FULLPIPE: Properly save object backreferences

2 files changed, 33 insertions, 2 deletions

diff --git a/engines/fullpipe/utils.cpp b/engines/fullpipe/utils.cpp
index fff2dad15b..5403adec68 100644
--- a/engines/fullpipe/utils.cpp
+++ b/engines/fullpipe/utils.cpp
@@ -460,10 +460,23 @@ CObject *MfcArchive::parseClass(bool *isCopyReturned) {
 }
 
 void MfcArchive::writeObject(CObject *obj) {
-	if (obj == NULL)
+	if (obj == NULL) {
 		writeUint16LE(0);
-	else
+	} else if (_objectHash.contains(obj)) {
+		int32 idx = _objectHash[obj];
+
+		if (idx < 0x7fff) {
+			writeUint16LE(idx);
+		} else {
+			writeUint16LE(0x7fff);
+			writeUint32LE(idx);
+		}
+	} else {
+		writeUint16LE(0xffff); // New class
+		_objectHash[obj] = _lastIndex++;
+
 		obj->save(*this);
+	}
 }
 
 char *genFileName(int superId, int sceneId, const char *ext) {
diff --git a/engines/fullpipe/utils.h b/engines/fullpipe/utils.h
index 5de919d383..44bda68cac 100644
--- a/engines/fullpipe/utils.h
+++ b/engines/fullpipe/utils.h
@@ -32,12 +32,30 @@ namespace Fullpipe {
 class CObject;
 class NGIArchive;
 
+struct Pointer_EqualTo {
+	bool operator()(const void *x, const void *y) const { return x == y; }
+};
+
+struct Pointer_Hash {
+	uint operator()(const void *x) const {
+#ifdef SCUMM_64BITS
+		uint64 v = (uint64)x;
+		return (v >> 32) ^ (v & 0xffffffff);
+#else
+		return (uint)x;
+#endif
+	}
+};
+
+typedef Common::HashMap<void *, int, Pointer_Hash, Pointer_EqualTo> ObjHash;
+
 typedef Common::HashMap<Common::String, int, Common::IgnoreCase_Hash, Common::IgnoreCase_EqualTo> ClassMap;
 
 class MfcArchive : public Common::SeekableReadStream, public Common::WriteStream {
 	ClassMap _classMap;
 	Common::Array<CObject *> _objectMap;
 	Common::Array<int> _objectIdMap;
+	ObjHash _objectHash;
 
 	int _lastIndex;
 	int _level;