+void wxBufferedDC::UseBuffer(wxCoord w, wxCoord h)
+{
+ wxCHECK_RET( w >= -1 && h >= -1, "Invalid buffer size" );
+
+ if ( !m_buffer || !m_buffer->IsOk() )
+ {
+ if ( w == -1 || h == -1 )
+ m_dc->GetSize(&w, &h);
+
+ m_buffer = wxSharedDCBufferManager::GetBuffer(w, h);
+ m_style |= wxBUFFER_USES_SHARED_BUFFER;
+ m_area.Set(w,h);
+ }
+ else
+ m_area = m_buffer->GetSize();
+
+ SelectObject(*m_buffer);
+
+ // now that the DC is valid we can inherit the attributes (fonts, colours,
+ // layout direction, ...) from the original DC
+ if ( m_dc && m_dc->IsOk() )
+ CopyAttributes(*m_dc);
+}
+
+void wxBufferedDC::UnMask()
+{
+ wxCHECK_RET( m_dc, wxT("no underlying wxDC?") );
+ wxASSERT_MSG( m_buffer && m_buffer->IsOk(), wxT("invalid backing store") );
+
+ wxCoord x = 0,
+ y = 0;
+
+ // Ensure the scale matches the device
+ SetUserScale(1.0, 1.0);
+
+ if ( m_style & wxBUFFER_CLIENT_AREA )
+ GetDeviceOrigin(&x, &y);
+
+ // It's possible that the buffer may be bigger than the area that needs to
+ // be drawn (the client size of the window is smaller than the bitmap, or
+ // a shared bitmap has been reused for a smaller area, etc.) so avoid
+ // blitting too much if possible, but only use the real DC size if the
+ // wxBUFFER_VIRTUAL_AREA style is not set.
+ int width = m_area.GetWidth(),
+ height = m_area.GetHeight();
+
+ if (! m_style & wxBUFFER_VIRTUAL_AREA)
+ {
+ int widthDC,
+ heightDC;
+ m_dc->GetSize(&widthDC, &heightDC);
+ width = wxMin(width, widthDC);
+ height = wxMin(height, heightDC);
+ }
+
+ m_dc->Blit(0, 0, width, height, this, -x, -y);
+ m_dc = NULL;