Refactor loading of SC6 information when scanning scenarios

src/openrct2/rct12/SawyerEncoding.cpp

@@ -0,0 +1,57 @@
+#pragma region Copyright (c) 2014-2016 OpenRCT2 Developers
+/*****************************************************************************
+ * OpenRCT2, an open source clone of Roller Coaster Tycoon 2.
+ *
+ * OpenRCT2 is the work of many authors, a full list can be found in contributors.md
+ * For more information, visit https://github.com/OpenRCT2/OpenRCT2
+ *
+ * OpenRCT2 is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * A full copy of the GNU General Public License can be found in licence.txt
+ *****************************************************************************/
+#pragma endregion
+
+#include "../core/IStream.hpp"
+#include "SawyerEncoding.h"
+
+extern "C"
+{
+    #include "../util/sawyercoding.h"
+}
+
+namespace SawyerEncoding
+{
+    bool TryReadChunk(void * dst, size_t expectedSize, IStream * stream)
+    {
+        uint64 originalPosition = stream->GetPosition();
+
+        bool success = false;
+        auto header = stream->ReadValue<sawyercoding_chunk_header>();
+        switch (header.encoding) {
+        case CHUNK_ENCODING_NONE:
+        case CHUNK_ENCODING_RLE:
+        case CHUNK_ENCODING_RLECOMPRESSED:
+        case CHUNK_ENCODING_ROTATE:
+            uint8 * compressedData = Memory::Allocate<uint8>(header.length);
+            if (stream->TryRead(compressedData, header.length) == header.length)
+            {
+                size_t uncompressedLength = sawyercoding_read_chunk_buffer((uint8 *)dst, compressedData, header, expectedSize);
+                if (uncompressedLength == expectedSize)
+                {
+                    success = true;
+                }
+            }
+            Memory::Free(compressedData);
+            break;
+        }
+
+        if (!success)
+        {
+            stream->SetPosition(originalPosition);
+        }
+        return success;
+    }
+}