src/x11/glcanvas.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        glcanvas.cpp
// Purpose:     wxGLCanvas, for using OpenGL with wxWidgets
//              Uses the GLX extension.
// Author:      Julian Smart and Wolfram Gloger
// Modified by:
// Created:     1995, 1999
// RCS-ID:      $Id$
// Copyright:   (c) Julian Smart, Wolfram Gloger
// Licence:   	wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
#pragma implementation "glcanvas.h"
#endif

#include "wx/setup.h"

#if wxUSE_GLCANVAS

#include "wx/glcanvas.h"
#include "wx/utils.h"
#include "wx/app.h"
#include "wx/log.h"

#ifdef __VMS
# pragma message disable nosimpint
#endif
#include <X11/Xlib.h>
#ifdef __VMS
# pragma message enable nosimpint
#endif
#include "wx/x11/private.h"

// DLL options compatibility check:
#include "wx/build.h"
WX_CHECK_BUILD_OPTIONS("wxGL")

static inline WXWindow wxGetClientAreaWindow(wxWindow* win)
{
#ifdef __WXMOTIF__
    return win->GetClientXWindow();
#else
    return win->GetClientAreaWindow();
#endif
}

#ifdef OLD_MESA
// workaround for bug in Mesa's glx.c
static int bitcount( unsigned long n )
{
    int bits;
    for (bits=0; n>0;) {
	if(n & 1) bits++;
	n = n >> 1;
    }
    return bits;
}
#endif

/*
 * GLContext implementation
 */

IMPLEMENT_CLASS(wxGLContext,wxObject)

wxGLContext::wxGLContext( bool WXUNUSED(isRGB), wxWindow *win,
                          const wxPalette& WXUNUSED(palette) )
{
    m_window = win;
    // m_widget = win->m_wxwindow;

    wxGLCanvas *gc = (wxGLCanvas*) win;
    XVisualInfo *vi = (XVisualInfo *) gc->m_vi;

    wxCHECK_RET( vi, wxT("invalid visual for OpenGL") );

    m_glContext = glXCreateContext( (Display *)wxGetDisplay(), vi,
                                    None, GL_TRUE);

    wxCHECK_RET( m_glContext, wxT("Couldn't create OpenGL context") );
}

wxGLContext::wxGLContext(
               bool WXUNUSED(isRGB), wxWindow *win,
               const wxPalette& WXUNUSED(palette),
               const wxGLContext *other        /* for sharing display lists */
)
{
    m_window = win;
    // m_widget = win->m_wxwindow;

    wxGLCanvas *gc = (wxGLCanvas*) win;
    XVisualInfo *vi = (XVisualInfo *) gc->m_vi;

    wxCHECK_RET( vi, wxT("invalid visual for OpenGL") );

    if( other != 0 )
        m_glContext = glXCreateContext( (Display *)wxGetDisplay(), vi,
                                        other->m_glContext, GL_TRUE );
    else
        m_glContext = glXCreateContext( (Display *)wxGetDisplay(), vi,
                                        None, GL_TRUE );

    wxCHECK_RET( m_glContext, wxT("Couldn't create OpenGL context") );
}

wxGLContext::~wxGLContext()
{
    if (!m_glContext) return;

    if (m_glContext == glXGetCurrentContext())
    {
        glXMakeCurrent( (Display*) wxGetDisplay(), None, NULL);
    }

    glXDestroyContext( (Display*) wxGetDisplay(), m_glContext );
}

void wxGLContext::SwapBuffers()
{
    if (m_glContext)
    {
        Display* display = (Display*) wxGetDisplay();
        glXSwapBuffers(display, (Window) wxGetClientAreaWindow(m_window));
    }
}

void wxGLContext::SetCurrent()
{
    if (m_glContext)
    {
        Display* display = (Display*) wxGetDisplay();
        glXMakeCurrent(display, (Window) wxGetClientAreaWindow(m_window),
                       m_glContext );;
    }
}

