Delta-v/Content.Client/Holopad/HolopadSystem.cs

using Content.Shared.Chat.TypingIndicator;
using Content.Shared.Holopad;
using Robust.Client.GameObjects;
using Robust.Client.Graphics;
using Robust.Shared.Prototypes;
using Robust.Shared.Timing;
using System.Linq;
using System.Numerics;
using DrawDepth = Content.Shared.DrawDepth.DrawDepth;

namespace Content.Client.Holopad;

public sealed class HolopadSystem : SharedHolopadSystem
{
    [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
    [Dependency] private readonly IGameTiming _timing = default!;
    [Dependency] private readonly SpriteSystem _sprite = default!;

    public override void Initialize()
    {
        base.Initialize();

        SubscribeLocalEvent<HolopadHologramComponent, ComponentStartup>(OnComponentStartup);
        SubscribeLocalEvent<HolopadHologramComponent, BeforePostShaderRenderEvent>(OnShaderRender);
        SubscribeAllEvent<TypingChangedEvent>(OnTypingChanged);
    }

    private void OnComponentStartup(Entity<HolopadHologramComponent> entity, ref ComponentStartup ev)
    {
        UpdateHologramSprite(entity, entity.Comp.LinkedEntity);
    }

    private void OnShaderRender(Entity<HolopadHologramComponent> entity, ref BeforePostShaderRenderEvent ev)
    {
        if (ev.Sprite.PostShader == null)
            return;

        UpdateHologramSprite(entity, entity.Comp.LinkedEntity);
    }

    private void OnTypingChanged(TypingChangedEvent ev, EntitySessionEventArgs args)
    {
        var uid = args.SenderSession.AttachedEntity;

        if (!Exists(uid))
            return;

        if (!HasComp<HolopadUserComponent>(uid))
            return;

        var netEv = new HolopadUserTypingChangedEvent(GetNetEntity(uid.Value), ev.State);
        RaiseNetworkEvent(netEv);
    }

    private void UpdateHologramSprite(EntityUid hologram, EntityUid? target)
    {
        // Get required components
        if (!TryComp<SpriteComponent>(hologram, out var hologramSprite) ||
            !TryComp<HolopadHologramComponent>(hologram, out var holopadhologram))
            return;

        // Remove all sprite layers
        for (var i = hologramSprite.AllLayers.Count() - 1; i >= 0; i--)
            _sprite.RemoveLayer((hologram, hologramSprite), i);

        if (TryComp<SpriteComponent>(target, out var targetSprite))
        {
            // Use the target's holographic avatar (if available)
            if (TryComp<HolographicAvatarComponent>(target, out var targetAvatar) &&
                targetAvatar.LayerData != null)
            {
                for (var i = 0; i < targetAvatar.LayerData.Length; i++)
                {
                    _sprite.AddLayer((hologram, hologramSprite), targetAvatar.LayerData[i], i);
                }
            }

            // Otherwise copy the target's current physical appearance
            else
            {
                _sprite.CopySprite((target.Value, targetSprite), (hologram, hologramSprite));
            }
        }

        // There is no target, display a default sprite instead (if available)
        else
        {
            if (string.IsNullOrEmpty(holopadhologram.RsiPath) || string.IsNullOrEmpty(holopadhologram.RsiState))
                return;

            var layer = new PrototypeLayerData
            {
                RsiPath = holopadhologram.RsiPath,
                State = holopadhologram.RsiState
            };

            _sprite.AddLayer((hologram, hologramSprite), layer, null);
        }

        // Override specific values
        _sprite.SetColor((hologram, hologramSprite), Color.White);
        _sprite.SetOffset((hologram, hologramSprite), holopadhologram.Offset);
        _sprite.SetDrawDepth((hologram, hologramSprite), (int)DrawDepth.Mobs);
        hologramSprite.NoRotation = true;
        hologramSprite.DirectionOverride = Direction.South;
        hologramSprite.EnableDirectionOverride = true;

        // Remove shading from all layers (except displacement maps)
        for (var i = 0; i < hologramSprite.AllLayers.Count(); i++)
        {
            if (_sprite.TryGetLayer((hologram, hologramSprite), i, out var layer, false) && layer.ShaderPrototype != "DisplacedDraw")
                hologramSprite.LayerSetShader(i, "unshaded");
        }

        UpdateHologramShader(hologram, hologramSprite, holopadhologram);
    }

    private void UpdateHologramShader(EntityUid uid, SpriteComponent sprite, HolopadHologramComponent holopadHologram)
    {
        // Find the texture height of the largest layer
        float texHeight = sprite.AllLayers.Max(x => x.PixelSize.Y);

        var instance = _prototypeManager.Index<ShaderPrototype>(holopadHologram.ShaderName).InstanceUnique();
        instance.SetParameter("color1", new Vector3(holopadHologram.Color1.R, holopadHologram.Color1.G, holopadHologram.Color1.B));
        instance.SetParameter("color2", new Vector3(holopadHologram.Color2.R, holopadHologram.Color2.G, holopadHologram.Color2.B));
        instance.SetParameter("alpha", holopadHologram.Alpha);
        instance.SetParameter("intensity", holopadHologram.Intensity);
        instance.SetParameter("texHeight", texHeight);
        instance.SetParameter("t", (float)_timing.CurTime.TotalSeconds * holopadHologram.ScrollRate);

        sprite.PostShader = instance;
        sprite.RaiseShaderEvent = true;
    }
}