Terrain - Gameplay Properties

Attrition Damage: In some game settings, entering an opponent's territory during ceasefire causes rapid damage to those units.

This attrition damage might have to wait till we impliment territories?

Moving attrition damage to its own task, targeted at the Diplomacy Demo Milestone.

Things lacking in the current implementation (as of [4640]):

• Inheritance. If a terrain has no default passability tag (one without type="..."), the engine should search for a passability matching an entity in the parent terrain XML. And conversely, if a default passability tag is present in the XML, the engine would never search the tags in the parent XML.
• Multiple entity types/classes in one tag. The XML reader should parse a comma-separated list of classes whereas it currently treats it as a single class name.
• Performance. Basically, what the code tries to do is a join on a list of (entity, class) pairs and a list of (class, passability) pairs, sorted on some criterion (by default, position in file - first named first matched, excluding the match-all default rule). The current implementation simply sticks all passability tags in a list, traversing the list in order to select a matching rule. Every time an entity is pathfinded over the terrain in question.