void wxGLContext::SetColour(const wxChar *colour)
{
    wxColour the_colour = wxTheColourDatabase->Find(colour);
    if(the_colour.Ok())
    {
        GLboolean b;
        glGetBooleanv(GL_RGBA_MODE, &b);
        if(b)
        {
            glColor3ub(the_colour.Red(),
                    the_colour.Green(),
                    the_colour.Blue());
        }
        else
        {
#ifdef __WXMOTIF__
            the_colour.AllocColour(m_window->GetXDisplay());
#else
            the_colour.CalcPixel(wxTheApp->GetMainColormap(wxGetDisplay()));
#endif
            GLint pix = (GLint)the_colour.GetPixel();
            if(pix == -1)
            {
                wxLogError(wxT("wxGLCanvas: cannot allocate color\n"));
                return;
            }
            glIndexi(pix);
        }
    }
}

void wxGLContext::SetupPixelFormat()
{
}

void wxGLContext::SetupPalette( const wxPalette& WXUNUSED(palette) )
{
}

wxPalette wxGLContext::CreateDefaultPalette()
{
    return wxNullPalette;
}


/*
 * GLCanvas implementation
 */

IMPLEMENT_CLASS(wxGLCanvas, wxScrolledWindow)

BEGIN_EVENT_TABLE(wxGLCanvas, wxScrolledWindow)
//    EVT_SIZE(wxGLCanvas::OnSize)
END_EVENT_TABLE()


wxGLCanvas::wxGLCanvas( wxWindow *parent, wxWindowID id,
                        const wxPoint& pos, const wxSize& size,
			long style, const wxString& name,
                        int *attribList,
			const wxPalette& palette )
: wxScrolledWindow(parent, id, pos, size, style, name)
{
    Create( parent, NULL, NULL, id, pos, size, style, name, attribList, palette );
}

wxGLCanvas::wxGLCanvas( wxWindow *parent,
                        const wxGLContext *shared,
                        wxWindowID id,
                        const wxPoint& pos, const wxSize& size,
			long style, const wxString& name,
                        int *attribList,
			const wxPalette& palette )
: wxScrolledWindow(parent, id, pos, size, style, name)
{
    Create( parent, shared, NULL, id, pos, size, style, name, attribList, palette );
}

wxGLCanvas::wxGLCanvas( wxWindow *parent,
                        const wxGLCanvas *shared,
                        wxWindowID id,
                        const wxPoint& pos, const wxSize& size,
			long style, const wxString& name,
                        int *attribList,
			const wxPalette& palette )
: wxScrolledWindow(parent, id, pos, size, style, name)
{
    Create( parent, NULL, shared, id, pos, size, style, name, attribList, palette );
}


/*
bool wxGLCanvas::Create(wxWindow *parent,
  const wxGLContext *shared, const wxGLCanvas *shared_context_of,
  wxWindowID id = -1, const wxPoint& pos,
  const wxSize& size, long style,
  const wxString& name, int *attribList, const wxPalette& palette):
    wxScrolledWindow(parent, id, pos, size, style, name)
*/

bool wxGLCanvas::Create( wxWindow *parent,
                         const wxGLContext *shared,
                         const wxGLCanvas *shared_context_of,
                         wxWindowID id,
                         const wxPoint& pos, const wxSize& size,
			 long style, const wxString& name,
                         int *attribList,
			 const wxPalette& palette)
{
    XVisualInfo *vi, vi_templ;
    XWindowAttributes xwa;
    int val, n;

    m_sharedContext = (wxGLContext*)shared;  // const_cast
    m_sharedContextOf = (wxGLCanvas*)shared_context_of;  // const_cast
    m_glContext = (wxGLContext*) NULL;

    Display* display = (Display*) wxGetDisplay();

    // Check for the presence of the GLX extension
    if(!glXQueryExtension(display, NULL, NULL)) {
	wxLogDebug(wxT("wxGLCanvas: GLX extension is missing\n"));
	return FALSE;
    }

    if(attribList) {
      int data[512], arg=0, p=0;

