imgui/imgui_widgets.cpp

// dear imgui, v1.64 WIP
// (widgets code)

#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif

#include "imgui.h"
#ifndef IMGUI_DEFINE_MATH_OPERATORS
#define IMGUI_DEFINE_MATH_OPERATORS
#endif
#include "imgui_internal.h"

#include <ctype.h>      // toupper, isprint

// Visual Studio warnings
#ifdef _MSC_VER
#pragma warning (disable: 4127) // condition expression is constant
#pragma warning (disable: 4996) // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen
#endif

// Clang/GCC warnings with -Weverything
#ifdef __clang__
#pragma clang diagnostic ignored "-Wformat-nonliteral"      // warning : format string is not a string literal              // passing non-literal to vsnformat(). yes, user passing incorrect format strings can crash the code.
#pragma clang diagnostic ignored "-Wsign-conversion"        // warning : implicit conversion changes signedness             //
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wformat-nonliteral"        // warning: format not a string literal, format string not checked
#if __GNUC__ >= 8
#pragma GCC diagnostic ignored "-Wclass-memaccess"          // warning: 'memset/memcpy' clearing/writing an object of type 'xxxx' with no trivial copy-assignment; use assignment or value-initialization instead
#endif
#endif

//-------------------------------------------------------------------------
// Forward Declarations
//-------------------------------------------------------------------------

//-------------------------------------------------------------------------
// SHARED UTILITIES
//-------------------------------------------------------------------------

//-------------------------------------------------------------------------
// WIDGETS: Text
// - TextUnformatted()
// - Text()
// - TextV()
// - TextColored()
// - TextColoredV()
// - TextDisabled()
// - TextDisabledV()
// - TextWrapped()
// - TextWrappedV()
// - LabelText()
// - LabelTextV()
// - BulletText()
// - BulletTextV()
//-------------------------------------------------------------------------

void ImGui::TextUnformatted(const char* text, const char* text_end)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;

    ImGuiContext& g = *GImGui;
    IM_ASSERT(text != NULL);
    const char* text_begin = text;
    if (text_end == NULL)
        text_end = text + strlen(text); // FIXME-OPT

    const ImVec2 text_pos(window->DC.CursorPos.x, window->DC.CursorPos.y + window->DC.CurrentLineTextBaseOffset);
    const float wrap_pos_x = window->DC.TextWrapPos;
    const bool wrap_enabled = wrap_pos_x >= 0.0f;
    if (text_end - text > 2000 && !wrap_enabled)
    {
        // Long text!
        // Perform manual coarse clipping to optimize for long multi-line text
        // From this point we will only compute the width of lines that are visible. Optimization only available when word-wrapping is disabled.
        // We also don't vertically center the text within the line full height, which is unlikely to matter because we are likely the biggest and only item on the line.
        const char* line = text;
        const float line_height = GetTextLineHeight();
        const ImRect clip_rect = window->ClipRect;
        ImVec2 text_size(0,0);

        if (text_pos.y <= clip_rect.Max.y)
        {
            ImVec2 pos = text_pos;

            // Lines to skip (can't skip when logging text)
            if (!g.LogEnabled)
            {
                int lines_skippable = (int)((clip_rect.Min.y - text_pos.y) / line_height);
                if (lines_skippable > 0)
                {
                    int lines_skipped = 0;
                    while (line < text_end && lines_skipped < lines_skippable)
                    {
                        const char* line_end = strchr(line, '\n');
                        if (!line_end)
                            line_end = text_end;
                        line = line_end + 1;
                        lines_skipped++;
                    }
                    pos.y += lines_skipped * line_height;
                }
            }

