Improve paper stamping experience (#17135)

Content.Client/Fax/AdminUI/AdminFaxEui.cs

@@ -1,4 +1,4 @@
-using Content.Client.Eui;
+using Content.Client.Eui;
 using Content.Shared.Eui;
 using Content.Shared.Fax;
 using JetBrains.Annotations;
@@ -15,7 +15,8 @@ public sealed class AdminFaxEui : BaseEui
         _window = new AdminFaxWindow();
         _window.OnClose += () => SendMessage(new AdminFaxEuiMsg.Close());
         _window.OnFollowFax += uid => SendMessage(new AdminFaxEuiMsg.Follow(uid));
-        _window.OnMessageSend += args => SendMessage(new AdminFaxEuiMsg.Send(args.uid, args.title, args.from, args.message, args.stamp));
+        _window.OnMessageSend += args => SendMessage(new AdminFaxEuiMsg.Send(args.uid, args.title,
+                    args.stampedBy, args.message, args.stampSprite, args.stampColor));
     }
 
     public override void Opened()

Content.Client/Fax/AdminUI/AdminFaxWindow.xaml

@@ -1,4 +1,4 @@
-<DefaultWindow xmlns="https://spacestation14.io"
+<DefaultWindow xmlns="https://spacestation14.io"
                Title="{Loc admin-fax-title}"
                MinWidth="400">
     <BoxContainer Orientation="Vertical" VerticalExpand="True">
@@ -21,6 +21,8 @@
             <Control MinWidth="5" />
             <OptionButton Name="StampSelector" HorizontalExpand="True" />
         </BoxContainer>
+        <Label Text="{Loc admin-fax-stamp-color}" />
+        <ColorSelectorSliders Margin="12 0 0 0" Name="StampColorSelector" Color="#BB3232"/>
         <Control MinHeight="10" />
         <Button Name="SendButton" Text="{Loc admin-fax-send}"></Button>
     </BoxContainer>

Content.Client/Fax/AdminUI/AdminFaxWindow.xaml.cs

@@ -1,4 +1,4 @@
-using Content.Shared.Fax;
+using Content.Shared.Fax;
 using Robust.Client.AutoGenerated;
 using Robust.Client.ResourceManagement;
 using Robust.Client.UserInterface.Controls;
@@ -13,7 +13,7 @@ public sealed partial class AdminFaxWindow : DefaultWindow
 {
     private const string StampsRsiPath = "/Textures/Objects/Misc/bureaucracy.rsi";
 
-    public Action<(EntityUid uid, string title, string from, string message, string stamp)>? OnMessageSend;
+    public Action<(EntityUid uid, string title, string stampedBy, string message, string stampSprite, Color stampColor)>? OnMessageSend;
     public Action<EntityUid>? OnFollowFax;
 
     public AdminFaxWindow()
@@ -28,6 +28,9 @@ public sealed partial class AdminFaxWindow : DefaultWindow
         FollowButton.OnPressed += FollowFax;
         SendButton.OnPressed += SendMessage;
 
+        // Don't use this, but ColorSelectorSliders requires it:
+        StampColorSelector.OnColorChanged += (Color) => {};
+
         var loc = IoCManager.Resolve<ILocalizationManager>();
         MessageEdit.Placeholder = new Rope.Leaf(loc.GetString("admin-fax-message-placeholder")); // TextEdit work only with Nodes
     }
@@ -90,6 +93,7 @@ public sealed partial class AdminFaxWindow : DefaultWindow
             return;
 
         var from = FromEdit.Text;
-        OnMessageSend?.Invoke((faxUid.Value, title, from, message, stamp));
+        var stampColor = StampColorSelector.Color;
+        OnMessageSend?.Invoke((faxUid.Value, title, from, message, stamp, stampColor));
     }
 }

Content.Client/Paper/UI/PaperBoundUserInterface.cs

@@ -5,67 +5,66 @@ using Robust.Shared.Input;
 using Robust.Shared.Utility;
 using static Content.Shared.Paper.SharedPaperComponent;
 
-namespace Content.Client.Paper.UI
+namespace Content.Client.Paper.UI;
+
+[UsedImplicitly]
+public sealed class PaperBoundUserInterface : BoundUserInterface
 {
-    [UsedImplicitly]
+    [ViewVariables]
-    public sealed class PaperBoundUserInterface : BoundUserInterface
+    private PaperWindow? _window;
+
+    public PaperBoundUserInterface(EntityUid owner, Enum uiKey) : base(owner, uiKey)
     {
-        [ViewVariables]
+    }
-        private PaperWindow? _window;
 
-        public PaperBoundUserInterface(EntityUid owner, Enum uiKey) : base(owner, uiKey)
+    protected override void Open()
+    {
+        base.Open();
+
+        _window = new PaperWindow();
+        _window.OnClose += Close;
+        _window.Input.OnKeyBindDown += args => // Solution while TextEdit don't have events
         {
-        }
+            if (args.Function == EngineKeyFunctions.TextSubmit)
-
-        protected override void Open()
-        {
-            base.Open();
-
-            _window = new PaperWindow();
-            _window.OnClose += Close;
-            _window.Input.OnKeyBindDown += args => // Solution while TextEdit don't have events
             {
-                if (args.Function == EngineKeyFunctions.TextSubmit)
+                var text = Rope.Collapse(_window.Input.TextRope);
-                {
+                Input_OnTextEntered(text);
-                    var text = Rope.Collapse(_window.Input.TextRope);
+                args.Handle();
-                    Input_OnTextEntered(text);
-                    args.Handle();
-                }
-            };
-
-            if (EntMan.TryGetComponent<PaperVisualsComponent>(Owner, out var visuals))
-            {
-                _window.InitVisuals(visuals);
             }
+        };
 
-            _window.OpenCentered();
+        if (EntMan.TryGetComponent<PaperVisualsComponent>(Owner, out var visuals))
+        {
+            _window.InitVisuals(Owner, visuals);
         }
 
-        protected override void UpdateState(BoundUserInterfaceState state)
+        _window.OpenCentered();
-        {
+    }
-            base.UpdateState(state);
-            _window?.Populate((PaperBoundUserInterfaceState) state);
-        }
 
