dlls/opengl32/wgl.c

   1 /* Window-specific OpenGL functions implementation.
   2  *
   3  * Copyright (c) 1999 Lionel Ulmer
   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include "config.h"
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include "windef.h"
  26 #include "winbase.h"
  27 #include "winuser.h"
  28 #include "winerror.h"
  29
  30 #include "wgl.h"
  31 #include "opengl_ext.h"
  32 #include "wine/debug.h"
  33 #include "wine/port.h"
  34
  35 WINE_DEFAULT_DEBUG_CHANNEL(opengl);
  36
  37 /* x11drv GDI escapes */
  38 #define X11DRV_ESCAPE 6789
  39 enum x11drv_escape_codes
  40 {
  41     X11DRV_GET_DISPLAY,   /* get X11 display for a DC */
  42     X11DRV_GET_DRAWABLE,  /* get current drawable for a DC */
  43     X11DRV_GET_FONT,      /* get current X font for a DC */
  44 };
  45
  46 void (*wine_tsx11_lock_ptr)(void) = NULL;
  47 void (*wine_tsx11_unlock_ptr)(void) = NULL;
  48
  49 static GLXContext default_cx = NULL;
  50 static Display *default_display;  /* display to use for default context */
  51
  52 static void *(*p_glXGetProcAddressARB)(const GLubyte *);
  53
  54 typedef struct wine_glcontext {
  55   HDC hdc;
  56   Display *display;
  57   GLXContext ctx;
  58   XVisualInfo *vis;
  59   struct wine_glcontext *next;
  60   struct wine_glcontext *prev;
  61 } Wine_GLContext;
  62 static Wine_GLContext *context_list;
  63
  64 static inline Wine_GLContext *get_context_from_GLXContext(GLXContext ctx)
  65 {
  66     Wine_GLContext *ret;
  67     for (ret = context_list; ret; ret = ret->next) if (ctx == ret->ctx) break;
  68     return ret;
  69 }
  70
  71 static inline void free_context(Wine_GLContext *context)
  72 {
  73   if (context->next != NULL) context->next->prev = context->prev;
  74   if (context->prev != NULL) context->prev->next = context->next;
  75   else context_list = context->next;
  76
  77   HeapFree(GetProcessHeap(), 0, context);
  78 }
  79
  80 static inline Wine_GLContext *alloc_context(void)
  81 {
  82   Wine_GLContext *ret;
  83
  84   if ((ret = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(Wine_GLContext))))
  85   {
  86       ret->next = context_list;
  87       if (context_list) context_list->prev = ret;
  88       context_list = ret;
  89   }
  90   return ret;
  91 }
  92
  93 inline static BOOL is_valid_context( Wine_GLContext *ctx )
  94 {
  95     Wine_GLContext *ptr;
  96     for (ptr = context_list; ptr; ptr = ptr->next) if (ptr == ctx) break;
  97     return (ptr != NULL);
  98 }
  99
 100 /* retrieve the X display to use on a given DC */
 101 inline static Display *get_display( HDC hdc )
 102 {
 103     Display *display;
 104     enum x11drv_escape_codes escape = X11DRV_GET_DISPLAY;
 105
 106     if (!ExtEscape( hdc, X11DRV_ESCAPE, sizeof(escape), (LPCSTR)&escape,
 107                     sizeof(display), (LPSTR)&display )) display = NULL;
 108     return display;
 109 }
 110
 111
 112 /* retrieve the X drawable to use on a given DC */
 113 inline static Drawable get_drawable( HDC hdc )
 114 {
 115     Drawable drawable;
 116     enum x11drv_escape_codes escape = X11DRV_GET_DRAWABLE;
 117
 118     if (!ExtEscape( hdc, X11DRV_ESCAPE, sizeof(escape), (LPCSTR)&escape,
 119                     sizeof(drawable), (LPSTR)&drawable )) drawable = 0;
 120     return drawable;
 121 }
 122
 123
 124 /* retrieve the X drawable to use on a given DC */
 125 inline static Font get_font( HDC hdc )
 126 {
 127     Font font;
 128     enum x11drv_escape_codes escape = X11DRV_GET_FONT;
 129
 130     if (!ExtEscape( hdc, X11DRV_ESCAPE, sizeof(escape), (LPCSTR)&escape,
 131                     sizeof(font), (LPSTR)&font )) font = 0;
