Allow projectiles to not collide with ships or asteroids

source/Engine.cpp

@@ -2147,12 +2147,15 @@ void Engine::DoCollisions(Projectile &projectile)
 	// shields the ship (unless the projectile has a blast radius).
 	vector<Collision> collisions;
 	const Government *gov = projectile.GetGovernment();
+	const Weapon &weapon = projectile.GetWeapon();
 
 	if(projectile.ShouldExplode())
 		collisions.emplace_back(nullptr, CollisionType::NONE, 0.);
-	else if(projectile.GetWeapon().IsPhasing() && projectile.Target())
+	else if(weapon.IsPhasing() && projectile.Target())
 	{
 		// "Phasing" projectiles that have a target will never hit any other ship.
+		// They also don't care whether the weapon has "no ship collisions" on, as
+		// otherwise a phasing projectile would never hit anything.
 		shared_ptr<Ship> target = projectile.TargetPtr();
 		if(target)
 		{
@@ -2165,7 +2168,7 @@ void Engine::DoCollisions(Projectile &projectile)
 	else
 	{
 		// For weapons with a trigger radius, check if any detectable object will set it off.
-		double triggerRadius = projectile.GetWeapon().TriggerRadius();
+		double triggerRadius = weapon.TriggerRadius();
 		if(triggerRadius)
 			for(const Body *body : shipCollisions.Circle(projectile.Position(), triggerRadius))
 				if(body == projectile.Target() || (gov->IsEnemy(body->GetGovernment())
@@ -2178,16 +2181,18 @@ void Engine::DoCollisions(Projectile &projectile)
 		// If nothing triggered the projectile, check for collisions with ships and asteroids.
 		if(collisions.empty())
 		{
-			const vector<Collision> &newShipHits = shipCollisions.Line(projectile);
-			collisions.insert(collisions.end(), newShipHits.begin(), newShipHits.end());
-
-			// "Phasing" projectiles can pass through asteroids. For all other
-			// projectiles, check if they've hit an asteroid.
-			if(!projectile.GetWeapon().IsPhasing())
+			if(weapon.CanCollideShips())
+			{
+				const vector<Collision> &newShipHits = shipCollisions.Line(projectile);
+				collisions.insert(collisions.end(), newShipHits.begin(), newShipHits.end());
+			}
+			if(weapon.CanCollideAsteroids())
 			{
 				const vector<Collision> &newAsteroidHits = asteroids.CollideAsteroids(projectile);
 				collisions.insert(collisions.end(), newAsteroidHits.begin(), newAsteroidHits.end());
-
+			}
+			if(weapon.CanCollideMinables())
+			{
 				const vector<Collision> &newMinableHits = asteroids.CollideMinables(projectile);
 				collisions.insert(collisions.end(), newMinableHits.begin(), newMinableHits.end());
 			}
@@ -2197,7 +2202,7 @@ void Engine::DoCollisions(Projectile &projectile)
 	// Sort the Collisions by increasing range so that the closer collisions are evaluated first.
 	sort(collisions.begin(), collisions.end());
 
-	// Run all collisiions until either the projectile dies or there are no more collisions left.
+	// Run all collisions until either the projectile dies or there are no more collisions left.
 	for(Collision &collision : collisions)
 	{
 		Body *hit = collision.HitBody();
@@ -2217,13 +2222,13 @@ void Engine::DoCollisions(Projectile &projectile)
 		// If this projectile has a blast radius, find all ships within its
 		// radius. Otherwise, only one is damaged.
 		// TODO: Also deal blast damage to minables?
-		double blastRadius = projectile.GetWeapon().BlastRadius();
+		double blastRadius = weapon.BlastRadius();
 		if(blastRadius)
 		{
 			// Even friendly ships can be hit by the blast, unless it is a
 			// "safe" weapon.
 			Point hitPos = projectile.Position() + range * projectile.Velocity();
-			bool isSafe = projectile.GetWeapon().IsSafe();
+			bool isSafe = weapon.IsSafe();
 			for(Body *body : shipCollisions.Circle(hitPos, blastRadius))
 			{
 				Ship *ship = reinterpret_cast<Ship *>(body);

source/Weapon.cpp

@@ -51,7 +51,13 @@ void Weapon::LoadWeapon(const DataNode &node)
 		else if(key == "safe")
 			isSafe = true;
 		else if(key == "phasing")
+		{
 			isPhasing = true;
+			// Phasing projectiles implicitly have no asteroid collisions
+			// for reverse compatibility.
+			canCollideAsteroids = false;
+			canCollideMinables = false;
+		}
 		else if(key == "no damage scaling")
 			isDamageScaled = false;
 		else if(key == "parallel")
@@ -60,6 +66,12 @@ void Weapon::LoadWeapon(const DataNode &node)
 			isGravitational = true;
 		else if(key == "fused")
 			isFused = true;
+		else if(key == "no ship collisions")
+			canCollideShips = false;
+		else if(key == "no asteroid collisions")
+			canCollideAsteroids = false;
+		else if(key == "no minable collisions")
+			canCollideMinables = false;
 		else if(child.Size() < 2)
 			child.PrintTrace("Skipping weapon attribute with no value specified:");
 		else if(key == "sprite")

source/Weapon.h

@@ -158,6 +158,10 @@ class Weapon {
 	// instead of simply disappearing or only creating a die effect. Blast radius
 	// weapons will cause a blast at the end of their lifetime.
 	bool IsFused() const;
+	// Whether projectiles from this weapon can directly collide with objects.
+	bool CanCollideShips() const;
+	bool CanCollideAsteroids() const;
+	bool CanCollideMinables() const;
 
 	// These values include all submunitions:
 	// Normal damage types:
@@ -244,6 +248,9 @@ class Weapon {
 	bool isDamageScaled = true;
 	bool isGravitational = false;
 	bool isFused = false;
+	bool canCollideShips = true;
+	bool canCollideAsteroids = true;
+	bool canCollideMinables = true;
 	// Guns and missiles are by default aimed a converged point at the
 	// maximum weapons range in front of the ship. When either the installed
 	// weapon or the gun-port (or both) have the isParallel attribute set
@@ -426,6 +433,9 @@ inline bool Weapon::IsPhasing() const { return isPhasing; }
 inline bool Weapon::IsDamageScaled() const { return isDamageScaled; }
 inline bool Weapon::IsGravitational() const { return isGravitational; }
 inline bool Weapon::IsFused() const { return isFused; }
+inline bool Weapon::CanCollideShips() const { return canCollideShips; }
+inline bool Weapon::CanCollideAsteroids() const { return canCollideAsteroids; }
+inline bool Weapon::CanCollideMinables() const { return canCollideMinables; }
 
 inline double Weapon::ShieldDamage() const { return TotalDamage(SHIELD_DAMAGE); }
 inline double Weapon::HullDamage() const { return TotalDamage(HULL_DAMAGE); }