Fix and enable collateral damage for missing missiles

Collateral damage was disabled, because after msl_hit() reported a
miss, the missile may or may not have reached the target.

Fix by splitting msl_launch() off msl_hit().

Drop the disabled collateral damage code for sector targets, because
sectors can't be missed.  Enable it for ships and land units.

Since msl_launch() returns whether the missile is sub-launched, drop
launch_missile() parameter sublaunch, and simplify its caller.

include/prototypes.h

@@ -492,8 +492,9 @@ extern int move_ground(struct sctstr *, struct sctstr *,
 		       int, int *);
 extern int fly_map(coord, coord);
 /* mslsub.c */
-extern int msl_hit(struct plnstr *, int, int, int, int, char *,
+extern int msl_launch(struct plnstr *, int, char *, coord, coord, natid,
-		   coord, coord, int);
+		      int *);
+extern int msl_hit(struct plnstr *, int, int, int, int, int, natid);
 extern void msl_sel(struct emp_qelem *, coord, coord, natid, int,
 		    int, int);
 extern int msl_abm_intercept(struct plnstr *, coord, coord, int);

src/lib/commands/laun.c

@@ -47,7 +47,7 @@
 #include "ship.h"
 
 static int launch_as(struct plnstr *pp);
-static int launch_missile(struct plnstr *pp, int sublaunch);
+static int launch_missile(struct plnstr *pp);
 static int launch_sat(struct plnstr *pp);
 static int msl_equip(struct plnstr *, char);
 
@@ -59,8 +59,6 @@ laun(void)
 {
     struct nstr_item nstr;
     struct plnstr plane;
-    struct shpstr ship;
-    int sublaunch;
     struct plchrstr *pcp;
     int retval, gone;
 
@@ -101,17 +99,11 @@ laun(void)
 	}
 	if (!pln_airbase_ok(&plane, 1, 1))
 	    continue;
-	sublaunch = 0;
-	if (plane.pln_ship >= 0) {
-	    getship(plane.pln_ship, &ship);
-	    if (mchr[(int)ship.shp_type].m_flags & M_SUB)
-		sublaunch = 1;
-	}
 	pr("%s at %s; range %d, eff %d%%\n", prplane(&plane),
 	   xyas(plane.pln_x, plane.pln_y, player->cnum),
 	   plane.pln_range, plane.pln_effic);
 	if (!(pcp->pl_flags & P_O)) {
-	    retval = launch_missile(&plane, sublaunch);
+	    retval = launch_missile(&plane);
 	    gone = 1;
 	} else if ((pcp->pl_flags & (P_M | P_O)) == (P_M | P_O)) {
 	    retval = launch_as(&plane);
@@ -160,8 +152,10 @@ launch_as(struct plnstr *pp)
     }
     if (msl_equip(pp, 'i') < 0)
 	return RET_FAIL;
-    if (msl_hit(pp, pln_def(&plane), EF_PLANE, 0, 0,
+    if (msl_launch(pp, EF_PLANE, prplane(&plane),
-		prplane(&plane), plane.pln_x, plane.pln_y, plane.pln_own)) {
+		   plane.pln_x, plane.pln_y, plane.pln_own, NULL) < 0)
+	return RET_OK;
+    if (msl_hit(pp, pln_def(&plane), EF_PLANE, 0, 0, 0, plane.pln_own)) {
 	pr("Satellite shot down\n");
 	mpr(plane.pln_own, "%s anti-sat destroyed %s over %s\n",
 	    cname(player->cnum), prplane(&plane),
@@ -175,16 +169,15 @@ launch_as(struct plnstr *pp)
 
