Tweaks to some sections of the code that recognise what shields the player has. Specifically:

* introducing the new friend, SH_FORCEHP (which is used as a bitmask to get the extra hitpoints of a force-shield user)
* P_DamageMobj now considers the unimplemented shield constants as well as the implemented ones.

src/d_player.h

@@ -196,6 +196,7 @@ typedef enum
 	SH_FIREFLOWER = 0x100,
 	// The force shield uses the lower 8 bits to count how many hits are left.
 	SH_FORCE = 0x200,
+	SH_FORCEHP = 0xFF, // to be used as a bitmask only
 
 	SH_STACK = SH_FIREFLOWER,
 	SH_NOSTACK = ~SH_STACK

src/p_inter.c

@@ -2972,20 +2972,28 @@ boolean P_DamageMobj(mobj_t *target, mobj_t *inflictor, mobj_t *source, INT32 da
 			if (!(target->player->pflags & (PF_NIGHTSMODE|PF_NIGHTSFALL)) && (maptol & TOL_NIGHTS))
 				return false;
 
+#define shieldtype (player->powers[pw_shield] & SH_NOSTACK)
 			switch (damagetype)
 			{
 				case DMG_WATER:
+					if (shieldtype == SH_BUBBLEWRAP
+					|| shieldtype == SH_ELEMENTAL)
+						return false; // Invincible to water damage
+					break;
 				case DMG_FIRE:
-					if ((player->powers[pw_shield] & SH_NOSTACK) == SH_ELEMENTAL)
+					if (shieldtype == SH_FLAMEAURA
-						return false; // Invincible to water/fire damage
+					|| shieldtype == SH_ELEMENTAL)
+						return false; // Invincible to fire damage
 					break;
 				case DMG_ELECTRIC:
-					if ((player->powers[pw_shield] & SH_NOSTACK) == SH_ATTRACT)
+					if (shieldtype == SH_ATTRACT
+					|| shieldtype == SH_THUNDERCOIN)
 						return false; // Invincible to electric damage
 					break;
 				default:
 					break;
 			}
+#undef shieldtype
 		}
 
 		if (player->pflags & PF_NIGHTSMODE) // NiGHTS damage handling

src/p_mobj.c

@@ -6326,9 +6326,9 @@ static boolean P_ShieldLook(mobj_t *thing, shieldtype_t shield)
 		return false;
 	}
 
-	if (shield == SH_FORCE && thing->movecount != (thing->target->player->powers[pw_shield] & 0xFF))
+	if (shield == SH_FORCE && thing->movecount != (thing->target->player->powers[pw_shield] & SH_FORCEHP))
 	{
-		thing->movecount = (thing->target->player->powers[pw_shield] & 0xFF);
+		thing->movecount = (thing->target->player->powers[pw_shield] & SH_FORCEHP);
 		if (thing->movecount < 1)
 		{
 			if (thing->info->painstate)

src/p_user.c

@@ -1392,7 +1392,7 @@ void P_SpawnShieldOrb(player_t *player)
 	if (player->powers[pw_shield] & SH_FORCE)
 	{
 		//Copy and pasted from P_ShieldLook in p_mobj.c
-		shieldobj->movecount = (player->powers[pw_shield] & 0xFF);
+		shieldobj->movecount = (player->powers[pw_shield] & SH_FORCEHP);
 		if (shieldobj->movecount < 1)
 		{
 			if (shieldobj->info->painstate)
@@ -6950,7 +6950,7 @@ static void P_MovePlayer(player_t *player)
 #endif
 						dashangle += ANGLE_180;
 						P_ResetPlayer(player);
-						player->homing = 2 + ((player->powers[pw_shield] & SH_NOSTACK) - SH_FORCE); // might get ridiculous with 256 hitpoints, don't you think?
+						player->homing = 2 + (player->powers[pw_shield] & SH_FORCEHP); // might get ridiculous with 256 hitpoints, don't you think?
 						S_StartSound(player->mo, sfx_s3k47);
 						P_SetPlayerMobjState(player->mo, S_PLAY_SPIN);
 						player->pflags |= PF_SPINNING|PF_THOKKED|PF_SHIELDABILITY;

src/st_stuff.c

@@ -800,7 +800,7 @@ static void ST_drawFirstPersonHUD(void)
 	// Graue 06-18-2004: no V_NOSCALESTART, no SCX, no SCY, snap to right
 	if (player->powers[pw_shield] & SH_FORCE)
 	{
-		if ((player->powers[pw_shield] & 0xFF) > 0 || leveltime & 1)
+		if ((player->powers[pw_shield] & SH_FORCEHP) > 0 || leveltime & 1)
 			p = forceshield;
 	}
 	else switch (player->powers[pw_shield] & SH_NOSTACK)