[opencl] Ruggedness index OpenCL program

resources/opencl_programs/ruggedness.cl

@@ -0,0 +1,51 @@
+__kernel void processNineCellWindow( __global float *scanLine1,
+                                     __global float *scanLine2,
+                                     __global float *scanLine3,
+                                     __global float *resultLine,
+                                     __global float *rasterParams )
+{
+
+  // Get the index of the current element
+  const int i = get_global_id(0);
+
+  float x11 = scanLine1[i];
+  float x12 = scanLine1[i+1];
+  float x13 = scanLine1[i+2];
+  float x21 = scanLine2[i];
+  float x22 = scanLine2[i+1];
+  float x23 = scanLine2[i+2];
+  float x31 = scanLine3[i];
+  float x32 = scanLine3[i+1];
+  float x33 = scanLine3[i+2];
+
+  if ( x22 == rasterParams[0] )
+  {
+     resultLine[i] = rasterParams[1];
+  }
+  else
+  {
+    // Nodata handling
+    if ( x11 == rasterParams[0] ) x11 = x22;
+    if ( x12 == rasterParams[0] ) x12 = x22;
+    if ( x13 == rasterParams[0] ) x13 = x22;
+    if ( x21 == rasterParams[0] ) x21 = x22;
+    if ( x23 == rasterParams[0] ) x23 = x22;
+    if ( x31 == rasterParams[0] ) x31 = x22;
+    if ( x32 == rasterParams[0] ) x32 = x22;
+    if ( x33 == rasterParams[0] ) x33 = x22;
+
+    float diff1 = x11 - x22;
+    float diff2 = x21 - x22;
+    float diff3 = x31 - x22;
+    float diff4 = x12 - x22;
+    float diff5 = x32 - x22;
+    float diff6 = x13 - x22;
+    float diff7 = x23 - x22;
+    float diff8 = x33 - x22;
+
+    resultLine[i] = sqrt(diff1 * diff1 + diff2 * diff2 +
+                         diff3 * diff3 + diff4 * diff4 +
+                         diff5 * diff5 + diff6 * diff6 +
+                         diff7 * diff7 + diff8 * diff8);
+  }
+}

src/analysis/raster/qgsruggednessfilter.h

@@ -42,7 +42,10 @@ class ANALYSIS_EXPORT QgsRuggednessFilter: public QgsNineCellFilter
   private:
     QgsRuggednessFilter();
 
-    //virtual QString _openClProgramBaseName() override { return QStringLiteral( "ruggedness" ); }
+    virtual const QString openClProgramBaseName() const override
+    {
+      return QStringLiteral( "ruggedness" );
+    }
 
 };