ImGui Integration

NG binds Dear ImGui over the SDL3 GPU backend. The binding is a set of native funs in lib/std/imgui.ng, lowered to $ngrt_imgui* symbols that are implemented by the C++ backend (src/native/imgui_ngrt.cpp, SDL3 GPU + Dear ImGui) and linked into executables that import the binding.

The frame loop

The NG program drives the loop itself:

import prelude;
import imgui;

fun main() -> unit {
    imguiInit();
    loop (frame = 0) {
        imguiEventLoop();
        imguiNewFrame();

        imguiBegin("Hello");
        imguiTextWrapped("immediate-mode from NG");
        if (imguiButton("Click me")) {
            print("clicked");
        }
        imguiEnd();

        imguiRender();
        if (not(imguiAborted())) { next (frame + 1); }
    }
    imguiCleanup();
}

Run with:

./build/ngi example/hello_gui.ng

The frame loop runs until the window closes (imguiAborted).

Binding surface

• Lifecycle: imguiInit, imguiCleanup, imguiEventLoop, imguiNewFrame, imguiRender, imguiAborted
• Windows: imguiBegin, imguiEnd, imguiSetNextWindowSize, imguiBeginChild, imguiEndChild
• Layout/text: imguiText, imguiTextWrapped, imguiSeparator
• Widgets: imguiButton, imguiCheckbox, imguiInputTextMultiline (returns the edited string — rebind it: source := imguiInputTextMultiline("##s", source, w, h);)
• Style/queries: imguiStyleColorsDark, imguiStyleColorsLight, imguiGetTime

The NG IDE

example/ng_ide.ng is a minimal IDE written in NG on this binding: a multiline editor, Run/Reset buttons, a theme toggle, and an output panel. Run compiles the editor text through the real pipeline via the prelude's std.system bindings, so diagnostics (type errors included) land in the output panel:

./build/ngi example/ng_ide.ng