]> git.saurik.com Git - wxWidgets.git/blob - src/gtk/glcanvas.cpp
Better temporary fix.
[wxWidgets.git] / src / gtk / glcanvas.cpp
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: src/gtk/glcanvas.cpp
3 // Purpose: wxGLCanvas, for using OpenGL/Mesa with wxWidgets and GTK
4 // Author: Robert Roebling
5 // Modified by:
6 // Created: 17/08/98
7 // RCS-ID: $Id$
8 // Copyright: (c) Robert Roebling
9 // Licence: wxWindows licence
10 /////////////////////////////////////////////////////////////////////////////
11
12 // For compilers that support precompilation, includes "wx.h".
13 #include "wx/wxprec.h"
14
15 #if wxUSE_GLCANVAS
16
17 #include "wx/glcanvas.h"
18
19 #ifndef WX_PRECOMP
20 #include "wx/app.h"
21 #include "wx/frame.h"
22 #include "wx/colour.h"
23 #endif // WX_PRECOMP
24
25 #include "wx/module.h"
26
27 extern "C"
28 {
29 #include "gtk/gtk.h"
30 #include "gdk/gdk.h"
31 #include "gdk/gdkx.h"
32 }
33
34 #include "wx/gtk/win_gtk.h"
35 #include "wx/gtk/private.h"
36
37 // DLL options compatibility check:
38 #include "wx/build.h"
39 WX_CHECK_BUILD_OPTIONS("wxGL")
40
41
42 //---------------------------------------------------------------------------
43 // static variables
44 //---------------------------------------------------------------------------
45 int wxGLCanvas::m_glxVersion = 0;
46
47 //---------------------------------------------------------------------------
48 // global data
49 //---------------------------------------------------------------------------
50
51 XVisualInfo *g_vi = (XVisualInfo*) NULL;
52
53 //---------------------------------------------------------------------------
54 // wxGLContext
55 //---------------------------------------------------------------------------
56
57 IMPLEMENT_CLASS(wxGLContext,wxObject)
58
59 wxGLContext::wxGLContext( bool WXUNUSED(isRGB), wxWindow *win, const wxPalette& WXUNUSED(palette) )
60 {
61 m_window = win;
62 m_widget = win->m_wxwindow;
63
64 wxGLCanvas *gc = (wxGLCanvas*) win;
65
66 if (wxGLCanvas::GetGLXVersion() >= 13)
67 {
68 // GLX >= 1.3
69 GLXFBConfig *fbc = gc->m_fbc;
70 wxCHECK_RET( fbc, _T("invalid GLXFBConfig for OpenGl") );
71 m_glContext = glXCreateNewContext( GDK_DISPLAY(), fbc[0], GLX_RGBA_TYPE, None, GL_TRUE );
72 }
73 else
74 {
75 // GLX <= 1.2
76 XVisualInfo *vi = (XVisualInfo *) gc->m_vi;
77 wxCHECK_RET( vi, _T("invalid visual for OpenGl") );
78 m_glContext = glXCreateContext( GDK_DISPLAY(), vi, None, GL_TRUE );
79 }
80
81 wxCHECK_RET( m_glContext, _T("Couldn't create OpenGl context") );
82 }
83
84 wxGLContext::wxGLContext(
85 bool WXUNUSED(isRGB), wxWindow *win,
86 const wxPalette& WXUNUSED(palette),
87 const wxGLContext *other /* for sharing display lists */
88 )
89 {
90 m_window = win;
91 m_widget = win->m_wxwindow;
92
93 wxGLCanvas *gc = (wxGLCanvas*) win;
94
95 if (wxGLCanvas::GetGLXVersion() >= 13)
96 {
97 // GLX >= 1.3
98 GLXFBConfig *fbc = gc->m_fbc;
99 wxCHECK_RET( fbc, _T("invalid GLXFBConfig for OpenGl") );
100 m_glContext = glXCreateNewContext( GDK_DISPLAY(), fbc[0], GLX_RGBA_TYPE,
101 other ? other->m_glContext : None,
102 GL_TRUE );
103 }
104 else
105 {
106 // GLX <= 1.2
107 XVisualInfo *vi = (XVisualInfo *) gc->m_vi;