 /*
  * Launch missile PP.
- * If SUBLAUNCH, it's sub-launched.
  * Return RET_OK if launched (even when missile explodes),
  * else RET_SYN or RET_FAIL.
  */
 static int
-launch_missile(struct plnstr *pp, int sublaunch)
+launch_missile(struct plnstr *pp)
 {
     struct plchrstr *pcp = plchr + pp->pln_type;
     coord sx, sy;
-    int n, dam;
+    int n, dam, sublaunch;
     char *cp;
     struct mchrstr *mcp;
     struct shpstr target_ship;
@@ -250,18 +243,12 @@ launch_missile(struct plnstr *pp, int sublaunch)
 		return RET_OK;
 	    }
 	}
-	if (!msl_hit(pp, SECT_HARDTARGET, EF_SECTOR, N_SCT_MISS,
+	if (msl_launch(pp, EF_SECTOR, "sector", sx, sy, sect.sct_own,
-		     N_SCT_SMISS, "sector", sx, sy, sect.sct_own)) {
+		       &sublaunch) < 0)
-#if 0
-	    /*
-	     * FIXME want collateral damage on miss, but we get here
-	     * too when launch fails or missile is intercepted
-	     */
-	    dam = pln_damage(pp, 's', 0);
-	    collateral_damage(sect.sct_x, sect.sct_y, dam, 0);
-#endif
 	    return RET_OK;
-	}
+	if (!msl_hit(pp, SECT_HARDTARGET, EF_SECTOR,
+		     N_SCT_MISS, N_SCT_SMISS, sublaunch, sect.sct_own))
+	    CANT_REACH();
 	if (getnuke(nuk_on_plane(pp), &nuke))
 	    detonate(&nuke, sx, sy, pp->pln_flags & PLN_AIRBURST);
 	else {
@@ -285,15 +272,16 @@ launch_missile(struct plnstr *pp, int sublaunch)
     } else {
 	if (msl_equip(pp, 'p') < 0)
 	    return RET_FAIL;
-	if (!msl_hit(pp, shp_hardtarget(&target_ship), EF_SHIP,
+	if (msl_launch(pp, EF_SHIP, prship(&target_ship),
-		     N_SHP_MISS, N_SHP_SMISS, prship(&target_ship),
 		       target_ship.shp_x, target_ship.shp_y,
+		       target_ship.shp_own, &sublaunch) < 0)
+	    return RET_OK;
+	if (!msl_hit(pp, shp_hardtarget(&target_ship), EF_SHIP,
+		     N_SHP_MISS, N_SHP_SMISS, sublaunch,
 		     target_ship.shp_own)) {
 	    pr("splash\n");
-#if 0 /* FIXME see above */
 	    dam = pln_damage(pp, 'p', 0);
-	    collateral_damage(target_ship.shp_x, target_ship.shp_y, dam, 0);
+	    collateral_damage(target_ship.shp_x, target_ship.shp_y, dam);
-#endif
 	    return RET_OK;
 	}
 	dam = pln_damage(pp, 'p', 1);

src/lib/subs/lndsub.c

@@ -720,7 +720,7 @@ lnd_missile_interdiction(struct emp_qelem *list, coord newx, coord newy,
 {
     int mindam = lnd_count(list) * 20;
     int hardtarget = lnd_easiest_target(list);
-    int dam, newdam;
+    int dam, newdam, sublaunch;
     struct plist *plp;
     struct emp_qelem msl_list, *qp, *newqp;
 
@@ -732,22 +732,18 @@ lnd_missile_interdiction(struct emp_qelem *list, coord newx, coord newy,
 	plp = (struct plist *)qp;
 
