_boolean("LIBGL_ALWAYS_SOFTWARE", false);
  81    if (disp->Options.ForceSoftware)
  82       _eglLog(_EGL_DEBUG, "Found 'LIBGL_ALWAYS_SOFTWARE' set, will use a CPU renderer");
  83
  84    best_drv = _eglMatchAndInitialize(disp);
  85    if (!best_drv && !disp->Options.ForceSoftware) {
  86       disp->Options.ForceSoftware = EGL_TRUE;
  87       best_drv = _eglMatchAndInitialize(disp);
  88    }
  89
  90    if (best_drv) {
  91       disp->Driver = best_drv;
  92       disp->Initialized = EGL_TRUE;
  93    }
  94
  95    return best_drv;
  96 }
  97
  98 __eglMustCastToProperFunctionPointerType
  99 _eglGetDriverProc(const char *procname)
 100 {
 101    if (_eglGetDriver() && _eglDriver.GetProcAddress)
 102       return _eglDriver.GetProcAddress(&_eglDriver, procname);
 103
 104    return NULL;
 105 }