 132     return font;
 133 }
 134
 135
 136 /***********************************************************************
 137  *              wglCreateContext (OPENGL32.@)
 138  */
 139 HGLRC WINAPI wglCreateContext(HDC hdc)
 140 {
 141   XVisualInfo *vis;
 142   Wine_GLContext *ret;
 143   int num;
 144   XVisualInfo template;
 145   Display *display = get_display( hdc );
 146
 147   TRACE("(%p)\n", hdc);
 148
 149   /* First, get the visual in use by the X11DRV */
 150   if (!display) return 0;
 151   template.visualid = (VisualID)GetPropA( GetDesktopWindow(), "__wine_x11_visual_id" );
 152   vis = XGetVisualInfo(display, VisualIDMask, &template, &num);
 153
 154   if (vis == NULL) {
 155     ERR("NULL visual !!!\n");
 156     /* Need to set errors here */
 157     return NULL;
 158   }
 159
 160   /* The context will be allocated in the wglMakeCurrent call */
 161   ENTER_GL();
 162   ret = alloc_context();
 163   LEAVE_GL();
 164   ret->hdc = hdc;
 165   ret->display = display;
 166   ret->vis = vis;
 167
 168   TRACE(" creating context %p (GL context creation delayed)\n", ret);
 169   return (HGLRC) ret;
 170 }
 171
 172 /***********************************************************************
 173  *              wglCreateLayerContext (OPENGL32.@)
 174  */
 175 HGLRC WINAPI wglCreateLayerContext(HDC hdc,
 176                                    int iLayerPlane) {
 177   TRACE("(%p,%d)\n", hdc, iLayerPlane);
 178
 179   if (iLayerPlane == 0) {
 180       return wglCreateContext(hdc);
 181   }
 182   FIXME(" no handler for layer %d\n", iLayerPlane);
 183
 184   return NULL;
 185 }
 186
 187 /***********************************************************************
 188  *              wglCopyContext (OPENGL32.@)
 189  */
 190 BOOL WINAPI wglCopyContext(HGLRC hglrcSrc,
 191                            HGLRC hglrcDst,
 192                            UINT mask) {
 193   FIXME("(%p,%p,%d)\n", hglrcSrc, hglrcDst, mask);
 194
 195   return FALSE;
 196 }
 197
 198 /***********************************************************************
 199  *              wglDeleteContext (OPENGL32.@)
 200  */
 201 BOOL WINAPI wglDeleteContext(HGLRC hglrc)
 202 {
 203   Wine_GLContext *ctx = (Wine_GLContext *) hglrc;
 204   BOOL ret = TRUE;
 205
 206   TRACE("(%p)\n", hglrc);
 207
 208   ENTER_GL();
 209   /* A game (Half Life not to name it) deletes twice the same context,
 210    * so make sure it is valid first */
 211   if (is_valid_context( ctx ))
 212   {
 213       if (ctx->ctx) glXDestroyContext(ctx->display, ctx->ctx);
 214       free_context(ctx);
 215   }
 216   else
 217   {
 218     WARN("Error deleting context !\n");
 219     SetLastError(ERROR_INVALID_HANDLE);
 220     ret = FALSE;
 221   }
 222   LEAVE_GL();
 223
 224   return ret;
 225 }
 226
 227 /***********************************************************************
 228  *              wglDescribeLayerPlane (OPENGL32.@)
 229  */
 230 BOOL WINAPI wglDescribeLayerPlane(HDC hdc,
 231                                   int iPixelFormat,
 232                                   int iLayerPlane,
 233                                   UINT nBytes,
 234                                   LPLAYERPLANEDESCRIPTOR plpd) {
 235   FIXME("(%p,%d,%d,%d,%p)\n", hdc, iPixelFormat, iLayerPlane, nBytes, plpd);
 236
 237   return FALSE;
 238 }
 239
 240 /***********************************************************************
 241  *              wglGetCurrentContext (OPENGL32.@)
 242  */
 243 HGLRC WINAPI wglGetCurrentContext(void) {
 244   GLXContext gl_ctx;
 245   Wine_GLContext *ret;
 246
 247   TRACE("()\n");
 248