      while( (attribList[arg]!=0) && (p<512) )
      {
        switch( attribList[arg++] )
        {
          case WX_GL_RGBA: data[p++] = GLX_RGBA; break;
          case WX_GL_BUFFER_SIZE:
            data[p++]=GLX_BUFFER_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_LEVEL:
            data[p++]=GLX_LEVEL; data[p++]=attribList[arg++]; break;
          case WX_GL_DOUBLEBUFFER: data[p++] = GLX_DOUBLEBUFFER; break;
          case WX_GL_STEREO: data[p++] = GLX_STEREO; break;
          case WX_GL_AUX_BUFFERS:
            data[p++]=GLX_AUX_BUFFERS; data[p++]=attribList[arg++]; break;
          case WX_GL_MIN_RED:
            data[p++]=GLX_RED_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_MIN_GREEN:
            data[p++]=GLX_GREEN_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_MIN_BLUE:
            data[p++]=GLX_BLUE_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_MIN_ALPHA:
            data[p++]=GLX_ALPHA_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_DEPTH_SIZE:
            data[p++]=GLX_DEPTH_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_STENCIL_SIZE:
            data[p++]=GLX_STENCIL_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_MIN_ACCUM_RED:
            data[p++]=GLX_ACCUM_RED_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_MIN_ACCUM_GREEN:
            data[p++]=GLX_ACCUM_GREEN_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_MIN_ACCUM_BLUE:
            data[p++]=GLX_ACCUM_BLUE_SIZE; data[p++]=attribList[arg++]; break;
          case WX_GL_MIN_ACCUM_ALPHA:
            data[p++]=GLX_ACCUM_ALPHA_SIZE; data[p++]=attribList[arg++]; break;
          default:
            break;
        }
      }
      data[p] = 0;

      attribList = (int*) data;
      // Get an appropriate visual
      vi = glXChooseVisual(display, DefaultScreen(display), attribList);
      if(!vi) return FALSE;

      // Here we should make sure that vi is the same visual as the
      // one used by the xwindow drawable in wxCanvas.  However,
      // there is currently no mechanism for this in wx_canvs.cc.
    } else {
	// By default, we use the visual of xwindow
        // NI: is this really senseful ? opengl in e.g. color index mode ?
	XGetWindowAttributes(display, (Window)wxGetClientAreaWindow(this), &xwa);
	vi_templ.visualid = XVisualIDFromVisual(xwa.visual);
	vi = XGetVisualInfo(display, VisualIDMask, &vi_templ, &n);
	if(!vi) return FALSE;
	glXGetConfig(display, vi, GLX_USE_GL, &val);
	if(!val) return FALSE;
	// Basically, this is it.  It should be possible to use vi
	// in glXCreateContext() below.  But this fails with Mesa.
	// I notified the Mesa author about it; there may be a fix.
#ifdef OLD_MESA
	// Construct an attribute list matching the visual
	int a_list[32];
	n = 0;
	if(vi->c_class==TrueColor || vi->c_class==DirectColor) { // RGBA visual
	    a_list[n++] = GLX_RGBA;
	    a_list[n++] = GLX_RED_SIZE;
	    a_list[n++] = bitcount(vi->red_mask);
	    a_list[n++] = GLX_GREEN_SIZE;
	    a_list[n++] = bitcount(vi->green_mask);
	    a_list[n++] = GLX_BLUE_SIZE;
	    a_list[n++] = bitcount(vi->blue_mask);
	    glXGetConfig(display, vi, GLX_ALPHA_SIZE, &val);
	    a_list[n++] = GLX_ALPHA_SIZE;
	    a_list[n++] = val;
	} else { // Color index visual
	    glXGetConfig(display, vi, GLX_BUFFER_SIZE, &val);
	    a_list[n++] = GLX_BUFFER_SIZE;
	    a_list[n++] = val;
	}
	a_list[n] = None;
	// XFree(vi);
	vi = glXChooseVisual(display, DefaultScreen(display), a_list);
	if(!vi) return FALSE;
#endif /* OLD_MESA */
    }

    m_vi = vi;  // safe for later use

    wxCHECK_MSG( m_vi, FALSE, wxT("required visual couldn't be found") );

    // Create the GLX context and make it current

    wxGLContext *share= m_sharedContext;
    if (share==NULL && m_sharedContextOf)
        share = m_sharedContextOf->GetContext();

    m_glContext = new wxGLContext( TRUE, this, wxNullPalette, share );

#ifndef OLD_MESA
    // XFree(vi);
#endif
    SetCurrent();

    return TRUE;
}

wxGLCanvas::~wxGLCanvas(void)
{
    XVisualInfo *vi = (XVisualInfo *) m_vi;

    if (vi) XFree( vi );
    if (m_glContext) delete m_glContext;

