ImGui-SFML tileset

void TileState::addTilesetMenu()
{
    const sf::Vector2f tilesetImagePos = ImGui::GetCursorScreenPos();

    ImGui::Image(*currentTileset->texture);

    // draw grid
    auto draw_list = ImGui::GetWindowDrawList();

    const auto tileSize = static_cast<float>(Tile::Size);
    const auto xTiles = static_cast<int>(currentTileset->numberOfTiles.x);
    const auto yTiles = static_cast<int>(currentTileset->numberOfTiles.y);

    // draw horizontal lines
    for (int x = 0; x < xTiles + 1; ++x) {
        draw_list->AddLine(ImVec2(tilesetImagePos.x + x * tileSize, tilesetImagePos.y),
            ImVec2(tilesetImagePos.x + x * tileSize, tilesetImagePos.y + yTiles * tileSize),
            ImColor(255, 255, 255));
    }

    // draw vertical lines
    for (int y = 0; y < yTiles + 1; ++y) {
        draw_list->AddLine(ImVec2(tilesetImagePos.x, tilesetImagePos.y + y * tileSize),
            ImVec2(tilesetImagePos.x + xTiles * tileSize, tilesetImagePos.y + y * tileSize),
            ImColor(255, 255, 255));
    }

    // check input
    if (ImGui::IsItemHovered()) {
        if (ImGui::IsMouseClicked(0)) {
            const auto relMousePos = static_cast<sf::Vector2i>(sf::Vector2f(ImGui::GetMousePos()) - tilesetImagePos);
            const auto tileId = currentTileset->getId(relMousePos);
            if (currentTileset->isInBounds(tileId)) {
                setSelectedTile(tileId);
            }
        }
    }

    const auto tileRect = static_cast<sf::FloatRect>(currentTileset->getTileTextureRect(selectedTileInfo.id));

    // highlight selected tile on tileset
    sf::Vector2f selectedTileTL = mh::getTopLeftCorner(tileRect);
    sf::Vector2f selectedTileBR = mh::getBottomRightCorner(tileRect);

    selectedTileTL += tilesetImagePos;
    selectedTileBR += tilesetImagePos;

    draw_list->AddRect(selectedTileTL, selectedTileBR,
        ImColor(255, 0, 0));
}