 249   ENTER_GL();
 250   gl_ctx = glXGetCurrentContext();
 251   ret = get_context_from_GLXContext(gl_ctx);
 252   LEAVE_GL();
 253
 254   TRACE(" returning %p (GL context %p)\n", ret, gl_ctx);
 255
 256   return ret;
 257 }
 258
 259 /***********************************************************************
 260  *              wglGetCurrentDC (OPENGL32.@)
 261  */
 262 HDC WINAPI wglGetCurrentDC(void) {
 263   GLXContext gl_ctx;
 264   Wine_GLContext *ret;
 265
 266   TRACE("()\n");
 267
 268   ENTER_GL();
 269   gl_ctx = glXGetCurrentContext();
 270   ret = get_context_from_GLXContext(gl_ctx);
 271   LEAVE_GL();
 272
 273   if (ret) {
 274     TRACE(" returning %p (GL context %p - Wine context %p)\n", ret->hdc, gl_ctx, ret);
 275     return ret->hdc;
 276   } else {
 277     TRACE(" no Wine context found for GLX context %p\n", gl_ctx);
 278     return 0;
 279   }
 280 }
 281
 282 /***********************************************************************
 283  *              wglGetLayerPaletteEntries (OPENGL32.@)
 284  */
 285 int WINAPI wglGetLayerPaletteEntries(HDC hdc,
 286                                      int iLayerPlane,
 287                                      int iStart,
 288                                      int cEntries,
 289                                      const COLORREF *pcr) {
 290   FIXME("(): stub !\n");
 291
 292   return 0;
 293 }
 294
 295 /***********************************************************************
 296  *              wglGetProcAddress (OPENGL32.@)
 297  */
 298 static int compar(const void *elt_a, const void *elt_b) {
 299   return strcmp(((OpenGL_extension *) elt_a)->name,
 300                 ((OpenGL_extension *) elt_b)->name);
 301 }
 302
 303 void* WINAPI wglGetProcAddress(LPCSTR  lpszProc) {
 304   void *local_func;
 305   static HMODULE hm = 0;
 306   OpenGL_extension  ext;
 307   OpenGL_extension *ext_ret;
 308
 309
 310   TRACE("(%s)\n", lpszProc);
 311
 312   if (hm == 0)
 313       hm = GetModuleHandleA("opengl32");
 314
 315   /* First, look if it's not already defined in the 'standard' OpenGL functions */
 316   if ((local_func = GetProcAddress(hm, lpszProc)) != NULL) {
 317     TRACE(" found function in 'standard' OpenGL functions (%p)\n", local_func);
 318     return local_func;
 319   }
 320
 321   if (p_glXGetProcAddressARB == NULL) {
 322     ERR("Warning : dynamic GL extension loading not supported by native GL library.");
 323     return NULL;
 324   }
 325
 326   /* After that, search in the thunks to find the real name of the extension */
 327   ext.name = (char *) lpszProc;
 328   ext_ret = (OpenGL_extension *) bsearch(&ext, extension_registry,
 329                                          extension_registry_size, sizeof(OpenGL_extension), compar);
 330
 331   if (ext_ret == NULL) {
 332     /* Some sanity checks :-) */
 333     ENTER_GL();
 334     local_func = p_glXGetProcAddressARB(lpszProc);
 335     LEAVE_GL();
 336     if (local_func != NULL) {
 337       ERR("Extension %s defined in the OpenGL library but NOT in opengl_ext.c... Please report (lionel.ulmer@free.fr) !\n", lpszProc);
 338       return NULL;
 339     }
 340
 341     WARN("Did not find extension %s in either Wine or your OpenGL library.\n", lpszProc);
 342     return NULL;
 343   } else {
 344     ENTER_GL();
 345     local_func = p_glXGetProcAddressARB(ext_ret->glx_name);
 346     LEAVE_GL();
 347
 348     /* After that, look at the extensions defined in the Linux OpenGL library */
 349     if (local_func == NULL) {
 350       char buf[256];
 351       void *ret = NULL;
 352
 353       /* Remove the 3 last letters (EXT, ARB, ...).