            // Lines to render
            if (line < text_end)
            {
                ImRect line_rect(pos, pos + ImVec2(FLT_MAX, line_height));
                while (line < text_end)
                {
                    const char* line_end = strchr(line, '\n');
                    if (IsClippedEx(line_rect, 0, false))
                        break;

                    const ImVec2 line_size = CalcTextSize(line, line_end, false);
                    text_size.x = ImMax(text_size.x, line_size.x);
                    RenderText(pos, line, line_end, false);
                    if (!line_end)
                        line_end = text_end;
                    line = line_end + 1;
                    line_rect.Min.y += line_height;
                    line_rect.Max.y += line_height;
                    pos.y += line_height;
                }

                // Count remaining lines
                int lines_skipped = 0;
                while (line < text_end)
                {
                    const char* line_end = strchr(line, '\n');
                    if (!line_end)
                        line_end = text_end;
                    line = line_end + 1;
                    lines_skipped++;
                }
                pos.y += lines_skipped * line_height;
            }

            text_size.y += (pos - text_pos).y;
        }

        ImRect bb(text_pos, text_pos + text_size);
        ItemSize(bb);
        ItemAdd(bb, 0);
    }
    else
    {
        const float wrap_width = wrap_enabled ? CalcWrapWidthForPos(window->DC.CursorPos, wrap_pos_x) : 0.0f;
        const ImVec2 text_size = CalcTextSize(text_begin, text_end, false, wrap_width);

        // Account of baseline offset
        ImRect bb(text_pos, text_pos + text_size);
        ItemSize(text_size);
        if (!ItemAdd(bb, 0))
            return;

        // Render (we don't hide text after ## in this end-user function)
        RenderTextWrapped(bb.Min, text_begin, text_end, wrap_width);
    }
}

void ImGui::Text(const char* fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    TextV(fmt, args);
    va_end(args);
}

void ImGui::TextV(const char* fmt, va_list args)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;

    ImGuiContext& g = *GImGui;
    const char* text_end = g.TempBuffer + ImFormatStringV(g.TempBuffer, IM_ARRAYSIZE(g.TempBuffer), fmt, args);
    TextUnformatted(g.TempBuffer, text_end);
}

void ImGui::TextColored(const ImVec4& col, const char* fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    TextColoredV(col, fmt, args);
    va_end(args);
}

void ImGui::TextColoredV(const ImVec4& col, const char* fmt, va_list args)
{
    PushStyleColor(ImGuiCol_Text, col);
    TextV(fmt, args);
    PopStyleColor();
}

void ImGui::TextDisabled(const char* fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    TextDisabledV(fmt, args);
    va_end(args);
}

void ImGui::TextDisabledV(const char* fmt, va_list args)
{
    PushStyleColor(ImGuiCol_Text, GImGui->Style.Colors[ImGuiCol_TextDisabled]);
    TextV(fmt, args);
    PopStyleColor();
}

void ImGui::TextWrapped(const char* fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    TextWrappedV(fmt, args);
    va_end(args);
}

void ImGui::TextWrappedV(const char* fmt, va_list args)
{
    bool need_wrap = (GImGui->CurrentWindow->DC.TextWrapPos < 0.0f);    // Keep existing wrap position is one ia already set
    if (need_wrap) PushTextWrapPos(0.0f);
    TextV(fmt, args);
    if (need_wrap) PopTextWrapPos();
}

void ImGui::LabelText(const char* label, const char* fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    LabelTextV(label, fmt, args);
    va_end(args);
}

// Add a label+text combo aligned to other label+value widgets
void ImGui::LabelTextV(const char* label, const char* fmt, va_list args)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;
    const float w = CalcItemWidth();

    const ImVec2 label_size = CalcTextSize(label, NULL, true);
    const ImRect value_bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(w, label_size.y + style.FramePadding.y*2));
    const ImRect total_bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(w + (label_size.x > 0.0f ? style.ItemInnerSpacing.x : 0.0f), style.FramePadding.y*2) + label_size);
    ItemSize(total_bb, style.FramePadding.y);
    if (!ItemAdd(total_bb, 0))
        return;

