SCI: Some updates to SCI32 kernel graphics functions

- Added a stub for kSetScroll, which sets the target picture immediately
for now
- Added an initial stub of kPalCycle (doesn't work correctly yet)
- Adjusted the signatures of kUpdateLine and kDeleteLine for LSL6
- Unmapped kSetHotRectangles again, with updated information on how it
is used in Phantasmagoria

1 files changed, 8 insertions, 0 deletions

diff --git a/engines/sci/graphics/frameout.cpp b/engines/sci/graphics/frameout.cpp
index 5b857fe3d8..31ad7a50aa 100644
--- a/engines/sci/graphics/frameout.cpp
+++ b/engines/sci/graphics/frameout.cpp
@@ -294,6 +294,10 @@ reg_t GfxFrameout::addPlaneLine(reg_t object, Common::Point startPoint, Common::
 }
 
 void GfxFrameout::updatePlaneLine(reg_t object, reg_t hunkId, Common::Point startPoint, Common::Point endPoint, byte color, byte priority, byte control) {
+	// Check if we're asked to update a line that was never added
+	if (object.isNull())
+		return;
+
 	for (PlaneList::iterator it = _planes.begin(); it != _planes.end(); ++it) {
 		if (it->object == object) {
 			for (PlaneLineList::iterator it2 = it->lines.begin(); it2 != it->lines.end(); ++it2) {
@@ -311,6 +315,10 @@ void GfxFrameout::updatePlaneLine(reg_t object, reg_t hunkId, Common::Point star
 }
 
 void GfxFrameout::deletePlaneLine(reg_t object, reg_t hunkId) {
+	// Check if we're asked to delete a line that was never added (happens during the intro of LSL6)
+	if (object.isNull())
+		return;
+
 	for (PlaneList::iterator it = _planes.begin(); it != _planes.end(); ++it) {
 		if (it->object == object) {
 			for (PlaneLineList::iterator it2 = it->lines.begin(); it2 != it->lines.end(); ++it2) {