Add back blindfire support lost in 99073e.

This was lost at the very beginning, when I first merged the baseq2 and
xatrix bugfixes into rogue. I did that by hand, not with my infamous
cleanup script. That came later for the big cleanup before version
2.00... For some reason my playstyle has a very low chance to trigger
blindfiring, so I never realized that it's missing and wasn't able to
reproduce the problem when it was reported in yquake2/yquake2#435.

Reported by @BjossiAlfreds in #34, closes #34.

src/monster/tank/tank.c

@@ -394,6 +394,8 @@ tank_pain(edict_t *self, edict_t *other /* unused */, float kick, int damage)
 		return; /* no pain anims in nightmare */
 	}
 
+	self->monsterinfo.aiflags &= ~AI_MANUAL_STEERING;
+
 	if (damage <= 30)
 	{
 		self->monsterinfo.currentmove = &tank_move_pain1;
@@ -465,12 +467,25 @@ TankRocket(edict_t *self)
 	vec3_t dir;
 	vec3_t vec;
 	int flash_number;
+	trace_t trace;
+	int rocketSpeed;
+	vec3_t target;
+	qboolean blindfire = false;
 
-	if (!self)
+	if (!self || !self->enemy || !self->enemy->inuse)
 	{
 		return;
 	}
 
+	if (self->monsterinfo.aiflags & AI_MANUAL_STEERING)
+	{
+		blindfire = true;
+	}
+	else
+	{
+		blindfire = false;
+	}
+
 	if (self->s.frame == FRAME_attak324)
 	{
 		flash_number = MZ2_TANK_ROCKET_1;
@@ -485,15 +500,111 @@ TankRocket(edict_t *self)
 	}
 
 	AngleVectors(self->s.angles, forward, right, NULL);
-	G_ProjectSource(self->s.origin, monster_flash_offset[flash_number], forward,
-			right, start);
+	G_ProjectSource(self->s.origin, monster_flash_offset[flash_number], forward, right, start);
 
+	rocketSpeed = 500 + (100 * skill->value);
+
+	if (blindfire)
+	{
+		VectorCopy (self->monsterinfo.blind_fire_target, target);
+	}
+	else
+	{
+		VectorCopy (self->enemy->s.origin, target);
+	}
+
+	if (blindfire)
+	{
+		VectorCopy(target, vec);
+		VectorSubtract(vec, start, dir);
+	}
+	else if(random() < 0.66 || (start[2] < self->enemy->absmin[2]))
+	{
+		// Don't shoot at the feed if enemy is above.
 		VectorCopy(self->enemy->s.origin, vec);
 		vec[2] += self->enemy->viewheight;
 		VectorSubtract(vec, start, dir);
+	}
+	else
+	{
+		// Shoot at the feed.
+		VectorCopy(self->enemy->s.origin, vec);
+		vec[2] = self->enemy->absmin[2];
+		VectorSubtract(vec, start, dir);
+	}
+
+	// Lead target: 20, 35, 50, 65 chance of leading.
+	if ((!blindfire) && ((random() < (0.2 + ((3 - skill->value) * 0.15)))))
+	{
+		float dist;
+		float time;
+
+		dist = VectorLength(dir);
+		time = dist/rocketSpeed;
+		VectorMA(vec, time, self->enemy->velocity, vec);
+		VectorSubtract(vec, start, dir);
+	}
+
 	VectorNormalize(dir);
 