 354
 355          I know that some extensions have more than 3 letters (MESA, NV,
 356          INTEL, ...), but this is only a stop-gap measure to fix buggy
 357          OpenGL drivers (moreover, it is only useful for old 1.0 apps
 358          that query the glBindTextureEXT extension).
 359       */
 360       strncpy(buf, ext_ret->glx_name, strlen(ext_ret->glx_name) - 3);
 361       buf[strlen(ext_ret->glx_name) - 3] = '\0';
 362       TRACE(" extension not found in the Linux OpenGL library, checking against libGL bug with %s..\n", buf);
 363
 364       ret = GetProcAddress(hm, buf);
 365       if (ret != NULL) {
 366         TRACE(" found function in main OpenGL library (%p) !\n", ret);
 367       } else {
 368         WARN("Did not find function %s (%s) in your OpenGL library !\n", lpszProc, ext_ret->glx_name);
 369       }
 370
 371       return ret;
 372     } else {
 373       TRACE(" returning function  (%p)\n", ext_ret->func);
 374       *(ext_ret->func_ptr) = local_func;
 375
 376       return ext_ret->func;
 377     }
 378   }
 379 }
 380
 381 /***********************************************************************
 382  *              wglMakeCurrent (OPENGL32.@)
 383  */
 384 BOOL WINAPI wglMakeCurrent(HDC hdc,
 385                            HGLRC hglrc) {
 386   BOOL ret;
 387
 388   TRACE("(%p,%p)\n", hdc, hglrc);
 389
 390   ENTER_GL();
 391   if (hglrc == NULL) {
 392       ret = glXMakeCurrent(default_display, None, NULL);
 393   } else {
 394       Wine_GLContext *ctx = (Wine_GLContext *) hglrc;
 395       Drawable drawable = get_drawable( hdc );
 396
 397       if (ctx->ctx == NULL) {
 398         ctx->ctx = glXCreateContext(ctx->display, ctx->vis, NULL, True);
 399         TRACE(" created a delayed OpenGL context (%p)\n", ctx->ctx);
 400       }
 401       ret = glXMakeCurrent(ctx->display, drawable, ctx->ctx);
 402   }
 403   LEAVE_GL();
 404   TRACE(" returning %s\n", (ret ? "True" : "False"));
 405   return ret;
 406 }
 407
 408 /***********************************************************************
 409  *              wglRealizeLayerPalette (OPENGL32.@)
 410  */
 411 BOOL WINAPI wglRealizeLayerPalette(HDC hdc,
 412                                    int iLayerPlane,
 413                                    BOOL bRealize) {
 414   FIXME("()\n");
 415
 416   return FALSE;
 417 }
 418
 419 /***********************************************************************
 420  *              wglSetLayerPaletteEntries (OPENGL32.@)
 421  */
 422 int WINAPI wglSetLayerPaletteEntries(HDC hdc,
 423                                      int iLayerPlane,
 424                                      int iStart,
 425                                      int cEntries,
 426                                      const COLORREF *pcr) {
 427   FIXME("(): stub !\n");
 428
 429   return 0;
 430 }
 431
 432 /***********************************************************************
 433  *              wglShareLists (OPENGL32.@)
 434  */
 435 BOOL WINAPI wglShareLists(HGLRC hglrc1,
 436                           HGLRC hglrc2) {
 437   Wine_GLContext *org  = (Wine_GLContext *) hglrc1;
 438   Wine_GLContext *dest = (Wine_GLContext *) hglrc2;
 439
 440   TRACE("(%p, %p)\n", org, dest);
 441
 442   if (dest->ctx != NULL) {
 443     ERR("Could not share display lists, context already created !\n");
 444     return FALSE;
 445   } else {
 446     if (org->ctx == NULL) {
 447       ENTER_GL();
 448       org->ctx = glXCreateContext(org->display, org->vis, NULL, True);
 449       LEAVE_GL();
 450       TRACE(" created a delayed OpenGL context (%p) for Wine context %p\n", org->ctx, org);
 451     }
 452
 453     ENTER_GL();
 454     /* Create the destination context with display lists shared */
