Files
OpenRA/OpenRA.Mods.Common/Projectiles/Railgun.cs
2024-07-29 21:56:36 +02:00

258 lines
9.0 KiB
C#

#region Copyright & License Information
/*
* Copyright (c) The OpenRA Developers and Contributors
* This file is part of OpenRA, which is free software. It is made
* available to you under the terms of the GNU General Public License
* as published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version. For more
* information, see COPYING.
*/
#endregion
using System.Collections.Generic;
using OpenRA.GameRules;
using OpenRA.Graphics;
using OpenRA.Mods.Common.Graphics;
using OpenRA.Mods.Common.Traits;
using OpenRA.Primitives;
using OpenRA.Traits;
namespace OpenRA.Mods.Common.Projectiles
{
[Desc("Laser effect with helix coiling around.")]
public class RailgunInfo : IProjectileInfo
{
[Desc("Damage all units hit by the beam instead of just the target?")]
public readonly bool DamageActorsInLine = false;
[Desc("The maximum/constant/incremental inaccuracy used in conjunction with the InaccuracyType property.")]
public readonly WDist Inaccuracy = WDist.Zero;
[Desc("Controls the way inaccuracy is calculated. Possible values are " +
"'Maximum' - scale from 0 to max with range, " +
"'PerCellIncrement' - scale from 0 with range, " +
"'Absolute' - use set value regardless of range.")]
public readonly InaccuracyType InaccuracyType = InaccuracyType.Maximum;
[Desc("Can this projectile be blocked when hitting actors with an IBlocksProjectiles trait.")]
public readonly bool Blockable = false;
[Desc("Duration of the beam and helix")]
public readonly int Duration = 15;
[Desc("Equivalent to sequence ZOffset. Controls Z sorting.")]
public readonly int ZOffset = 0;
[Desc("The width of the main trajectory. (\"beam\").")]
public readonly WDist BeamWidth = new(86);
[Desc("The shape of the beam. Accepts values Cylindrical or Flat.")]
public readonly BeamRenderableShape BeamShape = BeamRenderableShape.Cylindrical;
[Desc("Beam color in (A),R,G,B.")]
public readonly Color BeamColor = Color.FromArgb(128, 255, 255, 255);
[Desc("When true, this will override BeamColor parameter and draw the laser with player color."
+ " (Still uses BeamColor's alpha information)")]
public readonly bool BeamPlayerColor = false;
[Desc("Beam alpha gets + this value per tick during drawing; hence negative value makes it fade over time.")]
public readonly int BeamAlphaDeltaPerTick = -8;
[Desc("Thickness of the helix")]
public readonly WDist HelixThickness = new(32);
[Desc("The radius of the spiral effect. (WDist)")]
public readonly WDist HelixRadius = new(64);
[Desc("Height of one complete helix turn, measured parallel to the axis of the helix (WDist)")]
public readonly WDist HelixPitch = new(512);
[Desc("Helix radius gets + this value per tick during drawing")]
public readonly int HelixRadiusDeltaPerTick = 8;
[Desc("Helix alpha gets + this value per tick during drawing; hence negative value makes it fade over time.")]
public readonly int HelixAlphaDeltaPerTick = -8;
[Desc("Helix spins by this much over time each tick.")]
public readonly WAngle HelixAngleDeltaPerTick = new(16);
[Desc("Draw each cycle of helix with this many quantization steps")]
public readonly int QuantizationCount = 16;
[Desc("Helix color in (A),R,G,B.")]
public readonly Color HelixColor = Color.FromArgb(128, 255, 255, 255);
[Desc("Draw helix in PlayerColor? Overrides RGB part of the HelixColor. (Still uses HelixColor's alpha information)")]
public readonly bool HelixPlayerColor = false;
[Desc("Impact animation.")]
public readonly string HitAnim = null;
[Desc("Sequence of impact animation to use.")]
[SequenceReference(nameof(HitAnim), allowNullImage: true)]
public readonly string HitAnimSequence = "idle";
[PaletteReference]
public readonly string HitAnimPalette = "effect";
public IProjectile Create(ProjectileArgs args)
{
var bc = BeamPlayerColor ? Color.FromArgb(BeamColor.A, args.SourceActor.OwnerColor()) : BeamColor;
var hc = HelixPlayerColor ? Color.FromArgb(HelixColor.A, args.SourceActor.OwnerColor()) : HelixColor;
return new Railgun(args, this, bc, hc);
}
}
public class Railgun : IProjectile, ISync
{
readonly ProjectileArgs args;
readonly RailgunInfo info;
readonly Animation hitanim;
public readonly Color BeamColor;
public readonly Color HelixColor;
int ticks;
bool animationComplete;
[Sync]
WPos target;
// Computing these in Railgun instead of RailgunRenderable saves Info.Duration ticks of computation.
