Dependencies

Lysa UI requires a working Lysa Engine setup. Refer to the engine's own integration guide for compiler, CMake, Vulkan SDK, and Slang requirements. In addition, Lysa UI itself requires:

A C++23 compiler with C++ module support (same requirements as the engine).
CMake 3.29+.
The Lysa Engine and Vireo RHI already available as CMake subdirectories or submodules.

Integration

Lysa UI is intended to be used alongside Lysa Engine via a .env.cmake configuration file or by setting CMake variables directly.

1. Configure path variables

Create a .env.cmake file (or set variables in your top-level CMakeLists.txt) before adding the subdirectory:

# .env.cmake
set(VIREO_RHI_PROJECT_DIR    "path/to/vireo_rhi")
set(LYSA_ENGINE_PROJECT_DIR  "path/to/lysa_engine")
set(LYSA_UI_PROJECT_DIR      "path/to/lysa_ui")

2. Add Lysa UI to your CMakeLists.txt

Add the subdirectories and link against both lysa_engine and lysa_ui:

set(LUA_BINDINGS        OFF)
set(DIRECTX_BACKEND     ON)
set(FORWARD_RENDERER    ON)
set(DEFERRED_RENDERER   ON)
set(PHYSIC_ENGINE_JOLT  ON)
set(PHYSIC_ENGINE_PHYSX OFF)
if(WIN32)
    set(DIRECTX_BACKEND ON)
endif()
 
add_subdirectory(${LYSA_ENGINE_PROJECT_DIR})
add_subdirectory(${LYSA_UI_PROJECT_DIR})
 
add_executable(your_app
    src/Main.cpp
    # … your other source files …
)
target_link_libraries(your_app PUBLIC lysa_engine lysa_ui)

3. Import the module

In your C++ source files, import the top-level module to access all widget types:

import lysa.ui;

This single import re-exports every class (Widget, Window, WindowManager, Button, Text, TextEdit, all scroll bars, TreeView, and more) as well as all enumerations and UIEvent signal constants.

4. CMake options reference

Option	Default	Description
`LUA_BINDINGS`	OFF	Expose widget API to Lua via LuaBridge