import ImGui

// IMGUI_CHECKVERSION();
IMGUI_CHECKVERSION()

// ImGui::CreateContext();
let ctx = ImGuiCreateContext(nil)

// ImGuiIO& io = ImGui::GetIO();
let io = ImGuiGetIO()!

/// Build font atlas
var pixels: UnsafeMutablePointer<UInt8>?
var width: Int32 = 0
var height: Int32 = 0
var bytesPerPixel: Int32 = 0
// io.Fonts->GetTexDataAsRGBA32(&tex_pixels, &tex_w, &tex_h);
ImFontAtlas_GetTexDataAsRGBA32(io.pointee.Fonts, &pixels, &width, &height, &bytesPerPixel)

for n in 0 ..< 20 {
    print("NewFrame() \(n)")
    // io.DisplaySize = ImVec2(1920, 1080);
    io.pointee.DisplaySize = ImVec2(x: 1920, y: 1080)
    // io.DeltaTime = 1.0f / 60.0f;
    io.pointee.DeltaTime = 1.0 / 60.0
    // ImGui::NewFrame();
    ImGuiNewFrame()

    var f: Float = 0.0
    // ImGui::Text("Hello, world!");
    ImGuiTextV("Hello, world!")
    // ImGui::SliderFloat("float", &f, 0.0f, 1.0f);
    ImGuiSliderFloat("float", &f, 0.0, 1.0, nil, 1)
    // ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
    ImGuiTextV("Application average %.3f ms/frame (%.1f FPS)", 1000.0 / io.pointee.Framerate, io.pointee.Framerate)

    // ImGui::ShowDemoWindow(NULL);
    ImGuiShowDemoWindow(nil)

    // ImGui::Render();
    ImGuiRender()
}

print("DestroyContext()")
ImGuiDestroyContext(ctx)