-	monster_fire_rocket(self, start, dir, 50, 550, flash_number);
+	// Blindfire doesn't check target (done in checkattack). Paranoia:
+	// Make sure we're not shooting a target right next to us.
+	trace = gi.trace(start, vec3_origin, vec3_origin, vec, self, MASK_SHOT);
+
+	if (blindfire)
+	{
+		// Blindfire has different fail criteria for the trace
+		if (!(trace.startsolid || trace.allsolid || (trace.fraction < 0.5)))
+		{
+			monster_fire_rocket (self, start, dir, 50, rocketSpeed, flash_number);
+		}
+		else
+		{
+			// Try shifting the target to the left a little (to help counter large offset)
+			VectorCopy(target, vec);
+			VectorMA(vec, -20, right, vec);
+			VectorSubtract(vec, start, dir);
+			VectorNormalize(dir);
+
+			trace = gi.trace(start, vec3_origin, vec3_origin, vec, self, MASK_SHOT);
+
+			if (!(trace.startsolid || trace.allsolid || (trace.fraction < 0.5)))
+			{
+				monster_fire_rocket (self, start, dir, 50, rocketSpeed, flash_number);
+			}
+			else
+			{
+				// OK, that failed. Try to the right.
+				VectorCopy(target, vec);
+				VectorMA(vec, 20, right, vec);
+				VectorSubtract(vec, start, dir);
+				VectorNormalize(dir);
+
+				trace = gi.trace(start, vec3_origin, vec3_origin, vec, self, MASK_SHOT);
+
+				if (!(trace.startsolid || trace.allsolid || (trace.fraction < 0.5)))
+				{
+					monster_fire_rocket (self, start, dir, 50, rocketSpeed, flash_number);
+				}
+				else if ((g_showlogic) && (g_showlogic->value))
+				{
+					gi.dprintf ("tank avoiding blindfire shot\n");
+				}
+			}
+		}
+	}
+	else
+	{
+		trace = gi.trace(start, vec3_origin, vec3_origin, vec, self, MASK_SHOT);
+
+		if (trace.ent == self->enemy || trace.ent == world)
+		{
+			if (trace.fraction > 0.5 || (trace.ent && trace.ent->client))
+			{
+				monster_fire_rocket (self, start, dir, 50, rocketSpeed, MZ2_CHICK_ROCKET_1);
+			}
+		}
+	}
 }
 
 void
@@ -505,7 +616,7 @@ TankMachineGun(edict_t *self)
 	vec3_t forward, right;
 	int flash_number;
 
-	if (!self)
+	if (!self || !self->enemy || !self->enemy->inuse)
 	{
 		return;
 	}
@@ -564,9 +675,12 @@ mframe_t tank_frames_attack_blast[] = {
 	{ai_charge, 0, NULL},
 	{ai_charge, 0, TankBlaster}         /* 16 */
 };
-mmove_t tank_move_attack_blast =
-{FRAME_attak101, FRAME_attak116, tank_frames_attack_blast,
- tank_reattack_blaster};
+mmove_t tank_move_attack_blast = {
+	FRAME_attak101,
+	FRAME_attak116,
+	tank_frames_attack_blast,
+	tank_reattack_blaster
+};
 
 mframe_t tank_frames_reattack_blast[] = {
 	{ai_charge, 0, NULL},
@@ -820,6 +934,13 @@ tank_refire_rocket(edict_t *self)
 		return;
 	}
 
+	if (self->monsterinfo.aiflags & AI_MANUAL_STEERING)
+	{
+		self->monsterinfo.aiflags &= ~AI_MANUAL_STEERING;
+		self->monsterinfo.currentmove = &tank_move_attack_post_rocket;
+		return;
+	}
+
 	/* Only on hard or nightmare */
 	if (skill->value >= 2)
 	{
@@ -856,8 +977,9 @@ tank_attack(edict_t *self)
 	vec3_t vec;
 	float range;
 	float r;
+	float chance;
 
-	if (!self)
+	if (!self || !self->enemy || !self->enemy->inuse)
 	{
 		return;
 	}
@@ -869,6 +991,45 @@ tank_attack(edict_t *self)
 		return;
 	}
 
