NvCloth library v1.0.0

1 files changed, 163 insertions, 0 deletions

diff --git a/NvCloth/src/StackAllocator.h b/NvCloth/src/StackAllocator.h
new file mode 100644
index 0000000..7191517
--- /dev/null
+++ b/NvCloth/src/StackAllocator.h
@@ -0,0 +1,163 @@
+// This code contains NVIDIA Confidential Information and is disclosed to you
+// under a form of NVIDIA software license agreement provided separately to you.
+//
+// Notice
+// NVIDIA Corporation and its licensors retain all intellectual property and
+// proprietary rights in and to this software and related documentation and
+// any modifications thereto. Any use, reproduction, disclosure, or
+// distribution of this software and related documentation without an express
+// license agreement from NVIDIA Corporation is strictly prohibited.
+//
+// ALL NVIDIA DESIGN SPECIFICATIONS, CODE ARE PROVIDED "AS IS.". NVIDIA MAKES
+// NO WARRANTIES, EXPRESSED, IMPLIED, STATUTORY, OR OTHERWISE WITH RESPECT TO
+// THE MATERIALS, AND EXPRESSLY DISCLAIMS ALL IMPLIED WARRANTIES OF NONINFRINGEMENT,
+// MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE.
+//
+// Information and code furnished is believed to be accurate and reliable.
+// However, NVIDIA Corporation assumes no responsibility for the consequences of use of such
+// information or for any infringement of patents or other rights of third parties that may
+// result from its use. No license is granted by implication or otherwise under any patent
+// or patent rights of NVIDIA Corporation. Details are subject to change without notice.
+// This code supersedes and replaces all information previously supplied.
+// NVIDIA Corporation products are not authorized for use as critical
+// components in life support devices or systems without express written approval of
+// NVIDIA Corporation.
+//
+// Copyright (c) 2008-2017 NVIDIA Corporation. All rights reserved.
+// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
+// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.
+
+#pragma once
+
+#include "NvCloth/Callbacks.h"
+
+#if NV_LINUX_FAMILY
+#include <stdint.h> // intptr_t
+#endif
+
+namespace nv
+{
+namespace cloth
+{
+
+template <size_t align>
+class StackAllocator
+{
+	typedef unsigned char byte;
+
+	// todo: switch to offsets so size is consistent on x64
+	// mSize is just for book keeping so could be 4 bytes
+	struct Header
+	{
+		Header* mPrev;
+		size_t mSize : 31;
+		size_t mFree : 1;
+	};
+
+	StackAllocator(const StackAllocator&);
+	StackAllocator& operator = (const StackAllocator&);
+
+  public:
+	StackAllocator(void* buffer, size_t bufferSize)
+	: mBuffer(reinterpret_cast<byte*>(buffer)), mBufferSize(bufferSize), mFreeStart(mBuffer), mTop(0)
+	{
+	}
+
+	~StackAllocator()
+	{
+		NV_CLOTH_ASSERT(userBytes() == 0);
+	}
+
+	void* allocate(size_t numBytes)
+	{
+		// this is non-standard
+		if (!numBytes)
+			return 0;
+
+		uintptr_t unalignedStart = uintptr_t(mFreeStart) + sizeof(Header);
+
+		byte* allocStart = reinterpret_cast<byte*>((unalignedStart + (align - 1)) & ~(align - 1));
+		byte* allocEnd = allocStart + numBytes;
+
+		// ensure there is space for the alloc
+		NV_CLOTH_ASSERT(allocEnd <= mBuffer + mBufferSize);
+
+		Header* h = getHeader(allocStart);
+		h->mPrev = mTop;
+		h->mSize = numBytes;
+		h->mFree = false;
+
+		mTop = h;
+		mFreeStart = allocEnd;
+
+		return allocStart;
+	}
+
+	void deallocate(void* p)
+	{
+		if (!p)
+			return;
+
+		Header* h = getHeader(p);
+		h->mFree = true;
+
+		// unwind the stack to the next live alloc
+		while (mTop && mTop->mFree)
+		{
+			mFreeStart = reinterpret_cast<byte*>(mTop);
+			mTop = mTop->mPrev;
+		}
+	}
+
+  private:
+	// return the header for an allocation
+	inline Header* getHeader(void* p) const
+	{
+		NV_CLOTH_ASSERT((reinterpret_cast<uintptr_t>(p) & (align - 1)) == 0);
+		NV_CLOTH_ASSERT(reinterpret_cast<byte*>(p) >= mBuffer + sizeof(Header));
+		NV_CLOTH_ASSERT(reinterpret_cast<byte*>(p) < mBuffer + mBufferSize);
+
+		return reinterpret_cast<Header*>(p) - 1;
+	}
+
+  public:
+	// total user-allocated bytes not including any overhead
+	size_t userBytes() const
+	{
+		size_t total = 0;
+		Header* iter = mTop;
+		while (iter)
+		{
+			total += iter->mSize;
+			iter = iter->mPrev;
+		}
+
+		return total;
+	}
+
+	// total user-allocated bytes + overhead
+	size_t totalUsedBytes() const
+	{
+		return mFreeStart - mBuffer;
+	}
+
+	size_t remainingBytes() const
+	{
+		return mBufferSize - totalUsedBytes();
+	}
+
+	size_t wastedBytes() const
+	{
+		return totalUsedBytes() - userBytes();
+	}
+
+  private:
+	byte* const mBuffer;
+	const size_t mBufferSize;
+
+	byte* mFreeStart; // start of free space
+	Header* mTop;     // top allocation header
+};
+
+} // namespace cloth
+} // namespace nv