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_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);
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);
- // avoid blitting too much: if we were created for a bigger bitmap (and
- // reused for a smaller one later) we should only blit the real bitmap area
- // and not the full allocated back buffer
- int widthDC,
- heightDC;
-
- m_dc->GetSize(&widthDC, &heightDC);
+ // 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();
- int widthBuf = m_buffer->GetWidth(),
- heightBuf = m_buffer->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,
- wxMin(widthDC, widthBuf), wxMin(heightDC, heightBuf),
- this,
- -x, -y);
+ m_dc->Blit(0, 0, width, height, this, -x, -y);
m_dc = NULL;
if ( m_style & wxBUFFER_USES_SHARED_BUFFER )