108 wxCHECK_RET( vi, _T("invalid visual for OpenGl") );
109 m_glContext = glXCreateContext( GDK_DISPLAY(), vi,
110 other ? other->m_glContext : None,
111 GL_TRUE );
112 }
113
114 if ( !m_glContext )
115 {
116 wxFAIL_MSG( _T("Couldn't create OpenGl context") );
117 }
118 }
119
120 wxGLContext::~wxGLContext()
121 {
122 if (!m_glContext) return;
123
124 if (m_glContext == glXGetCurrentContext())
125 {
126 if (wxGLCanvas::GetGLXVersion() >= 13)
127 // GLX >= 1.3
128 glXMakeContextCurrent( GDK_DISPLAY(), None, None, NULL);
129 else
130 // GLX <= 1.2
131 glXMakeCurrent( GDK_DISPLAY(), None, NULL);
132 }
133
134 glXDestroyContext( GDK_DISPLAY(), m_glContext );
135 }
136
137 void wxGLContext::SwapBuffers()
138 {
139 if (m_glContext)
140 {
141 GdkWindow *window = GTK_PIZZA(m_widget)->bin_window;
142 glXSwapBuffers( GDK_DISPLAY(), GDK_WINDOW_XWINDOW( window ) );
143 }
144 }
145
146 void wxGLContext::SetCurrent()
147 {
148 if (m_glContext)
149 {
150 GdkWindow *window = GTK_PIZZA(m_widget)->bin_window;
151
152 if (wxGLCanvas::GetGLXVersion() >= 13)
153 // GLX >= 1.3
154 glXMakeContextCurrent( GDK_DISPLAY(), GDK_WINDOW_XWINDOW(window),
155 GDK_WINDOW_XWINDOW(window), m_glContext );
156 else
157 // GLX <= 1.2
158 glXMakeCurrent( GDK_DISPLAY(), GDK_WINDOW_XWINDOW(window), m_glContext );
159 }
160 }
161
162 void wxGLContext::SetColour(const wxChar *colour)
163 {
164 wxColour col = wxTheColourDatabase->Find(colour);
165 if (col.Ok())
166 {
167 float r = (float)(col.Red()/256.0);
168 float g = (float)(col.Green()/256.0);
169 float b = (float)(col.Blue()/256.0);
170 glColor3f( r, g, b);
171 }
172 }
173
174 void wxGLContext::SetupPixelFormat()
175 {
176 }
177
178 void wxGLContext::SetupPalette( const wxPalette& WXUNUSED(palette) )
179 {
180 }
181
182 wxPalette wxGLContext::CreateDefaultPalette()
183 {
184 return wxNullPalette;
185 }
186
187 //-----------------------------------------------------------------------------
188 // "realize" from m_wxwindow
189 //-----------------------------------------------------------------------------
190
191 extern "C" {
192 static gint
193 gtk_glwindow_realized_callback( GtkWidget *WXUNUSED(widget), wxGLCanvas *win )
194 {
195 if ( !win->m_glContext )
196 {
197 wxGLContext *share = win->m_sharedContext;
198 if ( !share && win->m_sharedContextOf )
199 share = win->m_sharedContextOf->GetContext();
200
201 win->m_glContext = new wxGLContext( TRUE, win, wxNullPalette, share );
202 }
203
204 return FALSE;
205 }
206 }
207
208 //-----------------------------------------------------------------------------
209 // "map" from m_wxwindow
210 //-----------------------------------------------------------------------------
211
212 extern "C" {
213 static gint
214 gtk_glwindow_map_callback( GtkWidget * WXUNUSED(widget), wxGLCanvas *win )
215 {
216 if (win->m_glContext/* && win->m_exposed*/)
217 {
218 wxPaintEvent event( win->GetId() );
219 event.SetEventObject( win );
220 win->GetEventHandler()->ProcessEvent( event );
221
222 win->m_exposed = false;
223 win->GetUpdateRegion().Clear();
224 }
225
226 return FALSE;
227 }
228 }
229
230 //-----------------------------------------------------------------------------
231 // "expose_event" of m_wxwindow
