ensure boxes don't spawn on goal

Assets/MainAssets/Scripts/Managers/CrowdBotSim_TrialManager.cs

@@ -199,15 +199,22 @@ public class CrowdBotSim_TrialManager : MonoBehaviour, TrialManager {
         float GOAL_X = -7;
         float ROBOT_Z = 0;
         float GOAL_Z = 0;
+        float ROBOT_R = 0.3f;
+        float GOAL_R = 0.5f;
+        float PAD_R = 1.0f;
+        float xmin = x - width / 2.0f;
+        float xmax = x + width / 2.0f;
+        float zmin = z - depth / 2.0f;
+        float zmax = z + depth / 2.0f;
         bool collides_with_robot_or_goal = false;
         if (
-            x < (ROBOT_X + width / 2.0f) && x > (ROBOT_X - width / 2.0f) &&
-            z < (ROBOT_Z + depth / 2.0f) && z > (ROBOT_Z - depth / 2.0f)
+            ROBOT_X > (xmin - ROBOT_R - PAD_R) && ROBOT_X < (xmax + ROBOT_R + PAD_R) &&
+            ROBOT_Z > (zmin - ROBOT_R - PAD_R) && ROBOT_Z < (zmax + ROBOT_R + PAD_R)
             )
             collides_with_robot_or_goal = true;
         if (
-            x < (GOAL_X + width / 2.0f) && x > (GOAL_X - width / 2.0f) &&
-            z < (GOAL_Z + depth / 2.0f) && z > (GOAL_Z - depth / 2.0f)
+            GOAL_X > (xmin - GOAL_R - PAD_R) && GOAL_X < (xmax + GOAL_R + PAD_R) &&
+            GOAL_Z > (zmin - GOAL_R - PAD_R) && GOAL_Z < (zmax + GOAL_R + PAD_R)
             )
             collides_with_robot_or_goal = true;
         return collides_with_robot_or_goal;