Optimized LimitBoneWeightsProcess. Added SmallVector to reduce heap allocations. Simplified algorithm and removed unnecessary copying.

2020-03-22 12:47:42 +02:00
parent 0c3933ca7c
commit d5d30c898b
3 changed files with 212 additions and 72 deletions
@@ -0,0 +1,148 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2020, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* 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 notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"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.
+
+----------------------------------------------------------------------
+*/
+
+/** @file Defines small vector with inplace storage.
+Based on CppCon 2016: Chandler Carruth "High Performance Code 201: Hybrid Data Structures" */
+
+#pragma once
+#ifndef AI_SMALLVECTOR_H_INC
+#define AI_SMALLVECTOR_H_INC
+
+#ifdef __GNUC__
+#   pragma GCC system_header
+#endif
+
+namespace Assimp {
+
+// --------------------------------------------------------------------------------------------
+/** \brief Small vector with inplace storage. Reduces heap allocations when list is shorter
+than initial capasity
+ */
+template<typename T, unsigned int Capasity>
+class SmallVector
+{
+public:
+    SmallVector()
+        : mStorage(mInplaceStorage)
+        , mSize(0)
+        , mCapasity(Capasity)
+    {
+    }
+
+    ~SmallVector()
+    {
+        if (mStorage != mInplaceStorage) {
+            delete [] mStorage;
+        }
+    }
+
+    void push_back(const T& item)
+    {
+        if (mSize < mCapasity) {
+            mStorage[mSize++] = item;
+        }
+        else push_back_and_grow(item);
+    }
+
+    void resize(unsigned int newSize)
+    {
+        if (newSize > mCapasity)
+            grow(newSize);
+        mSize = newSize;
+    }
+
+    unsigned int size() const
+    {
+        return mSize;
+    }
+
+    T* begin()
+    {
+        return mStorage;
+    }
+
+    T* end()
+    {
+        return &mStorage[mSize];
+    }
+
+    T* begin() const
+    {
+        return mStorage;
+    }
+
+    T* end() const
+    {
+        return &mStorage[mSize];
+    }
+
+private:
+    void grow(unsigned int newCapasity)
+    {
+        T* pOldStorage = mStorage;
+        T* pNewStorage = new T[newCapasity];
+
+        std::memcpy(pNewStorage, pOldStorage, mSize * sizeof(T));
+
+        mStorage = pNewStorage;
+        mCapasity = newCapasity;
+
+        if (pOldStorage != mInplaceStorage)
+            delete [] pOldStorage;
+    }
+
+    void push_back_and_grow(const T& item)
+    {
+        grow(mCapasity + Capasity);
+
+        mStorage[mSize++] = item;
+    }
+
+    T* mStorage;
+    unsigned int mSize;
+    unsigned int mCapasity;
+    T mInplaceStorage[Capasity];
+};
+
+} // end namespace Assimp
+
+#endif // !! AI_SMALLVECTOR_H_INC