using RenderTexture within ImGui::Begin() and ImGui::End()?

[Thanh-Binh]

Dear all,
I tried to update my old application from SFML2.6 in SFML3.0.0 with the lastest ImGUI, but I can not display anything within ImGui::Begin() and ImGui::End()?
Belows is my code (slightly modified your example).
Could you please help me?

Thanks.

`
#include "imgui.h" // necessary for ImGui::*, imgui-SFML.h doesn't include imgui.h

#include "imgui-sfml/imgui-SFML.h" // for ImGui::SFML::* functions and SFML-specific overloads

#include <SFML/Graphics.hpp>

int main()
{
sf::RenderWindow window(sf::VideoMode({1280, 720}), "ImGui + SFML = <3");
window.setFramerateLimit(60);
if (!ImGui::SFML::Init(window))
return -1;

sf::RenderWindow childWindow(sf::VideoMode({640, 480}), "ImGui-SFML Child window");
childWindow.setFramerateLimit(60);
if (!ImGui::SFML::Init(childWindow))
    return -1;

sf::RenderTexture rt;

sf::Clock deltaClock;
while (window.isOpen())
{
    // Main window event processing
    while (const auto event = window.pollEvent())
    {
        ImGui::SFML::ProcessEvent(window, *event);
        if (event->is<sf::Event::Closed>())
        {
            if (childWindow.isOpen())
            {
                childWindow.close();
            }
            window.close();
            ImGui::SFML::Shutdown(); // will shutdown all windows
            return 0;                // return here so that we don't call Update/Render
        }
    }

    // Child window event processing
    if (childWindow.isOpen())
    {
        while (const auto event = childWindow.pollEvent())
        {
            ImGui::SFML::ProcessEvent(childWindow, *event);
            if (event->is<sf::Event::Closed>())
            {
                childWindow.close();
                ImGui::SFML::Shutdown(childWindow);
            }
        }
    }

    // Update
    const sf::Time dt = deltaClock.restart();
    ImGui::SFML::Update(window, dt);
    if (childWindow.isOpen())
    {
        ImGui::SFML::Update(childWindow, dt);
    }

    // Add ImGui widgets in the first window
    ImGui::SFML::SetCurrentWindow(window);
    ImGui::Begin("Hello, world!");
    ImGui::Button("Look at this pretty button");
    ImGui::End();

    // Add ImGui widgets in the child window
    if (childWindow.isOpen())
    {
        ImGui::SFML::SetCurrentWindow(childWindow);
        ImGui::Begin("Works in a second window!");
        ImGui::Button("My Example button");

        sf::RectangleShape rs_horizontal;
        rs_horizontal.setPosition(sf::Vector2f(0.0f, 0));
        rs_horizontal.setSize(sf::Vector2f(100, 100));
        rs_horizontal.setFillColor(sf::Color::White);

        rt.draw(rs_horizontal);
        rt.display();
        ImGui::Image(rt);

        ImGui::End();
    }

    // Main window drawing
    sf::CircleShape shape(100.f);
    shape.setFillColor(sf::Color::Green);

    window.clear();
    window.draw(shape);
    ImGui::SFML::Render(window);
    window.display();

    // Child window drawing
    if (childWindow.isOpen())
    {
        sf::CircleShape shape2(50.f);
        shape2.setFillColor(sf::Color::Red);

        childWindow.clear();
        childWindow.draw(shape2);
        ImGui::SFML::Render(childWindow);
        childWindow.display();
    }
}

}
`