initial commit, 4.5 stable

thirdparty/cvtt/ConvectionKernels_PackedCovarianceMatrix.h

@@ -0,0 +1,68 @@
+#pragma once
+#ifndef __CVTT_COVARIANCEMATRIX_H__
+#define __CVTT_COVARIANCEMATRIX_H__
+
+namespace cvtt
+{
+    namespace Internal
+    {
+
+        template<int TMatrixSize>
+        class PackedCovarianceMatrix
+        {
+        public:
+            // 0: xx,
+            // 1: xy, yy
+            // 3: xz, yz, zz 
+            // 6: xw, yw, zw, ww
+            // ... etc.
+            static const int PyramidSize = (TMatrixSize * (TMatrixSize + 1)) / 2;
+
+            typedef ParallelMath::Float MFloat;
+
+            PackedCovarianceMatrix()
+            {
+                for (int i = 0; i < PyramidSize; i++)
+                    m_values[i] = ParallelMath::MakeFloatZero();
+            }
+
+            void Add(const ParallelMath::Float *vec, const ParallelMath::Float &weight)
+            {
+                int index = 0;
+                for (int row = 0; row < TMatrixSize; row++)
+                {
+                    for (int col = 0; col <= row; col++)
+                    {
+                        m_values[index] = m_values[index] + vec[row] * vec[col] * weight;
+                        index++;
+                    }
+                }
+            }
+
+            void Product(MFloat *outVec, const MFloat *inVec)
+            {
+                for (int row = 0; row < TMatrixSize; row++)
+                {
+                    MFloat sum = ParallelMath::MakeFloatZero();
+
+                    int index = (row * (row + 1)) >> 1;
+                    for (int col = 0; col < TMatrixSize; col++)
+                    {
+                        sum = sum + inVec[col] * m_values[index];
+                        if (col >= row)
+                            index += col + 1;
+                        else
+                            index++;
+                    }
+
+                    outVec[row] = sum;
+                }
+            }
+
+        private:
+            ParallelMath::Float m_values[PyramidSize];
+        };
+    }
+}
+
+#endif