-        private void Input_OnTextEntered(string text)
+    protected override void UpdateState(BoundUserInterfaceState state)
+    {
+        base.UpdateState(state);
+        _window?.Populate((PaperBoundUserInterfaceState) state);
+    }
+
+    private void Input_OnTextEntered(string text)
+    {
+        if (!string.IsNullOrEmpty(text))
         {
-            if (!string.IsNullOrEmpty(text))
+            SendMessage(new PaperInputTextMessage(text));
+
+            if (_window != null)
             {
-                SendMessage(new PaperInputTextMessage(text));
+                _window.Input.TextRope = Rope.Leaf.Empty;
-
+                _window.Input.CursorPosition = new TextEdit.CursorPos(0, TextEdit.LineBreakBias.Top);
-                if (_window != null)
-                {
-                    _window.Input.TextRope = Rope.Leaf.Empty;
-                    _window.Input.CursorPosition = new TextEdit.CursorPos(0, TextEdit.LineBreakBias.Top);
-                }
             }
         }
-
+    }
-        protected override void Dispose(bool disposing)
+
-        {
+    protected override void Dispose(bool disposing)
-            base.Dispose(disposing);
+    {
-            if (!disposing) return;
+        base.Dispose(disposing);
-            _window?.Dispose();
+        if (!disposing) return;
-        }
+        _window?.Dispose();
     }
 }

Content.Client/Paper/UI/PaperWindow.xaml

@@ -20,7 +20,8 @@
                             <TextEdit Name="Input" StyleClasses="PaperLineEdit" Access="Public" />
                         </PanelContainer>
                     </BoxContainer>
-                    <BoxContainer Name="StampDisplay" Orientation="Vertical" VerticalAlignment="Bottom" Margin="6"/>
+                    <paper:StampCollection Name="StampDisplay" VerticalAlignment="Bottom" Margin="6"/>
+
                 </PanelContainer>
             </ScrollContainer>
         </PanelContainer>

Content.Client/Paper/UI/PaperWindow.xaml.cs

@@ -44,8 +44,11 @@ namespace Content.Client.Paper.UI
         ///     Initialize this UI according to <code>visuals</code> Initializes
         ///     textures, recalculates sizes, and applies some layout rules.
         /// </summary>
-        public void InitVisuals(PaperVisualsComponent visuals)
+        public void InitVisuals(EntityUid entity, PaperVisualsComponent visuals)
         {
+            // Randomize the placement of any stamps based on the entity UID
+            // so that there's some variety in different papers.
+            StampDisplay.PlacementSeed = (int)entity;
             var resCache = IoCManager.Resolve<IResourceCache>();
 
             // Initialize the background:
@@ -206,9 +209,10 @@ namespace Content.Client.Paper.UI
             BlankPaperIndicator.Visible = !isEditing && state.Text.Length == 0;
 
             StampDisplay.RemoveAllChildren();
+            StampDisplay.RemoveStamps();
             foreach(var stamper in state.StampedBy)
             {
-                StampDisplay.AddChild(new StampWidget{ Stamper = stamper });
+                StampDisplay.AddStamp(new StampWidget{ StampInfo = stamper });
             }
         }
 
@@ -220,7 +224,7 @@ namespace Content.Client.Paper.UI
         /// </summary>
         protected override DragMode GetDragModeFor(Vector2 relativeMousePos)
         {
-            var mode = DragMode.Move;
+            var mode = DragMode.None;
 
             // Be quite generous with resize margins:
             if (relativeMousePos.Y < DRAG_MARGIN_SIZE)
@@ -241,6 +245,10 @@ namespace Content.Client.Paper.UI
                 mode |= DragMode.Right;
             }
 
+            if((mode & _allowedResizeModes) == DragMode.None)
+            {
+                return DragMode.Move;
+            }
             return mode & _allowedResizeModes;
         }
     }

Content.Client/Paper/UI/StampCollection.xaml

@@ -0,0 +1,5 @@
+<paper:StampCollection xmlns="https://spacestation14.io"
+    xmlns:paper="clr-namespace:Content.Client.Paper.UI"
+    MinSize="150 150">
+
+</paper:StampCollection>

