Fix collision detection for Missiles and Bullets.

OpenRA.Mods.Common/Effects/Bullet.cs

@@ -50,6 +50,12 @@ namespace OpenRA.Mods.Common.Effects
 		[Desc("Is this blocked by actors with BlocksProjectiles trait.")]
 		public readonly bool Blockable = true;
 
+		[Desc("Width of projectile (used for finding blocking actors).")]
+		public readonly WDist Width = new WDist(1);
+
+		[Desc("Extra search radius beyond path for blocking actors.")]
+		public readonly WDist TargetExtraSearchRadius = new WDist(2048);
+
 		[Desc("Arc in WAngles, two values indicate variable arc.")]
 		public readonly WAngle[] Angle = { WAngle.Zero };
 
@@ -156,8 +162,19 @@ namespace OpenRA.Mods.Common.Effects
 			if (anim != null)
 				anim.Tick();
 
+			var lastPos = pos;
 			pos = WPos.LerpQuadratic(args.Source, target, angle, ticks, length);
 
+			// Check for walls or other blocking obstacles
+			var shouldExplode = false;
+			WPos blockedPos;
+			if (info.Blockable && BlocksProjectiles.AnyBlockingActorsBetween(world, lastPos, pos, info.Width,
+				info.TargetExtraSearchRadius, out blockedPos))
+			{
+				pos = blockedPos;
+				shouldExplode = true;
+			}
+
 			if (!string.IsNullOrEmpty(info.Trail) && --smokeTicks < 0)
 			{
 				var delayedPos = WPos.LerpQuadratic(args.Source, target, angle, ticks - info.TrailDelay, length);
@@ -168,8 +185,8 @@ namespace OpenRA.Mods.Common.Effects
 			if (info.ContrailLength > 0)
 				contrail.Update(pos);
 
-			var shouldExplode = ticks++ >= length // Flight length reached/exceeded
-				|| (info.Blockable && BlocksProjectiles.AnyBlockingActorAt(world, pos)); // Hit a wall or other blocking obstacle
+			// Flight length reached / exceeded
+			shouldExplode |= ticks++ >= length;
 
 			if (shouldExplode)
 				Explode(world);

OpenRA.Mods.Common/Effects/Missile.cs

@@ -58,6 +58,12 @@ namespace OpenRA.Mods.Common.Effects
 		[Desc("Is the missile blocked by actors with BlocksProjectiles: trait.")]
 		public readonly bool Blockable = true;
 
+		[Desc("Width of projectile (used for finding blocking actors).")]
+		public readonly WDist Width = new WDist(1);
+
+		[Desc("Extra search radius beyond path for blocking actors.")]
+		public readonly WDist TargetExtraSearchRadius = new WDist(2048);
+
 		[Desc("Maximum offset at the maximum range")]
 		public readonly WDist Inaccuracy = WDist.Zero;
 
@@ -773,8 +779,19 @@ namespace OpenRA.Mods.Common.Effects
 			renderFacing = WAngle.ArcTan(move.Z - move.Y, move.X).Angle / 4 - 64;
 
 			// Move the missile
+			var lastPos = pos;
 			pos += move;
 
+			// Check for walls or other blocking obstacles
+			var shouldExplode = false;
+			WPos blockedPos;
+			if (info.Blockable && BlocksProjectiles.AnyBlockingActorsBetween(world, lastPos, pos, info.Width,
+				info.TargetExtraSearchRadius, out blockedPos))
+			{
+				pos = blockedPos;
+				shouldExplode = true;
+			}
+
 			// Create the smoke trail effect
 			if (!string.IsNullOrEmpty(info.TrailImage) && --ticksToNextSmoke < 0 && (state != States.Freefall || info.TrailWhenDeactivated))
 			{
@@ -786,14 +803,10 @@ namespace OpenRA.Mods.Common.Effects
 				contrail.Update(pos);
 
 			var cell = world.Map.CellContaining(pos);
-
-			// NOTE: High speeds might cause the missile to miss the target or fly through obstacles
-			//       In that case, big moves should probably be decomposed into multiple smaller ones with hit checks
 			var height = world.Map.DistanceAboveTerrain(pos);
-			var shouldExplode = (height.Length < 0) // Hit the ground
-				|| (relTarDist < info.CloseEnough.Length) // Within range
+			shouldExplode |= height.Length < 0 // Hit the ground
+				|| relTarDist < info.CloseEnough.Length // Within range
 				|| (info.ExplodeWhenEmpty && info.RangeLimit != 0 && ticks > info.RangeLimit) // Ran out of fuel
-				|| (info.Blockable && BlocksProjectiles.AnyBlockingActorAt(world, pos)) // Hit a wall or other blocking obstacle
 				|| !world.Map.Contains(cell) // This also avoids an IndexOutOfRangeException in GetTerrainInfo below.
 				|| (!string.IsNullOrEmpty(info.BoundToTerrainType) && world.Map.GetTerrainInfo(cell).Type != info.BoundToTerrainType) // Hit incompatible terrain
 				|| (height.Length < info.AirburstAltitude.Length && relTarHorDist < info.CloseEnough.Length); // Airburst