 455     dest->ctx = glXCreateContext(org->display, dest->vis, org->ctx, True);
 456     LEAVE_GL();
 457     TRACE(" created a delayed OpenGL context (%p) for Wine context %p sharing lists with OpenGL ctx %p\n", dest->ctx, dest, org->ctx);
 458   }
 459
 460   return TRUE;
 461 }
 462
 463 /***********************************************************************
 464  *              wglSwapLayerBuffers (OPENGL32.@)
 465  */
 466 BOOL WINAPI wglSwapLayerBuffers(HDC hdc,
 467                                 UINT fuPlanes) {
 468   TRACE("(%p, %08x)\n", hdc, fuPlanes);
 469
 470   if (fuPlanes & WGL_SWAP_MAIN_PLANE) {
 471     if (!SwapBuffers(hdc)) return FALSE;
 472     fuPlanes &= ~WGL_SWAP_MAIN_PLANE;
 473   }
 474
 475   if (fuPlanes) {
 476     WARN("Following layers unhandled : %08x\n", fuPlanes);
 477   }
 478
 479   return TRUE;
 480 }
 481
 482 /***********************************************************************
 483  *              wglUseFontBitmapsA (OPENGL32.@)
 484  */
 485 BOOL WINAPI wglUseFontBitmapsA(HDC hdc,
 486                                DWORD first,
 487                                DWORD count,
 488                                DWORD listBase)
 489 {
 490   Font fid = get_font( hdc );
 491
 492   TRACE("(%p, %ld, %ld, %ld) using font %ld\n", hdc, first, count, listBase, fid);
 493
 494   if (fid == 0) {
 495     /* We are running using client-side rendering fonts... */
 496     GLYPHMETRICS gm;
 497     static const MAT2 id = { { 0, 1 }, { 0, 0 }, { 0, 0 }, { 0, 0 } };
 498     int glyph;
 499     int size = 0;
 500     void *bitmap = NULL, *gl_bitmap = NULL;
 501     int org_alignment;
 502
 503     ENTER_GL();
 504     glGetIntegerv(GL_UNPACK_ALIGNMENT, &org_alignment);
 505     glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
 506     LEAVE_GL();
 507
 508     for (glyph = first; glyph < first + count; glyph++) {
 509       int needed_size = GetGlyphOutlineA(hdc, glyph, GGO_BITMAP, &gm, 0, NULL, &id);
 510       int height, width_int;
 511
 512       if (needed_size == GDI_ERROR) goto error;
 513       if (needed_size > size) {
 514         size = needed_size;
 515         if (bitmap) HeapFree(GetProcessHeap(), 0, bitmap);
 516         if (gl_bitmap) HeapFree(GetProcessHeap(), 0, gl_bitmap);
 517         bitmap = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, size);
 518         gl_bitmap = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, size);
 519       }
 520       if (GetGlyphOutlineA(hdc, glyph, GGO_BITMAP, &gm, size, bitmap, &id) == GDI_ERROR) goto error;
 521       if (TRACE_ON(opengl)) {
 522         unsigned int height, width, bitmask;
 523         unsigned char *bitmap_ = (unsigned char *) bitmap;
 524
 525         DPRINTF("Glyph : %d\n", glyph);
 526         DPRINTF("  - bbox : %d x %d\n", gm.gmBlackBoxX, gm.gmBlackBoxY);
 527         DPRINTF("  - origin : (%ld , %ld)\n", gm.gmptGlyphOrigin.x, gm.gmptGlyphOrigin.y);
 528         DPRINTF("  - increment : %d - %d\n", gm.gmCellIncX, gm.gmCellIncY);
 529         DPRINTF("  - size : %d\n", needed_size);
 530         DPRINTF("  - bitmap : \n");
 531         for (height = 0; height < gm.gmBlackBoxY; height++) {
 532           DPRINTF("      ");
 533           for (width = 0, bitmask = 0x80; width < gm.gmBlackBoxX; width++, bitmask >>= 1) {
 534             if (bitmask == 0) {
 535               bitmap_ += 1;
 536               bitmask = 0x80;
 537             }
 538             if (*bitmap_ & bitmask)
 539               DPRINTF("*");
 540             else
 541               DPRINTF(" ");
 542           }
 543           bitmap_ += (4 - (((unsigned int) bitmap_) & 0x03));
 544           DPRINTF("\n");
 545         }
 546       }
 547
 548       /* For some obscure reasons, I seem to need to rotate the glyph for OpenGL to be happy.
