DREAMWEB: Create and use FileHeader struct

4 files changed, 43 insertions, 13 deletions

diff --git a/engines/dreamweb/dreamweb.h b/engines/dreamweb/dreamweb.h
index b20b4c9258..8181d04706 100644
--- a/engines/dreamweb/dreamweb.h
+++ b/engines/dreamweb/dreamweb.h
@@ -42,9 +42,7 @@
 
 namespace DreamGen {
 
-// TODO: Unsure if these values are constant or
-// should be replaced with &backObject() and &mainMan()
-// or some kind of enum...
+// These are for ReelRoutine::reelPointer, which is a callback field.
 const uint16 addr_backobject = 0xc170;
 const uint16 addr_mainman = 0xc138;
 
diff --git a/engines/dreamweb/saveload.cpp b/engines/dreamweb/saveload.cpp
index 2e79d1dbed..79f6caeb31 100644
--- a/engines/dreamweb/saveload.cpp
+++ b/engines/dreamweb/saveload.cpp
@@ -321,13 +321,23 @@ void DreamGenContext::savePosition(unsigned int slot, const uint8 *descbuf) {
 
 	openForSave(slot);
 
+	// Initialize new header
+	FileHeader header;
+
+	// Note: _desc is not zero-terminated
+	const char *desc = "DREAMWEB DATA FILE COPYRIGHT 1992 CREATIVE REALITY";
+	assert(strlen(desc) == sizeof(header._desc));
+	memcpy(header._desc, desc, sizeof(header._desc));
+	memset(&header._len[0], 0, sizeof(header._len));
+	memset(&header._padding[0], 0, sizeof(header._padding));
+
 	// fill length fields in savegame file header
 	uint16 len[6] = { 17, kLengthofvars, kLengthofextra,
 	                  4*kNumchanges, 48, kLenofreelrouts };
 	for (int i = 0; i < 6; ++i)
-		data.word(kFiledata + 2*i) = len[i];
+		header.setLen(i, len[i]);
 
-	engine->writeToSaveFile(data.ptr(kFileheader, kHeaderlen), kHeaderlen);
+	engine->writeToSaveFile((const uint8 *)&header, kHeaderlen);
 	engine->writeToSaveFile(descbuf, len[0]);
 	engine->writeToSaveFile(data.ptr(kStartvars, len[1]), len[1]);
 	engine->writeToSaveFile(getSegment(data.word(kExtras)).ptr(kExframedata, len[2]), len[2]);
@@ -343,12 +353,14 @@ void DreamGenContext::loadPosition(unsigned int slot) {
 
 	openForLoad(slot);
 
-	engine->readFromSaveFile(cs.ptr(kFileheader, kHeaderlen), kHeaderlen);
+	FileHeader header;
+
+	engine->readFromSaveFile((uint8 *)&header, kHeaderlen);
 
 	// read segment lengths from savegame file header
 	int len[6];
 	for (int i = 0; i < 6; ++i)
-		len[i] = cs.word(kFiledata + 2*i);
+		len[i] = header.len(i);
 	if (len[0] != 17)
 		::error("Error loading save: description buffer isn't 17 bytes");
 
@@ -372,15 +384,17 @@ void DreamGenContext::loadPosition(unsigned int slot) {
 unsigned int DreamGenContext::scanForNames() {
 	unsigned int count = 0;
 
+	FileHeader header;
+
 	for (unsigned int slot = 0; slot < 7; ++slot) {
 
 		if (!openForLoad(slot)) continue;
 
 		++count;
 
-		engine->readFromSaveFile(cs.ptr(kFileheader, kHeaderlen), kHeaderlen);
+		engine->readFromSaveFile((uint8 *)&header, kHeaderlen);
 
-		if (cs.word(kFiledata) != 17) {
+		if (header.len(0) != 17) {
 			::warning("Error loading save: description buffer isn't 17 bytes");
 			closeFile();
 			continue;
diff --git a/engines/dreamweb/structs.h b/engines/dreamweb/structs.h
index 2440d182be..106b27ea84 100644
--- a/engines/dreamweb/structs.h
+++ b/engines/dreamweb/structs.h
@@ -262,3 +262,17 @@ struct Sound {
 	uint8 b5;
 };
 
+struct FileHeader {
+	char _desc[50];
+	uint16 _len[20];
+	uint8 _padding[6];
+
+	uint16 len(unsigned int i) const {
+		assert(i < 20);
+		return READ_LE_UINT16(&_len[i]);
+	}
+	void setLen(unsigned int i, uint16 length) {
+		assert(i < 20);
+		WRITE_LE_UINT16(&_len[i], length);
+	}
+};
diff --git a/engines/dreamweb/stubs.cpp b/engines/dreamweb/stubs.cpp
index 4c36e5e1c5..4b3428e47d 100644
--- a/engines/dreamweb/stubs.cpp
+++ b/engines/dreamweb/stubs.cpp
@@ -580,9 +580,11 @@ uint8 *DreamGenContext::textUnder() {
 }
 
 uint16 DreamGenContext::standardLoad(const char *fileName) {
+	FileHeader header;
+
 	engine->openFile(fileName);
-	engine->readFromFile(cs.ptr(kFileheader, kHeaderlen), kHeaderlen);
-	uint16 sizeInBytes = cs.word(kFiledata);
+	engine->readFromFile((uint8 *)&header, kHeaderlen);
+	uint16 sizeInBytes = header.len(0);
 	uint16 result = allocateMem((sizeInBytes + 15) / 16);
 	engine->readFromFile(getSegment(result).ptr(0, 0), sizeInBytes);
 	engine->closeFile();
@@ -2421,12 +2423,14 @@ void DreamGenContext::loadRoomData(const Room &room, bool skipDat) {
 	engine->openFile(room.name);
 	cs.word(kHandle) = 1; //only one handle
 	flags._c = false;
-	readHeader();
+
+	FileHeader header;
+	engine->readFromFile((uint8 *)&header, kHeaderlen);
 
 	// read segment lengths from room file header
 	int len[15];
 	for (int i = 0; i < 15; ++i)
-		len[i] = cs.word(kFiledata + 2*i);
+		len[i] = header.len(i);
 
 	data.word(kBackdrop) = allocateAndLoad(len[0]);
 	clearAndLoad(data.word(kWorkspace), 0, len[1], 132*66); // 132*66 = maplen