How to make Opengl work with gdi?

[waterj]

I added some codes in wx sample "opegl/penguis". I just want to show a little bitmap in the left top corner of GLCanvs, but it didn't work. Is it possible to make opengl work with common gdi?

Code: Select all

void TestGLCanvas::OnPaint( wxPaintEvent& WXUNUSED(event) )
{
    // must always be here
    wxPaintDC dc(this);

#ifndef __WXMOTIF__
    if (!GetContext()) return;
#endif

    SetCurrent();

    // Initialize OpenGL
    if (!m_gldata.initialized)
    {
        InitGL();
        ResetProjectionMode();
        m_gldata.initialized = true;
    }

    // Clear
    glClearColor( 0.3f, 0.4f, 0.6f, 1.0f );
    glClear( GL_DEPTH_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  	// Swap

	wxBitmap img;
	img.LoadFile("c:/hr2000/bmp/22.bmp", wxBITMAP_TYPE_BMP);
	dc.BeginDrawing();
	dc.DrawBitmap(img, 0, 0);
	dc.EndDrawing();

   // Transformations
    glLoadIdentity();
    glTranslatef( 0.0f, 0.0f, -20.0f );
    GLfloat m[4][4];
    build_rotmatrix( m, m_gldata.quat );
    glMultMatrixf( &m[0][0] );

    m_renderer.Render();

    // Flush
    glFlush();
 	// Swap
    SwapBuffers();


}

[/code]

[upCASE]

Just a quick thought: Does it work when displaying the bitmap after SwapBuffers()?

[waterj]

Just a quick thought: Does it work when displaying the bitmap after SwapBuffers()?

Yes, bitmap showed after SwapBuffers. But my old MFC program are mixed OpenGL with GDI, so bitmap displaying might happen before SwapBuffers. I added a PFD_SUPPORT_GDI flag to wxGLCanvas and made wxMSW version work. But I don't know what to do with wxGTK.

[waterj]

??