 549          As Wine does not seem to support the MAT2 field, I need to do it myself.... */
 550       width_int = (gm.gmBlackBoxX + 31) / 32;
 551       for (height = 0; height < gm.gmBlackBoxY; height++) {
 552         int width;
 553         for (width = 0; width < width_int; width++) {
 554           ((int *) gl_bitmap)[(gm.gmBlackBoxY - height - 1) * width_int + width] =
 555             ((int *) bitmap)[height * width_int + width];
 556         }
 557       }
 558
 559       ENTER_GL();
 560       glNewList(listBase++, GL_COMPILE);
 561       glBitmap(gm.gmBlackBoxX, gm.gmBlackBoxY, gm.gmptGlyphOrigin.x, gm.gmBlackBoxY - gm.gmptGlyphOrigin.y, gm.gmCellIncX, gm.gmCellIncY, gl_bitmap);
 562       glEndList();
 563       LEAVE_GL();
 564     }
 565
 566     ENTER_GL();
 567     glPixelStorei(GL_UNPACK_ALIGNMENT, org_alignment);
 568     LEAVE_GL();
 569
 570     if (bitmap) HeapFree(GetProcessHeap(), 0, bitmap);
 571     if (gl_bitmap) HeapFree(GetProcessHeap(), 0, gl_bitmap);
 572     return TRUE;
 573
 574   error:
 575     ENTER_GL();
 576     glPixelStorei(GL_UNPACK_ALIGNMENT, org_alignment);
 577     LEAVE_GL();
 578
 579     if (bitmap) HeapFree(GetProcessHeap(), 0, bitmap);
 580     if (gl_bitmap) HeapFree(GetProcessHeap(), 0, gl_bitmap);
 581     return FALSE;
 582   }
 583
 584   ENTER_GL();
 585   /* I assume that the glyphs are at the same position for X and for Windows */
 586   glXUseXFont(fid, first, count, listBase);
 587   LEAVE_GL();
 588   return TRUE;
 589 }
 590
 591 /***********************************************************************
 592  *              wglUseFontOutlinesA (OPENGL32.@)
 593  */
 594 BOOL WINAPI wglUseFontOutlinesA(HDC hdc,
 595                                 DWORD first,
 596                                 DWORD count,
 597                                 DWORD listBase,
 598                                 FLOAT deviation,
 599                                 FLOAT extrusion,
 600                                 int format,
 601                                 LPGLYPHMETRICSFLOAT lpgmf) {
 602   FIXME("(): stub !\n");
 603
 604   return FALSE;
 605 }
 606
 607 /* No need to load any other libraries as according to the ABI, libGL should be self-sufficient and
 608    include all dependencies
 609 */
 610 #ifndef SONAME_LIBGL
 611 #define SONAME_LIBGL "libGL.so"
 612 #endif
 613
 614 /* This is for brain-dead applications that use OpenGL functions before even
 615    creating a rendering context.... */
 616 static BOOL process_attach(void)
 617 {
 618   XWindowAttributes win_attr;
 619   Visual *rootVisual;
 620   int num;
 621   XVisualInfo template;
 622   HDC hdc;
 623   XVisualInfo *vis = NULL;
 624   Window root = (Window)GetPropA( GetDesktopWindow(), "__wine_x11_whole_window" );
 625   HMODULE mod = GetModuleHandleA( "x11drv.dll" );
 626   void *opengl_handle;
 627   const char *extensions = NULL;
 628
 629   if (!root || !mod)
 630   {
 631       ERR("X11DRV not loaded. Cannot create default context.\n");
 632       return FALSE;
 633   }
 634
 635   wine_tsx11_lock_ptr   = (void *)GetProcAddress( mod, "wine_tsx11_lock" );
 636   wine_tsx11_unlock_ptr = (void *)GetProcAddress( mod, "wine_tsx11_unlock" );
 637
 638   hdc = GetDC(0);
 639   default_display = get_display( hdc );
 640   ReleaseDC( 0, hdc );
 641   if (!default_display)
 642   {
