Made projectile-only swords fully aimable (#198).

CHANGELOG.md

@@ -40,6 +40,7 @@
 	- Fixed the `Volcano`, `Blood Butcherer`, and a few other melee weapons using incorrect rotations & locations for their particle effects.
 	- Fixed the following projectile-only swords not getting the broadsword overhaul: `Night's Edge`, `Excalibur`, `True Excalibur`, `True Night's Edge`, `Terra Blade`, `The Horseman's Blade`.
 	- Fixed `Blade of Grass` and projectile-only swords being able to create projectiles during a power attack charge.
+	- Fixed projectile-only swords not being fully aimable.
 
 # 5.0 BETA 13B
 

Common/Hooks/Items/IModifyItemNewProjectile.cs

@@ -0,0 +1,73 @@
+using System;
+using Microsoft.Xna.Framework;
+using Terraria;
+using Terraria.DataStructures;
+using Terraria.ModLoader;
+using Terraria.ModLoader.Core;
+using Hook = TerrariaOverhaul.Common.Hooks.Items.IModifyItemNewProjectile;
+
+namespace TerrariaOverhaul.Common.Hooks.Items;
+
+public interface IModifyItemNewProjectile
+{
+	//TODO: Use ref fields when they are available.
+	public ref struct Args
+	{
+		public IEntitySource Source;
+		public Vector2 Position;
+		public Vector2 Velocity;
+		public int Type;
+		public int Damage;
+		public float Knockback;
+		public int Owner;
+		public float AI0;
+		public float AI1;
+		public float AI2;
+	}
+
+	public static readonly GlobalHookList<GlobalItem> Hook = ItemLoader.AddModHook(new GlobalHookList<GlobalItem>(typeof(Hook).GetMethod(nameof(ModifyShootProjectile))));
+
+	void ModifyShootProjectile(Player player, Item item, in Args args, ref Args result);
+
+	public static void Invoke(Player player, Item item, in Args args, ref Args result)
+	{
+		(item.ModItem as Hook)?.ModifyShootProjectile(player, item, in args, ref result);
+
+		foreach (Hook g in Hook.Enumerate(item)) {
+			g.ModifyShootProjectile(player, item, in args, ref result);
+		}
+	}
+}
+
+public sealed class ItemOnShootProjectileImplementation : ILoadable
+{
+	public void Load(Mod mod)
+	{
+		On_Projectile.NewProjectile_IEntitySource_float_float_float_float_int_int_float_int_float_float_float += (orig, entitySource, x, y, speedX, speedY, type, damage, knockback, owner, ai0, ai1, ai2) => {
+			if (entitySource is EntitySource_ItemUse_WithAmmo parentSource && parentSource.Entity is Player player) {
+				Hook.Args data;
+
+				data.Source = entitySource;
+				data.Position = new Vector2(x, y);
+				data.Velocity = new Vector2(speedX, speedY);
+				data.Type = type;
+				data.Damage = damage;
+				data.Knockback = knockback;
+				data.Owner = owner;
+				data.AI0 = ai0;
+				data.AI1 = ai1;
+				data.AI2 = ai2;
+
+				var args = data;
+
+				Hook.Invoke(player, parentSource.Item, in args, ref data);
+
+				(x, y, speedX, speedY, ai0, ai1, ai2) = (data.Position.X, data.Position.Y, data.Velocity.X, data.Velocity.Y, data.AI0, data.AI1, data.AI2);
+			}
+
+			return orig(entitySource, x, y, speedX, speedY, type, damage, knockback, owner, ai0, ai1, ai2);
+		};
+	}
+
+	public void Unload() { }
+}

Common/Melee/ItemMeleeAttackAiming.cs

@@ -1,6 +1,7 @@
 using System;
 using Microsoft.Xna.Framework;
 using Terraria;
+using Terraria.DataStructures;
 using Terraria.ID;
 using Terraria.ModLoader;
 using TerrariaOverhaul.Common.Damage;
@@ -11,7 +12,7 @@
 
 namespace TerrariaOverhaul.Common.Melee;
 
-public sealed class ItemMeleeAttackAiming : ItemComponent, ICanMeleeCollideWithNPC
+public sealed class ItemMeleeAttackAiming : ItemComponent, ICanMeleeCollideWithNPC, IModifyItemNewProjectile
 {
 	private Vector2 attackDirection;
 	private float attackAngle;
@@ -47,7 +48,7 @@ public override void ModifyHitNPC(Item item, Player player, NPC target, ref NPC.
 		}
 	}
 
-	public bool? CanMeleeCollideWithNPC(Item item, Player player, NPC target, Rectangle itemRectangle)
+	bool? ICanMeleeCollideWithNPC.CanMeleeCollideWithNPC(Item item, Player player, NPC target, Rectangle itemRectangle)
 	{
 		if (!Enabled) {
 			return null;
@@ -63,6 +64,16 @@ public override void ModifyHitNPC(Item item, Player player, NPC target, ref NPC.
 		return CollisionUtils.CheckRectangleVsArcCollision(target.getRect(), player.Center, AttackAngle, MathHelper.Pi * 0.5f, range);
 	}
 
+	void IModifyItemNewProjectile.ModifyShootProjectile(Player player, Item item, in IModifyItemNewProjectile.Args args, ref IModifyItemNewProjectile.Args result)
+	{
+		// Makes always horizontally-facing projectiles aimable.
+		if (args.Source is EntitySource_ItemUse_WithAmmo && args.Velocity.Y == 0f && args.Velocity.X == player.direction) {
+			if (item.TryGetGlobalItem(out ItemMeleeAttackAiming aiming)) {
+				result.Velocity = aiming.AttackDirection;
+			}
+		}
+	}
+
 	public static float GetAttackRange(Item item, Player player, Rectangle? itemRectangle = null)
 	{
 		Rectangle itemHitbox = GetMeleeHitbox(player, item);