    // Display* display = (Display*) GetXDisplay();
    // if(glx_cx) glXDestroyContext(display, glx_cx);
}

void wxGLCanvas::SwapBuffers()
{
    if( m_glContext ) m_glContext->SwapBuffers();

    // Display* display = (Display*) GetXDisplay();
    // if(glx_cx) glXSwapBuffers(display, (Window) GetClientAreaWindow());
}

void wxGLCanvas::SetCurrent()
{
    if( m_glContext ) m_glContext->SetCurrent();

    // Display* display = (Display*) GetXDisplay();
    // if(glx_cx) glXMakeCurrent(display, (Window) GetClientAreaWindow(), glx_cx);
}

void wxGLCanvas::SetColour(const wxChar *col)
{
    if( m_glContext ) m_glContext->SetColour(col);
}

#endif
    // wxUSE_GLCANVAS
Commit	Line	Data
	1	/////////////////////////////////////////////////////////////////////////////
	2	// Name: glcanvas.cpp
	3	// Purpose: wxGLCanvas, for using OpenGL with wxWidgets
	4	// Uses the GLX extension.
	5	// Author: Julian Smart and Wolfram Gloger
	6	// Modified by:
	7	// Created: 1995, 1999
	8	// RCS-ID: $Id$
	9	// Copyright: (c) Julian Smart, Wolfram Gloger
	10	// Licence: wxWindows licence
	11	/////////////////////////////////////////////////////////////////////////////
	12
	13	#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
	14	#pragma implementation "glcanvas.h"
	15	#endif
	16
	17	#include "wx/setup.h"
	18
	19	#if wxUSE_GLCANVAS
	20
	21	#include "wx/glcanvas.h"
	22	#include "wx/utils.h"
	23	#include "wx/app.h"
	24	#include "wx/log.h"
	25
	26	#ifdef __VMS
	27	# pragma message disable nosimpint
	28	#endif
	29	#include <X11/Xlib.h>
	30	#ifdef __VMS
	31	# pragma message enable nosimpint
	32	#endif
	33	#include "wx/x11/private.h"
	34
	35	// DLL options compatibility check:
	36	#include "wx/build.h"
	37	WX_CHECK_BUILD_OPTIONS("wxGL")
	38
	39	static inline WXWindow wxGetClientAreaWindow(wxWindow* win)
	40	{
	41	#ifdef __WXMOTIF__
	42	return win->GetClientXWindow();
	43	#else
	44	return win->GetClientAreaWindow();
	45	#endif
	46	}
	47
	48	#ifdef OLD_MESA
	49	// workaround for bug in Mesa's glx.c
	50	static int bitcount( unsigned long n )
	51	{
	52	int bits;
	53	for (bits=0; n>0;) {
	54	if(n & 1) bits++;
	55	n = n >> 1;
	56	}
	57	return bits;
	58	}
	59	#endif
	60
	61	/*
	62	* GLContext implementation
	63	*/
	64
	65	IMPLEMENT_CLASS(wxGLContext,wxObject)
	66
	67	wxGLContext::wxGLContext( bool WXUNUSED(isRGB), wxWindow *win,
	68	const wxPalette& WXUNUSED(palette) )
	69	{
	70	m_window = win;
	71	// m_widget = win->m_wxwindow;
	72
	73	wxGLCanvas gc = (wxGLCanvas) win;
	74	XVisualInfo vi = (XVisualInfo ) gc->m_vi;
	75
	76	wxCHECK_RET( vi, wxT("invalid visual for OpenGL") );
	77
	78	m_glContext = glXCreateContext( (Display *)wxGetDisplay(), vi,
	79	None, GL_TRUE);
	80
	81	wxCHECK_RET( m_glContext, wxT("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	XVisualInfo vi = (XVisualInfo ) gc->m_vi;
	95
	96	wxCHECK_RET( vi, wxT("invalid visual for OpenGL") );
	97
	98	if( other != 0 )
	99	m_glContext = glXCreateContext( (Display *)wxGetDisplay(), vi,
	100	other->m_glContext, GL_TRUE );
	101	else
	102	m_glContext = glXCreateContext( (Display *)wxGetDisplay(), vi,
	103	None, GL_TRUE );
