Guinevere

A GPU accelerated immediate mode GUI system built on SkiaSharp, designed for high-performance applications with modern graphics APIs support. You can use it to create rich and beautiful apps.

Important

Guinevere is a very new library. While an earlier iteration is actively used within the Turian Game Engine, this specific library hasn't yet established a track record of reliability in production environments.

Highlights

• Cross-Platform: Windows, Linux & Mac
• Immediate Mode
• 100% C# with Latest .NET
• GPU Accelerated Rendering
• Fluent API
• Multiple Graphics API Support
• Multiple Framework Integrations

Integration	Graphics API	C# Framework	Use Case
Vulkan.SilkNET	Vulkan	Silk.NET	Maximum performance, modern graphics
OpenGl.SilkNET	OpenGL	Silk.NET	High-performance applications (Recommended)
OpenGl.OpenTK	OpenGL	OpenTK	Game development, tools
OpenGl.Raylib	OpenGL	Raylib-cs	Simple games, prototypes

Table of Contents

• Highlights
• Quick Start
• Features
  • Layout
  • Interactive Elements
  • Text & Styling
  • Animation
  • Shapes & Effects
  • Scrolling & Clipping
  • Advanced Controls
  • Performance
• Samples
• License
• Acknowledgments

Quick Start

Starting a New App

1. Create a new .NET project:

   dotnet new console -n MyGuinevereApp
   cd MyGuinevereApp

2. Install Guinevere and an integration package:

   dotnet add package org.mass4.Guinevere
   dotnet add package org.mass4.Guinevere.OpenGL.SilkNET

3. Basic Usage:

   using Guinevere;
   using Guinevere.OpenGL.SilkNET;
   
   public abstract class Program
   {
       public static void Main()
       {
           var gui = new Gui();
           using var win = new GuiWindow(gui);
   
           win.RunGui(() =>
           {
               gui.DrawRect(gui.ScreenRect, Color.mass4org);
               gui.DrawText("Hello, world!");
           });
       }
   }

---

Features

Layout

• Flexible box model: margins, padding, gaps, alignment

• Horizontal/vertical flow with Direction(Axis.Horizontal|Vertical)

• Responsive sizing: Expand(), ExpandWidth(), ExpandHeight()

• Content alignment with AlignContent(x, y)

  // Flexible layout with alignment and spacing
  using (gui.Node().Expand()
      .Direction(Axis.Horizontal)
      .Gap(20)
      .Margin(30)
      .Padding(15)
      .AlignContent(0.5f, 0.2f)
      .Enter())
  {
      // Children laid out horizontally with gaps
  }
  
  // Responsive sizing
  gui.Node().ExpandWidth().Height(100).Margin(10, 20).Padding(5, 10, 15, 20);

Interactive Elements

• Built-in controls: buttons, checkboxes, toggles, dropdowns

• Text input variants: single-line, password, multiline

• Focus management and keyboard navigation

• Custom interactables for arbitrary shapes/regions

  // Common controls
  if (gui.Button("Click me!")) { /* ... */ }
  gui.Checkbox(ref checkbox, "Enable feature");
  gui.Toggle(ref toggle, "Dark mode");
  gui.Dropdown(options, ref dropdown);
  
  // Text inputs
  textInput = gui.TextInput(textInput);
  passwordInput = gui.PasswordInput(passwordInput);
  textArea = gui.TextArea(textArea);
  
  // Custom interactive area with shape
  var interactable = gui.GetInteractable();
  if (interactable.OnHover()) gui.DrawBackgroundRect(Color.LightBlue);
  if (interactable.OnClick()) Console.WriteLine("Clicked!");
  
  var shape = Shape.Circle(50);
  var shaped = gui.GetInteractable(position, shape);

Text & Styling

• Rich text rendering with Unicode and emoji

• Wrapping, sizes, and color control

• Theming via transient color changes

  gui.DrawText("Title", 24, Color.White);
  gui.DrawText("Wrapped text", 12, Color.Gray, wrapWidth: 300);
  gui.SetTextColor(Color.Red); // all text from now on will be red by default
  gui.DrawText("Red text");
  gui.SetTextColor(Color.White);

