namespace ImGui {
    
    bool BufferingBar(const char* label, float value,  const ImVec2& size_arg, const ImU32& bg_col, const ImU32& fg_col) {
        ImGuiWindow* window = GetCurrentWindow();
        if (window->SkipItems)
            return false;
        
        ImGuiContext& g = *GImGui;
        const ImGuiStyle& style = g.Style;
        const ImGuiID id = window->GetID(label);
        ImVec2 pos = window->DC.CursorPos;
        ImVec2 size = size_arg;
        size.x -= style.FramePadding.x * 2;
        
        const ImRect bb(pos, ImVec2(pos.x + size.x, pos.y + size.y));
        ItemSize(bb, style.FramePadding.y);
        if (!ItemAdd(bb, id))
            return false;
        
        // Render
        const float circleStart = size.x * 0.7f;
        const float circleEnd = size.x;
        const float circleWidth = circleEnd - circleStart;
        
        window->DrawList->AddRectFilled(bb.Min, ImVec2(pos.x + circleStart, bb.Max.y), bg_col);
        window->DrawList->AddRectFilled(bb.Min, ImVec2(pos.x + circleStart*value, bb.Max.y), fg_col);
        
        const float t = g.Time;
        const float r = size.y / 2;
        const float speed = 1.5f;
        
        const float a = speed*0;
        const float b = speed*0.333f;
        const float c = speed*0.666f;
        
        const float o1 = (circleWidth+r) * (t+a - speed * (int)((t+a) / speed)) / speed;
        const float o2 = (circleWidth+r) * (t+b - speed * (int)((t+b) / speed)) / speed;
        const float o3 = (circleWidth+r) * (t+c - speed * (int)((t+c) / speed)) / speed;
        
        window->DrawList->AddCircleFilled(ImVec2(pos.x + circleEnd - o1, bb.Min.y + r), r, bg_col);
        window->DrawList->AddCircleFilled(ImVec2(pos.x + circleEnd - o2, bb.Min.y + r), r, bg_col);
        window->DrawList->AddCircleFilled(ImVec2(pos.x + circleEnd - o3, bb.Min.y + r), r, bg_col);
    }
    bool Spinner(const char* label, float radius, int thickness, const ImU32& color) {
        ImGuiWindow* window = GetCurrentWindow();
        if (window->SkipItems)
            return false;
        
        ImGuiContext& g = *GImGui;
        const ImGuiStyle& style = g.Style;
        const ImGuiID id = window->GetID(label);
        
        ImVec2 pos = window->DC.CursorPos;
        ImVec2 size((radius )*2, (radius + style.FramePadding.y)*2);
        
        const ImRect bb(pos, ImVec2(pos.x + size.x, pos.y + size.y));
        ItemSize(bb, style.FramePadding.y);
        if (!ItemAdd(bb, id))
            return false;
        
        // Render
        window->DrawList->PathClear();
        
        int num_segments = 30;
        int start = abs(ImSin(g.Time*1.8f)*(num_segments-5));
        
        const float a_min = IM_PI*2.0f * ((float)start) / (float)num_segments;
        const float a_max = IM_PI*2.0f * ((float)num_segments-3) / (float)num_segments;
        const ImVec2 centre = ImVec2(pos.x+radius, pos.y+radius+style.FramePadding.y);
        
        for (int i = 0; i < num_segments; i++) {
            const float a = a_min + ((float)i / (float)num_segments) * (a_max - a_min);
            window->DrawList->PathLineTo(ImVec2(centre.x + ImCos(a+g.Time*8) * radius,
                                                centre.y + ImSin(a+g.Time*8) * radius));
        }
        window->DrawList->PathStroke(color, false, thickness);
    }
    
}

ImGui::Begin("Progress Indicators");
        const ImU32 col = ImGui::GetColorU32(ImGuiCol_ButtonHovered);
        const ImU32 bg = ImGui::GetColorU32(ImGuiCol_Button);
        ImGui::Spinner("##spinner", 15, 6, col);
        ImGui::BufferingBar("##buffer_bar", 0.7f, ImVec2(400, 6), bg, col);
        
ImGui::End();