Moony z level hack (#15031)

* save work

* Adds Z levels

* a

* ladders + parallax scroll

* zoom out not in

* oops, sandbox

* oops i broke the law

* run ci

* fuck

---------

Co-authored-by: moonheart08 <moonheart08@users.noreply.github.com>

Content.Client/Viewport/ScalingViewport.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using Robust.Client.Graphics;
 using Robust.Client.Input;
 using Robust.Client.UserInterface;
@@ -24,7 +25,9 @@ namespace Content.Client.Viewport
 
         // Internal viewport creation is deferred.
         private IClydeViewport? _viewport;
+        private List<IClydeViewport> _lowerPorts = new();
         private IEye? _eye;
+        private IEye[] _lowerEyes = new IEye[] {};
         private Vector2i _viewportSize;
         private int _curRenderScale;
         private ScalingViewportStretchMode _stretchMode = ScalingViewportStretchMode.Bilinear;
@@ -50,6 +53,27 @@ namespace Content.Client.Viewport
             }
         }
 
+        public IEye[] LowerEyes
+        {
+            get => _lowerEyes;
+            set
+            {
+                var old = value;
+                _lowerEyes = value;
+                if (old.Length != value.Length)
+                {
+                    InvalidateViewport();
+                    Logger.Debug("Eyes updated..");
+                }
+
+
+                foreach (var (eye, port) in _lowerEyes.Zip(_lowerPorts))
+                {
+                    port.Eye = eye;
+                }
+            }
+        }
+
         /// <summary>
         ///     The size, in unscaled pixels, of the internal viewport.
         /// </summary>
@@ -137,6 +161,11 @@ namespace Content.Client.Viewport
 
             _viewport!.Render();
 
+            foreach (var viewport in _lowerPorts)
+            {
+                viewport.Render();
+            }
+
             if (_queuedScreenshots.Count != 0)
             {
                 var callbacks = _queuedScreenshots.ToArray();
@@ -155,6 +184,10 @@ namespace Content.Client.Viewport
             var drawBox = GetDrawBox();
             var drawBoxGlobal = drawBox.Translated(GlobalPixelPosition);
             _viewport.RenderScreenOverlaysBelow(handle, this, drawBoxGlobal);
+            foreach (var viewport in _lowerPorts.AsEnumerable().Reverse())
+            {
+                handle.DrawTextureRect(viewport.RenderTarget.Texture, drawBox);
+            }
             handle.DrawTextureRect(_viewport.RenderTarget.Texture, drawBox);
             _viewport.RenderScreenOverlaysAbove(handle, this, drawBoxGlobal);
         }
@@ -224,6 +257,23 @@ namespace Content.Client.Viewport
                 {
                     Filter = StretchMode == ScalingViewportStretchMode.Bilinear,
                 });
+            _viewport.ClearColor = Color.Blue.WithAlpha(0.02f);
+
+            _lowerPorts.Clear();
+            for (var i = 0; i < _lowerEyes.Length; i++)
+            {
+                _lowerPorts.Add(_clyde.CreateViewport(
+                    ViewportSize * renderScale,
+                    new TextureSampleParameters
+                    {
+                        Filter = StretchMode == ScalingViewportStretchMode.Bilinear,
+                    }));
+                _lowerPorts[i].RenderScale = (renderScale, renderScale);
+                _lowerPorts[i].ClearColor = Color.Blue.WithAlpha(0.02f);
+
+                _lowerPorts[i].Eye = _lowerEyes[i];
+                _lowerPorts[i].Eye!.Zoom =  _lowerPorts[i].Eye!.Zoom * (1.02f + i * 0.02f);
+            }
 
             _viewport.RenderScale = (renderScale, renderScale);
 
@@ -241,6 +291,11 @@ namespace Content.Client.Viewport
         {
             _viewport?.Dispose();
             _viewport = null;
+            foreach (var port in _lowerPorts)
+            {
+                port.Dispose();
+            }
+            _lowerPorts = new();
         }
 
         public MapCoordinates ScreenToMap(Vector2 coords)
@@ -291,7 +346,7 @@ namespace Content.Client.Viewport
 
         private void EnsureViewportCreated()
         {
-            if (_viewport == null)
+            if (_viewport == null || _lowerPorts.Count != _lowerEyes.Length)
             {
                 RegenerateViewport();
             }