    // Render
    const char* value_text_begin = &g.TempBuffer[0];
    const char* value_text_end = value_text_begin + ImFormatStringV(g.TempBuffer, IM_ARRAYSIZE(g.TempBuffer), fmt, args);
    RenderTextClipped(value_bb.Min, value_bb.Max, value_text_begin, value_text_end, NULL, ImVec2(0.0f,0.5f));
    if (label_size.x > 0.0f)
        RenderText(ImVec2(value_bb.Max.x + style.ItemInnerSpacing.x, value_bb.Min.y + style.FramePadding.y), label);
}

void ImGui::BulletText(const char* fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    BulletTextV(fmt, args);
    va_end(args);
}

// Text with a little bullet aligned to the typical tree node.
void ImGui::BulletTextV(const char* fmt, va_list args)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;

    const char* text_begin = g.TempBuffer;
    const char* text_end = text_begin + ImFormatStringV(g.TempBuffer, IM_ARRAYSIZE(g.TempBuffer), fmt, args);
    const ImVec2 label_size = CalcTextSize(text_begin, text_end, false);
    const float text_base_offset_y = ImMax(0.0f, window->DC.CurrentLineTextBaseOffset); // Latch before ItemSize changes it
    const float line_height = ImMax(ImMin(window->DC.CurrentLineSize.y, g.FontSize + g.Style.FramePadding.y*2), g.FontSize);
    const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(g.FontSize + (label_size.x > 0.0f ? (label_size.x + style.FramePadding.x*2) : 0.0f), ImMax(line_height, label_size.y)));  // Empty text doesn't add padding
    ItemSize(bb);
    if (!ItemAdd(bb, 0))
        return;

    // Render
    RenderBullet(bb.Min + ImVec2(style.FramePadding.x + g.FontSize*0.5f, line_height*0.5f));
    RenderText(bb.Min+ImVec2(g.FontSize + style.FramePadding.x*2, text_base_offset_y), text_begin, text_end, false);
}

//-------------------------------------------------------------------------
// WIDGETS: Main
// - ButtonBehavior() [Internal]
// - Button()
// - SmallButton()
// - InvisibleButton()
// - ArrowButton()
// - CloseButton() [Internal]
// - CollapseButton() [Internal]
// - Image()
// - ImageButton()
// - Checkbox()
// - CheckboxFlags()
// - RadioButton()
// - ProgressBar()
// - Bullet()
//-------------------------------------------------------------------------

bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool* out_held, ImGuiButtonFlags flags)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = GetCurrentWindow();

    if (flags & ImGuiButtonFlags_Disabled)
    {
        if (out_hovered) *out_hovered = false;
        if (out_held) *out_held = false;
        if (g.ActiveId == id) ClearActiveID();
        return false;
    }

    // Default behavior requires click+release on same spot
    if ((flags & (ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnClick | ImGuiButtonFlags_PressedOnRelease | ImGuiButtonFlags_PressedOnDoubleClick)) == 0)
        flags |= ImGuiButtonFlags_PressedOnClickRelease;

    ImGuiWindow* backup_hovered_window = g.HoveredWindow;
    if ((flags & ImGuiButtonFlags_FlattenChildren) && g.HoveredRootWindow == window)
        g.HoveredWindow = window;

    bool pressed = false;
    bool hovered = ItemHoverable(bb, id);

    // Drag source doesn't report as hovered
    if (hovered && g.DragDropActive && g.DragDropPayload.SourceId == id && !(g.DragDropSourceFlags & ImGuiDragDropFlags_SourceNoDisableHover))
        hovered = false;

    // Special mode for Drag and Drop where holding button pressed for a long time while dragging another item triggers the button
    if (g.DragDropActive && (flags & ImGuiButtonFlags_PressedOnDragDropHold) && !(g.DragDropSourceFlags & ImGuiDragDropFlags_SourceNoHoldToOpenOthers))
        if (IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem))
        {
            hovered = true;
            SetHoveredID(id);
            if (CalcTypematicPressedRepeatAmount(g.HoveredIdTimer + 0.0001f, g.HoveredIdTimer + 0.0001f - g.IO.DeltaTime, 0.01f, 0.70f)) // FIXME: Our formula for CalcTypematicPressedRepeatAmount() is fishy
            {
                pressed = true;
                FocusWindow(window);
            }
        }

    if ((flags & ImGuiButtonFlags_FlattenChildren) && g.HoveredRootWindow == window)
        g.HoveredWindow = backup_hovered_window;