232 //-----------------------------------------------------------------------------
233
234 extern "C" {
235 static void
236 gtk_glwindow_expose_callback( GtkWidget *WXUNUSED(widget), GdkEventExpose *gdk_event, wxGLCanvas *win )
237 {
238 if (g_isIdle)
239 wxapp_install_idle_handler();
240
241 win->m_exposed = true;
242
243 win->GetUpdateRegion().Union( gdk_event->area.x,
244 gdk_event->area.y,
245 gdk_event->area.width,
246 gdk_event->area.height );
247 }
248 }
249
250 //-----------------------------------------------------------------------------
251 // "size_allocate" of m_wxwindow
252 //-----------------------------------------------------------------------------
253
254 extern "C" {
255 static void
256 gtk_glcanvas_size_callback( GtkWidget *WXUNUSED(widget), GtkAllocation* alloc, wxGLCanvas *win )
257 {
258 if (g_isIdle)
259 wxapp_install_idle_handler();
260
261 if (!win->m_hasVMT)
262 return;
263
264 wxSizeEvent event( wxSize(win->m_width,win->m_height), win->GetId() );
265 event.SetEventObject( win );
266 win->GetEventHandler()->ProcessEvent( event );
267 }
268 }
269
270 //---------------------------------------------------------------------------
271 // wxGlCanvas
272 //---------------------------------------------------------------------------
273
274 IMPLEMENT_CLASS(wxGLCanvas, wxWindow)
275
276 BEGIN_EVENT_TABLE(wxGLCanvas, wxWindow)
277 EVT_SIZE(wxGLCanvas::OnSize)
278 END_EVENT_TABLE()
279
280 wxGLCanvas::wxGLCanvas( wxWindow *parent, wxWindowID id,
281 const wxPoint& pos, const wxSize& size,
282 long style, const wxString& name,
283 int *attribList,
284 const wxPalette& palette )
285 {
286 Create( parent, NULL, NULL, id, pos, size, style, name, attribList, palette );
287 }
288
289 wxGLCanvas::wxGLCanvas( wxWindow *parent,
290 const wxGLContext *shared,
291 wxWindowID id,
292 const wxPoint& pos, const wxSize& size,
293 long style, const wxString& name,
294 int *attribList,
295 const wxPalette& palette )
296 {
297 Create( parent, shared, NULL, id, pos, size, style, name, attribList, palette );
298 }
299
300 wxGLCanvas::wxGLCanvas( wxWindow *parent,
301 const wxGLCanvas *shared,
302 wxWindowID id,
303 const wxPoint& pos, const wxSize& size,
304 long style, const wxString& name,
305 int *attribList,
306 const wxPalette& palette )
307 {
308 Create( parent, NULL, shared, id, pos, size, style, name, attribList, palette );
309 }
310
311 bool wxGLCanvas::Create( wxWindow *parent,
312 const wxGLContext *shared,
313 const wxGLCanvas *shared_context_of,
314 wxWindowID id,
315 const wxPoint& pos, const wxSize& size,
316 long style, const wxString& name,
317 int *attribList,
318 const wxPalette& palette)
319 {
320 m_sharedContext = (wxGLContext*)shared; // const_cast
321 m_sharedContextOf = (wxGLCanvas*)shared_context_of; // const_cast
322 m_glContext = (wxGLContext*) NULL;
323
324 m_exposed = false;
325 m_noExpose = true;
326 m_nativeSizeEvent = true;
327 m_fbc = NULL;
328 m_vi = NULL;
329
330 // to be sure the glx version is known
331 wxGLCanvas::QueryGLXVersion();
332
333 if (wxGLCanvas::GetGLXVersion() >= 13)
334 {
335 // GLX >= 1.3 uses a GLXFBConfig
336 GLXFBConfig * fbc = NULL;
337 if (wxTheApp->m_glFBCInfo != NULL)
