Fixed error when evaluating a tabulated function exactly at its end

platforms/opencl/src/OpenCLExpressionUtilities.cpp

@@ -121,6 +121,7 @@ void OpenCLExpressionUtilities::processExpression(stringstream& out, const Expre
             out << "float x = " << getTempName(node.getChildren()[0], temps) << ";\n";
             out << "if (x >= params.x && x <= params.y) {\n";
             out << "int index = (int) (floor((x-params.x)*params.z));\n";
+            out << "index = min(index, (int) params.w);\n";
             out << "float4 coeff = " << functions[i].second << "[index];\n";
             out << "x = (x-params.x)*params.z-index;\n";
             if (valueNode != NULL)

platforms/opencl/src/OpenCLKernels.cpp

@@ -1583,7 +1583,7 @@ void OpenCLCalcCustomNonbondedForceKernel::initialize(const System& system, cons
         string arrayName = prefix+"table"+intToString(i);
         functionDefinitions.push_back(make_pair(name, arrayName));
         functions[name] = &fp;
-        tabulatedFunctionParamsVec[i] = mm_float4((float) min, (float) max, (float) ((values.size()-1)/(max-min)), 0.0f);
+        tabulatedFunctionParamsVec[i] = mm_float4((float) min, (float) max, (float) ((values.size()-1)/(max-min)), values.size()-2);
         vector<mm_float4> f = OpenCLExpressionUtilities::computeFunctionCoefficients(values, interpolating);
         tabulatedFunctions.push_back(new OpenCLArray<mm_float4>(cl, values.size()-1, "TabulatedFunction"));
         tabulatedFunctions[tabulatedFunctions.size()-1]->upload(f);
@@ -1922,7 +1922,7 @@ void OpenCLCalcCustomGBForceKernel::initialize(const System& system, const Custo
         string arrayName = prefix+"table"+intToString(i);
         functionDefinitions.push_back(make_pair(name, arrayName));
         functions[name] = &fp;
-        tabulatedFunctionParamsVec[i] = mm_float4((float) min, (float) max, (float) ((values.size()-1)/(max-min)), 0.0f);
+        tabulatedFunctionParamsVec[i] = mm_float4((float) min, (float) max, (float) ((values.size()-1)/(max-min)), values.size()-2);
         vector<mm_float4> f = OpenCLExpressionUtilities::computeFunctionCoefficients(values, interpolating);
         tabulatedFunctions.push_back(new OpenCLArray<mm_float4>(cl, values.size()-1, "TabulatedFunction"));
         tabulatedFunctions[tabulatedFunctions.size()-1]->upload(f);
@@ -2962,7 +2962,7 @@ void OpenCLCalcCustomHbondForceKernel::initialize(const System& system, const Cu
         string arrayName = "table"+intToString(i);
         functionDefinitions.push_back(make_pair(name, arrayName));
         functions[name] = &fp;
-        tabulatedFunctionParamsVec[i] = mm_float4((float) min, (float) max, (float) ((values.size()-1)/(max-min)), 0.0f);
+        tabulatedFunctionParamsVec[i] = mm_float4((float) min, (float) max, (float) ((values.size()-1)/(max-min)), values.size()-2);
         vector<mm_float4> f = OpenCLExpressionUtilities::computeFunctionCoefficients(values, interpolating);
         tabulatedFunctions.push_back(new OpenCLArray<mm_float4>(cl, values.size()-1, "TabulatedFunction"));
         tabulatedFunctions[tabulatedFunctions.size()-1]->upload(f);