Content.Client/Paper/UI/StampCollection.xaml.cs

@@ -0,0 +1,98 @@
+using System.Numerics;
+using Robust.Client.AutoGenerated;
+using Robust.Client.UserInterface.Controls;
+using Robust.Client.UserInterface.XAML;
+using Robust.Shared.Random;
+
+namespace Content.Client.Paper.UI;
+
+[GenerateTypedNameReferences]
+public sealed partial class StampCollection : Container
+{
+    private List<StampWidget> _stamps = new();
+
+    /// Seed for random number generator to place stamps deterministically
+    public int PlacementSeed;
+
+    public StampCollection()
+    {
+        RobustXamlLoader.Load(this);
+    }
+
+    /// <summary>
+    /// Remove any stamps from the page
+    /// </summary>
+    public void RemoveStamps()
+    {
+        _stamps.Clear();
+        InvalidateArrange();
+    }
+
+    /// <summary>
+    /// Adds a stamp to the display; will perform
+    /// automatic layout.
+    /// </summary>
+    public void AddStamp(StampWidget s)
+    {
+        _stamps.Add(s);
+        AddChild(s);
+    }
+
+    protected override Vector2 ArrangeOverride(Vector2 finalSize)
+    {
+        var random = new Random(PlacementSeed);
+        var r = (finalSize * 0.5f).Length();
+        var dtheta = -MathHelper.DegreesToRadians(90);
+        var theta0 = random.Next(0, 3) * dtheta;
+        var thisCenter = PixelSizeBox.TopLeft + finalSize * UIScale * 0.5f;
+
+        // Here's where we lay out the stamps. The first stamp goes in the
+        // center of this container; subsequent stamps will chose an angle
+        // (theta) to place the center of the stamp. The stamp is moved out
+        // as far as it can in that direction, taking the size and
+        // orientation of the stamp into account.
+        for (var i = 0; i < _stamps.Count; i++)
+        {
+            var stampOrientation = MathHelper.DegreesToRadians((random.NextFloat() - 0.5f) * 10.0f) ;
+            _stamps[i].Orientation = stampOrientation;
+
+            var theta = theta0 + dtheta * 0.5f + dtheta * i + (i > 4 ? MathF.Log(1 + i / 4) * dtheta : 0); // There is probably a better way to lay these out, to minimize overlaps
+            var childCenterOnCircle = thisCenter;
+            if (i > 0)
+            {
+                // First stamp can go in the center. Subsequent stamps have to find space.
+                childCenterOnCircle += new Vector2(MathF.Cos(theta), MathF.Sin(theta)) * r * UIScale;
+            }
+
+            var childHeLocal = _stamps[i].DesiredPixelSize * 0.5f;
+            var c = childHeLocal * MathF.Abs(MathF.Cos(stampOrientation));
+            var s = childHeLocal * MathF.Abs(MathF.Sin(stampOrientation));
+            var childHePage = new Vector2(c.X + s.Y, s.X + c.Y);
+            var controlBox = new UIBox2(PixelSizeBox.TopLeft, PixelSizeBox.TopLeft + finalSize * UIScale);
+            var clampedCenter = Clamp(Shrink(controlBox, childHePage), childCenterOnCircle);
+            var finalPosition = clampedCenter - childHePage;
+            var finalPositionAsInt = new Vector2i((int)finalPosition.X, (int)finalPosition.Y);
+            _stamps[i].ArrangePixel(new UIBox2i(finalPositionAsInt, finalPositionAsInt + _stamps[i].DesiredPixelSize));
+        }
+
+        return finalSize;
+    }
+
+    /// <summary>
+    /// Shrink a UIBox2 by a half extents, moving both the top-left and
+    /// bottom-right closer together.
+    /// </summary>
+    private UIBox2 Shrink(UIBox2 box, Vector2 shrinkHe)
+    {
+        return new UIBox2(box.TopLeft + shrinkHe, box.BottomRight - shrinkHe);
+    }
+
+    /// <summary>
+    /// Returns the input vector clamped to be within the UIBox
+    /// </summary>
+    private Vector2 Clamp(UIBox2 box, Vector2 point)
+    {
+        return Vector2.Min(box.BottomRight, Vector2.Max(box.TopLeft, point));
+    }
+}
+

Content.Client/Paper/UI/StampLabel.xaml

@@ -0,0 +1,2 @@
+<paper:StampLabel xmlns="https://spacestation14.io"
+    xmlns:paper="clr-namespace:Content.Client.Paper.UI" />

Content.Client/Paper/UI/StampLabel.xaml.cs

@@ -0,0 +1,56 @@
+using System.Numerics;
+using Robust.Client.AutoGenerated;
+using Robust.Client.Graphics;
+using Robust.Client.UserInterface.Controls;
+using Robust.Client.UserInterface.XAML;
+using Robust.Shared.Prototypes;
+
+namespace Content.Client.Paper.UI;
+
+[GenerateTypedNameReferences]
+public sealed partial class StampLabel : Label
+{
+    /// A scale that's applied to the text to ensure it
+    /// fits in the allowed space.
+    private Vector2 _textScaling = Vector2.One;
+
+    /// Shader used to draw the stamps
+    private ShaderInstance? _stampShader;
+
+    /// Allows an additional orientation to be applied to
+    /// this control.
+    public float Orientation = 0.0f;
+
+    public StampLabel()
+    {
+        RobustXamlLoader.Load(this);
+
+        var prototypes = IoCManager.Resolve<IPrototypeManager>();
+        _stampShader = prototypes.Index<ShaderPrototype>("PaperStamp").InstanceUnique();
+    }
+
+    protected override Vector2 MeasureOverride(Vector2 availableSize)
+    {
+        var desiredTextSize = base.MeasureOverride(availableSize);
+        var clampedScale = Vector2.Min(availableSize / desiredTextSize, Vector2.One);
+        var keepAspectRatio = MathF.Min(clampedScale.X, clampedScale.Y);
+        const float shimmerReduction = 0.1f;
+        _textScaling = Vector2.One * MathF.Round(keepAspectRatio / shimmerReduction) * shimmerReduction;
+        return desiredTextSize;
+    }
+
+    protected override void Draw(DrawingHandleScreen handle)
+    {
+        var offset = new Vector2(PixelPosition.X * MathF.Cos(Orientation) - PixelPosition.Y * MathF.Sin(Orientation),
+                PixelPosition.Y * MathF.Cos(Orientation) + PixelPosition.X * MathF.Sin(Orientation));
+
+        _stampShader?.SetParameter("objCoord", GlobalPosition * UIScale * new Vector2(1, -1));
+        handle.UseShader(_stampShader);
+        handle.SetTransform(GlobalPixelPosition - PixelPosition + offset, Orientation, _textScaling);
+        base.Draw(handle);
+
+        // Restore a sane transform+shader
+        handle.SetTransform(Matrix3.Identity);
+        handle.UseShader(null);
+    }
+}

Content.Client/Paper/UI/StampWidget.xaml

@@ -4,22 +4,7 @@
     xmlns:gfx="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client"
     xmlns:paper="clr-namespace:Content.Client.Paper.UI" HorizontalAlignment="Center" Margin="6">
 
-    <BoxContainer Orientation="Vertical">
+    <paper:StampLabel Name="StampedByLabel" StyleClasses="LabelHeadingBigger"
-        <PanelContainer>
+        FontColorOverride="{x:Static style:StyleNano.DangerousRedFore}"
-            <PanelContainer.PanelOverride>
+        Margin="12 6 12 6"/>
-                <gfx:StyleBoxFlat BackgroundColor="{x:Static style:StyleNano.DangerousRedFore}" />
-            </PanelContainer.PanelOverride>
-            <Control MinSize="3 3" />
-        </PanelContainer>
-
-        <Label Name="StampedByLabel" StyleClasses="LabelHeadingBigger" FontColorOverride="{x:Static style:StyleNano.DangerousRedFore}" Margin="12 6 12 6"/>
-
-        <PanelContainer>
-            <PanelContainer.PanelOverride>
-                <gfx:StyleBoxFlat BackgroundColor="{x:Static style:StyleNano.DangerousRedFore}" />
-            </PanelContainer.PanelOverride>
-            <Control MinSize="3 3" />
-        </PanelContainer>
-
-    </BoxContainer>
 </paper:StampWidget>

