GLScope: modulo for trace color repetition

sdrgui/gui/glscope.cpp

@@ -52,6 +52,7 @@ GLScope::GLScope(QWidget *parent) : QGLWidget(parent),
     m_timeOfsProMill(0),
     m_triggerPre(0),
     m_traceSize(0),
+    m_traceModulo(0),
     m_timeBase(1),
     m_timeOffset(0),
     m_focusedTraceIndex(0),
@@ -891,7 +892,7 @@ void GLScope::setTraceSize(int traceSize, bool emitSignal)
     m_mutex.lock();
     m_traceSize = traceSize;
     m_q3Colors.allocate(3*traceSize);
-    setColorPalette(traceSize, m_q3Colors.m_array);
+    setColorPalette(traceSize, m_traceModulo, m_q3Colors.m_array);
     m_configChanged = true;
     m_mutex.unlock();
     update();
@@ -1972,11 +1973,12 @@ void GLScope::drawCircle(float cx, float cy, float r, int num_segments, bool dot
 }
 
 // https://stackoverflow.com/questions/19452530/how-to-render-a-rainbow-spectrum
-void GLScope::setColorPalette(int nbVertices, GLfloat *colors)
+void GLScope::setColorPalette(int nbVertices, int modulo, GLfloat *colors)
 {
     for (int v = 0; v < nbVertices; v++)
     {
-        float x = 0.8f*(((float) v)/nbVertices);
+        int ci = modulo < 2 ? v : v % modulo;
+        float x = 0.8f*(((float) ci)/modulo);
         QColor c = QColor::fromHslF(x, 0.8f, 0.6f);
         colors[3*v] = c.redF();
         colors[3*v+1] = c.greenF();

sdrgui/gui/glscope.h

@@ -81,6 +81,7 @@ public:
     void setDisplayXYPoints(bool value) { m_displayXYPoints = value; }
     void setDisplayXYPolarGrid(bool value) { m_displayPolGrid = value; }
     const QAtomicInt& getProcessingTraceIndex() const { return m_processingTraceIndex; }
+    void setTraceModulo(int modulo) { m_traceModulo = modulo; }
 
 signals:
     void sampleRateChanged(int);
@@ -105,6 +106,7 @@ private:
     int m_timeOfsProMill;
     uint32_t m_triggerPre;
     int m_traceSize;
+    int m_traceModulo; //!< ineffective if <2
     int m_timeBase;
     int m_timeOffset;
     uint32_t m_focusedTraceIndex;
@@ -189,7 +191,7 @@ private:
     void drawRectGrid2();
     void drawPolarGrid2();
     static void drawCircle(float cx, float cy, float r, int num_segments, bool dotted, GLfloat *vertices);
-    static void setColorPalette(int nbVertices, GLfloat *colors);
+    static void setColorPalette(int nbVertices, int modulo, GLfloat *colors);
 
 protected slots:
     void cleanup();