Refactoring in explosion sounds.

gameelement/canvas.go

@@ -327,6 +327,13 @@ func (c *Canvas) UpdateEnemies() {
 	for _, e := range c.enemies {
 		if !c.gameover {
 			e.SetTarget(c.hero.Pos)
+
+			if e.GetEnemyState() == gamedata.EnemyStateExploding && !e.ExplosionInitiated() {
+				if c.eventmap[gamedata.GameEventExplosion] != nil {
+					c.eventmap[gamedata.GameEventExplosion]()
+				}
+				e.SetExplosionInitiated()
+			}
 		} else {
 			e.SetTarget(e.GetPosition())
 		}