Content.Client/Paper/UI/StampWidget.xaml.cs

@@ -1,23 +1,59 @@
+using System.Numerics;
 using Content.Shared.Paper;
 using Robust.Client.AutoGenerated;
+using Robust.Client.Graphics;
+using Robust.Client.ResourceManagement;
 using Robust.Client.UserInterface.Controls;
-using Robust.Client.UserInterface.CustomControls;
 using Robust.Client.UserInterface.XAML;
-using Robust.Shared.Utility;
+using Robust.Shared.Prototypes;
 
-namespace Content.Client.Paper.UI
+namespace Content.Client.Paper.UI;
+
+[GenerateTypedNameReferences]
+public sealed partial class StampWidget : PanelContainer
 {
-    [GenerateTypedNameReferences]
+    private StyleBoxTexture _borderTexture;
-    public sealed partial class StampWidget : Container
+    private ShaderInstance? _stampShader;
-    {
-        public string? Stamper {
-            get => StampedByLabel.Text;
-            set => StampedByLabel.Text = value;
-        }
 
-        public StampWidget()
+    public float Orientation
-        {
+    {
-            RobustXamlLoader.Load(this);
+        get => StampedByLabel.Orientation;
+        set => StampedByLabel.Orientation = value;
+    }
+
+    public StampDisplayInfo StampInfo {
+        set {
+            StampedByLabel.Text = Loc.GetString(value.StampedName);
+            StampedByLabel.FontColorOverride = value.StampedColor;
+            ModulateSelfOverride = value.StampedColor;
         }
     }
+
+    public StampWidget()
+    {
+        RobustXamlLoader.Load(this);
+        var resCache = IoCManager.Resolve<IResourceCache>();
+        var borderImage = resCache.GetResource<TextureResource>(
+                "/Textures/Interface/Paper/paper_stamp_border.svg.96dpi.png");
+        _borderTexture = new StyleBoxTexture {
+            Texture = borderImage,
+        };
+        _borderTexture.SetPatchMargin(StyleBoxTexture.Margin.All, 7.0f);
+        PanelOverride = _borderTexture;
+
+        var prototypes = IoCManager.Resolve<IPrototypeManager>();
+        _stampShader = prototypes.Index<ShaderPrototype>("PaperStamp").InstanceUnique();
+    }
+
+    protected override void Draw(DrawingHandleScreen handle)
+    {
+        _stampShader?.SetParameter("objCoord", GlobalPosition * UIScale * new Vector2(1, -1));
+        handle.UseShader(_stampShader);
+        handle.SetTransform(GlobalPosition * UIScale, Orientation, Vector2.One);
+        base.Draw(handle);
+
+        // Restore a sane transform+shader
+        handle.SetTransform(Matrix3.Identity);
+        handle.UseShader(null);
+    }
 }

Content.Server/Fax/AdminUI/AdminFaxEui.cs

@@ -1,9 +1,10 @@
-using Content.Server.DeviceNetwork.Components;
+using Content.Server.DeviceNetwork.Components;
 using Content.Server.EUI;
 using Content.Server.Ghost.Components;
 using Content.Shared.Eui;
 using Content.Shared.Fax;
 using Content.Shared.Follower;
+using Content.Shared.Paper;
 
 namespace Content.Server.Fax.AdminUI;
 
@@ -53,7 +54,8 @@ public sealed class AdminFaxEui : BaseEui
             }
             case AdminFaxEuiMsg.Send sendData:
             {
-                var printout = new FaxPrintout(sendData.Content, sendData.Title, null, sendData.StampState, new() { sendData.From });
+                var printout = new FaxPrintout(sendData.Content, sendData.Title, null, sendData.StampState,
+                        new() { new StampDisplayInfo { StampedName = sendData.From, StampedColor = sendData.StampColor } });
                 _faxSystem.Receive(sendData.Target, printout);
                 break;
             }

Content.Server/Fax/FaxMachineComponent.cs

@@ -1,4 +1,5 @@
 using Content.Shared.Containers.ItemSlots;
+using Content.Shared.Paper;
 using Robust.Shared.Audio;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype;
@@ -136,18 +137,18 @@ public sealed class FaxPrintout
     public string? StampState { get; }
 
     [DataField("stampedBy")]
-    public List<string> StampedBy { get; } = new();
+    public List<StampDisplayInfo> StampedBy { get; } = new();
 
     private FaxPrintout()
     {
     }
 
-    public FaxPrintout(string content, string name, string? prototypeId = null, string? stampState = null, List<string>? stampedBy = null)
+    public FaxPrintout(string content, string name, string? prototypeId = null, string? stampState = null, List<StampDisplayInfo>? stampedBy = null)
     {
         Content = content;
         Name = name;
         PrototypeId = prototypeId ?? "";
         StampState = stampState;
-        StampedBy = stampedBy ?? new List<string>();
+        StampedBy = stampedBy ?? new List<StampDisplayInfo>();
     }
 }

Content.Server/Fax/FaxSystem.cs

@@ -16,6 +16,7 @@ using Content.Shared.Emag.Components;
 using Content.Shared.Emag.Systems;
 using Content.Shared.Fax;
 using Content.Shared.Interaction;
+using Content.Shared.Paper;
 using Robust.Server.GameObjects;
 using Robust.Shared.Audio;
 using Robust.Shared.Containers;
@@ -272,7 +273,7 @@ public sealed class FaxSystem : EntitySystem
                         return;
 
                     args.Data.TryGetValue(FaxConstants.FaxPaperStampStateData, out string? stampState);
-                    args.Data.TryGetValue(FaxConstants.FaxPaperStampedByData, out List<string>? stampedBy);
+                    args.Data.TryGetValue(FaxConstants.FaxPaperStampedByData, out List<StampDisplayInfo>? stampedBy);
                     args.Data.TryGetValue(FaxConstants.FaxPaperPrototypeData, out string? prototypeId);
 
                     var printout = new FaxPrintout(content, name, prototypeId, stampState, stampedBy);
@@ -461,9 +462,9 @@ public sealed class FaxSystem : EntitySystem
             // Apply stamps
             if (printout.StampState != null)
             {
-                foreach (var stampedBy in printout.StampedBy)
+                foreach (var stamp in printout.StampedBy)
                 {
-                    _paperSystem.TryStamp(printed, stampedBy, printout.StampState);
+                    _paperSystem.TryStamp(printed, stamp, printout.StampState);
                 }
             }
         }

