add dialog

entity.lua

@@ -16,7 +16,9 @@ function Entity:initialize(t)
 	self.collision = t.collision --"none", "moveable", "unmoveable"
 	self.sprite = repSprite
 	self.shaAmount = t.sha or 1
-	self.onBump = t.onBump or function(self) return true end
+	-- onBump is a method (see Entity:onBump) so mixins like Dialogable can
+	-- override it; a per-instance t.onBump still wins when supplied.
+	if t.onBump then self.onBump = t.onBump end
 	self.tick = t.tick or function(self) return true end
 
 	self.drawOffset = {x = 0, y = 0}
@@ -163,6 +165,10 @@ function Entity:sha()
 	return math.random(-worldSha, worldSha) * .125 * drawScale
 end
 
+function Entity:onBump()
+	return true
+end
+
 function Entity:bump()
 	return self:onBump()
 end