338 {
339 fbc = (GLXFBConfig *) wxTheApp->m_glFBCInfo;
340 m_canFreeFBC = false; // owned by wxTheApp - don't free upon destruction
341 }
342 else
343 {
344 fbc = (GLXFBConfig *) wxGLCanvas::ChooseGLFBC(attribList);
345 m_canFreeFBC = true;
346 }
347 m_fbc = fbc; // save for later use
348 wxCHECK_MSG( m_fbc, false, _T("required FBConfig couldn't be found") );
349 }
350
351 XVisualInfo *vi = NULL;
352 if (wxTheApp->m_glVisualInfo != NULL)
353 {
354 vi = (XVisualInfo *)wxTheApp->m_glVisualInfo;
355 m_canFreeVi = false; // owned by wxTheApp - don't free upon destruction
356 }
357 else
358 {
359 if (wxGLCanvas::GetGLXVersion() >= 13)
360 // GLX >= 1.3
361 vi = glXGetVisualFromFBConfig(GDK_DISPLAY(), m_fbc[0]);
362 else
363 // GLX <= 1.2
364 vi = (XVisualInfo *) ChooseGLVisual(attribList);
365
366 m_canFreeVi = true;
367 }
368
369 m_vi = vi; // save for later use
370
371 wxCHECK_MSG( m_vi, false, _T("required visual couldn't be found") );
372 GdkVisual *visual;
373 GdkColormap *colormap;
374
375 // MR: This needs a fix for lower gtk+ versions too. Might need to rethink logic (FIXME)
376 #if defined(__WXGTK20__) && GTK_CHECK_VERSION(2,2,0)
377 if (!gtk_check_version(2,2,0))
378 {
379 wxWindow::Create( parent, id, pos, size, style, name );
380
381 m_glWidget = m_wxwindow;
382
383 GdkScreen *screen = gtk_widget_get_screen( m_glWidget );
384 colormap = gdk_screen_get_default_colormap(screen);
385 visual = gdk_colormap_get_visual(colormap);
386
387 if (GDK_VISUAL_XVISUAL(visual)->visualid != vi->visualid)
388 {
389 visual = gdk_x11_screen_lookup_visual( screen, vi->visualid );
390 colormap = gdk_colormap_new(visual, FALSE);
391 }
392
393 gtk_widget_set_colormap( m_glWidget, colormap );
394 }
395 else
396 #endif
397 {
398 visual = gdkx_visual_get( vi->visualid );
399 colormap = gdk_colormap_new( visual, TRUE );
400
401 gtk_widget_push_colormap( colormap );
402
403 wxWindow::Create( parent, id, pos, size, style, name );
404 m_glWidget = m_wxwindow;
405 }
406
407 gtk_widget_set_double_buffered( m_glWidget, FALSE );
408
409 g_signal_connect (m_wxwindow, "realize",
410 G_CALLBACK (gtk_glwindow_realized_callback),
411 this);
412 g_signal_connect (m_wxwindow, "map",
413 G_CALLBACK (gtk_glwindow_map_callback),
414 this);
415 g_signal_connect (m_wxwindow, "expose_event",
416 G_CALLBACK (gtk_glwindow_expose_callback),
417 this);
418 g_signal_connect (m_widget, "size_allocate",
419 G_CALLBACK (gtk_glcanvas_size_callback),
420 this);
421
422 if (gtk_check_version(2,2,0) != NULL)
423 {
424 gtk_widget_pop_colormap();
425 }
426
427 // if our parent window is already visible, we had been realized before we
428 // connected to the "realize" signal and hence our m_glContext hasn't been
429 // initialized yet and we have to do it now
430 if (GTK_WIDGET_REALIZED(m_wxwindow))
431 gtk_glwindow_realized_callback( m_wxwindow, this );
432
433 if (GTK_WIDGET_MAPPED(m_wxwindow))
434 gtk_glwindow_map_callback( m_wxwindow, this );
435
436 return true;
437 }
438
439 wxGLCanvas::~wxGLCanvas()
440 {
441 GLXFBConfig * fbc = (GLXFBConfig *) m_fbc;
442 if (fbc && m_canFreeFBC)
443 XFree( fbc );
444
445 XVisualInfo *vi = (XVisualInfo *) m_vi;
446 if (vi && m_canFreeVi)