 643       ERR("X11DRV not loaded. Cannot get display for screen DC.\n");
 644       return FALSE;
 645   }
 646
 647   ENTER_GL();
 648
 649   /* Try to get the visual from the Root Window.  We can't use the standard (presumably
 650      double buffered) X11DRV visual with the Root Window, since we don't know if the Root
 651      Window was created using the standard X11DRV visual, and glXMakeCurrent can't deal
 652      with mismatched visuals.  Note that the Root Window visual may not be double
 653      buffered, so apps actually attempting to render this way may flicker */
 654   if (XGetWindowAttributes( default_display, root, &win_attr ))
 655   {
 656     rootVisual = win_attr.visual;
 657   }
 658   else
 659   {
 660     /* Get the default visual, since we can't seem to get the attributes from the
 661        Root Window.  Let's hope that the Root Window Visual matches the DefaultVisual */
 662     rootVisual = DefaultVisual( default_display, DefaultScreen(default_display) );
 663   }
 664
 665   template.visualid = XVisualIDFromVisual(rootVisual);
 666   vis = XGetVisualInfo(default_display, VisualIDMask, &template, &num);
 667   if (vis != NULL) default_cx = glXCreateContext(default_display, vis, 0, GL_TRUE);
 668   if (default_cx != NULL) glXMakeCurrent(default_display, root, default_cx);
 669   extensions = glXQueryExtensionsString(default_display, DefaultScreen(default_display));
 670   XFree(vis);
 671   LEAVE_GL();
 672
 673   if ((extensions != NULL) && (strstr(extensions, "GLX_ARB_get_proc_address"))) {
 674     opengl_handle = wine_dlopen(SONAME_LIBGL, RTLD_NOW|RTLD_GLOBAL, NULL, 0);
 675     if (opengl_handle != NULL) {
 676       p_glXGetProcAddressARB = wine_dlsym(opengl_handle, "glXGetProcAddressARB", NULL, 0);
 677       wine_dlclose(opengl_handle, NULL, 0);
 678     }
 679   }
 680
 681   if (default_cx == NULL) {
 682     ERR("Could not create default context.\n");
 683   }
 684   return TRUE;
 685 }
 686
 687 /**********************************************************************/
 688
 689 /* Some WGL extensions... */
 690 static const char *WGL_extensions = "WGL_ARB_extensions_string WGL_EXT_extensions_string";
 691
 692 /**********************************************************************/
 693
 694 const char * WINAPI wglGetExtensionsStringEXT(void) {
 695     TRACE("() returning \"%s\"\n", WGL_extensions);
 696
 697     return WGL_extensions;
 698 }
 699
 700 /**********************************************************************/
 701
 702 static void process_detach(void)
 703 {
 704   glXDestroyContext(default_display, default_cx);
 705 }
 706
 707 /***********************************************************************
 708  *              wglGetExtensionsStringARB(OPENGL32.@)
 709  */
 710 const char * WINAPI wglGetExtensionsStringARB(HDC hdc) {
 711
 712   return wglGetExtensionsStringEXT();
 713 }
 714
 715
 716 /***********************************************************************
 717  *           OpenGL initialisation routine
 718  */
 719 BOOL WINAPI DllMain( HINSTANCE hinst, DWORD reason, LPVOID reserved )
 720 {
 721     switch(reason)
 722     {
 723     case DLL_PROCESS_ATTACH:
 724         DisableThreadLibraryCalls(hinst);
 725         return process_attach();
 726     case DLL_PROCESS_DETACH:
 727         process_detach();
 728         break;
 729     }
 730     return TRUE;
 731 }