Content.Server/Nuke/NukeCodePaperSystem.cs

@@ -5,6 +5,7 @@ using Content.Server.Fax;
 using Content.Server.Paper;
 using Content.Server.Station.Components;
 using Content.Server.Station.Systems;
+using Content.Shared.Paper;
 using Robust.Shared.Random;
 using Robust.Shared.Utility;
 
@@ -66,7 +67,11 @@ namespace Content.Server.Nuke
                     Loc.GetString("nuke-codes-fax-paper-name"),
                     null,
                     "paper_stamp-centcom",
-                    new() { Loc.GetString("stamp-component-stamped-name-centcom") });
+                    new List<StampDisplayInfo>
+                    {
+                        new StampDisplayInfo { StampedName = Loc.GetString("stamp-component-stamped-name-centcom"), StampedColor = Color.FromHex("#BB3232") },
+                    }
+                );
                 _faxSystem.Receive(faxEnt, printout, null, fax);
 
                 wasSent = true;

Content.Server/Paper/PaperComponent.cs

@@ -1,24 +1,24 @@
 using Content.Shared.Paper;
 using Robust.Shared.GameStates;
 
-namespace Content.Server.Paper
+namespace Content.Server.Paper;
+
+[NetworkedComponent, RegisterComponent]
+public sealed class PaperComponent : SharedPaperComponent
 {
-    [NetworkedComponent, RegisterComponent]
+    public PaperAction Mode;
-    public sealed class PaperComponent : SharedPaperComponent
+    [DataField("content")]
-    {
+    public string Content { get; set; } = "";
-        public PaperAction Mode;
-        [DataField("content")]
-        public string Content { get; set; } = "";
 
-        [DataField("contentSize")]
+    [DataField("contentSize")]
-        public int ContentSize { get; set; } = 6000;
+    public int ContentSize { get; set; } = 6000;
 
-        [DataField("stampedBy")]
+    [DataField("stampedBy")]
-        public List<string> StampedBy { get; set; } = new();
+    public List<StampDisplayInfo> StampedBy { get; set; } = new();
-        /// <summary>
+
-        ///     Stamp to be displayed on the paper, state from beauracracy.rsi
+    /// <summary>
-        /// </summary>
+    ///     Stamp to be displayed on the paper, state from beauracracy.rsi
-        [DataField("stampState")]
+    /// </summary>
-        public string? StampState { get; set; }
+    [DataField("stampState")]
-    }
+    public string? StampState { get; set; }
 }

Content.Server/Paper/PaperSystem.cs

@@ -1,3 +1,4 @@
+using System.Linq;
 using Content.Server.Administration.Logs;
 using Content.Server.Popups;
 using Content.Server.UserInterface;
@@ -90,7 +91,7 @@ namespace Content.Server.Paper
 
             if (paperComp.StampedBy.Count > 0)
             {
-                var commaSeparated = string.Join(", ", paperComp.StampedBy);
+                var commaSeparated = string.Join(", ", paperComp.StampedBy.Select(s => Loc.GetString(s.StampedName)));
                 args.PushMarkup(
                     Loc.GetString(
                         "paper-component-examine-detail-stamped-by", ("paper", uid), ("stamps", commaSeparated))
@@ -114,13 +115,15 @@ namespace Content.Server.Paper
             }
 
             // If a stamp, attempt to stamp paper
-            if (TryComp<StampComponent>(args.Used, out var stampComp) && TryStamp(uid, stampComp.StampedName, stampComp.StampState, paperComp))
+            if (TryComp<StampComponent>(args.Used, out var stampComp) && TryStamp(uid, GetStampInfo(stampComp), stampComp.StampState, paperComp))
             {
                 // successfully stamped, play popup
-                var stampPaperOtherMessage = Loc.GetString("paper-component-action-stamp-paper-other", ("user", Identity.Entity(args.User, EntityManager)), ("target", Identity.Entity(args.Target, EntityManager)), ("stamp", args.Used));
+                var stampPaperOtherMessage = Loc.GetString("paper-component-action-stamp-paper-other",
-                _popupSystem.PopupEntity(stampPaperOtherMessage, args.User, Filter.PvsExcept(args.User, entityManager: EntityManager), true);
+                        ("user", args.User), ("target", args.Target), ("stamp", args.Used));
 
-                var stampPaperSelfMessage = Loc.GetString("paper-component-action-stamp-paper-self", ("target", Identity.Entity(args.Target, EntityManager)), ("stamp", args.Used));
+                _popupSystem.PopupEntity(stampPaperOtherMessage, args.User, Filter.PvsExcept(args.User, entityManager: EntityManager), true);
+                var stampPaperSelfMessage = Loc.GetString("paper-component-action-stamp-paper-self",
+                        ("target", args.Target), ("stamp", args.Used));
                 _popupSystem.PopupEntity(stampPaperSelfMessage, args.User, args.User);
 
                 _audio.PlayPvs(stampComp.Sound, uid);
@@ -129,6 +132,14 @@ namespace Content.Server.Paper
             }
         }
 
