text: //
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  //  * Redistributions of source code must retain the above copyright
  //    notice, this list of conditions and the following disclaimer.
  //  * Redistributions in binary form must reproduce the above copyright
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  //    documentation and/or other materials provided with the distribution.
  //  * Neither the name of NVIDIA CORPORATION nor the names of its
  //    contributors may be used to endorse or promote products derived
  //    from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  // PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  // OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  //
  // Copyright (c) 2018 NVIDIA Corporation. All rights reserved.
  
  
  #ifndef PARAM_ARRAY_H
  #define PARAM_ARRAY_H
  
  #include "nvparameterized/NvParameterized.h"
  #include "PsUserAllocated.h"
  #include "PxAssert.h"
  
  namespace nvidia
  {
  namespace apex
  {
  
  struct ParamDynamicArrayStruct
  {
  	void* buf;
  	bool isAllocated;
  	int elementSize;
  	int arraySizes[1];
  };
  
  
  template <class ElemType>
  class ParamArray : public physx::UserAllocated
  {
  public:
  
  	ParamArray() : mParams(NULL), mArrayHandle(0), mArrayStruct(NULL) {}
  
  	ParamArray(NvParameterized::Interface* params, const char* arrayName, ParamDynamicArrayStruct* arrayStruct) :
  		mParams(params),
  		mArrayHandle(*params),
  		mArrayStruct(arrayStruct)
  	{
  		PX_ASSERT(mParams);
  
  		mParams->getParameterHandle(arrayName, mArrayHandle);
  
  		PX_ASSERT(mArrayStruct->elementSize == sizeof(ElemType));
  	}
  
  	ParamArray(NvParameterized::Interface* params, const NvParameterized::Handle& handle, ParamDynamicArrayStruct* arrayStruct) :
  		mParams(params),
  		mArrayHandle(handle),
  		mArrayStruct(arrayStruct)
  	{
  		PX_ASSERT(mArrayStruct->elementSize == sizeof(ElemType));
  	}
  
  	PX_INLINE bool init(NvParameterized::Interface* params, const char* arrayName, ParamDynamicArrayStruct* arrayStruct)
  	{
  		if (mParams == NULL && mArrayStruct == NULL)
  		{
  			mParams = params;
  			mArrayStruct = arrayStruct;
  			mArrayHandle.setInterface(mParams);
  			mParams->getParameterHandle(arrayName, mArrayHandle);
  
  			PX_ASSERT(mArrayStruct->elementSize == sizeof(ElemType));
  
  			return true;
  		}
  		return false;
  	}
  
  	PX_INLINE uint32_t size() const
  	{
  		// this only works for fixed structs
  		//return (uint32_t)mArrayHandle.parameterDefinition()->arraySize(0);
  		int outSize = 0;
  		if (mParams != NULL)
  		{
  			PX_ASSERT(mArrayHandle.getConstInterface() == mParams);
  			mArrayHandle.getArraySize(outSize);
  		}
  		return (uint32_t)outSize;
  	}
  
  	/**
  	Returns a constant reference to an element in the sequence.
  	*/
  	PX_INLINE const ElemType& operator[](unsigned int n) const
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  #if _DEBUG
  		uint32_t NxParamArraySize = 0;
  		mArrayHandle.getArraySize((int&)NxParamArraySize);
  		PX_ASSERT(NxParamArraySize > n);
  #endif
  		return ((ElemType*)mArrayStruct->buf)[n];
  	}
  
  	/**
  	Returns a reference to an element in the sequence.
  	*/
  	PX_INLINE ElemType& operator[](unsigned int n)
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  		//NvParameterized::Handle indexHandle;
  		//arrayHandle.getChildHandle( n, indexHandle );
  #if _DEBUG
  		uint32_t NxParamArraySize = 0;
  		mArrayHandle.getArraySize((int&)NxParamArraySize);
  		PX_ASSERT(NxParamArraySize > n);
  #endif
  		return ((ElemType*)mArrayStruct->buf)[n];
  	}
  
  	// resize is marginally useful because the ElemType doesn't have proper
  	// copy constructors, and if strings are withing ElemType that doesn't work well
  	PX_INLINE void resize(unsigned int n)
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  		PX_ASSERT(mParams == mArrayHandle.getConstInterface());
  		mArrayHandle.resizeArray((int32_t)n);
  	}
  
  	// pushBack is marginally useful because the ElemType doesn't have proper
  	// copy constructors, and if strings are withing ElemType that doesn't work well
  	PX_INLINE void pushBack(const ElemType& x)
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  
  		int32_t paramArraySize = 0;
  
  		mArrayHandle.getArraySize(paramArraySize);
  		mArrayHandle.resizeArray(paramArraySize + 1);
  
  		((ElemType*)mArrayStruct->buf)[(uint32_t)paramArraySize] = x;
  	}
  
  	PX_INLINE ElemType& pushBack()
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  
  		int32_t paramArraySize = 0;
  
  		mArrayHandle.getArraySize(paramArraySize);
  		mArrayHandle.resizeArray(paramArraySize + 1);
  
  		return ((ElemType*)mArrayStruct->buf)[(uint32_t)paramArraySize];
  	}
  
  	PX_INLINE void replaceWithLast(unsigned position)
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  
  		uint32_t arraySize = size();
  		PX_ASSERT(position < arraySize);
  		if (position != arraySize - 1)
  		{
  			// TODO should we call the destructor here or not?
  			//(*this)[position].~ElemType();
  
  			ElemType elem = back();
  
  			// put the replaced one in the back (possibly to be deleted)
  			(*this)[arraySize - 1] = (*this)[position];
  
  			(*this)[position] = elem;
  		}
  		popBack();
  	}
  
  	PX_INLINE bool isEmpty() const
  	{
  		return size() == 0;
  	}
  
  	PX_INLINE ElemType* begin()
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  		return &((ElemType*)mArrayStruct->buf)[0];
  	}
  
  	PX_INLINE ElemType* end()
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  		return &((ElemType*)mArrayStruct->buf)[size()];
  	}
  
  	PX_INLINE ElemType& front()
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  		return ((ElemType*)mArrayStruct->buf)[0];
  	}
  
  	PX_INLINE ElemType& back()
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  		return ((ElemType*)mArrayStruct->buf)[size() - 1];
  	}
  
  	PX_INLINE void clear()
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  		resize(0);
  	}
  
  	PX_INLINE void popBack()
  	{
  		PX_ASSERT(mParams != NULL && mArrayStruct != NULL);
  		resize(size() - 1);
  	}
  
  private:
  	NvParameterized::Interface*	mParams;
  	NvParameterized::Handle		mArrayHandle;
  	ParamDynamicArrayStruct*	mArrayStruct;
  };
  
  }
  } // end namespace nvidia::apex
  
  #endif
  
  