+	if (self->monsterinfo.attack_state == AS_BLIND)
+	{
+		if (self->monsterinfo.blind_fire_delay < 1.0)
+		{
+			chance = 1.0;
+		}
+		else if (self->monsterinfo.blind_fire_delay < 7.5)
+		{
+			chance = 0.4;
+		}
+		else
+		{
+			chance = 0.1;
+		}
+
+		r = random();
+
+		self->monsterinfo.blind_fire_delay += 3.2 + 2.0 + random() * 3.0;
+
+		// Don't shoot at the origin.
+		if (VectorCompare (self->monsterinfo.blind_fire_target, vec3_origin))
+		{
+			return;
+		}
+
+		// Don't shoot if the dice say not to.
+		if (r > chance)
+		{
+			return;
+		}
+
+		// turn on manual steering to signal both manual steering and blindfire
+		self->monsterinfo.aiflags |= AI_MANUAL_STEERING;
+		self->monsterinfo.currentmove = &tank_move_attack_fire_rocket;
+		self->monsterinfo.attack_finished = level.time + 3.0 + 2*random();
+		self->pain_debounce_time = level.time + 5.0; // no pain for a while
+		return;
+	}
+
 	VectorSubtract(self->enemy->s.origin, self->s.origin, vec);
 	range = VectorLength(vec);
 
@@ -986,8 +1147,7 @@ tank_die(edict_t *self, edict_t *inflictor /* unused */, edict_t *attacker /* un
 	/* check for gib */
 	if (self->health <= self->gib_health)
 	{
-		gi.sound(self, CHAN_VOICE, gi.soundindex(
-						"misc/udeath.wav"), 1, ATTN_NORM, 0);
+		gi.sound(self, CHAN_VOICE, gi.soundindex("misc/udeath.wav"), 1, ATTN_NORM, 0);
 
 		for (n = 0; n < 1 /*4*/; n++)
 		{
@@ -1018,6 +1178,20 @@ tank_die(edict_t *self, edict_t *inflictor /* unused */, edict_t *attacker /* un
 	self->monsterinfo.currentmove = &tank_move_death;
 }
 
+qboolean tank_blocked(edict_t *self, float dist)
+{
+	if (blocked_checkshot(self, 0.25 + (0.05 * skill->value) ))
+	{
+		return true;
+	}
+
+	if(blocked_checkplat(self, dist))
+	{
+		return true;
+	}
+
+	return false;
+}
 
 /*
  * QUAKED monster_tank (1 .5 0) (-32 -32 -16) (32 32 72) Ambush Trigger_Spawn Sight
@@ -1086,6 +1260,7 @@ SP_monster_tank(edict_t *self)
 	self->monsterinfo.melee = NULL;
 	self->monsterinfo.sight = tank_sight;
 	self->monsterinfo.idle = tank_idle;
+	self->monsterinfo.blocked = tank_blocked;
 
 	gi.linkentity(self);
 
@@ -1094,6 +1269,9 @@ SP_monster_tank(edict_t *self)
 
 	walkmonster_start(self);
 
+	self->monsterinfo.aiflags |= AI_IGNORE_SHOTS;
+	self->monsterinfo.blindfire = true;
+
 	if (strcmp(self->classname, "monster_tank_commander") == 0)
 	{
 		self->s.skinnum = 2;

src/savegame/tables/gamefunc_decs.h

@@ -330,6 +330,7 @@ extern void tank_windup ( edict_t * self ) ;
 extern void tank_thud ( edict_t * self ) ;
 extern void tank_footstep ( edict_t * self ) ;
 extern void tank_sight ( edict_t * self , edict_t * other ) ;
+extern qboolean tank_blocked( edict_t *self, float dist );
 extern void SP_monster_supertank ( edict_t * self ) ;
 extern qboolean supertank_blocked ( edict_t * self , float dist ) ;
 extern void supertank_die ( edict_t * self , edict_t * inflictor , edict_t * attacker , int damage , vec3_t point ) ;

src/savegame/tables/gamefunc_list.h

@@ -330,6 +330,7 @@
 {"tank_thud", (byte *)tank_thud},
 {"tank_footstep", (byte *)tank_footstep},
 {"tank_sight", (byte *)tank_sight},
+{"tank_blocked", (byte *)tank_blocked},
 {"SP_monster_supertank", (byte *)SP_monster_supertank},
 {"supertank_blocked", (byte *)supertank_blocked},
 {"supertank_die", (byte *)supertank_die},