+        private StampDisplayInfo GetStampInfo(StampComponent stamp)
+        {
+            return new StampDisplayInfo {
+                StampedName = stamp.StampedName,
+                StampedColor = stamp.StampedColor
+            };
+        }
+
         private void OnInputTextMessage(EntityUid uid, PaperComponent paperComp, PaperInputTextMessage args)
         {
             if (string.IsNullOrEmpty(args.Text))
@@ -161,17 +172,19 @@ namespace Content.Server.Paper
         /// <summary>
         ///     Accepts the name and state to be stamped onto the paper, returns true if successful.
         /// </summary>
-        public bool TryStamp(EntityUid uid, string stampName, string stampState, PaperComponent? paperComp = null)
+        public bool TryStamp(EntityUid uid, StampDisplayInfo stampInfo, string spriteStampState, PaperComponent? paperComp = null)
         {
             if (!Resolve(uid, ref paperComp))
                 return false;
 
-            if (!paperComp.StampedBy.Contains(Loc.GetString(stampName)))
+            if (!paperComp.StampedBy.Contains(stampInfo))
             {
-                paperComp.StampedBy.Add(Loc.GetString(stampName));
+                paperComp.StampedBy.Add(stampInfo);
                 if (paperComp.StampState == null && TryComp<AppearanceComponent>(uid, out var appearance))
                 {
-                    paperComp.StampState = stampState;
+                    paperComp.StampState = spriteStampState;
+                    // Would be nice to be able to display multiple sprites on the paper
+                    // but most of the existing images overlap
                     _appearance.SetData(uid, PaperVisuals.Stamp, paperComp.StampState, appearance);
                 }
             }

Content.Shared/Fax/AdminFaxEui.cs

@@ -1,4 +1,4 @@
-using Content.Shared.Eui;
+using Content.Shared.Eui;
 using Robust.Shared.Serialization;
 
 namespace Content.Shared.Fax;
@@ -55,14 +55,16 @@ public static class AdminFaxEuiMsg
         public string From { get; }
         public string Content { get; }
         public string StampState { get; }
+        public Color StampColor { get; }
 
-        public Send(EntityUid target, string title, string from, string content, string stamp)
+        public Send(EntityUid target, string title, string from, string content, string stamp, Color stampColor)
         {
             Target = target;
             Title = title;
             From = from;
             Content = content;
             StampState = stamp;
+            StampColor = stampColor;
         }
     }
 }

Content.Shared/Paper/SharedPaperComponent.cs

@@ -1,60 +1,59 @@
 using Robust.Shared.Serialization;
 
-namespace Content.Shared.Paper
+namespace Content.Shared.Paper;
+
+public abstract class SharedPaperComponent : Component
 {
-    public abstract class SharedPaperComponent : Component
+    [Serializable, NetSerializable]
+    public sealed class PaperBoundUserInterfaceState : BoundUserInterfaceState
     {
-        [Serializable, NetSerializable]
+        public readonly string Text;
-        public sealed class PaperBoundUserInterfaceState : BoundUserInterfaceState
+        public readonly List<StampDisplayInfo> StampedBy;
+        public readonly PaperAction Mode;
+
+        public PaperBoundUserInterfaceState(string text, List<StampDisplayInfo> stampedBy, PaperAction mode = PaperAction.Read)
         {
-            public readonly string Text;
+            Text = text;
-            public readonly List<string> StampedBy;
+            StampedBy = stampedBy;
-            public readonly PaperAction Mode;
+            Mode = mode;
-
-            public PaperBoundUserInterfaceState(string text, List<string> stampedBy, PaperAction mode = PaperAction.Read)
-            {
-                Text = text;
-                StampedBy = stampedBy;
-                Mode = mode;
-            }
-        }
-
-        [Serializable, NetSerializable]
-        public sealed class PaperInputTextMessage : BoundUserInterfaceMessage
-        {
-            public readonly string Text;
-
-            public PaperInputTextMessage(string text)
-            {
-                Text = text;
-            }
-        }
-
-        [Serializable, NetSerializable]
-        public enum PaperUiKey
-        {
-            Key
-        }
-
-        [Serializable, NetSerializable]
-        public enum PaperAction
-        {
-            Read,
-            Write,
-        }
-
-        [Serializable, NetSerializable]
-        public enum PaperVisuals : byte
-        {
-            Status,
-            Stamp
-        }
-
-        [Serializable, NetSerializable]
-        public enum PaperStatus : byte
-        {
-            Blank,
-            Written
         }
     }
+
+    [Serializable, NetSerializable]
+    public sealed class PaperInputTextMessage : BoundUserInterfaceMessage
+    {
+        public readonly string Text;
+
+        public PaperInputTextMessage(string text)
+        {
+            Text = text;
+        }
+    }
+
+    [Serializable, NetSerializable]
+    public enum PaperUiKey
+    {
+        Key
+    }
+
+    [Serializable, NetSerializable]
+    public enum PaperAction
+    {
+        Read,
+        Write,
+    }
+
+    [Serializable, NetSerializable]
+    public enum PaperVisuals : byte
+    {
+        Status,
+        Stamp
+    }
+
+    [Serializable, NetSerializable]
+    public enum PaperStatus : byte
+    {
+        Blank,
+        Written
+    }
 }

Content.Shared/Paper/StampComponent.cs

@@ -1,25 +1,52 @@
+using Robust.Shared.Serialization;
 using Robust.Shared.Audio;
 
-namespace Content.Shared.Paper
+namespace Content.Shared.Paper;
-{
-    [RegisterComponent]
-    public sealed class StampComponent : Component
-    {
-        /// <summary>
-        ///     The loc string name that will be stamped to the piece of paper on examine.
-        /// </summary>
-        [DataField("stampedName")]
-        public string StampedName { get; set; } = "stamp-component-stamped-name-default";
-        /// <summary>
-        ///     Tne sprite state of the stamp to display on the paper from bureacracy.rsi.
-        /// </summary>
-        [DataField("stampState")]
-        public string StampState { get; set; } = "paper_stamp-generic";
 