// Fortunately, railguns don't track the target.
public int CycleCount { get; private set; }
public WVec SourceToTarget { get; private set; }
public WVec ForwardStep { get; private set; }
public WVec LeftVector { get; private set; }
public WVec UpVector { get; private set; }
public WAngle AngleStep { get; private set; }
public Railgun(ProjectileArgs args, RailgunInfo info, Color beamColor, Color helixColor)
{
this.args = args;
this.info = info;
target = args.PassiveTarget;
BeamColor = beamColor;
HelixColor = helixColor;
if (info.Inaccuracy.Length > 0)
{
var maxInaccuracyOffset = Util.GetProjectileInaccuracy(info.Inaccuracy.Length, info.InaccuracyType, args);
target += WVec.FromPDF(args.SourceActor.World.SharedRandom, 2) * maxInaccuracyOffset / 1024;
}
if (!string.IsNullOrEmpty(info.HitAnim))
hitanim = new Animation(args.SourceActor.World, info.HitAnim);
CalculateVectors();
}
void CalculateVectors()
{
// Check for blocking actors
if (info.Blockable && BlocksProjectiles.AnyBlockingActorsBetween(args.SourceActor.World, args.SourceActor.Owner, target, args.Source,
info.BeamWidth, out var blockedPos))
target = blockedPos;
// Note: WAngle.Sin(x) = 1024 * Math.Sin(2pi/1024 * x)
AngleStep = new WAngle(1024 / info.QuantizationCount);
SourceToTarget = target - args.Source;
// Forward step, pointing from src to target.
// QuantizationCont * forwardStep == One cycle of beam in src2target direction.
ForwardStep = info.HelixPitch.Length * SourceToTarget / (info.QuantizationCount * SourceToTarget.Length);
// An easy vector to find which is perpendicular vector to forwardStep, with 0 Z component
LeftVector = new WVec(ForwardStep.Y, -ForwardStep.X, 0);
if (LeftVector.LengthSquared != 0)
LeftVector = 1024 * LeftVector / LeftVector.Length;
// Vector that is pointing upwards from the ground
UpVector = new WVec(
-ForwardStep.X * ForwardStep.Z,
-ForwardStep.Z * ForwardStep.Y,
ForwardStep.X * ForwardStep.X + ForwardStep.Y * ForwardStep.Y);
if (UpVector.LengthSquared != 0)
UpVector = 1024 * UpVector / UpVector.Length;
//// LeftVector and UpVector are unit vectors of size 1024.
CycleCount = SourceToTarget.Length / info.HelixPitch.Length;
if (SourceToTarget.Length % info.HelixPitch.Length != 0)
CycleCount++; // math.ceil, int version.
// Using ForwardStep * CycleCount, the helix and the main beam gets "out of sync"
// if drawn from source to target. Instead, the main beam is drawn from source to end point of helix.
// Trade-off between computation vs Railgun weapon range.
// Modders must not have too large range for railgun weapons.
SourceToTarget = info.QuantizationCount * CycleCount * ForwardStep;
}
public void Tick(World world)
{
if (ticks == 0)
{
if (hitanim != null)
hitanim.PlayThen(info.HitAnimSequence, () => animationComplete = true);
else
animationComplete = true;
if (!info.DamageActorsInLine)
{
var warheadArgs = new WarheadArgs(args)
{
ImpactOrientation = new WRot(WAngle.Zero, Util.GetVerticalAngle(args.Source, target), args.Facing),
ImpactPosition = target,
};
args.Weapon.Impact(Target.FromPos(target), warheadArgs);
}
else
{
var actors = world.FindActorsOnLine(args.Source, target, info.BeamWidth);
foreach (var a in actors)
{
var warheadArgs = new WarheadArgs(args)
{
ImpactOrientation = new WRot(WAngle.Zero, Util.GetVerticalAngle(args.Source, target), args.Facing),
// Calculating an impact position is bogus for line damage.
// FindActorsOnLine guarantees that the beam touches the target's HitShape,
// so we just assume a center hit to avoid bogus warhead recalculations.
ImpactPosition = a.CenterPosition,
};
args.Weapon.Impact(Target.FromActor(a), warheadArgs);
}
}
}
hitanim?.Tick();
if (ticks++ > info.Duration && animationComplete)
world.AddFrameEndTask(w => w.Remove(this));
}
public IEnumerable<IRenderable> Render(WorldRenderer wr)
{
if (wr.World.FogObscures(target) &&
wr.World.FogObscures(args.Source))
yield break;
if (ticks < info.Duration)
{
yield return new RailgunHelixRenderable(args.Source, info.ZOffset, this, info, ticks);
yield return new BeamRenderable(args.Source, info.ZOffset, SourceToTarget, info.BeamShape, info.BeamWidth,
Color.FromArgb(BeamColor.A + info.BeamAlphaDeltaPerTick * ticks, BeamColor));
}
if (hitanim != null)
foreach (var r in hitanim.Render(target, wr.Palette(info.HitAnimPalette)))
yield return r;
}
}
}