crystall-punk-14/Content.Client/Graphics/Overlays/GradientCircleMask.cs

using Content.Shared.GameObjects.Components.Mobs;
using Robust.Client.Graphics.Drawing;
using Robust.Client.Graphics.Overlays;
using Robust.Client.Graphics.Shaders;
using Robust.Client.Interfaces.Graphics.ClientEye;
using Robust.Shared.IoC;
using Robust.Shared.Maths;
using Robust.Shared.Prototypes;

namespace Content.Client.Graphics.Overlays
{
    public class GradientCircleMaskOverlay : Overlay
    {
        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
        [Dependency] private readonly IEyeManager _eyeManager = default!;

        public override OverlaySpace Space => OverlaySpace.WorldSpace;
        private readonly ShaderInstance _shader;

        public GradientCircleMaskOverlay() : base(nameof(SharedOverlayID.GradientCircleMaskOverlay))
        {
            IoCManager.InjectDependencies(this);
            _shader = _prototypeManager.Index<ShaderPrototype>("GradientCircleMask").Instance();
        }

        protected override void Draw(DrawingHandleBase handle, OverlaySpace currentSpace)
        {
            handle.UseShader(_shader);
            var worldHandle = (DrawingHandleWorld)handle;
            var viewport = _eyeManager.GetWorldViewport();
            worldHandle.DrawRect(viewport, Color.White);
        }
    }
}