imgui/examples/example_allegro5/main.cpp

// Dear ImGui: standalone example application for Allegro 5
// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
// Read online: https://github.com/ocornut/imgui/tree/master/docs

// On Windows, you can install Allegro5 using vcpkg:
//   git clone https://github.com/Microsoft/vcpkg
//   cd vcpkg
//   bootstrap - vcpkg.bat
//   vcpkg install allegro5 --triplet=x86-windows   ; for win32
//   vcpkg install allegro5 --triplet=x64-windows   ; for win64
//   vcpkg integrate install                        ; register include and libs in Visual Studio

#include <stdint.h>
#include <allegro5/allegro.h>
#include <allegro5/allegro_primitives.h>
#include "imgui.h"
#include "imgui_impl_allegro5.h"

// Forward declarations of helper functions
bool MainLoopStep(ALLEGRO_DISPLAY* display, ALLEGRO_EVENT_QUEUE* queue);

// Main code
int main(int, char**)
{
    // Setup Allegro
    al_init();
    al_install_keyboard();
    al_install_mouse();
    al_init_primitives_addon();

    // Create window with graphics context and event queue
    al_set_new_display_flags(ALLEGRO_RESIZABLE);
    ALLEGRO_DISPLAY* display = al_create_display(1280, 720);
    al_set_window_title(display, "Dear ImGui Allegro 5 example");
    ALLEGRO_EVENT_QUEUE* queue = al_create_event_queue();
    al_register_event_source(queue, al_get_display_event_source(display));
    al_register_event_source(queue, al_get_keyboard_event_source());
    al_register_event_source(queue, al_get_mouse_event_source());

    // Setup Dear ImGui context
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); (void)io;
    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;        // Enable Docking

    // Setup Dear ImGui style
    ImGui::StyleColorsDark();
    //ImGui::StyleColorsLight();

    // Setup Platform/Renderer backends
    ImGui_ImplAllegro5_Init(display);

    // Load Fonts
    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
    // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
    // - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
    // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
    // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
    // - Read 'docs/FONTS.md' for more instructions and details.
    // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
    //io.Fonts->AddFontDefault();
    //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
    //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
    //IM_ASSERT(font != NULL);

    // Main loop
    while (true)
    {
        if (!MainLoopStep(display, queue))
            break;
    }

    // Cleanup
    ImGui_ImplAllegro5_Shutdown();
    ImGui::DestroyContext();
    al_destroy_event_queue(queue);
    al_destroy_display(display);

    return 0;
}

bool MainLoopStep(ALLEGRO_DISPLAY* display, ALLEGRO_EVENT_QUEUE* queue)
{
    // Poll and handle events (inputs, window resize, etc.)
    // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
    // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
    // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
    // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
    bool done = false;
    ALLEGRO_EVENT ev;
    while (al_get_next_event(queue, &ev))
    {
        ImGui_ImplAllegro5_ProcessEvent(&ev);
        if (ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
            done = true;
        if (ev.type == ALLEGRO_EVENT_DISPLAY_RESIZE)
        {
            ImGui_ImplAllegro5_InvalidateDeviceObjects();
            al_acknowledge_resize(display);
            ImGui_ImplAllegro5_CreateDeviceObjects();
        }
    }
    if (done)
        return false;

    // Start the Dear ImGui frame
    ImGui_ImplAllegro5_NewFrame();
    ImGui::NewFrame();

    // Our state
    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
    static bool show_demo_window = true;
    static bool show_another_window = false;
    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

    // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
    if (show_demo_window)
        ImGui::ShowDemoWindow(&show_demo_window);

    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
    {
        static float f = 0.0f;
        static int counter = 0;

        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.

        ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
        ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
        ImGui::Checkbox("Another Window", &show_another_window);

        ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
        ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
            counter++;
        ImGui::SameLine();
        ImGui::Text("counter = %d", counter);

        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
        ImGui::End();
    }

    // 3. Show another simple window.
    if (show_another_window)
    {
        ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
        ImGui::Text("Hello from another window!");
        if (ImGui::Button("Close Me"))
            show_another_window = false;
        ImGui::End();
    }

    // Rendering
    ImGui::Render();
    al_clear_to_color(al_map_rgba_f(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w));
    ImGui_ImplAllegro5_RenderDrawData(ImGui::GetDrawData());
    al_flip_display();

    return true;
}