 	if (dam < mindam && mission_pln_equip(plp, NULL, 'p') >= 0) {
+	    if (msl_launch(&plp->plane, EF_LAND, "troops",
+			   newx, newy, victim, &sublaunch) < 0)
+		goto use_up_msl;
 	    if (msl_hit(&plp->plane, hardtarget, EF_LAND,
-			N_LND_MISS, N_LND_SMISS,
+			N_LND_MISS, N_LND_SMISS, sublaunch, victim)) {
-			"troops", newx, newy, victim)) {
 		newdam = pln_damage(&plp->plane, 'p', 1);
 		dam += newdam;
-#if 0
-	    /*
-	     * FIXME want collateral damage on miss, but we get here
-	     * too when launch fails or missile is intercepted
-	     */
 	    } else {
-		/* Missiles that miss have to hit somewhere! */
 		newdam = pln_damage(&plp->plane, 'p', 0);
 		collateral_damage(newx, newy, newdam);
-#endif
 	    }
+	use_up_msl:
 	    plp->plane.pln_effic = 0;
 	    putplane(plp->plane.pln_uid, &plp->plane);
 	}

src/lib/subs/mission.c

@@ -389,7 +389,7 @@ perform_mission(coord x, coord y, natid victim, struct emp_qelem *list,
     struct plchrstr *pcp;
     int dam = 0, dam2;
     natid plane_owner = 0;
-    int md, range, air_dam;
+    int md, range, air_dam, sublaunch;
     double hitchance, vrange;
     int targeting_ships = *s == 's'; /* "subs" or "ships" FIXME gross! */
 
@@ -562,22 +562,15 @@ perform_mission(coord x, coord y, natid victim, struct emp_qelem *list,
 	    && !CANT_HAPPEN(hardtarget != SECT_HARDTARGET
 			    || (plp->pcp->pl_flags & P_MAR))
 	    && mission_pln_equip(plp, NULL, 'p') >= 0) {
-	    if (msl_hit(&plp->plane, SECT_HARDTARGET, EF_SECTOR,
+	    if (msl_launch(&plp->plane, EF_SECTOR, "sector", x, y, victim,
-			N_SCT_MISS, N_SCT_SMISS,
+			   &sublaunch) < 0)
-			"sector", x, y, victim)) {
+		goto use_up_msl;
+	    if (!msl_hit(&plp->plane, SECT_HARDTARGET, EF_SECTOR,
+			N_SCT_MISS, N_SCT_SMISS, sublaunch, victim))
+		CANT_REACH();
 	    dam2 = pln_damage(&plp->plane, 'p', 1);
 	    air_dam += dam2;
-#if 0
+	use_up_msl:
-	    /*
-	     * FIXME want collateral damage on miss, but we get here
-	     * too when launch fails or missile is intercepted
-	     */
-	    } else {
-		/* Missiles that miss have to hit somewhere! */
-		dam2 = pln_damage(&plp->plane, 'p', 0);
-		collateral_damage(x, y, dam2);
-#endif
-	    }
 	    plp->plane.pln_effic = 0;
 	    putplane(plp->plane.pln_uid, &plp->plane);
 	}

src/lib/subs/mslsub.c

@@ -30,6 +30,7 @@
  *  Known contributors to this file:
  *     Ken Stevens, 1995
  *     Steve McClure, 1996-2000
+ *     Markus Armbruster, 2004-2009
  */
 
 #include <config.h>
@@ -54,15 +55,13 @@
 #include "xy.h"
 
 int
-msl_hit(struct plnstr *pp, int hardtarget, int type, int news_item,
+msl_launch(struct plnstr *pp, int type, char *what, coord x, coord y,
-	int snews_item, char *what, coord x, coord y, int victim)
+	   natid victim, int *sublaunchp)
 {
-    int hit;
     struct shpstr ship;
     struct sctstr sect;
     int sublaunch = 0;
     struct plchrstr *pcp = plchr + pp->pln_type;
-    int hitchance;
     char *from;
     int dam;
 
@@ -108,7 +107,7 @@ msl_hit(struct plnstr *pp, int hardtarget, int type, int news_item,
 		putsect(&sect);
 	    }
 	}
-	return 0;
+	return -1;
     }
 
     CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED);
@@ -123,13 +122,25 @@ msl_hit(struct plnstr *pp, int hardtarget, int type, int news_item,
 
     if ((pcp->pl_flags & P_T && !(pcp->pl_flags & P_MAR))) {
 	if (msl_abm_intercept(pp, x, y, sublaunch))
-	    return 0;
+	    return -1;
     }
     if (pcp->pl_flags & P_MAR) {
 	if (shp_missile_defense(x, y, pp->pln_own, pln_def(pp))) {
+	    return -1;
+	}
+    }
+
+    if (sublaunchp)
+	*sublaunchp = sublaunch;
     return 0;
 }
-    }
+
+int
+msl_hit(struct plnstr *pp, int hardtarget, int type,
+	int news_item, int snews_item, int sublaunch, natid victim)
+{
+    struct plchrstr *pcp = plchr + pp->pln_type;
+    int hitchance, hit;
 
     if (nuk_on_plane(pp) >= 0) {
 	mpr(pp->pln_own, "\tArming nuclear warheads...\n");
@@ -294,8 +305,9 @@ msl_intercept(struct plnstr *msl, struct sctstr *sp, int sublaunch,
 		def_name, who, att_name, cname(sp->sct_own));
 	}
 
-	if (msl_hit(pp, pln_def(msl), EF_PLANE, 0, 0,
+	if (msl_launch(pp, EF_PLANE, att_name, sp->sct_x, sp->sct_y,
-		    att_name, sp->sct_x, sp->sct_y, msl->pln_own)) {
+		       msl->pln_own, NULL) >= 0
+	    && msl_hit(pp, pln_def(msl), EF_PLANE, 0, 0, 0, msl->pln_own)) {
 	    mpr(msl->pln_own, "%s destroyed by %s %s!\n",
 		att_name, cname(pp->pln_own), def_name);
 	    mpr(sp->sct_own, "%s %s intercepted!\n", who, att_name);

src/lib/subs/shpsub.c

@@ -480,7 +480,7 @@ static int
 shp_missile_interdiction(struct emp_qelem *list, coord newx, coord newy,
 			 natid victim)
 {
-    int dam;
+    int dam, sublaunch;
     int stopping = 0;
     struct emp_qelem msl_list, *qp, *newqp;
     struct plist *plp;
@@ -494,11 +494,12 @@ shp_missile_interdiction(struct emp_qelem *list, coord newx, coord newy,
 
 	mvs = most_valuable_ship(list, newx, newy);
 	if (mvs && mission_pln_equip(plp, NULL, 'p') >= 0) {
+	    if (msl_launch(&plp->plane, EF_SHIP, prship(&mvs->unit.ship),
+			   newx, newy, victim, &sublaunch) < 0)
+		goto use_up_msl;
 	    if (msl_hit(&plp->plane,
-			shp_hardtarget(&mvs->unit.ship),
+			shp_hardtarget(&mvs->unit.ship), EF_SHIP,
-			EF_SHIP, N_SHP_MISS, N_SHP_SMISS,
+			N_SHP_MISS, N_SHP_SMISS, sublaunch, victim)) {
-			prship(&mvs->unit.ship),
-			newx, newy, victim)) {
 		dam = pln_damage(&plp->plane, 'p', 1);
 		if (dam) {
 		    mpr(victim,
@@ -507,17 +508,11 @@ shp_missile_interdiction(struct emp_qelem *list, coord newx, coord newy,
 		    shp_damage_one(mvs, dam);
 		    stopping = 1;
 		}
-#if 0
-	    /*
-	     * FIXME want collateral damage on miss, but we get here
-	     * too when launch fails or missile is intercepted
-	     */
 	    } else {
-		/* Missiles that miss have to hit somewhere! */
 		dam = pln_damage(&plp->plane, 'p', 0);
 		collateral_damage(newx, newy, dam);
-#endif
 	    }
+	use_up_msl:
 	    plp->plane.pln_effic = 0;
 	    putplane(plp->plane.pln_uid, &plp->plane);
 	}