-        [DataField("sound")]
+/// <summary>
-        public SoundSpecifier Sound = new SoundPathSpecifier("/Audio/Items/Stamp/thick_stamp_sub.ogg")
+///     Set of required information to draw a stamp in UIs, where
-        {
+///     representing the state of the stamp at the point in time
-            Params = AudioParams.Default.WithVolume(-2f).WithMaxDistance(5f)
+///     when it was applied to a paper. These fields mirror the
-        };
+///     equivalent in the component.
+/// </summary>
+[DataDefinition, Serializable, NetSerializable]
+public struct StampDisplayInfo
+{
+    StampDisplayInfo(string s)
+    {
+        StampedName = s;
     }
+
+    [DataField("stampedName")]
+    public string StampedName;
+
+    [DataField("stampedColor")]
+    public Color StampedColor;
+};
+
+[RegisterComponent]
+public sealed class StampComponent : Component
+{
+    /// <summary>
+    ///     The loc string name that will be stamped to the piece of paper on examine.
+    /// </summary>
+    [DataField("stampedName")]
+    public string StampedName { get; set; } = "stamp-component-stamped-name-default";
+    /// <summary>
+    ///     Tne sprite state of the stamp to display on the paper from bureacracy.rsi.
+    /// </summary>
+    [DataField("stampState")]
+    public string StampState { get; set; } = "paper_stamp-generic";
+
+    /// <summary>
+    /// The color of the ink used by the stamp in UIs
+    /// </summary>
+    [DataField("stampedColor")]
+    public Color StampedColor = Color.FromHex("#BB3232"); // StyleNano.DangerousRedFore
+
+    [DataField("sound")]
+    public SoundSpecifier Sound = new SoundPathSpecifier("/Audio/Items/Stamp/thick_stamp_sub.ogg")
+    {
+        Params = AudioParams.Default.WithVolume(-2f).WithMaxDistance(5f)
+    };
 }

Resources/Locale/en-US/fax/fax-admin.ftl

@@ -1,4 +1,4 @@
-# Command
+# Command
 cmd-faxui-desc = Open admin window for sending faxes
 cmd-faxui-help = Usage: faxui
 
@@ -7,7 +7,8 @@ admin-fax-title = Admin Fax Manager
 admin-fax-fax = Fax:
 admin-fax-follow = Follow
 admin-fax-title-placeholder = Paper name...
-admin-fax-from-placeholder = From who...
+admin-fax-from-placeholder = Stamped by...
 admin-fax-message-placeholder = Your message here...
-admin-fax-stamp = Stamp:
+admin-fax-stamp = Stamp icon:
+admin-fax-stamp-color = Stamp color:
 admin-fax-send = Send

Resources/Maps/core.yml

@@ -91310,7 +91310,8 @@ entities:
       type: Transform
     - stampState: paper_stamp-syndicate
       stampedBy:
-      - Syndicate
+      - stampedName: stamp-component-stamped-name-syndicate
+        stampedColor: '#850000'
       content: >-
         Operative, i have succeeded in the mission and this is the remainder of the evidence. I am hiding it behind this wall and escaping ASAP.
 

Resources/Prototypes/Entities/Objects/Misc/paper.yml

@@ -421,6 +421,7 @@
   - type: Stamp
     stampedName: stamp-component-stamped-name-default
     stampState: "paper_stamp-generic"
+    stampedColor: "#a23e3e"
     sound:
       path: /Audio/Items/Stamp/thick_stamp_sub.ogg
       params:
@@ -454,6 +455,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-captain
+    stampedColor: "#3681bb"
     stampState: "paper_stamp-cap"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -466,6 +468,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-centcom
+    stampedColor: "#006600"
     stampState: "paper_stamp-centcom"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -478,6 +481,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-chaplain
+    stampedColor: "#d70601"
     stampState: "paper_stamp-chaplain"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -490,6 +494,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-clown
+    stampedColor: "#ff33cc"
     stampState: "paper_stamp-clown"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -505,6 +510,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-ce
+    stampedColor: "#c69b17"
     stampState: "paper_stamp-ce"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -517,6 +523,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-cmo
+    stampedColor: "#33ccff"
     stampState: "paper_stamp-cmo"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -529,6 +536,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-hop
+    stampedColor: "#6ec0ea"
     stampState: "paper_stamp-hop"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -541,6 +549,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-hos
+    stampedColor: "#cc0000"
     stampState: "paper_stamp-hos"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -553,6 +562,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-mime
+    stampedColor: "#777777"
     stampState: "paper_stamp-mime"
     # TODO remove sound from mime's rubber stamp
   - type: Sprite
@@ -566,6 +576,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-qm
+    stampedColor: "#a23e3e"
     stampState: "paper_stamp-qm"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -578,6 +589,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-rd
+    stampedColor: "#1f66a0"
     stampState: "paper_stamp-rd"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -590,6 +602,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-trader
+    stampedColor: "#000000"
     stampState: "paper_stamp-trader"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -602,6 +615,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-syndicate
+    stampedColor: "#850000"
     stampState: "paper_stamp-syndicate"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -614,6 +628,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-warden
+    stampedColor: "#5b0000"
     stampState: "paper_stamp-warden"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -626,6 +641,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-approved
+    stampedColor: "#00be00"
     stampState: "paper_stamp-ok"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi
@@ -638,6 +654,7 @@
   components:
   - type: Stamp
     stampedName: stamp-component-stamped-name-denied
+    stampedColor: "#a23e3e"
     stampState: "paper_stamp-deny"
   - type: Sprite
     sprite: Objects/Misc/bureaucracy.rsi

Resources/Prototypes/Shaders/shaders.yml

@@ -71,3 +71,8 @@
   id: Stealth
   kind: source
   path: "/Textures/Shaders/stealth.swsl"
+
+- type: shader
+  id: PaperStamp
+  kind: source
+  path: "/Textures/Shaders/paperstamp.swsl"

