Add Assimp library in thirdparty

From https://github.com/assimp/assimp repo at d2b45377e4b09a1f43be95e45553afcc06b03f4b

thirdparty/assimp/code/ImproveCacheLocality.h

@@ -0,0 +1,100 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, 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 a post processing step to reorder faces for
+ better cache locality*/
+#ifndef AI_IMPROVECACHELOCALITY_H_INC
+#define AI_IMPROVECACHELOCALITY_H_INC
+
+#include "BaseProcess.h"
+#include <assimp/types.h>
+
+struct aiMesh;
+
+namespace Assimp
+{
+
+// ---------------------------------------------------------------------------
+/** The ImproveCacheLocalityProcess reorders all faces for improved vertex
+ *  cache locality. It tries to arrange all faces to fans and to render
+ *  faces which share vertices directly one after the other.
+ *
+ *  @note This step expects triagulated input data.
+ */
+class ImproveCacheLocalityProcess : public BaseProcess
+{
+public:
+
+    ImproveCacheLocalityProcess();
+    ~ImproveCacheLocalityProcess();
+
+public:
+
+    // -------------------------------------------------------------------
+    // Check whether the pp step is active
+    bool IsActive( unsigned int pFlags) const;
+
+    // -------------------------------------------------------------------
+    // Executes the pp step on a given scene
+    void Execute( aiScene* pScene);
+
+    // -------------------------------------------------------------------
+    // Configures the pp step
+    void SetupProperties(const Importer* pImp);
+
+protected:
+    // -------------------------------------------------------------------
+    /** Executes the postprocessing step on the given mesh
+     * @param pMesh The mesh to process.
+     * @param meshNum Index of the mesh to process
+     */
+    float ProcessMesh( aiMesh* pMesh, unsigned int meshNum);
+
+private:
+    //! Configuration parameter: specifies the size of the cache to
+    //! optimize the vertex data for.
+    unsigned int configCacheDepth;
+};
+
+} // end of namespace Assimp
+
+#endif // AI_IMPROVECACHELOCALITY_H_INC