	104
	105	wxCHECK_RET( m_glContext, wxT("Couldn't create OpenGL context") );
	106	}
	107
	108	wxGLContext::~wxGLContext()
	109	{
	110	if (!m_glContext) return;
	111
	112	if (m_glContext == glXGetCurrentContext())
	113	{
	114	glXMakeCurrent( (Display*) wxGetDisplay(), None, NULL);
	115	}
	116
	117	glXDestroyContext( (Display*) wxGetDisplay(), m_glContext );
	118	}
	119
	120	void wxGLContext::SwapBuffers()
	121	{
	122	if (m_glContext)
	123	{
	124	Display* display = (Display*) wxGetDisplay();
	125	glXSwapBuffers(display, (Window) wxGetClientAreaWindow(m_window));
	126	}
	127	}
	128
	129	void wxGLContext::SetCurrent()
	130	{
	131	if (m_glContext)
	132	{
	133	Display* display = (Display*) wxGetDisplay();
	134	glXMakeCurrent(display, (Window) wxGetClientAreaWindow(m_window),
	135	m_glContext );;
	136	}
	137	}
	138
	139	void wxGLContext::SetColour(const wxChar *colour)
	140	{
	141	wxColour the_colour = wxTheColourDatabase->Find(colour);
	142	if(the_colour.Ok())
	143	{
	144	GLboolean b;
	145	glGetBooleanv(GL_RGBA_MODE, &b);
	146	if(b)
	147	{
	148	glColor3ub(the_colour.Red(),
	149	the_colour.Green(),
	150	the_colour.Blue());
	151	}
	152	else
	153	{
	154	#ifdef __WXMOTIF__
	155	the_colour.AllocColour(m_window->GetXDisplay());
	156	#else
	157	the_colour.CalcPixel(wxTheApp->GetMainColormap(wxGetDisplay()));
	158	#endif
	159	GLint pix = (GLint)the_colour.GetPixel();
	160	if(pix == -1)
	161	{
	162	wxLogError(wxT("wxGLCanvas: cannot allocate color\n"));
	163	return;
	164	}
	165	glIndexi(pix);
	166	}
	167	}
	168	}
	169
	170	void wxGLContext::SetupPixelFormat()
	171	{
	172	}
	173
	174	void wxGLContext::SetupPalette( const wxPalette& WXUNUSED(palette) )
	175	{
	176	}
	177
	178	wxPalette wxGLContext::CreateDefaultPalette()
	179	{
	180	return wxNullPalette;
	181	}
	182
	183
	184
	185
	186	/*
	187	* GLCanvas implementation
	188	*/
	189
	190	IMPLEMENT_CLASS(wxGLCanvas, wxScrolledWindow)
	191
	192	BEGIN_EVENT_TABLE(wxGLCanvas, wxScrolledWindow)
	193	// EVT_SIZE(wxGLCanvas::OnSize)
	194	END_EVENT_TABLE()
	195
	196
	197	wxGLCanvas::wxGLCanvas( wxWindow *parent, wxWindowID id,
	198	const wxPoint& pos, const wxSize& size,
	199	long style, const wxString& name,
	200	int *attribList,
	201	const wxPalette& palette )
	202	: wxScrolledWindow(parent, id, pos, size, style, name)
	203	{
	204	Create( parent, NULL, NULL, id, pos, size, style, name, attribList, palette );
	205	}
	206
	207	wxGLCanvas::wxGLCanvas( wxWindow *parent,
	208	const wxGLContext *shared,
	209	wxWindowID id,
	210	const wxPoint& pos, const wxSize& size,
	211	long style, const wxString& name,
	212	int *attribList,
	213	const wxPalette& palette )
	214	: wxScrolledWindow(parent, id, pos, size, style, name)
	215	{
	216	Create( parent, shared, NULL, id, pos, size, style, name, attribList, palette );
	217	}
	218
	219	wxGLCanvas::wxGLCanvas( wxWindow *parent,
	220	const wxGLCanvas *shared,
	221	wxWindowID id,
	222	const wxPoint& pos, const wxSize& size,
	223	long style, const wxString& name,
	224	int *attribList,
	225	const wxPalette& palette )
	226	: wxScrolledWindow(parent, id, pos, size, style, name)
	227	{
