TEENAGENT: Add Resource code to precompute Dialog Offsets.

This should allow the removal of most/all of the hardcoded eseg
addresses in the Dialog calls.

engines/teenagent/resources.cpp

@@ -57,6 +57,32 @@ quick note on varia resources:
 #define DSEG_SIZE 59280 // 0xe790
 #define ESEG_SIZE 35810 // 0x8be2
 
+void Resources::precomputeDialogOffsets() {
+	dialogOffsets.push_back(0);
+	int n = 0;
+	uint8 current, last = 0xff;
+	for (uint i = 0; i < eseg.size(); i++) {
+		current = eseg.get_byte(i);
+
+		if (n == 4) {
+			dialogOffsets.push_back(i);
+			n = 0;
+		}
+
+		if (current != 0x00 && last == 0x00)
+			n = 0;
+
+		if (current == 0x00)
+			n++;
+
+		last = current;
+	}
+
+	debug(1, "Resources::precomputeDialogOffsets() - Found %d dialogs", dialogOffsets.size());
+	for (uint i = 0; i < dialogOffsets.size(); i++)
+		debug(1, "\tDialog #%d: Offset 0x%04x", i, dialogOffsets[i]);
+}
+
 bool Resources::loadArchives(const ADGameDescription *gd) {
 	Common::File *dat_file = new Common::File();
 	if (!dat_file->open("teenagent.dat")) {
@@ -73,6 +99,8 @@ bool Resources::loadArchives(const ADGameDescription *gd) {
 
 	delete dat;
 
+	precomputeDialogOffsets();
+
 	FilePack varia;
 	varia.open("varia.res");
 	font7.load(varia, 7);

engines/teenagent/resources.h

@@ -52,8 +52,16 @@ class Resources {
 	FilePack off, on, ons, lan000, lan500, sam_mmm, sam_sam, mmm, voices;
 #endif
 
-	Segment cseg, dseg, eseg;
+	Segment cseg, dseg;
 	Font font7, font8;
+
+	const byte *getDialog(uint16 dialogNum) { return eseg.ptr(dialogOffsets[dialogNum]); }
+
+	Segment eseg;
+private:
+	void precomputeDialogOffsets();
+
+	Common::Array<uint16> dialogOffsets;
 };
 
 } // End of namespace TeenAgent