    // AllowOverlap mode (rarely used) requires previous frame HoveredId to be null or to match. This allows using patterns where a later submitted widget overlaps a previous one.
    if (hovered && (flags & ImGuiButtonFlags_AllowItemOverlap) && (g.HoveredIdPreviousFrame != id && g.HoveredIdPreviousFrame != 0))
        hovered = false;

    // Mouse
    if (hovered)
    {
        if (!(flags & ImGuiButtonFlags_NoKeyModifiers) || (!g.IO.KeyCtrl && !g.IO.KeyShift && !g.IO.KeyAlt))
        {
            //                        | CLICKING        | HOLDING with ImGuiButtonFlags_Repeat
            // PressedOnClickRelease  |  <on release>*  |  <on repeat> <on repeat> .. (NOT on release)  <-- MOST COMMON! (*) only if both click/release were over bounds
            // PressedOnClick         |  <on click>     |  <on click> <on repeat> <on repeat> ..
            // PressedOnRelease       |  <on release>   |  <on repeat> <on repeat> .. (NOT on release)
            // PressedOnDoubleClick   |  <on dclick>    |  <on dclick> <on repeat> <on repeat> ..
            // FIXME-NAV: We don't honor those different behaviors.
            if ((flags & ImGuiButtonFlags_PressedOnClickRelease) && g.IO.MouseClicked[0])
            {
                SetActiveID(id, window);
                if (!(flags & ImGuiButtonFlags_NoNavFocus))
                    SetFocusID(id, window);
                FocusWindow(window);
            }
            if (((flags & ImGuiButtonFlags_PressedOnClick) && g.IO.MouseClicked[0]) || ((flags & ImGuiButtonFlags_PressedOnDoubleClick) && g.IO.MouseDoubleClicked[0]))
            {
                pressed = true;
                if (flags & ImGuiButtonFlags_NoHoldingActiveID)
                    ClearActiveID();
                else
                    SetActiveID(id, window); // Hold on ID
                FocusWindow(window);
            }
            if ((flags & ImGuiButtonFlags_PressedOnRelease) && g.IO.MouseReleased[0])
            {
                if (!((flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[0] >= g.IO.KeyRepeatDelay))  // Repeat mode trumps <on release>
                    pressed = true;
                ClearActiveID();
            }

            // 'Repeat' mode acts when held regardless of _PressedOn flags (see table above).
            // Relies on repeat logic of IsMouseClicked() but we may as well do it ourselves if we end up exposing finer RepeatDelay/RepeatRate settings.
            if ((flags & ImGuiButtonFlags_Repeat) && g.ActiveId == id && g.IO.MouseDownDuration[0] > 0.0f && IsMouseClicked(0, true))
                pressed = true;
        }

        if (pressed)
            g.NavDisableHighlight = true;
    }

    // Gamepad/Keyboard navigation
    // We report navigated item as hovered but we don't set g.HoveredId to not interfere with mouse.
    if (g.NavId == id && !g.NavDisableHighlight && g.NavDisableMouseHover && (g.ActiveId == 0 || g.ActiveId == id || g.ActiveId == window->MoveId))
        hovered = true;

