Change project structure;

Added new c# binding;

native/external/assimp/Base64.hpp

@@ -0,0 +1,92 @@
+/*
+---------------------------------------------------------------------------
+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.
+---------------------------------------------------------------------------
+*/
+
+#pragma once
+#ifndef AI_BASE64_HPP_INC
+#define AI_BASE64_HPP_INC
+
+#include <assimp/defs.h>
+
+#include <stdint.h>
+#include <vector>
+#include <string>
+
+namespace Assimp {
+namespace Base64 {
+
+/// @brief Will encode the given character buffer from UTF64 to ASCII
+/// @param in           The UTF-64 buffer.
+/// @param inLength     The size of the buffer
+/// @param out          The encoded ASCII string.
+ASSIMP_API void Encode(const uint8_t *in, size_t inLength, std::string &out);
+
+/// @brief Will encode the given character buffer from UTF64 to ASCII.
+/// @param in   A vector, which contains the buffer for encoding.
+/// @param out  The encoded ASCII string.
+ASSIMP_API void Encode(const std::vector<uint8_t> &in, std::string &out);
+
+/// @brief Will encode the given character buffer from UTF64 to ASCII.
+/// @param in   A vector, which contains the buffer for encoding.
+/// @return The encoded ASCII string.
+ASSIMP_API std::string Encode(const std::vector<uint8_t> &in);
+
+/// @brief Will decode the given character buffer from ASCII to UTF64.
+/// @param in           The ASCII buffer to decode.
+/// @param inLength     The size of the buffer.
+/// @param out          The decoded buffer.
+/// @return The new buffer size.
+ASSIMP_API size_t Decode(const char *in, size_t inLength, uint8_t *&out);
+
+/// @brief Will decode the given character buffer from ASCII to UTF64.
+/// @param in   The ASCII buffer to decode as a std::string.
+/// @param out  The decoded buffer.
+/// @return The new buffer size.
+ASSIMP_API size_t Decode(const std::string &in, std::vector<uint8_t> &out);
+
+/// @brief Will decode the given character buffer from ASCII to UTF64.
+/// @param in   The ASCII string.
+/// @return The decoded buffer in a vector.
+ASSIMP_API std::vector<uint8_t> Decode(const std::string &in);
+
+} // namespace Base64
+} // namespace Assimp
+
+#endif // AI_BASE64_HPP_INC