Add support for some custom VST opcodes

Source/PluginProcessor.cpp

@@ -845,6 +845,36 @@ void PaulstretchpluginAudioProcessor::timerCallback(int id)
 	}
 }
 
+pointer_sized_int PaulstretchpluginAudioProcessor::handleVstPluginCanDo(int32 index, pointer_sized_int value, void * ptr, float opt)
+{
+	if (strcmp((char*)ptr, "xenakios") == 0)
+	{
+		if (index == 0)
+		{
+			double t0 = *getFloatParameter(cpi_soundstart);
+			double t1 = *getFloatParameter(cpi_soundend);
+			m_outlen = (t1-t0)*m_stretch_source->getInfileLengthSeconds()*(*getFloatParameter(cpi_stretchamount));
+			std::cout << "host requested output length, result " << m_outlen << "\n";
+			return pointer_sized_int(&m_outlen);
+		}
+		if (index == 1 && (void*)value!=nullptr)
+		{
+			String fn(CharPointer_UTF8((char*)value));
+			std::cout << "host requested to set audio file " << fn << "\n";
+			auto err = setAudioFile(File(fn));
+			std::cout << err << "\n";
+		}
+		return 1;
+	}
+	
+	return pointer_sized_int();
+}
+
+pointer_sized_int PaulstretchpluginAudioProcessor::handleVstManufacturerSpecific(int32 index, pointer_sized_int value, void * ptr, float opt)
+{
+	return pointer_sized_int();
+}
+
 void PaulstretchpluginAudioProcessor::finishRecording(int lenrecording)
 {
 	m_is_recording = false;

Source/PluginProcessor.h

@@ -115,7 +115,7 @@ public:
 class PaulstretchpluginAudioProcessorEditor;
 
 class PaulstretchpluginAudioProcessor  : public AudioProcessor, 
-	public MultiTimer
+	public MultiTimer, public VSTCallbackHandler
 {
 public:
 	using EditorType = PaulstretchpluginAudioProcessorEditor;
@@ -202,6 +202,16 @@ public:
     shared_envelope m_free_filter_envelope;
 	bool m_import_dlg_open = false;
 	
+	pointer_sized_int handleVstPluginCanDo(int32 index,
+		pointer_sized_int value,
+		void* ptr,
+		float opt) override;
+
+	pointer_sized_int handleVstManufacturerSpecific(int32 index,
+		pointer_sized_int value,
+		void* ptr,
+		float opt) override;
+
 private:
 	
 	
@@ -244,6 +254,7 @@ private:
 	float m_cur_playrangeoffset = 0.0;
 	void updateStretchParametersFromPluginParameters(ProcessParameters& pars);
 	std::array<AudioParameterBool*, 9> m_sm_enab_pars;
+	double m_outlen = 0.0;
 	//==============================================================================
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (PaulstretchpluginAudioProcessor)
 };