Change project structure;

Added new c# binding;

native/external/assimp/DefaultIOStream.h

@@ -0,0 +1,139 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2025, 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
+ *  @brief Default file I/O using fXXX()-family of functions
+ */
+#pragma once
+#ifndef AI_DEFAULTIOSTREAM_H_INC
+#define AI_DEFAULTIOSTREAM_H_INC
+
+#ifdef __GNUC__
+#   pragma GCC system_header
+#endif
+
+#include <cstdio>
+#include <assimp/IOStream.hpp>
+#include <assimp/importerdesc.h>
+
+namespace Assimp {
+
+// ----------------------------------------------------------------------------------
+//! @class  DefaultIOStream
+//! @brief  Default IO implementation, use standard IO operations
+//! @note   An instance of this class can exist without a valid file handle
+//!         attached to it. All calls fail, but the instance can nevertheless be
+//!         used with no restrictions.
+class ASSIMP_API DefaultIOStream : public IOStream {
+    friend class DefaultIOSystem;
+#if __ANDROID__
+# if __ANDROID_API__ > 9
+#  if defined(AI_CONFIG_ANDROID_JNI_ASSIMP_MANAGER_SUPPORT)
+    friend class AndroidJNIIOSystem;
+#  endif // defined(AI_CONFIG_ANDROID_JNI_ASSIMP_MANAGER_SUPPORT)
+# endif // __ANDROID_API__ > 9
+#endif // __ANDROID__
+
+protected:
+    /// @brief
+    DefaultIOStream() AI_NO_EXCEPT;
+
+    /// @brief The class constructor with the file name and the stream.
+    /// @param pFile        The file-streaam
+    /// @param strFilename  The file name
+    DefaultIOStream(FILE* pFile, const std::string &strFilename);
+
+public:
+    /** Destructor public to allow simple deletion to close the file. */
+    ~DefaultIOStream () override;
+
+    // -------------------------------------------------------------------
+    /// Read from stream
+    size_t Read(void* pvBuffer, size_t pSize, size_t pCount) override;
+
+    // -------------------------------------------------------------------
+    /// Write to stream
+    size_t Write(const void* pvBuffer, size_t pSize, size_t pCount) override;
+
+    // -------------------------------------------------------------------
+    /// Seek specific position
+    aiReturn Seek(size_t pOffset, aiOrigin pOrigin) override;
+
+    // -------------------------------------------------------------------
+    /// Get current seek position
+    size_t Tell() const override;
+
+    // -------------------------------------------------------------------
+    /// Get size of file
+    size_t FileSize() const override;
+
+    // -------------------------------------------------------------------
+    /// Flush file contents
+    void Flush() override;
+
+private:
+    FILE* mFile;
+    std::string mFilename;
+    mutable size_t mCachedSize;
+};
+
+// ----------------------------------------------------------------------------------
+AI_FORCE_INLINE DefaultIOStream::DefaultIOStream() AI_NO_EXCEPT :
+        mFile(nullptr),
+        mFilename(),
+        mCachedSize(SIZE_MAX) {
+    // empty
+}
+
+// ----------------------------------------------------------------------------------
+AI_FORCE_INLINE DefaultIOStream::DefaultIOStream (FILE* pFile, const std::string &strFilename) :
+        mFile(pFile),
+        mFilename(strFilename),
+        mCachedSize(SIZE_MAX) {
+    // empty
+}
+
+// ----------------------------------------------------------------------------------
+
+} // ns assimp
+
+#endif //!!AI_DEFAULTIOSTREAM_H_INC