Static analysis optimizations

This changelist addresses a handful of static analysis optimizations flagged by PVS-Studio and cppcheck.

Author: jstone-lucasfilm

source/MaterialXGenMdl/Nodes/ClosureLayerNodeMdl.cpp

@@ -159,7 +159,7 @@ void ClosureLayerNodeMdl::emitFunctionCall(const ShaderNode& _node, GenContext&
 }
 
 void ClosureLayerNodeMdl::emitBsdfOverBsdfFunctionCalls(
-    ShaderNode& node,
+    const ShaderNode& node,
     GenContext& context,
     ShaderStage& stage,
     const ShaderGenerator& shadergen,
@@ -231,7 +231,7 @@ void ClosureLayerNodeMdl::emitBsdfOverBsdfFunctionCalls(
 }
 
 void ClosureLayerNodeMdl::emitBsdfOverBsdfFunctionCalls_thinFilm(
-    ShaderNode& node,
+    const ShaderNode& node,
     GenContext& context,
     ShaderStage& stage,
     const ShaderGenerator& shadergen,

source/MaterialXGenMdl/Nodes/ClosureLayerNodeMdl.h

@@ -76,7 +76,7 @@ class MX_GENMDL_API ClosureLayerNodeMdl : public CarryThinFilmParameters<ShaderN
     void emitFunctionCall(const ShaderNode& node, GenContext& context, ShaderStage& stage) const override;
 
     void emitBsdfOverBsdfFunctionCalls(
-        ShaderNode& node,
+        const ShaderNode& node,
         GenContext& context,
         ShaderStage& stage,
         const ShaderGenerator& shadergen,
@@ -85,7 +85,7 @@ class MX_GENMDL_API ClosureLayerNodeMdl : public CarryThinFilmParameters<ShaderN
         ShaderOutput* output) const;
 
     void emitBsdfOverBsdfFunctionCalls_thinFilm(
-        ShaderNode& node,
+        const ShaderNode& node,
         GenContext& context,
         ShaderStage& stage,
         const ShaderGenerator& shadergen,

source/MaterialXGenShader/UnitSystem.cpp

@@ -118,9 +118,9 @@ UnitTransform::UnitTransform(const string& ss, const string& ts, const TypeDesc*
 
 const string UnitSystem::UNITSYTEM_NAME = "default_unit_system";
 
-UnitSystem::UnitSystem(const string& target)
+UnitSystem::UnitSystem(const string& target) :
+    _target(createValidName(target))
 {
-    _target = createValidName(target);
 }
 
 void UnitSystem::loadLibrary(DocumentPtr document)

source/MaterialXGenShader/UnitSystem.h

@@ -85,7 +85,7 @@ class MX_GENSHADER_API UnitSystem
 
   protected:
     // Protected constructor
-    UnitSystem(const string& language);
+    UnitSystem(const string& target);
 
   protected:
     UnitConverterRegistryPtr _unitRegistry;

source/MaterialXGraphEditor/Graph.cpp

@@ -3509,13 +3509,12 @@ void Graph::shaderPopup()
 void Graph::handleRenderViewInputs(ImVec2 minValue, float width, float height)
 {
     ImVec2 mousePos = ImGui::GetMousePos();
-    mx::Vector2 mxMousePos = mx::Vector2(mousePos.x, mousePos.y);
-    ImVec2 dragDelta = ImGui::GetMouseDragDelta();
-    float scrollAmt = ImGui::GetIO().MouseWheel;
-    int button = -1;
-    bool down = false;
     if (mousePos.x > minValue.x && mousePos.x < (minValue.x + width) && mousePos.y > minValue.y && mousePos.y < (minValue.y + height))
     {
+        mx::Vector2 mxMousePos = mx::Vector2(mousePos.x, mousePos.y);
+        float scrollAmt = ImGui::GetIO().MouseWheel;
+        int button = -1;
+        bool down = false;
         if (ImGui::IsMouseDragging(0) || ImGui::IsMouseDragging(1))
         {
             _renderer->setMouseMotionEvent(mxMousePos);

source/PyMaterialX/PyMaterialXCore/PyElement.cpp

@@ -90,7 +90,7 @@ void bindPyElement(py::module& mod)
         .def("hasSourceUri", &mx::Element::hasSourceUri)
         .def("getSourceUri", &mx::Element::getSourceUri)
         .def("getActiveSourceUri", &mx::Element::getActiveSourceUri)
-        .def("validate", [](mx::Element& elem)
+        .def("validate", [](const mx::Element& elem)
             {
                 std::string message;
                 bool res = elem.validate(&message);