From 3b969ac05868d40a9bee7281716b065ab2a94d2a Mon Sep 17 00:00:00 2001
From: f4exb <f4exb06@gmail.com>
Date: Thu, 30 Nov 2023 14:10:36 +0100
Subject: [PATCH] Scope: Added derivative of magnitude squared to the list of
 projections

---
 sdrbase/dsp/projector.cpp | 16 ++++++++++++++++
 sdrbase/dsp/projector.h   |  2 ++
 sdrgui/gui/glscope.cpp    |  1 +
 sdrgui/gui/glscopegui.cpp |  1 +
 4 files changed, 20 insertions(+)

diff --git a/sdrbase/dsp/projector.cpp b/sdrbase/dsp/projector.cpp
index 820ae2ddb..e0845b80f 100644
--- a/sdrbase/dsp/projector.cpp
+++ b/sdrbase/dsp/projector.cpp
@@ -60,6 +60,15 @@ Real Projector::run(const Sample& s)
             v = re*re + im*im;
         }
             break;
+        case ProjectionDMagSq:
+        {
+            Real re = s.m_real / SDR_RX_SCALEF;
+            Real im = s.m_imag / SDR_RX_SCALEF;
+            Real curMagSq = re*re + im*im;
+            v = curMagSq - m_prevVal;
+            m_prevVal = curMagSq;
+        }
+            break;
         case ProjectionMagDB:
         {
             Real re = s.m_real / SDR_RX_SCALEF;
@@ -235,6 +244,13 @@ Real Projector::run(const std::complex<float>& s)
         case ProjectionMagSq:
             v = std::norm(s);
             break;
+        case ProjectionDMagSq:
+        {
+            Real curMagSq = std::norm(s);
+            v = curMagSq - m_prevVal;
+            m_prevVal = curMagSq;
+        }
+            break;
         case ProjectionMagDB:
         {
             Real magsq = std::norm(s);
diff --git a/sdrbase/dsp/projector.h b/sdrbase/dsp/projector.h
index d31bedb3d..cc5a58c7c 100644
--- a/sdrbase/dsp/projector.h
+++ b/sdrbase/dsp/projector.h
@@ -33,6 +33,7 @@ public:
         ProjectionImag,     //!< Extract imaginary part
         ProjectionMagLin,   //!< Calculate linear magnitude or modulus
         ProjectionMagSq,    //!< Calculate linear squared magnitude or power
+        ProjectionDMagSq,   //!< Calculate time derivative of linear squared magnitude or power
         ProjectionMagDB,    //!< Calculate logarithmic (dB) of squared magnitude
         ProjectionPhase,    //!< Calculate phase
         ProjectionDOAP,     //!< Calculate ambiguous DOA from phase as phase difference (assuming positive)
@@ -60,6 +61,7 @@ private:
     static Real normalizeAngle(Real angle);
     ProjectionType m_projectionType;
     Real m_prevArg;
+    Real m_prevVal;
     Real *m_cache;
     bool m_cacheMaster;
 };
diff --git a/sdrgui/gui/glscope.cpp b/sdrgui/gui/glscope.cpp
index 04cdce1b6..d036f9cf5 100644
--- a/sdrgui/gui/glscope.cpp
+++ b/sdrgui/gui/glscope.cpp
@@ -1893,6 +1893,7 @@ void GLScope::setYScale(ScaleEngine &scale, uint32_t highlightedTraceIndex)
         break;
     case Projector::ProjectionMagLin:
     case Projector::ProjectionMagSq:
+    case Projector::ProjectionDMagSq:
         if (amp_range < 1e-9) {
             scale.setRange(Unit::None, amp_ofs * 1e12, amp_range * 1e12 + amp_ofs * 1e12);
         } else if (amp_range < 1e-6) {
diff --git a/sdrgui/gui/glscopegui.cpp b/sdrgui/gui/glscopegui.cpp
index 0e050472d..8d6aa7589 100644
--- a/sdrgui/gui/glscopegui.cpp
+++ b/sdrgui/gui/glscopegui.cpp
@@ -1315,6 +1315,7 @@ void GLScopeGUI::fillProjectionCombo(QComboBox* comboBox)
     comboBox->addItem("Imag", Projector::ProjectionImag);
     comboBox->addItem("Mag", Projector::ProjectionMagLin);
     comboBox->addItem("MagSq", Projector::ProjectionMagSq);
+    comboBox->addItem("dMagSq", Projector::ProjectionDMagSq);
     comboBox->addItem("MagdB", Projector::ProjectionMagDB);
     comboBox->addItem("Phi", Projector::ProjectionPhase);
     comboBox->addItem("DOAP", Projector::ProjectionDOAP);