Bug 1454 - GraphUI Scene: Elevate active (selected) shape (add z-offset) and select (pick) in Z descending order

Picking (select) a shape shall process all shapes in Z descending order,
i.e. top shape first. This is a bug currently.

Note: Picking (selecting) a shape using a (mouse-)pointer device
is active by mouse-moved and not only mouse-clicked.
Therefor, we select shapes by mouse-over.

The active selected shape shall have an elevated Z offset to be rendered on top
of the others on same plane.
- This avoids them being rendered below others while moving them around etc.
- This also avoids flickering of overlapping shapes with mouse over.
- This stabilizes the UI experience

1 files changed, 14 insertions, 0 deletions

diff --git a/src/graphui/classes/com/jogamp/graph/ui/Shape.java b/src/graphui/classes/com/jogamp/graph/ui/Shape.java
index 70ceb9f95..db7d7d9c2 100644
--- a/src/graphui/classes/com/jogamp/graph/ui/Shape.java
+++ b/src/graphui/classes/com/jogamp/graph/ui/Shape.java
@@ -1559,6 +1559,20 @@ public abstract class Shape {
             }
         } };
 
+    public static Comparator<Shape> ZDescendingComparator = new Comparator<Shape>() {
+        @Override
+        public int compare(final Shape s1, final Shape s2) {
+            final float s1Z = s1.getScaledMinZ()+s1.getPosition().z();
+            final float s2Z = s2.getScaledMinZ()+s2.getPosition().z();
+            if( FloatUtil.isEqual2(s1Z, s2Z) ) {
+                return 0;
+            } else if( s1Z < s2Z ){
+                return 1;
+            } else {
+                return -1;
+            }
+        } };
+
     //
     //
     //