win32ss/gdi/gdi32/misc/wingl.c

   1 /*
   2  *  ReactOS Gdi32
   3  *  Copyright (C) 2003 ReactOS Team
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18  *
  19  *
  20  *
  21  *
  22  */
  23
  24 #include <precomp.h>
  25
  26 #define NDEBUG
  27 #include <debug.h>
  28
  29
  30
  31 typedef int  (WINAPI *CHOOSEPIXELFMT) (HDC, CONST PIXELFORMATDESCRIPTOR *);
  32 typedef BOOL (WINAPI *SETPIXELFMT) (HDC, int, CONST PIXELFORMATDESCRIPTOR *);
  33 typedef BOOL (WINAPI *SWAPBUFFERS) (HDC hdc);
  34 typedef int  (WINAPI *DESCRIBEPIXELFMT) (HDC, int, UINT, LPPIXELFORMATDESCRIPTOR);
  35 typedef int  (WINAPI *GETPIXELFMT) (HDC);
  36
  37
  38 static CHOOSEPIXELFMT    glChoosePixelFormat   = NULL;
  39 static SETPIXELFMT       glSetPixelFormat      = NULL;
  40 static SWAPBUFFERS       glSwapBuffers         = NULL;
  41 static DESCRIBEPIXELFMT  glDescribePixelFormat = NULL;
  42 static GETPIXELFMT       glGetPixelFormat      = NULL;
  43
  44 /*
  45                 OpenGL Handle.
  46 */
  47 HINSTANCE                hOpenGL               = NULL;
  48
  49 static BOOL OpenGLInitFunction(PCSTR name,
  50                                FARPROC *funcptr)
  51 {
  52     PVOID func;
  53
  54     func = (PVOID)GetProcAddress(hOpenGL, name);
  55     if (func != NULL)
  56     {
  57         (void)InterlockedCompareExchangePointer((PVOID*)funcptr,
  58                                                 func,
  59                                                 NULL);
  60         return TRUE;
  61     }
  62
  63     return FALSE;
  64 }
  65
  66 static BOOL OpenGLEnable(void)
  67 {
  68     HMODULE hModOpengl32;
  69     BOOL Ret = TRUE;
  70
  71     hModOpengl32 = LoadLibraryW(L"OPENGL32.DLL");
  72     if (hModOpengl32 == NULL)
  73         return FALSE;
  74
  75     if (InterlockedCompareExchangePointer((PVOID*)&hOpenGL,
  76                                           (PVOID)hModOpengl32,
  77                                           NULL) != NULL)
  78     {
  79         FreeLibrary(hModOpengl32);
  80
  81         /* NOTE: Even though another thread was faster loading the
  82                  library we can't just bail out here. We really need
  83                  to *try* to locate every function. This is slow but
  84                  thread-safe */
  85     }
  86
  87
  88     if (!OpenGLInitFunction("wglChoosePixelFormat", &glChoosePixelFormat))
  89         Ret = FALSE;
  90
  91     if (!OpenGLInitFunction("wglSetPixelFormat", &glSetPixelFormat))
  92         Ret = FALSE;
  93
  94     if (!OpenGLInitFunction("wglSwapBuffers", &glSwapBuffers))
  95         Ret = FALSE;
  96
  97     if (!OpenGLInitFunction("wglDescribePixelFormat", &glDescribePixelFormat))
  98         Ret = FALSE;
  99
 100     if (!OpenGLInitFunction("wglGetPixelFormat", &glGetPixelFormat))
 101         Ret = FALSE;
 102
 103     return Ret;
 104 }
 105
 106
 107
 108 /*
 109  * @implemented
 110  */
 111 INT
 112 WINAPI
 113 ChoosePixelFormat(HDC  hdc,
 114                   CONST PIXELFORMATDESCRIPTOR * ppfd)
 115 {
 116     if (glChoosePixelFormat == NULL)
 117         if (OpenGLEnable() == FALSE)
 118             return(0);
 119
 120     return(glChoosePixelFormat(hdc, ppfd));
 121 }
 122
 123
 124
 125 /*
 126  * @implemented
 127  */
 128 INT
 129 WINAPI
 130 DescribePixelFormat(HDC  hdc,
 131                     INT  iPixelFormat,
 132                     UINT  nBytes,
 133                     LPPIXELFORMATDESCRIPTOR  ppfd)
 134 {
 135     if (glDescribePixelFormat == NULL)
 136         if (OpenGLEnable() == FALSE)
 137             return(0);
 138
 139     return(glDescribePixelFormat(hdc, iPixelFormat, nBytes, ppfd));
 140 }
 141
 142
 143
 144 /*
 145  * @implemented
 146  */
 147 INT
 148 WINAPI
 149 GetPixelFormat(HDC  hdc)
 150 {
 151     if (glGetPixelFormat == NULL)
 152         if (OpenGLEnable() == FALSE)
 153             return(0);
 154
 155     return(glGetPixelFormat(hdc));
 156 }
 157
 158
 159
 160 /*
 161  * @implemented
 162  */
 163 BOOL
 164 WINAPI
 165 SetPixelFormat(HDC  hdc,
 166                INT  iPixelFormat,
 167                CONST PIXELFORMATDESCRIPTOR * ppfd)
 168 {
 169     /* Can only be set once */
 170     INT current = GetPixelFormat(hdc);
 171     if(current) return current == iPixelFormat ;
 172
 173     if (glSetPixelFormat == NULL)
 174         if (OpenGLEnable() == FALSE)
 175             return(0);
 176
 177     return(glSetPixelFormat(hdc, iPixelFormat, ppfd));
 178 }
 179
 180
 181
 182 /*
 183  * @implemented
 184  */
 185 BOOL
 186 WINAPI
 187 SwapBuffers(HDC  hdc)
 188 {
 189     if (glSwapBuffers == NULL)
 190         if (OpenGLEnable() == FALSE)
 191             return(0);
 192
 193
 194     return(glSwapBuffers(hdc));
 195 }
 196
 197
 198 /*
 199         Do this here for now.
 200 */
 201
 202 /* EOF */