do not synthesize anything if frequency is above half of samplerate

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@909 0778d3d1-df1d-0410-868b-ea421aaaa00d

src/core/oscillator.cpp

@@ -55,6 +55,11 @@ oscillator::oscillator( const intModel & _wave_shape_model,
 void oscillator::update( sampleFrame * _ab, const fpp_t _frames,
 							const ch_cnt_t _chnl )
 {
+	if( m_freq >= engine::getMixer()->sampleRate()/2 )
+	{
+		mixer::clearAudioBuffer( _ab, _frames );
+		return;
+	}
 	if( m_subOsc != NULL )
 	{
 		switch( m_modulationAlgoModel.value() )