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UnrealEngine/Engine/Source/ThirdParty/MaterialX/MaterialX-1.38.10/source/MaterialXGenShader/Factory.h
2025-05-18 13:04:45 +08:00

63 lines
1.6 KiB
C++

//
// Copyright Contributors to the MaterialX Project
// SPDX-License-Identifier: Apache-2.0
//
#ifndef MATERIALX_FACTORY_H
#define MATERIALX_FACTORY_H
/// @file
/// Class instantiator factory helper class
#include <MaterialXCore/Library.h>
MATERIALX_NAMESPACE_BEGIN
/// @class Factory
/// Factory class for creating instances of classes given their type name.
template <class T> class Factory
{
public:
using Ptr = shared_ptr<T>;
using CreatorFunction = Ptr (*)();
using CreatorMap = std::unordered_map<string, CreatorFunction>;
/// Register a new class given a unique type name
/// and a creator function for the class.
void registerClass(const string& typeName, CreatorFunction f)
{
_creatorMap[typeName] = f;
}
/// Determine if a class has been registered for a type name
bool classRegistered(const string& typeName) const
{
return _creatorMap.find(typeName) != _creatorMap.end();
}
/// Unregister a registered class
void unregisterClass(const string& typeName)
{
auto it = _creatorMap.find(typeName);
if (it != _creatorMap.end())
{
_creatorMap.erase(it);
}
}
/// Create a new instance of the class with given type name.
/// Returns nullptr if no class with given name is registered.
Ptr create(const string& typeName) const
{
auto it = _creatorMap.find(typeName);
return (it != _creatorMap.end() ? it->second() : nullptr);
}
private:
CreatorMap _creatorMap;
};
MATERIALX_NAMESPACE_END
#endif // MATERIALX_FACTORY_H