447 XFree( vi );
448
449 delete m_glContext;
450 }
451
452 void* wxGLCanvas::ChooseGLVisual(int *attribList)
453 {
454 int data[512];
455 GetGLAttribListFromWX( attribList, data );
456 attribList = (int*) data;
457
458 Display *dpy = GDK_DISPLAY();
459
460 return glXChooseVisual( dpy, DefaultScreen(dpy), attribList );
461 }
462
463 void* wxGLCanvas::ChooseGLFBC(int *attribList)
464 {
465 int data[512];
466 GetGLAttribListFromWX( attribList, data );
467 attribList = (int*) data;
468
469 int returned;
470 return glXChooseFBConfig( GDK_DISPLAY(), DefaultScreen(GDK_DISPLAY()),
471 attribList, &returned );
472 }
473
474
475 void wxGLCanvas::GetGLAttribListFromWX(int *wx_attribList, int *gl_attribList )
476 {
477 if (!wx_attribList)
478 {
479 if (wxGLCanvas::GetGLXVersion() >= 13)
480 // leave GLX >= 1.3 choose the default attributes
481 gl_attribList[0] = 0;
482 else
483 {
484 int i = 0;
485 // default settings if attriblist = 0
486 gl_attribList[i++] = GLX_RGBA;
487 gl_attribList[i++] = GLX_DOUBLEBUFFER;
488 gl_attribList[i++] = GLX_DEPTH_SIZE; gl_attribList[i++] = 1;
489 gl_attribList[i++] = GLX_RED_SIZE; gl_attribList[i++] = 1;
490 gl_attribList[i++] = GLX_GREEN_SIZE; gl_attribList[i++] = 1;
491 gl_attribList[i++] = GLX_BLUE_SIZE; gl_attribList[i++] = 1;
492 gl_attribList[i++] = GLX_ALPHA_SIZE; gl_attribList[i++] = 0;
493 gl_attribList[i++] = None;
494 }
495 }
496 else
497 {
498 int arg=0, p=0;
499 while( (wx_attribList[arg]!=0) && (p<510) )
500 {
501 switch( wx_attribList[arg++] )
502 {
503 case WX_GL_RGBA:
504 if (wxGLCanvas::GetGLXVersion() <= 12)
505 // for GLX >= 1.3, GLX_RGBA is useless (setting this flags will crash on most opengl implm)
506 gl_attribList[p++] = GLX_RGBA;
507 break;
508 case WX_GL_BUFFER_SIZE:
509 gl_attribList[p++] = GLX_BUFFER_SIZE;
510 gl_attribList[p++] = wx_attribList[arg++];
511 break;
512 case WX_GL_LEVEL:
513 gl_attribList[p++] = GLX_LEVEL;
514 gl_attribList[p++] = wx_attribList[arg++];
515 break;
516 case WX_GL_DOUBLEBUFFER:
517 if (wxGLCanvas::GetGLXVersion() <= 12)
518 gl_attribList[p++] = GLX_DOUBLEBUFFER;
519 else
520 // for GLX >= 1.3, GLX_DOUBLEBUFFER format is different (1 <=> True)
521 // it seems this flag is useless for some hardware opengl implementation.
522 // but for Mesa 6.2.1, this flag is used so don't ignore it.
523 gl_attribList[p++] = GLX_DOUBLEBUFFER;
524 gl_attribList[p++] = 1;
525 break;
526 case WX_GL_STEREO:
527 gl_attribList[p++] = GLX_STEREO;
528 break;
529 case WX_GL_AUX_BUFFERS:
530 gl_attribList[p++] = GLX_AUX_BUFFERS;
531 gl_attribList[p++] = wx_attribList[arg++];
532 break;
533 case WX_GL_MIN_RED:
534 gl_attribList[p++] = GLX_RED_SIZE;
535 gl_attribList[p++] = wx_attribList[arg++];
536 break;
537 case WX_GL_MIN_GREEN:
538 gl_attribList[p++] = GLX_GREEN_SIZE;
539 gl_attribList[p++] = wx_attribList[arg++];
540 break;
541 case WX_GL_MIN_BLUE:
542 gl_attribList[p++] = GLX_BLUE_SIZE;
543 gl_attribList[p++] = wx_attribList[arg++];
544 break;
545 case WX_GL_MIN_ALPHA:
546 gl_attribList[p++] = GLX_ALPHA_SIZE;
547 gl_attribList[p++] = wx_attribList[arg++];
548 break;
549 case WX_GL_DEPTH_SIZE:
550 gl_attribList[p++] = GLX_DEPTH_SIZE;
551 gl_attribList[p++] = wx_attribList[arg++];
