lfo display caching

src/surge-xt/gui/SurgeGUIEditor.cpp

@@ -3008,6 +3008,17 @@ void SurgeGUIEditor::moveTopLeftTo(float tx, float ty)
 
 void SurgeGUIEditor::resizeWindow(float zf) { setZoomFactor(zf, true); }
 
+/*
+   Called when compiling the lua code from formula editor.
+   It is called before the draw call.
+*/
+
+void SurgeGUIEditor::forceLfoDisplayRepaint()
+{
+    if (lfoDisplay)
+        lfoDisplay->forceRepaint = true;
+}
+
 void SurgeGUIEditor::setZoomFactor(float zf) { setZoomFactor(zf, false); }
 
 void SurgeGUIEditor::setZoomFactor(float zf, bool resizeWindow)
@@ -3043,6 +3054,9 @@ void SurgeGUIEditor::setZoomFactor(float zf, bool resizeWindow)
     if (oscWaveform)
         oscWaveform->setZoomFactor(zoomFactor);
 
+    if (lfoDisplay)
+        lfoDisplay->setZoomFactor(zoomFactor);
+
     setBitmapZoomFactor(zoomFactor);
     rezoomOverlays();
 }

src/surge-xt/gui/SurgeGUIEditor.h

@@ -261,6 +261,8 @@ class SurgeGUIEditor : public Surge::GUI::IComponentTagValue::Listener,
 
     SurgeSynthesizer *synth = nullptr;
 
+    void forceLfoDisplayRepaint();
+
   private:
     void openOrRecreateEditor();
     std::unique_ptr<Surge::Overlays::OverlayComponent> makeStorePatchDialog();

src/surge-xt/gui/overlays/LuaEditors.cpp

@@ -950,6 +950,7 @@ void FormulaModulatorEditor::applyCode()
     editor->undoManager()->pushFormula(scene, lfo_id, *formulastorage);
     formulastorage->setFormula(mainDocument->getAllContent().toStdString());
     storage->getPatch().isDirty = true;
+    editor->forceLfoDisplayRepaint();
     updateDebuggerIfNeeded();
     editor->repaintFrame();
     juce::SystemClipboard::copyTextToClipboard(formulastorage->formulaString);

src/surge-xt/gui/overlays/MSEGEditor.cpp

@@ -2791,6 +2791,7 @@ struct MSEGCanvas : public juce::Component, public Surge::GUI::SkinConsumingComp
             storage->getPatch().isDirty = true;
             tagForUndo();
         }
+        this->sge->forceLfoDisplayRepaint();
         onModelChanged();
         repaint();
     }

src/surge-xt/gui/widgets/LFOAndStepDisplay.cpp

@@ -63,6 +63,9 @@ LFOAndStepDisplay::LFOAndStepDisplay(SurgeGUIEditor *e)
     setAccessible(true);
     setFocusContainerType(juce::Component::FocusContainerType::focusContainer);
 
+    backingImage = std::make_unique<juce::Image>(juce::Image::PixelFormat::ARGB, 50, 50, true);
+    waveformIsUpdated = true;
+
     typeLayer = std::make_unique<OverlayAsAccessibleContainer>("LFO Type");
     addAndMakeVisible(*typeLayer);
     for (int i = 0; i < n_lfo_types; ++i)
@@ -414,12 +417,81 @@ void LFOAndStepDisplay::paint(juce::Graphics &g)
     }
     else
     {
-        paintWaveform(g);
+
+        if (!paramsHasChanged())
+        {
+            g.drawImage(*backingImage, getLocalBounds().toFloat(),
+                        juce::RectanglePlacement::fillDestination);
+            paintTypeSelector(g);
+            return;
+        }
+        else
+        {
+            juce::Colour color =
+                juce::Colour((unsigned char)0, (unsigned char)0, (unsigned char)0, 0.f);
+
+            backingImage->clear(backingImage->getBounds());
+        }
+
+        juce::Graphics gr = juce::Graphics(*backingImage);
+        float zoomFloat = (float)zoomFactor / 100.f;
+
+        gr.addTransform(juce::AffineTransform().scale(zoomFloat * 2.f));
+
+        paintWaveform(gr);
+
+        g.drawImage(*backingImage, getLocalBounds().toFloat(),
+                    juce::RectanglePlacement::fillDestination);
+        waveformIsUpdated = false;
     }
 
     paintTypeSelector(g);
 }
 
+bool LFOAndStepDisplay::paramsHasChanged()
+{
+    bool hasChanged = false;
+
+    auto *p = &lfodata->rate;      // look in the definition of LFOStorage for which param is first
+    while (p <= &lfodata->release) // and last
+    {
+
+        if (paramsFromLastDrawCall[p->param_id_in_scene].i != p->val.i)
+            hasChanged = true;
+
+        paramsFromLastDrawCall[p->param_id_in_scene].i = p->val.i;
+        ++p;
+    };
+
+    if (lfoStorageFromLastDrawingCall != lfodata)
+        hasChanged = true;
+
+    if (forceRepaint)
+    {
+        hasChanged = true;
+        forceRepaint = false;
+    }
+
+    lfoStorageFromLastDrawingCall = lfodata;
+
+    return hasChanged;
+}
+
+void LFOAndStepDisplay::setZoomFactor(int zoom)
+{
+
+    if (zoomFactor != zoom)
+    {
+        float zoomFloat = (float)zoom / 100.f;
+        forceRepaint = true;
+        backingImage = std::make_unique<juce::Image>(juce::Image::PixelFormat::ARGB,
+                                                     outer.getWidth() * zoomFloat * 2,
+                                                     outer.getHeight() * zoomFloat * 2, true);
+    }
+
+    zoomFactor = zoom;
+}
+
 void LFOAndStepDisplay::paintWaveform(juce::Graphics &g)
 {
     TimeB mainTimer("-- paintWaveform");
@@ -2440,7 +2512,7 @@ void LFOAndStepDisplay::updateShapeTo(int i)
 
         sge->refresh_mod();
         sge->broadcastPluginAutomationChangeFor(&(lfodata->shape));
-
+        forceRepaint = true;
         repaint();
 
         sge->lfoShapeChanged(prior, i);

src/surge-xt/gui/widgets/LFOAndStepDisplay.h

@@ -56,6 +56,17 @@ struct LFOAndStepDisplay : public juce::Component,
     bool isFormula() { return lfodata->shape.val.i == lt_formula; }
     bool isUnipolar() { return lfodata->unipolar.val.b; }
 
+    void setZoomFactor(int);
+    int zoomFactor;
+    std::unique_ptr<juce::Image> backingImage;
+    bool waveformIsUpdated;
+    bool forceRepaint;
+    LFOStorage *lfoStorageFromLastDrawingCall;
+    pdata paramsFromLastDrawCall[n_scene_params];
+    int zoomFactorFromLastDrawCall;
+
+    bool paramsHasChanged();
+
     void repaintIfIdIsInRange(int id)
     {
         auto *firstLfoParam = &lfodata->rate;
@@ -83,6 +94,7 @@ struct LFOAndStepDisplay : public juce::Component,
     {
         if (isAnythingTemposynced())
         {
+            forceRepaint = true;
             repaint();
         }
     }