Resolves #8236

Lasers deal more damage to grilles, and clicking directly on the grille
makes it more likely for the grille to absorb the projectile.

code/game/objects/structures/grille.dm

@@ -67,22 +67,29 @@
 
 	//Flimsy grilles aren't so great at stopping projectiles. However they can absorb some of the impact
 	var/damage = Proj.damage
-	var/passthrough
-	if(damage > 30)
-		passthrough = 1
-		if(prob(20))
-			Proj.damage *= 0.5 //weaken the projectile
-	else
-		//weaker bullets are affected to a greater extent
-		if(prob(20))
-			passthrough = 0
-		else
-			Proj.damage *= 0.5 //weaken the projectile
-			passthrough = 1
+	var/passthrough = 0
+	
+	//20% chance that the grille provides a bit more cover than usual. Support structure for example might take up 20% of the grille's area.
+	//If they click on the grille itself then we assume they are aiming at the grille itself and the extra cover behaviour is always used.
+	switch(Proj.damage_type)
+		if(BRUTE)
+			//bullets 
+			if(Proj.original == src || prob(20))
+				Proj.damage *= between(0, Proj.damage/60, 0.5)
+				if(prob(max((damage-10)/25, 0))*100)
+					passthrough = 1
+			else
+				Proj.damage *= between(0, Proj.damage/60, 1)
+				passthrough = 1
+		if(BURN)
+			//beams and other projectiles are either blocked completely by grilles or stop half the damage.
+			if(!(Proj.original == src || prob(20)))
+				Proj.damage *= 0.5
+				passthrough = 1
 	
 	if(passthrough)
 		. = -1
-		damage *= 0.1 //if the bullet passes through then the grille avoids most of the damage
+		damage = between(0, (damage - Proj.damage)*(Proj.damage_type == BRUTE? 0.4 : 1), 10) //if the bullet passes through then the grille avoids most of the damage
 	
 	src.health -= damage*0.2
 	spawn(0) healthcheck() //spawn to make sure we return properly if the grille is deleted