SCI32: "Improve" comparison algorithm for planes and screen items

This adds a slightly more accurate comparison algorithm that will
at least ensure that all the engine-generated planes and screen
items with matching priorities will be sorted above
script-generated planes and screen items, like in the original
engine. It still does not sort script-generated items by memory
handle order, so if that is ever a thing that actually happens,
those may still be in the wrong order.

1 files changed, 14 insertions, 1 deletions

diff --git a/engines/sci/graphics/plane32.cpp b/engines/sci/graphics/plane32.cpp
index 7d1487bd7c..0a0b0ad561 100644
--- a/engines/sci/graphics/plane32.cpp
+++ b/engines/sci/graphics/plane32.cpp
@@ -447,7 +447,20 @@ void Plane::calcLists(Plane &visiblePlane, const PlaneList &planeList, DrawList
 					if (j < _screenItemList.size() && sli) {
 						if (!sli->_updated && !sli->_deleted && !sli->_created) {
 							ScreenItem *item = dli->screenItem;
-							if (sli->_priority > item->_priority /* TODO: || (sli->_priority == item->_priority && sli->_object > item->_object)*/) {
+
+							bool isAbove = false;
+							if (sli->_priority > item->_priority) {
+								isAbove = true;
+							}
+							else if (sli->_priority == item->_priority) {
+								if (sli->_object.isNumber() && item->_object.isNumber()) {
+									isAbove = sli->_object > item->_object;
+								} else if (sli->_object.isNumber()) {
+									isAbove = true;
+								}
+							}
+
+							if (isAbove) {
 								if (dli->rect.intersects(sli->_screenRect)) {
 									drawList.add(sli, dli->rect.findIntersectingRect(sli->_screenRect));
 								}