	228	Create( parent, NULL, shared, id, pos, size, style, name, attribList, palette );
	229	}
	230
	231
	232	/*
	233	bool wxGLCanvas::Create(wxWindow *parent,
	234	const wxGLContext shared, const wxGLCanvas shared_context_of,
	235	wxWindowID id = -1, const wxPoint& pos,
	236	const wxSize& size, long style,
	237	const wxString& name, int *attribList, const wxPalette& palette):
	238	wxScrolledWindow(parent, id, pos, size, style, name)
	239	*/
	240
	241	bool wxGLCanvas::Create( wxWindow *parent,
	242	const wxGLContext *shared,
	243	const wxGLCanvas *shared_context_of,
	244	wxWindowID id,
	245	const wxPoint& pos, const wxSize& size,
	246	long style, const wxString& name,
	247	int *attribList,
	248	const wxPalette& palette)
	249	{
	250	XVisualInfo *vi, vi_templ;
	251	XWindowAttributes xwa;
	252	int val, n;
	253
	254	m_sharedContext = (wxGLContext*)shared; // const_cast
	255	m_sharedContextOf = (wxGLCanvas*)shared_context_of; // const_cast
	256	m_glContext = (wxGLContext*) NULL;
	257
	258	Display* display = (Display*) wxGetDisplay();
	259
	260	// Check for the presence of the GLX extension
	261	if(!glXQueryExtension(display, NULL, NULL)) {
	262	wxLogDebug(wxT("wxGLCanvas: GLX extension is missing\n"));
	263	return FALSE;
	264	}
	265
	266	if(attribList) {
	267	int data[512], arg=0, p=0;
	268
	269	while( (attribList[arg]!=0) && (p<512) )
	270	{
	271	switch( attribList[arg++] )
	272	{
	273	case WX_GL_RGBA: data[p++] = GLX_RGBA; break;
	274	case WX_GL_BUFFER_SIZE:
	275	data[p++]=GLX_BUFFER_SIZE; data[p++]=attribList[arg++]; break;
	276	case WX_GL_LEVEL:
	277	data[p++]=GLX_LEVEL; data[p++]=attribList[arg++]; break;
	278	case WX_GL_DOUBLEBUFFER: data[p++] = GLX_DOUBLEBUFFER; break;
	279	case WX_GL_STEREO: data[p++] = GLX_STEREO; break;
	280	case WX_GL_AUX_BUFFERS:
	281	data[p++]=GLX_AUX_BUFFERS; data[p++]=attribList[arg++]; break;
	282	case WX_GL_MIN_RED:
	283	data[p++]=GLX_RED_SIZE; data[p++]=attribList[arg++]; break;
	284	case WX_GL_MIN_GREEN:
	285	data[p++]=GLX_GREEN_SIZE; data[p++]=attribList[arg++]; break;
	286	case WX_GL_MIN_BLUE:
	287	data[p++]=GLX_BLUE_SIZE; data[p++]=attribList[arg++]; break;
	288	case WX_GL_MIN_ALPHA:
	289	data[p++]=GLX_ALPHA_SIZE; data[p++]=attribList[arg++]; break;
	290	case WX_GL_DEPTH_SIZE:
	291	data[p++]=GLX_DEPTH_SIZE; data[p++]=attribList[arg++]; break;
	292	case WX_GL_STENCIL_SIZE:
	293	data[p++]=GLX_STENCIL_SIZE; data[p++]=attribList[arg++]; break;
	294	case WX_GL_MIN_ACCUM_RED:
	295	data[p++]=GLX_ACCUM_RED_SIZE; data[p++]=attribList[arg++]; break;
	296	case WX_GL_MIN_ACCUM_GREEN:
	297	data[p++]=GLX_ACCUM_GREEN_SIZE; data[p++]=attribList[arg++]; break;
	298	case WX_GL_MIN_ACCUM_BLUE:
	299	data[p++]=GLX_ACCUM_BLUE_SIZE; data[p++]=attribList[arg++]; break;
	300	case WX_GL_MIN_ACCUM_ALPHA:
	301	data[p++]=GLX_ACCUM_ALPHA_SIZE; data[p++]=attribList[arg++]; break;
	302	default:
	303	break;
	304	}
	305	}
	306	data[p] = 0;
	307
	308	attribList = (int*) data;
	309	// Get an appropriate visual
	310	vi = glXChooseVisual(display, DefaultScreen(display), attribList);
	311	if(!vi) return FALSE;
	312
	313	// Here we should make sure that vi is the same visual as the