552 break;
553 case WX_GL_STENCIL_SIZE:
554 gl_attribList[p++] = GLX_STENCIL_SIZE;
555 gl_attribList[p++] = wx_attribList[arg++];
556 break;
557 case WX_GL_MIN_ACCUM_RED:
558 gl_attribList[p++] = GLX_ACCUM_RED_SIZE;
559 gl_attribList[p++] = wx_attribList[arg++];
560 break;
561 case WX_GL_MIN_ACCUM_GREEN:
562 gl_attribList[p++] = GLX_ACCUM_GREEN_SIZE;
563 gl_attribList[p++] = wx_attribList[arg++];
564 break;
565 case WX_GL_MIN_ACCUM_BLUE:
566 gl_attribList[p++] = GLX_ACCUM_BLUE_SIZE;
567 gl_attribList[p++] = wx_attribList[arg++];
568 break;
569 case WX_GL_MIN_ACCUM_ALPHA:
570 gl_attribList[p++] = GLX_ACCUM_ALPHA_SIZE;
571 gl_attribList[p++] = wx_attribList[arg++];
572 break;
573 default:
574 break;
575 }
576 }
577
578 gl_attribList[p] = 0;
579 }
580 }
581
582 void wxGLCanvas::QueryGLXVersion()
583 {
584 if (m_glxVersion == 0)
585 {
586 // check the GLX version
587 int glxMajorVer, glxMinorVer;
588 bool ok = glXQueryVersion(GDK_DISPLAY(), &glxMajorVer, &glxMinorVer);
589 wxASSERT_MSG( ok, _T("GLX version not found") );
590 if (!ok)
591 m_glxVersion = 10; // 1.0 by default
592 else
593 m_glxVersion = glxMajorVer*10 + glxMinorVer;
594 }
595 }
596
597 int wxGLCanvas::GetGLXVersion()
598 {
599 wxASSERT_MSG( m_glxVersion>0, _T("GLX version has not been initialized with wxGLCanvas::QueryGLXVersion()") );
600 return m_glxVersion;
601 }
602
603
604 void wxGLCanvas::SwapBuffers()
605 {
606 if (m_glContext)
607 m_glContext->SwapBuffers();
608 }
609
610 void wxGLCanvas::OnSize(wxSizeEvent& WXUNUSED(event))
611 {
612 }
613
614 void wxGLCanvas::SetCurrent()
615 {
616 if (m_glContext)
617 m_glContext->SetCurrent();
618 }
619
620 void wxGLCanvas::SetColour( const wxChar *colour )
621 {
622 if (m_glContext)
623 m_glContext->SetColour( colour );
624 }
625
626 void wxGLCanvas::OnInternalIdle()
627 {
628 if (m_glContext && m_exposed)
629 {
630 wxPaintEvent event( GetId() );
631 event.SetEventObject( this );
632 GetEventHandler()->ProcessEvent( event );
633
634 m_exposed = false;
635 GetUpdateRegion().Clear();
636 }
637
638 wxWindow::OnInternalIdle();
639 }
640
641
642
643 //---------------------------------------------------------------------------
644 // wxGLApp
645 //---------------------------------------------------------------------------
646
647 IMPLEMENT_CLASS(wxGLApp, wxApp)
648
649 wxGLApp::~wxGLApp()
650 {
651 if (m_glFBCInfo)
652 XFree(m_glFBCInfo);
653 if (m_glVisualInfo)
654 XFree(m_glVisualInfo);
655 }
656
657 bool wxGLApp::InitGLVisual(int *attribList)
658 {
659 wxGLCanvas::QueryGLXVersion();
660
661 if (wxGLCanvas::GetGLXVersion() >= 13)
662 {
663 // GLX >= 1.3
664 if (m_glFBCInfo)
665 XFree(m_glFBCInfo);
666 m_glFBCInfo = wxGLCanvas::ChooseGLFBC(attribList);
667
668 if (m_glFBCInfo)
669 {
670 if (m_glVisualInfo)
671 XFree(m_glVisualInfo);
672 m_glVisualInfo = glXGetVisualFromFBConfig(GDK_DISPLAY(), ((GLXFBConfig *)m_glFBCInfo)[0]);
673 }
674 return (m_glFBCInfo != NULL) && (m_glVisualInfo != NULL);
675 }
676 else
677 {
678 // GLX <= 1.2
679 if (m_glVisualInfo)
680 XFree(m_glVisualInfo);
681 m_glVisualInfo = wxGLCanvas::ChooseGLVisual(attribList);
682 return m_glVisualInfo != NULL;
683 }
684 }
685
686 #endif
687 // wxUSE_GLCANVAS