CGE: Fix loading of vol.cat file to be endian safe

2 files changed, 43 insertions, 14 deletions

diff --git a/engines/cge/btfile.cpp b/engines/cge/btfile.cpp
index 1f987340b7..7ecfa94e9b 100644
--- a/engines/cge/btfile.cpp
+++ b/engines/cge/btfile.cpp
@@ -31,6 +31,7 @@
 #include "cge/cge.h"
 #include "common/debug.h"
 #include "common/debug-channels.h"
+#include "common/memstream.h"
 
 namespace CGE {
 
@@ -61,8 +62,8 @@ void BtFile::putPage(int lev, bool hard) {
 	debugC(1, kCGEDebugFile, "BtFile::putPage(%d, %s)", lev, hard ? "true" : "false");
 
 	if (hard || _buff[lev]._updt) {
-		seek(_buff[lev]._pgNo * sizeof(BtPage));
-		write((uint8 *) _buff[lev]._page, sizeof(BtPage));
+		seek(_buff[lev]._pgNo * kBtSize);
+		write((uint8 *) _buff[lev]._page, kBtSize);
 		_buff[lev]._updt = false;
 	}
 }
@@ -72,17 +73,25 @@ BtPage *BtFile::getPage(int lev, uint16 pgn) {
 	debugC(1, kCGEDebugFile, "BtFile::getPage(%d, %d)", lev, pgn);
 
 	if (_buff[lev]._pgNo != pgn) {
-		int32 pos = pgn * sizeof(BtPage);
+		int32 pos = pgn * kBtSize;
 		putPage(lev, false);
 		_buff[lev]._pgNo = pgn;
 		if (size() > pos) {
-			seek((uint32) pgn * sizeof(BtPage));
-			read((uint8 *) _buff[lev]._page, sizeof(BtPage));
+			seek((uint32) pgn * kBtSize);
+
+			// Read in the page
+			byte buffer[kBtSize];
+			int bytesRead = read(buffer, kBtSize);
+
+			// Unpack it into the page structure
+			Common::MemoryReadStream stream(buffer, bytesRead, DisposeAfterUse::NO);
+			_buff[lev]._page->read(stream);
+
 			_buff[lev]._updt = false;
 		} else {
+			memset(&_buff[lev]._page, 0, kBtSize);
 			_buff[lev]._page->_hea._count = 0;
 			_buff[lev]._page->_hea._down = kBtValNone;
-			memset(_buff[lev]._page->_data, '\0', sizeof(_buff[lev]._page->_data));
 			_buff[lev]._updt = true;
 		}
 		_buff[lev]._indx = -1;
@@ -152,4 +161,24 @@ void BtFile::make(BtKeypack *keypack, uint16 count) {
 	}
 }
 
+void BtPage::read(Common::ReadStream &s) {
+	_hea._count = s.readUint16LE();
+	_hea._down = s.readUint16LE();
+
+	if (_hea._down == kBtValNone) {
+		// Leaf list
+		for (int i = 0; i < kBtLeafCount; ++i) {
+			s.read(_lea[i]._key, kBtKeySize);
+			_lea[i]._mark = s.readUint32LE();
+			_lea[i]._size = s.readUint16LE();
+		}
+	} else {
+		// Root index
+		for (int i = 0; i < kBtInnerCount; ++i) {
+			s.read(_inn[i]._key, kBtKeySize);
+			_inn[i]._down = s.readUint16LE();
+		}
+	}
+}
+
 } // End of namespace CGE
diff --git a/engines/cge/btfile.h b/engines/cge/btfile.h
index 6b7155d43d..26b008bea6 100644
--- a/engines/cge/btfile.h
+++ b/engines/cge/btfile.h
@@ -29,18 +29,19 @@
 #define __CGE_BTFILE__
 
 #include "cge/general.h"
+#include "common/stream.h"
 
 namespace CGE {
 
 #define kBtSize      1024
 #define kBtKeySize   13
 #define kBtLevel     2
+#define kBtInnerCount ((kBtSize - 4 /*sizeof(Hea) */) / (kBtKeySize + 2 /*sizeof(Inner) */))
+#define kBtLeafCount ((kBtSize - 4 /*sizeof(Hea) */) / (kBtKeySize + 4 + 2 /*sizeof(BtKeypack) */))
 
 #define kBtValNone   0xFFFF
 #define kBtValRoot   0
 
-#include "common/pack-start.h"	// START STRUCT PACKING
-
 struct BtKeypack {
 	char _key[kBtKeySize];
 	uint32 _mark;
@@ -61,16 +62,15 @@ struct BtPage {
 	Hea _hea;
 	union {
 		// dummy filler to make proper size of union
-		uint8 _data[kBtSize - sizeof(Hea)];
+		uint8 _data[kBtSize - 4 /*sizeof(Hea) */];
 		// inner version of data: key + word-sized page link
-		Inner _inn[(kBtSize - sizeof(Hea)) / sizeof(Inner)];
+		Inner _inn[kBtInnerCount];
 		// leaf version of data: key + all user data
-		BtKeypack _lea[(kBtSize - sizeof(Hea)) / sizeof(BtKeypack)];
+		BtKeypack _lea[kBtLeafCount];
 	};
-};
-
-#include "common/pack-end.h"	// END STRUCT PACKING
 
+	void read(Common::ReadStream &s);
+};
 
 class BtFile : public IoHand {
 	struct {