Resources/Textures/Interface/Paper/paper_stamp_border.svg

@@ -0,0 +1,103 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   width="35.0625"
+   height="34"
+   viewBox="0 0 35.0625 34"
+   fill="none"
+   version="1.1"
+   id="svg4"
+   sodipodi:docname="paper_stamp_border.svg"
+   inkscape:version="1.2.2 (b0a8486541, 2022-12-01)"
+   inkscape:export-filename="paper_stamp_border.svg.96dpi.png"
+   inkscape:export-xdpi="96"
+   inkscape:export-ydpi="96"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:dc="http://purl.org/dc/elements/1.1/">
+  <metadata
+     id="metadata10">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs8">
+    <inkscape:path-effect
+       effect="powerclip"
+       id="path-effect302"
+       is_visible="true"
+       lpeversion="1"
+       inverse="true"
+       flatten="false"
+       hide_clip="false"
+       message="Use fill-rule evenodd on &lt;b&gt;fill and stroke&lt;/b&gt; dialog if no flatten result after convert clip to paths." />
+    <clipPath
+       clipPathUnits="userSpaceOnUse"
+       id="clipPath298">
+      <rect
+         x="2.6084003"
+         y="2.5943766"
+         width="26.783199"
+         height="26.811247"
+         rx="4.1848745"
+         fill="#ffffff"
+         id="rect300"
+         style="display:none;stroke-width:0.837413"
+         d="M 6.7932749,2.5943766 H 25.206725 c 2.318421,0 4.184875,1.866454 4.184875,4.1848745 V 25.220749 c 0,2.31842 -1.866454,4.184874 -4.184875,4.184874 H 6.7932749 c -2.3184205,0 -4.1848746,-1.866454 -4.1848746,-4.184874 V 6.7792511 c 0,-2.3184205 1.8664541,-4.1848745 4.1848746,-4.1848745 z" />
+      <path
+         id="lpe_path-effect302"
+         style="stroke-width:0.837413"
+         class="powerclip"
+         d="M -5,-5 H 37 V 37 H -5 Z M 6.7932749,2.5943766 c -2.3184205,0 -4.1848746,1.866454 -4.1848746,4.1848745 V 25.220749 c 0,2.31842 1.8664541,4.184874 4.1848746,4.184874 H 25.206725 c 2.318421,0 4.184875,-1.866454 4.184875,-4.184874 V 6.7792511 c 0,-2.3184205 -1.866454,-4.1848745 -4.184875,-4.1848745 z" />
+    </clipPath>
+  </defs>
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="1916"
+     inkscape:window-height="1034"
+     id="namedview6"
+     showgrid="false"
+     fit-margin-top="0"
+     fit-margin-left="0"
+     fit-margin-right="0"
+     fit-margin-bottom="0"
+     inkscape:zoom="15.527471"
+     inkscape:cx="6.7300077"
+     inkscape:cy="17.16313"
+     inkscape:window-x="0"
+     inkscape:window-y="44"
+     inkscape:window-maximized="0"
+     inkscape:current-layer="svg4"
+     inkscape:showpageshadow="2"
+     inkscape:pagecheckerboard="true"
+     inkscape:deskcolor="#d1d1d1" />
+  <path
+     x="0"
+     y="0"
+     width="32"
+     height="32"
+     rx="5"
+     fill="#ffffff"
+     id="rect2"
+     clip-path="url(#clipPath298)"
+     inkscape:path-effect="#path-effect302"
+     d="m 5,0 h 22 c 2.77,0 5,2.23 5,5 v 22 c 0,2.77 -2.23,5 -5,5 H 5 C 2.23,32 0,29.77 0,27 V 5 C 0,2.23 2.23,0 5,0 Z"
+     sodipodi:type="rect"
+     transform="translate(1,1)" />
+</svg>

Resources/Textures/Shaders/paperstamp.swsl

@@ -0,0 +1,53 @@
+// Object position in screen space. Allows the noise to
+// have a constant screen-space size, without being
+// affected by the widget layout/position.
+uniform highp vec2 objCoord;
+
+// Magic, well-known 2d random function; makes perlin-like noise
+highp vec2 random(highp vec2 uv){
+    uv = vec2( dot(uv, vec2(127.1,311.7) ),
+               dot(uv, vec2(269.5,183.3) ) );
+    return -1.0 + 2.0 * fract(sin(uv) * 43758.5453123);
+}
+
+highp float noise(highp vec2 uv) {
+    highp vec2 uv_i = floor(uv);
+    highp vec2 uv_f = fract(uv);
+
+    highp vec2 t = smoothstep(0.0, 1.0, uv_f);
+
+    // Sample the random function and run a bilinear filter to smooth it out
+    highp float tl = dot( random(uv_i + vec2(0.0,0.0) ), uv_f - vec2(0.0,0.0) );
+    highp float tr = dot( random(uv_i + vec2(1.0,0.0) ), uv_f - vec2(1.0,0.0) );
+    highp float bl = dot( random(uv_i + vec2(0.0,1.0) ), uv_f - vec2(0.0,1.0) );
+    highp float br = dot( random(uv_i + vec2(1.0,1.0) ), uv_f - vec2(1.0,1.0) );
+
+    highp float tA = mix( tl, tr, t.x );
+    highp float tB = mix( bl, br, t.x );
+    return mix( tA, tB, t.y ) + 0.5;
+}
+
+void fragment() {
+    // Stamps have orientation, and the texture sampling is nearest
+    // pixel, so run a bilinear filter to smooth out the edges.
+    {
+        highp vec4 tl = texture2D(TEXTURE, UV);
+        highp vec4 tr = texture2D(TEXTURE, UV + vec2(TEXTURE_PIXEL_SIZE.x, 0.0));
+        highp vec4 bl = texture2D(TEXTURE, UV + vec2(0.0, TEXTURE_PIXEL_SIZE.y));
+        highp vec4 br = texture2D(TEXTURE, UV + TEXTURE_PIXEL_SIZE);
+
+        highp vec2 textureSize = 1.0 / TEXTURE_PIXEL_SIZE;
+        highp vec2 f = fract( UV * textureSize );
+        highp vec4 tA = mix( tl, tr, f.x );
+        highp vec4 tB = mix( bl, br, f.x );
+        COLOR = mix( tA, tB, f.y );
+    }
+
+    // Add a bit of noise to mimic imperfect contact with the paper
+    {
+        float stampNoise = noise((FRAGCOORD.xy - objCoord) * vec2(0.03, 0.03)) *
+                           noise((FRAGCOORD.xy - objCoord) * vec2(0.08, 0.08));
+        COLOR.a *= min(0.9, 0.4 + smoothstep(0.05, 0.3, stampNoise));
+    }
+}
+