	314	// one used by the xwindow drawable in wxCanvas. However,
	315	// there is currently no mechanism for this in wx_canvs.cc.
	316	} else {
	317	// By default, we use the visual of xwindow
	318	// NI: is this really senseful ? opengl in e.g. color index mode ?
	319	XGetWindowAttributes(display, (Window)wxGetClientAreaWindow(this), &xwa);
	320	vi_templ.visualid = XVisualIDFromVisual(xwa.visual);
	321	vi = XGetVisualInfo(display, VisualIDMask, &vi_templ, &n);
	322	if(!vi) return FALSE;
	323	glXGetConfig(display, vi, GLX_USE_GL, &val);
	324	if(!val) return FALSE;
	325	// Basically, this is it. It should be possible to use vi
	326	// in glXCreateContext() below. But this fails with Mesa.
	327	// I notified the Mesa author about it; there may be a fix.
	328	#ifdef OLD_MESA
	329	// Construct an attribute list matching the visual
	330	int a_list[32];
	331	n = 0;
	332	if(vi->c_class==TrueColor \|\| vi->c_class==DirectColor) { // RGBA visual
	333	a_list[n++] = GLX_RGBA;
	334	a_list[n++] = GLX_RED_SIZE;
	335	a_list[n++] = bitcount(vi->red_mask);
	336	a_list[n++] = GLX_GREEN_SIZE;
	337	a_list[n++] = bitcount(vi->green_mask);
	338	a_list[n++] = GLX_BLUE_SIZE;
	339	a_list[n++] = bitcount(vi->blue_mask);
	340	glXGetConfig(display, vi, GLX_ALPHA_SIZE, &val);
	341	a_list[n++] = GLX_ALPHA_SIZE;
	342	a_list[n++] = val;
	343	} else { // Color index visual
	344	glXGetConfig(display, vi, GLX_BUFFER_SIZE, &val);
	345	a_list[n++] = GLX_BUFFER_SIZE;
	346	a_list[n++] = val;
	347	}
	348	a_list[n] = None;
	349	// XFree(vi);
	350	vi = glXChooseVisual(display, DefaultScreen(display), a_list);
	351	if(!vi) return FALSE;
	352	#endif /* OLD_MESA */
	353	}
	354
	355	m_vi = vi; // safe for later use
	356
	357	wxCHECK_MSG( m_vi, FALSE, wxT("required visual couldn't be found") );
	358
	359	// Create the GLX context and make it current
	360
	361	wxGLContext *share= m_sharedContext;
	362	if (share==NULL && m_sharedContextOf)
	363	share = m_sharedContextOf->GetContext();
	364
	365	m_glContext = new wxGLContext( TRUE, this, wxNullPalette, share );
	366
	367	#ifndef OLD_MESA
	368	// XFree(vi);
	369	#endif
	370	SetCurrent();
	371
	372	return TRUE;
	373	}
	374
	375	wxGLCanvas::~wxGLCanvas(void)
	376	{
	377	XVisualInfo vi = (XVisualInfo ) m_vi;
	378
	379	if (vi) XFree( vi );
	380	if (m_glContext) delete m_glContext;
	381
	382	// Display* display = (Display*) GetXDisplay();
	383	// if(glx_cx) glXDestroyContext(display, glx_cx);
	384	}
	385
	386	void wxGLCanvas::SwapBuffers()
	387	{
	388	if( m_glContext ) m_glContext->SwapBuffers();
	389
	390	// Display* display = (Display*) GetXDisplay();
	391	// if(glx_cx) glXSwapBuffers(display, (Window) GetClientAreaWindow());
	392	}
	393
	394	void wxGLCanvas::SetCurrent()
	395	{
	396	if( m_glContext ) m_glContext->SetCurrent();
	397
	398	// Display* display = (Display*) GetXDisplay();
	399	// if(glx_cx) glXMakeCurrent(display, (Window) GetClientAreaWindow(), glx_cx);
	400	}
	401
	402	void wxGLCanvas::SetColour(const wxChar *col)
	403	{
	404	if( m_glContext ) m_glContext->SetColour(col);
	405	}
	406
	407	#endif
	408	// wxUSE_GLCANVAS
	409