DREAMWEB: Convert workoutFrames to C++

4 files changed, 56 insertions, 88 deletions

diff --git a/engines/dreamweb/dreambase.h b/engines/dreamweb/dreambase.h
index 28feb5b975..f52ada2a72 100644
--- a/engines/dreamweb/dreambase.h
+++ b/engines/dreamweb/dreambase.h
@@ -69,6 +69,7 @@ public:
 	Common::Point _lineData[200];		// Output of Bresenham
 	void checkDest(const RoomPaths *roomsPaths);
 	RoomPaths *getRoomsPaths();
+	void workoutFrames();
 
 	// from print.cpp
 	uint8 getNextWord(const Frame *charSet, const uint8 *string, uint8 *totalWidth, uint8 *charCount);
diff --git a/engines/dreamweb/dreamgen.cpp b/engines/dreamweb/dreamgen.cpp
index 3a9fb57541..209cabe107 100644
--- a/engines/dreamweb/dreamgen.cpp
+++ b/engines/dreamweb/dreamgen.cpp
@@ -6908,93 +6908,6 @@ searchmess:
 	printDirect();
 }
 
-void DreamGenContext::workoutFrames() {
-	STACK_CHECK;
-	bx = data.word(kLinestartx);
-	_add(bx, 32);
-	ax = data.word(kLineendx);
-	_add(ax, 32);
-	_sub(bx, ax);
-	if (!flags.c())
-		goto notneg1;
-	_neg(bx);
-notneg1:
-	cx = data.word(kLinestarty);
-	_add(cx, 32);
-	ax = data.word(kLineendy);
-	_add(ax, 32);
-	_sub(cx, ax);
-	if (!flags.c())
-		goto notneg2;
-	_neg(cx);
-notneg2:
-	_cmp(bx, cx);
-	if (!flags.c())
-		goto tendstohoriz;
-	dl = 2;
-	ax = cx;
-	_shr(ax, 1);
-	_cmp(bx, ax);
-	if (flags.c())
-		goto gotquad;
-	dl = 1;
-	goto gotquad;
-tendstohoriz:
-	dl = 0;
-	ax = bx;
-	_shr(ax, 1);
-	_cmp(cx, ax);
-	if (flags.c())
-		goto gotquad;
-	dl = 1;
-	goto gotquad;
-gotquad:
-	bx = data.word(kLinestartx);
-	_add(bx, 32);
-	ax = data.word(kLineendx);
-	_add(ax, 32);
-	_sub(bx, ax);
-	if (flags.c())
-		goto isinright;
-	cx = data.word(kLinestarty);
-	_add(cx, 32);
-	ax = data.word(kLineendy);
-	_add(ax, 32);
-	_sub(cx, ax);
-	if (!flags.c())
-		goto topleft;
-	_cmp(dl, 1);
-	if (flags.z())
-		goto noswap1;
-	_xor(dl, 2);
-noswap1:
-	_add(dl, 4);
-	goto success;
-topleft:
-	_add(dl, 6);
-	goto success;
-isinright:
-	cx = data.word(kLinestarty);
-	_add(cx, 32);
-	ax = data.word(kLineendy);
-	_add(ax, 32);
-	_sub(cx, ax);
-	if (!flags.c())
-		goto botright;
-	_add(dl, 2);
-	goto success;
-botright:
-	_cmp(dl, 1);
-	if (flags.z())
-		goto noswap2;
-	_xor(dl, 2);
-noswap2:
-success:
-	_and(dl, 7);
-	data.byte(kTurntoface) = dl;
-	data.byte(kTurndirection) = 0;
-}
-
 void DreamGenContext::getUnderZoom() {
 	STACK_CHECK;
 	di = (8)+5;
diff --git a/engines/dreamweb/dreamgen.h b/engines/dreamweb/dreamgen.h
index 0fb155b6a5..3ac92218a8 100644
--- a/engines/dreamweb/dreamgen.h
+++ b/engines/dreamweb/dreamgen.h
@@ -600,7 +600,6 @@ public:
 	void cantDrop();
 	void putUnderZoom();
 	void findInvPos();
-	void workoutFrames();
 	void rollEndCredits();
 	void getKeyAndLogo();
 	void selectOb();
diff --git a/engines/dreamweb/pathfind.cpp b/engines/dreamweb/pathfind.cpp
index 0f717a983f..439ac9b177 100644
--- a/engines/dreamweb/pathfind.cpp
+++ b/engines/dreamweb/pathfind.cpp
@@ -269,4 +269,59 @@ void DreamGenContext::bresenhams() {
 	}
 }
 
+void DreamBase::workoutFrames() {
+	byte tmp;
+	uint16 diffx, diffy;
+
+	// FIXME: Paranoia asserts, to be removed after sufficient play
+	// testing has happened. Background: The original code used to add
+	// 32 to the four values listed in the asserts below. Which seems
+	// nonsensical, as only the differences of the values matter, so the
+	// +32 cancels out. Unless there is an overflow somewhere... So we
+	// check for that here.
+	assert(data.word(kLinestartx) < 0xFFFF - 32);
+	assert(data.word(kLineendx)   < 0xFFFF - 32);
+	assert(data.word(kLinestarty) < 0xFFFF - 32);
+	assert(data.word(kLineendy)   < 0xFFFF - 32);
+
+
+	diffx = ABS(data.word(kLinestartx) - data.word(kLineendx));
+	diffy = ABS(data.word(kLinestarty) - data.word(kLineendy));
+
+	if (diffx < diffy) {
+		tmp = 2;
+		if (diffx >= (diffy >> 1))
+			tmp = 1;
+	} else {
+		// tendstohoriz
+		tmp = 0;
+		if (diffy >= (diffx >> 1))
+			tmp = 1;
+	}
+
+	if (data.word(kLinestartx) >= data.word(kLineendx)) {
+		// isinleft
+		if (data.word(kLinestarty) < data.word(kLineendy)) {
+			if (tmp != 1)
+				tmp ^= 2;
+			tmp += 4;
+		} else {
+			// topleft
+			tmp += 6;
+		}
+	} else {
+		// isinright
+		if (data.word(kLinestarty) < data.word(kLineendy)) {
+			tmp += 2;
+		} else {
+			// botright
+			if (tmp != 1)
+				tmp ^= 2;
+		}
+	}
+
+	data.byte(kTurntoface) = tmp & 7;
+	data.byte(kTurndirection) = 0;
+}
+
 } // End of namespace DreamGen