4 files changed, 48 insertions, 8 deletions
diff --git a/engines/sci/engine/kernel32.cpp b/engines/sci/engine/kernel32.cpp
index d6fe995467..d984bf4117 100644
--- a/engines/sci/engine/kernel32.cpp
+++ b/engines/sci/engine/kernel32.cpp
@@ -640,13 +640,26 @@ reg_t kSave(EngineState *s, int argc, reg_t *argv) {
 reg_t kAddScreenItem(EngineState *s, int argc, reg_t *argv) {
 	reg_t viewObj = argv[0];
 	uint16 viewId = GET_SEL32V(s->_segMan, viewObj, view);
-	int16 loopNo = GET_SEL32V(s->_segMan, viewObj, loop);
-	int16 celNo = GET_SEL32V(s->_segMan, viewObj, cel);
-	int16 leftPos = GET_SEL32V(s->_segMan, viewObj, x);
-	int16 topPos = GET_SEL32V(s->_segMan, viewObj, y);
+	uint16 loopNo = GET_SEL32V(s->_segMan, viewObj, loop);
+	uint16 celNo = GET_SEL32V(s->_segMan, viewObj, cel);
+	uint16 leftPos = GET_SEL32V(s->_segMan, viewObj, x);
+	uint16 topPos = GET_SEL32V(s->_segMan, viewObj, y);
 	int16 priority = GET_SEL32V(s->_segMan, viewObj, priority);
 	//int16 control = 0;
 
+	// Theoretically, leftPos and topPos should be sane
+	// Apparently, sometimes they're not, therefore I'm adding some sanity checks here so that 
+	// the hack underneath does not try and draw cels outside the screen coordinates
+	if (leftPos >= (int16)s->_gui->getScreenWidth()) {
+		warning("kAddScreenItem: invalid left position (%d), resetting to 0", leftPos);
+		leftPos = 0;
+	}
+
+	if (topPos >= s->_gui->getScreenHeight()) {
+		warning("kAddScreenItem: invalid top position (%d), resetting to 0", topPos);
+		topPos = 0;
+	}
+
 	// HACK: just draw the view on screen
 	if (viewId != 0xffff)
 		s->_gui->drawCel(viewId, loopNo, celNo, leftPos, topPos, priority, 0);
@@ -661,13 +674,26 @@ reg_t kAddScreenItem(EngineState *s, int argc, reg_t *argv) {
 reg_t kUpdateScreenItem(EngineState *s, int argc, reg_t *argv) {
 	reg_t viewObj = argv[0];
 	uint16 viewId = GET_SEL32V(s->_segMan, viewObj, view);
-	int16 loopNo = GET_SEL32V(s->_segMan, viewObj, loop);
-	int16 celNo = GET_SEL32V(s->_segMan, viewObj, cel);
-	int16 leftPos = GET_SEL32V(s->_segMan, viewObj, x);
-	int16 topPos = GET_SEL32V(s->_segMan, viewObj, y);
+	uint16 loopNo = GET_SEL32V(s->_segMan, viewObj, loop);
+	uint16 celNo = GET_SEL32V(s->_segMan, viewObj, cel);
+	uint16 leftPos = GET_SEL32V(s->_segMan, viewObj, x);
+	uint16 topPos = GET_SEL32V(s->_segMan, viewObj, y);
 	int16 priority = GET_SEL32V(s->_segMan, viewObj, priority);
 	//int16 control = 0;
 	
+	// Theoretically, leftPos and topPos should be sane
+	// Apparently, sometimes they're not, therefore I'm adding some sanity checks here so that 
+	// the hack underneath does not try and draw cels outside the screen coordinates
+	if (leftPos >= s->_gui->getScreenWidth()) {
+		warning("kUpdateScreenItem: invalid left position (%d), resetting to 0", leftPos);
+		leftPos = 0;
+	}
+
+	if (topPos >= s->_gui->getScreenHeight()) {
+		warning("kUpdateScreenItem: invalid top position (%d), resetting to 0", topPos);
+		topPos = 0;
+	}
+
 	// HACK: just draw the view on screen
 	if (viewId != 0xffff)
 		s->_gui->drawCel(viewId, loopNo, celNo, leftPos, topPos, priority, 0);
diff --git a/engines/sci/gui/gui.cpp b/engines/sci/gui/gui.cpp
index 33d124cc54..fcbe4f9a05 100644
--- a/engines/sci/gui/gui.cpp
+++ b/engines/sci/gui/gui.cpp
@@ -823,6 +823,14 @@ void SciGui::portraitShow(Common::String resourceName, Common::Point position, u
 void SciGui::portraitUnload(uint16 portraitId) {
 }
 
+uint16 SciGui::getScreenWidth() {
+	return _screen->_displayWidth;
+}
+
+uint16 SciGui::getScreenHeight() {
+	return _screen->_displayHeight;
+}
+
 bool SciGui::debugUndither(bool flag) {
 	_screen->unditherSetState(flag);
 	return false;
diff --git a/engines/sci/gui/gui.h b/engines/sci/gui/gui.h
index 4db3d931d2..ee1604d25b 100644
--- a/engines/sci/gui/gui.h
+++ b/engines/sci/gui/gui.h
@@ -149,6 +149,9 @@ public:
 	virtual void portraitShow(Common::String resourceName, Common::Point position, uint16 resourceNum, uint16 noun, uint16 verb, uint16 cond, uint16 seq);
 	virtual void portraitUnload(uint16 portraitId);
 
+	virtual uint16 getScreenWidth();
+	virtual uint16 getScreenHeight();
+
 	virtual bool debugUndither(bool flag);
 	virtual bool debugShowMap(int mapNo);
 
diff --git a/engines/sci/gui32/gui32.h b/engines/sci/gui32/gui32.h
index 7646d0c026..2bd13ae850 100644
--- a/engines/sci/gui32/gui32.h
+++ b/engines/sci/gui32/gui32.h
@@ -108,6 +108,9 @@ public:
 	void setCursorPos(Common::Point pos);
 	void moveCursor(Common::Point pos);
 
+	uint16 getScreenWidth() { return 320; }
+	uint16 getScreenHeight() { return 200; }
+
 	bool debugUndither(bool flag);
 	bool debugShowMap(int mapNo);