Performance improvements for painting waveform during capture mode etc

Source/PluginEditor.cpp

@@ -243,6 +243,7 @@ void PaulstretchpluginAudioProcessorEditor::timerCallback(int id)
 			infotext += " (offline rendering)";
 		if (processor.m_playposinfo.isPlaying)
 			infotext += " "+String(processor.m_playposinfo.timeInSeconds,1);
+		infotext += " " + String(m_wavecomponent.m_image_init_count) + " " + String(m_wavecomponent.m_image_update_count);
 		m_info_label.setText(infotext, dontSendNotification);
 		m_perfmeter.repaint();
 	}
@@ -394,8 +395,21 @@ WaveformComponent::~WaveformComponent()
 
 void WaveformComponent::changeListenerCallback(ChangeBroadcaster * /*cb*/)
 {
-	m_waveimage = Image();
-	repaint();
+	jassert(MessageManager::getInstance()->isThisTheMessageThread());
+	m_image_dirty = true;
+	//repaint();
+}
+
+void WaveformComponent::updateCachedImage()
+{
+	Graphics tempg(m_waveimage);
+	tempg.fillAll(Colours::black);
+	tempg.setColour(Colours::darkgrey);
+	double thumblen = m_thumbnail->getTotalLength();
+	m_thumbnail->drawChannels(tempg, { 0,0,getWidth(),getHeight() - m_topmargin },
+		thumblen*m_view_range.getStart(), thumblen*m_view_range.getEnd(), 1.0f);
+	m_image_dirty = false;
+	++m_image_update_count;
 }
 
 void WaveformComponent::paint(Graphics & g)
@@ -425,16 +439,17 @@ void WaveformComponent::paint(Graphics & g)
 	bool m_use_cached_image = true;
 	if (m_use_cached_image == true)
 	{
-		if (m_waveimage.isValid() == false || m_waveimage.getWidth() != getWidth()
+		if (m_image_dirty == true || m_waveimage.getWidth() != getWidth()
 			|| m_waveimage.getHeight() != getHeight() - m_topmargin)
 		{
 			//Logger::writeToLog("updating cached waveform image");
-			m_waveimage = Image(Image::ARGB, getWidth(), getHeight() - m_topmargin, true);
-			Graphics tempg(m_waveimage);
-			tempg.fillAll(Colours::black);
-			tempg.setColour(Colours::darkgrey);
-			m_thumbnail->drawChannels(tempg, { 0,0,getWidth(),getHeight() - m_topmargin },
-				thumblen*m_view_range.getStart(), thumblen*m_view_range.getEnd(), 1.0f);
+			if (m_waveimage.getWidth() != getWidth()
+				|| m_waveimage.getHeight() != getHeight() - m_topmargin)
+			{
+				m_waveimage = Image(Image::ARGB, getWidth(), getHeight() - m_topmargin, true);
+				++m_image_init_count;
+			}
+			updateCachedImage();
 		}
 		g.drawImage(m_waveimage, 0, m_topmargin, getWidth(), getHeight() - m_topmargin, 0, 0, getWidth(), getHeight() - m_topmargin);
 

Source/PluginEditor.h

@@ -115,6 +115,8 @@ public:
 	void setViewRange(Range<double> rng);
 	Value ShowFileCacheRange;
 	void setRecordingPosition(double pos) { m_rec_pos = pos; }
+	int m_image_init_count = 0;
+	int m_image_update_count = 0;
 private:
 	AudioThumbnail* m_thumbnail = nullptr;
 	Range<double> m_view_range{ 0.0,1.0 };
@@ -128,13 +130,14 @@ private:
 	int m_topmargin = 0;
 	int getTimeSelectionEdge(int x, int y);
 	std::pair<Range<double>, Range<double>> m_file_cached;
-	
+	bool m_image_dirty = false;
 	Image m_waveimage;
 	OpenGLContext m_ogl;
 	bool m_use_opengl = false;
 	double m_rec_pos = 0.0;
 	bool m_lock_timesel_set = false;
     bool m_using_audio_buffer = false;
+	void updateCachedImage();
 };
 
 class SpectralChainEditor : public Component

paulstretchplugin.jucer

@@ -7,7 +7,7 @@
               buildVST3="0" buildAU="1" buildAUv3="0" buildRTAS="0" buildAAX="0"
               buildStandalone="1" enableIAA="0" pluginName="PaulXStretch" pluginDesc="PaulXStretch"
               pluginManufacturer="Xenakios" pluginManufacturerCode="XenS" pluginCode="Fn1r"
-              pluginChannelConfigs="{2,2},{2,4}, {2,8}, {8,8}" pluginIsSynth="0"
+              pluginChannelConfigs="{2,4}, {2,8}, {8,8}, {2,2}" pluginIsSynth="0"
               pluginWantsMidiIn="0" pluginProducesMidiOut="0" pluginIsMidiEffectPlugin="0"
               pluginEditorRequiresKeys="0" pluginAUExportPrefix="paulxstretchAU"
               pluginRTASCategory="" aaxIdentifier="com.yourcompany.paulstretchplugin"