homing weapons more or less work now

OpenRa.Game/Effects/Bullet.cs

@@ -0,0 +1,91 @@
+using System;
+using System.Collections.Generic;
+using OpenRa.Game.GameRules;
+using OpenRa.Game.Graphics;
+
+namespace OpenRa.Game.Effects
+{
+	class Bullet : IEffect
+	{
+		readonly Player Owner;
+		readonly Actor FiredBy;
+		readonly WeaponInfo Weapon;
+		readonly ProjectileInfo Projectile;
+		readonly WarheadInfo Warhead;
+		readonly int2 Src;
+		readonly int2 Dest;
+		readonly int2 VisualDest;
+
+		int t = 0;
+		Animation anim;
+
+		const int BaseBulletSpeed = 100;		/* pixels / 40ms frame */
+
+		/* src, dest are *pixel* coords */
+		public Bullet(string weapon, Player owner, Actor firedBy, 
+			int2 src, int2 dest)
+		{
+			Owner = owner;
+			FiredBy = firedBy;
+			Src = src;
+			Dest = dest;
+			VisualDest = Dest + new int2(
+						Game.CosmeticRandom.Next(-10, 10),
+						Game.CosmeticRandom.Next(-10, 10));
+			Weapon = Rules.WeaponInfo[weapon];
+			Projectile = Rules.ProjectileInfo[Weapon.Projectile];
+			Warhead = Rules.WarheadInfo[Weapon.Warhead];
+
+			if (Projectile.Image != null && Projectile.Image != "none")
+			{
+				anim = new Animation(Projectile.Image);
+				if (Projectile.Rotates)
+					Traits.Util.PlayFacing(anim, "idle", () => Traits.Util.GetFacing((dest - src).ToFloat2(), 0));
+				else
+					anim.PlayRepeating("idle");
+			}
+		}
+
+		int TotalTime() { return (Dest - Src).Length * BaseBulletSpeed / Weapon.Speed; }
+
+		public void Tick()
+		{
+			if (t == 0)
+				Sound.Play(Weapon.Report + ".aud");
+
+			t += 40;
+
+			if (t > TotalTime())		/* remove finished bullets */
+			{
+				Game.world.AddFrameEndTask(w => w.Remove(this));
+				Combat.DoImpact(Dest, VisualDest, Weapon, Projectile, Warhead, FiredBy);
+			}
+		}
+
+		const float height = .1f;
+
+		public IEnumerable<Tuple<Sprite, float2, int>> Render()
+		{
+			if (anim != null)
+			{
+				var pos = float2.Lerp(
+						Src.ToFloat2(),
+						VisualDest.ToFloat2(),
+						(float)t / TotalTime()) - 0.5f * anim.Image.size;
+
+				if (Projectile.High || Projectile.Arcing)
+				{
+					if (Projectile.Shadow)
+						yield return Tuple.New(anim.Image, pos, 8);
+
+					var at = (float)t / TotalTime();
+					var highPos = pos - new float2(0, (VisualDest - Src).Length * height * 4 * at * (1 - at));
+
+					yield return Tuple.New(anim.Image, highPos, Owner.Palette);
+				}
+				else
+					yield return Tuple.New(anim.Image, pos, Owner.Palette);
+			}
+		}
+	}
+}