gerald24/kotlin-imgui

Kotlin bindings for Dear ImGui

Kotlin/Multiplatform bindings and wrapper for Dear ImGui

This is meant to be a Kotlin-friendly wrapper (and binding) for Dear ImGui. It is experimental, as I am iterating on the API design and considering optimisations.

The current implementations are based on kgl for OpenGL and GLFW.

To build, you just need to clone and run ./gradlew build.

Usage

repositories {
    maven("https://maven.pkg.github.com/Dominaezzz/kotlin-imgui") {
        credentials {
            username = System.getenv("GITHUB_USER") // Your GitHub username.
            password = System.getenv("GITHUB_TOKEN") // A GitHub token with `read:packages`.
        }
    }
}

dependencies {
    implementation("com.kotlin-imgui:imgui:$imguiVersion")
    implementation("com.kotlin-imgui:imgui-glfw:$imguiVersion")
    implementation("com.kotlin-imgui:imgui-opengl:$imguiVersion")

    // For jvm binaries
    implementation("com.kotlin-imgui:cimgui-jvmlinuxx64:$imguiVersion")
    implementation("com.kotlin-imgui:cimgui-jvmmacosx64:$imguiVersion")
    implementation("com.kotlin-imgui:cimgui-jvmmingwx64:$imguiVersion")

    // Optional
    implementation("com.kgl:kgl-glfw:$kglVersion")
    implementation("com.kgl:kgl-glfw-static:$kglVersion")
    implementation("com.kgl:kgl-opengl:$kglVersion")
}

After kotlin-imgui is set up in your application, you can use it from anywhere in your program loop:

with(ImGui) {
    text("Hello, world ${123}")
    if (button("Save")) {
        mySaveFunction()
    }
    inputText("string", buf)
    sliderFloat("float", ::f, 0.0f, 1.0f)
}

Result:

(settings: Dark style (left), Light style (right) / Font: Roboto-Medium, 16px / Rounding: 5)

Code:

// Create a window called "My First Tool", with a menu bar.
begin("My First Tool", ::myToolActive, ImGuiWindowFlags.MenuBar)
menuBar {
    menu("File") {
        if (menuItem("Open..", "Ctrl+O")) { /* Do stuff */ }
        if (menuItem("Save", "Ctrl+S"))   { /* Do stuff */ }
        if (menuItem("Close", "Ctrl+W"))  { myToolActive = false }
    }
}

// Edit a color (stored as FloatArray[4])
colorEdit4("Color", myColor)

// Plot some values
val myValues = floatArrayOf(0.2f, 0.1f, 1f, 0.5f, 0.9f, 2.2f)
plotLines("Frame Times", myValues)
 
// Display contents in a scrolling region
textColored(Vec4(1.0f , 1.0f, 0.0f, 1.0f), "Important Stuff")
beginChild("Scrolling")
for (n in 0 until 50) {
    text("${n.toString().padStart(4, '0')}: Some text")
}
endChild()
end()

Result:

More information about how the api work is here.

Notes

• Functions with variadic/va_list arguments have been skipped See #1. So formatting will have to be done in Koltin.
• If ImGui.setNextWindowSizeConstraints is called with a callback, it must be followed by a call to ImGui.begin to release the callback.
• Supports LinuxX64, MingwX64 and MacosX64 via JVM or Native. I will add more targets on demand.
• The safe api (wrapper) supports almost all of the original Dear ImGui api but if you need something it does not provide you can depend on cimgui and use it directly. Remember to play nice with the wrapper when doing so.