Imp

Imp is a lightweight, sprite-based rendering framework for F#, supporting both OpenGL (desktop/android) and WebGL (web). Inspired by Elmish and React Native, it provides a declarative way to build high-performance 2D applications with a functional architecture.

🔹 Why Imp? The name comes from an Imp, a small mischievous creature, similar to a sprite! Imp is designed to be a fast and lightweight sprite renderer for building graphical applications.

🚀 Try the demo: davidtme.github.io/imp

Features

• 🎮 Sprite-Based Rendering – Optimized for rendering 2D sprites efficiently.
• 🏗 Elmish-Like Architecture – Write declarative UI code, similar to React Native in F#.
• 🖥 Cross-Platform Support – OpenGL for desktop/android apps and WebGL for browser-based applications.
• 🎨 Declarative Scene Composition – Manage scenes and sprites with a structured, functional approach.
• 🚀 GPU-Accelerated Performance – Leverages OpenGL/WebGL for smooth, high-performance rendering.
• 📦 Web-Based & Local Asset Management – Load and manage textures, sprites, and other resources effortlessly.
• 💡 F#-First Development – Functional, type-safe, and expressive API.
• 🌐 Fable Integration – Uses Fable to compile F# to JavaScript for seamless web development.

Installation

You can install Imp via NuGet:

dotnet add package Imp

Example Usage

With Imp, you can quickly set up a WebGL scene:

module Client.SimpleWeb.App

// Import required modules for application setup and rendering
open Imp
open Imp.Setup

// Define the name of the texture to be used in the application
let texture = "f-sharp-logo"

// Initialize a data manager for handling web-based data operations
let dataManager = WebDataManager(baseUrl = ".")
// Register the texture name with the data manager
dataManager.AddTextureName(texture)

// Define a function to create the main view of the application
let sampleView () =
    // The view function serves as the root container for the scene
    view () {
        // The sceneRenderer sets up the rendering environment, including the background color
        sceneRenderer (backgroundColor = { R = 29; G = 41; B = 61 }) {
            // The singleRenderer renders individual sprites one at a time
            singleRenderer () { 
                // Define a sprite with its position, dimensions, and texture properties
                sprite (
                    x = 50, // Horizontal position of the sprite
                    y = 50, // Vertical position of the sprite
                    z = 0, // Depth position of the sprite
                    width = 255, // Width of the sprite in pixels
                    height = 255, // Height of the sprite in pixels
                    texture = texture, // Name of the texture to apply to the sprite
                    textureX = 0, // X-coordinate of the texture region to use
                    textureY = 0, // Y-coordinate of the texture region to use
                    textureWidth = 255, // Width of the texture region to use
                    textureHeight = 255 // Height of the texture region to use
                )
            }
        }
    }

// Create a WebGL display for rendering the application
let display = WebGLDisplay(elementId = "App", width = 800, height = 600) // Specify the HTML element and display dimensions
// Attach the data manager, the root view, and an optional per-frame callback to the display
display.AttachView dataManager (sampleView ()) None
// Start the rendering loop for the display
display.Run()

For an example of Elmish-style architecture, check out the SmallWorld.fs file in the repository.

Getting Started

Clone the repository and explore the sample applications to see Imp in action!

Contributing

Contributions are welcome! If you'd like to contribute to Imp, please follow these steps:

1. Fork the repository.
2. Create a new branch for your feature or bugfix.
3. Commit your changes and push them to your fork.
4. Submit a pull request with a detailed description of your changes.

License

This project is licensed under the MIT License.

Support

If you encounter any issues or have questions, feel free to open an issue on the GitHub repository.