Evan

Evan is a library for 3D rendering and input handling for applications on OpenXR devices and traditional platforms. It is built on top of OpenXR and Vulkan, providing a high-level interface for developers to create immersive experiences.

Key Features

• 3D Primitives: Built-in support for rendering common 3D shapes like cubes, spheres, and text.
• Event Handling: Comprehensive event system for handling user input and interactions.

Quick Start

int main() {
    return 0;
}

Documentation

• How Evan Works - Comprehensive guide to concepts, lifecycle, and usage patterns
• Architecture Documentation - Detailed overview of the system's design and components
• Technical Choices Documentation - Insights into design decisions and technologies

Prerequisites

For Building Evan, you will need:

• Vulkan SDK

# macOS
brew install vulkan-loader vulkan-headers molten-vk glfw

# Ubuntu/Debian
sudo apt install libvulkan-dev libglfw3-dev

# Fedora
sudo dnf install vulkan-devel glfw-devel

Building

Evan builds as a static library along with examples and tests:

mkdir build && cd build
 
# For desktop (GLFW)
cmake .. -DBUILD_FOR_GLFW=ON
 
# For XR (OpenXR)
cmake .. -DBUILD_FOR_OPENXR=ON
 
cmake --build .

Running Examples

You can also build and run the several examples included in the examples/ directory to see Evan in action:

cmake .. -DBUILD_EXAMPLES=ON #-DBUILD_FOR_GLFW=ON or -DBUILD_FOR_OPENXR=ON depending on your target platform
cmake --build .

Then you can find the compiled examples in the ./examples/ directory:

# Hello World (minimal)
./examples/hello_world/hello_world
 
# Button Counter (interactive)
./examples/button_counter/button_counter
 
# Basic Demo (comprehensive)
./examples/basic_demo/basic_demo

Running Tests

To run the test suite:

./tests/test_evan

Using Evan in Your Project

Evan builds as a static library (libevan.a) with minimal dependencies. To use it in your CMake project:

# Link with Evan (core library has no external dependencies)
target_link_libraries(your_target PRIVATE evan)
 
# Add SDL3 and OpenGL only if you need them for your custom renderer
# target_link_libraries(your_target PRIVATE SDL3::SDL3 ${OPENGL_LIBRARIES})

Examples

The examples/ directory contains sample applications demonstrating Evan's features. Each example is organized in its own subdirectory:

• hello_world/: Minimal example showing basic Evan usage
• button_counter/: Interactive example demonstrating event handling and state management
• basic_demo/: Comprehensive example showing component hierarchy, event handling, and 3D primitive rendering