Disable ZIP compression, and comment out CRC32 checks, to improve loa…

…ding times.

It turns out ZIP decompression is pretty slow, and the optional CRC32 check on data integrity is even slower (at least as implemented by miniz).  Long-term plan is to switch to LZ4 or some other compression method, see issue #3, but for now simply disabling compression and commenting out the CRC32 is easy and gets things loading quite a bit faster.

asset-internal.h

@@ -27,7 +27,7 @@ namespace Framework
 	{
 		enum PACKVER
 		{
-			PACKVER_Current = 2,
+			PACKVER_Current = 3,
 		};
 
 		enum MESHVER

asset.cpp

@@ -329,7 +329,7 @@ namespace Framework
 
 				CHECK_WARN(CheckPathChars(zipPath));
 
-				if (!mz_zip_writer_add_mem(pZipOut, zipPath, pData, sizeBytes, MZ_DEFAULT_LEVEL))
+				if (!mz_zip_writer_add_mem(pZipOut, zipPath, pData, sizeBytes, MZ_NO_COMPRESSION))
 				{
 					WARN("Couldn't add file %s to archive", zipPath);
 					return false;
@@ -345,7 +345,7 @@ namespace Framework
 
 				CHECK_WARN(CheckPathChars(assetPath));
 
-				if (!mz_zip_writer_add_mem(pZipOut, assetPath, pData, sizeBytes, MZ_DEFAULT_LEVEL))
+				if (!mz_zip_writer_add_mem(pZipOut, assetPath, pData, sizeBytes, MZ_NO_COMPRESSION))
 				{
 					WARN("Couldn't add file %s to archive", assetPath);
 					return false;

miniz.c

@@ -3588,7 +3588,8 @@ mz_bool mz_zip_reader_extract_to_mem_no_alloc(mz_zip_archive *pZip, mz_uint file
     // The file is stored or the caller has requested the compressed data.
     if (pZip->m_pRead(pZip->m_pIO_opaque, cur_file_ofs, pBuf, (size_t)needed_size) != needed_size)
       return MZ_FALSE;
-    return ((flags & MZ_ZIP_FLAG_COMPRESSED_DATA) != 0) || (mz_crc32(MZ_CRC32_INIT, (const mz_uint8 *)pBuf, (size_t)file_stat.m_uncomp_size) == file_stat.m_crc32);
+    // NRR: commented out CRC32 check to save time
+    return MZ_TRUE; /*((flags & MZ_ZIP_FLAG_COMPRESSED_DATA) != 0) || (mz_crc32(MZ_CRC32_INIT, (const mz_uint8 *)pBuf, (size_t)file_stat.m_uncomp_size) == file_stat.m_crc32);*/
   }
 
   // Decompress the file either directly from memory or from a file input buffer.
@@ -3652,7 +3653,8 @@ mz_bool mz_zip_reader_extract_to_mem_no_alloc(mz_zip_archive *pZip, mz_uint file
   if (status == TINFL_STATUS_DONE)
   {
     // Make sure the entire file was decompressed, and check its CRC.
-    if ((out_buf_ofs != file_stat.m_uncomp_size) || (mz_crc32(MZ_CRC32_INIT, (const mz_uint8 *)pBuf, (size_t)file_stat.m_uncomp_size) != file_stat.m_crc32))
+    // NRR: commented out CRC32 check to save time
+    if ((out_buf_ofs != file_stat.m_uncomp_size) /*|| (mz_crc32(MZ_CRC32_INIT, (const mz_uint8 *)pBuf, (size_t)file_stat.m_uncomp_size) != file_stat.m_crc32)*/)
       status = TINFL_STATUS_FAILED;
   }