Animation

• Smooth value/state transitions

• AnimationFloat and AnimateBool01() helpers

• Easing functions: Linear, EaseIn/Out, SmoothStep, BackOut, ElasticOut, BounceOut

• Live metrics: ActiveAnimationCount

  var fade = gui.AnimateBool01(isVisible, 0.5f, Easing.SmoothStep);
  var animFloat = gui.GetAnimationFloat(value);
  animFloat.AnimateTo(target, 0.3f, Easing.ElasticOut);
  var v = animFloat.GetValue();
  
  // Status
  gui.DrawText($"Active animations: {gui.ActiveAnimationCount}", 12, Color.White);

Shapes & Effects

• Basic shapes: circle, rectangle, arc

• Fills: solid, linear/radial gradients

• Borders and rounded corners

• Shadows: inner/outer with blur and spread

• Shape operations: union, subtract, intersect, transform

  // Basic shape & gradient
  gui.DrawShape(center, Shape.Circle(100))
      .LinearGradientColor(Color.Red, Color.Blue, Angle.Degrees(45))
      .InnerShadow(Color.Black, new Vector2(0, 2), blur: 5, spread: -2)
      .OuterShadow(Color.Gray, new Vector2(2, 2), blur: 8, spread: 0);
  
  // Composition
  var combined = Shape.Circle(60) + Shape.Rectangle(80, 40);
  gui.DrawShape(center, combined);
  
  // Simple rect helpers
  gui.DrawBackgroundRect(Color.Blue, radius: 10);
  // gui.DrawRectBorder(rect, Color.Red, thickness: 2);

Scrolling & Clipping

• Scrollbars: ScrollY() / ScrollX()

• Clip content to node bounds: ClipContent()

• Programmatic control: ScrollToTop(), SetScrollPercentage()

• Custom clip shapes with SetClipArea()

  using (gui.Node(400, 300).Enter())
  {
      gui.ScrollY(Color.Black, Color.Gray);
      gui.ClipContent();
  
      for (int i = 0; i < 50; i++)
          gui.DrawText($"Line {i + 1}", 14, Color.White);
  }
  
  // Programmatic control
  gui.ScrollToTop("scrollNodeId");
  gui.SetScrollPercentage("scrollNodeId", Axis.Vertical, 0.5f);
  
  // Custom clip area
  gui.SetClipArea(gui.CurrentNode, Shape.Circle(100));

Advanced Controls

• Tabs: horizontal, pill, and vertical variants

• Menus, dropdowns, and window chrome utilities

• Z-index layering and transforms

  private static int activeTab = 0;
  
  gui.Tabs(ref activeTab, tabs =>
  {
      tabs.Tab("Home", () => gui.DrawText("Home content", 12, Color.Gray));
      tabs.Tab("Settings", () => gui.DrawText("Settings content", 12, Color.Gray));
      tabs.Tab("About", () => gui.DrawText("About content", 12, Color.Gray));
  });
  
  // Window UI & transforms
  gui.DrawWindowTitlebar();
  gui.SetZIndex(10);
  // gui.SetTransform(Matrix3x2.CreateScale(1.2f, 1.2f, center));

Performance

• GPU-accelerated rendering via SkiaSharp

• Immediate mode with minimal memory overhead

• Dirty-flag updates and multi-pass rendering

• Real-time metrics: FPS, frame count, delta time

  // Pass-based work split
  if (gui.Pass == Pass.Pass1Layout)
  {
      // Layout calculations
  }
  else if (gui.Pass == Pass.Pass2Render)
  {
      // Rendering only
  }
  
  // Metrics
  gui.DrawText($"FPS: {gui.Time.SmoothFps:F1}", 12, Color.White);
  gui.DrawText($"Frame: {gui.Time.Frames}", 12, Color.White);
  gui.DrawText($"Delta: {gui.Time.DeltaTime * 1000:F1}ms", 12, Color.White);

Samples

The repository includes comprehensive Samples demonstrating various features.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Acknowledgments

• SkiaSharp: The foundation of our rendering system
• OpenTK: OpenGL bindings for .NET
• Raylib-cs: C# bindings
• Silk.NET: Modern .NET bindings for graphics APIs
• NUKE: Build automation system
• PanGui: Inspiration for the API
• Prowl.Paper: Inspiration for the API