X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/125817d0e302ec5f4a3ae0186ac97c477a35455e..beb2638a997914bd12c55e81589adebd90af9ed2:/src/common/dcbufcmn.cpp?ds=inline diff --git a/src/common/dcbufcmn.cpp b/src/common/dcbufcmn.cpp index b38b4f1f67..6ae9f3ef82 100644 --- a/src/common/dcbufcmn.cpp +++ b/src/common/dcbufcmn.cpp @@ -34,6 +34,9 @@ // implementation // ============================================================================ +IMPLEMENT_DYNAMIC_CLASS(wxBufferedDC,wxMemoryDC) +IMPLEMENT_ABSTRACT_CLASS(wxBufferedPaintDC,wxBufferedDC) + // ---------------------------------------------------------------------------- // wxSharedDCBufferManager: helper class maintaining backing store bitmap // ---------------------------------------------------------------------------- @@ -56,6 +59,14 @@ public: h > ms_buffer->GetHeight() ) { delete ms_buffer; + + // we must always return a valid bitmap but creating a bitmap of + // size 0 would fail, so create a 1*1 bitmap in this case + if ( !w ) + w = 1; + if ( !h ) + h = 1; + ms_buffer = new wxBitmap(w, h); } @@ -117,8 +128,21 @@ void wxBufferedDC::UnMask() if ( m_style & wxBUFFER_CLIENT_AREA ) GetDeviceOrigin(&x, &y); - m_dc->Blit(0, 0, m_buffer->GetWidth(), m_buffer->GetHeight(), - this, -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); + + int widthBuf = m_buffer->GetWidth(), + heightBuf = m_buffer->GetHeight(); + + m_dc->Blit(0, 0, + wxMin(widthDC, widthBuf), wxMin(heightDC, heightBuf), + this, + -x, -y); m_dc = NULL; if ( m_style & wxBUFFER_USES_SHARED_BUFFER )