    if (g.NavActivateDownId == id)
    {
        bool nav_activated_by_code = (g.NavActivateId == id);
        bool nav_activated_by_inputs = IsNavInputPressed(ImGuiNavInput_Activate, (flags & ImGuiButtonFlags_Repeat) ? ImGuiInputReadMode_Repeat : ImGuiInputReadMode_Pressed);
        if (nav_activated_by_code || nav_activated_by_inputs)
            pressed = true;
        if (nav_activated_by_code || nav_activated_by_inputs || g.ActiveId == id)
        {
            // Set active id so it can be queried by user via IsItemActive(), equivalent of holding the mouse button.
            g.NavActivateId = id; // This is so SetActiveId assign a Nav source
            SetActiveID(id, window);
            if (!(flags & ImGuiButtonFlags_NoNavFocus))
                SetFocusID(id, window);
            g.ActiveIdAllowNavDirFlags = (1 << ImGuiDir_Left) | (1 << ImGuiDir_Right) | (1 << ImGuiDir_Up) | (1 << ImGuiDir_Down);
        }
    }

    bool held = false;
    if (g.ActiveId == id)
    {
        if (g.ActiveIdSource == ImGuiInputSource_Mouse)
        {
            if (g.ActiveIdIsJustActivated)
                g.ActiveIdClickOffset = g.IO.MousePos - bb.Min;
            if (g.IO.MouseDown[0])
            {
                held = true;
            }
            else
            {
                if (hovered && (flags & ImGuiButtonFlags_PressedOnClickRelease))
                    if (!((flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[0] >= g.IO.KeyRepeatDelay))  // Repeat mode trumps <on release>
                        if (!g.DragDropActive)
                            pressed = true;
                ClearActiveID();
            }
            if (!(flags & ImGuiButtonFlags_NoNavFocus))
                g.NavDisableHighlight = true;
        }
        else if (g.ActiveIdSource == ImGuiInputSource_Nav)
        {
            if (g.NavActivateDownId != id)
                ClearActiveID();
        }
    }

    if (out_hovered) *out_hovered = hovered;
    if (out_held) *out_held = held;

    return pressed;
}

bool ImGui::ButtonEx(const char* label, const ImVec2& size_arg, ImGuiButtonFlags flags)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;
    const ImGuiID id = window->GetID(label);
    const ImVec2 label_size = CalcTextSize(label, NULL, true);

    ImVec2 pos = window->DC.CursorPos;
    if ((flags & ImGuiButtonFlags_AlignTextBaseLine) && style.FramePadding.y < window->DC.CurrentLineTextBaseOffset) // Try to vertically align buttons that are smaller/have no padding so that text baseline matches (bit hacky, since it shouldn't be a flag)
        pos.y += window->DC.CurrentLineTextBaseOffset - style.FramePadding.y;
    ImVec2 size = CalcItemSize(size_arg, label_size.x + style.FramePadding.x * 2.0f, label_size.y + style.FramePadding.y * 2.0f);

    const ImRect bb(pos, pos + size);
    ItemSize(bb, style.FramePadding.y);
    if (!ItemAdd(bb, id))
        return false;

    if (window->DC.ItemFlags & ImGuiItemFlags_ButtonRepeat)
        flags |= ImGuiButtonFlags_Repeat;
    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held, flags);
    if (pressed)
        MarkItemEdited(id);

    // Render
    const ImU32 col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
    RenderNavHighlight(bb, id);
    RenderFrame(bb.Min, bb.Max, col, true, style.FrameRounding);
    RenderTextClipped(bb.Min + style.FramePadding, bb.Max - style.FramePadding, label, NULL, &label_size, style.ButtonTextAlign, &bb);

    // Automatically close popups
    //if (pressed && !(flags & ImGuiButtonFlags_DontClosePopups) && (window->Flags & ImGuiWindowFlags_Popup))
    //    CloseCurrentPopup();

    return pressed;
}

bool ImGui::Button(const char* label, const ImVec2& size_arg)
{
    return ButtonEx(label, size_arg, 0);
}

// Small buttons fits within text without additional vertical spacing.
bool ImGui::SmallButton(const char* label)
{
    ImGuiContext& g = *GImGui;
    float backup_padding_y = g.Style.FramePadding.y;
    g.Style.FramePadding.y = 0.0f;
    bool pressed = ButtonEx(label, ImVec2(0, 0), ImGuiButtonFlags_AlignTextBaseLine);
    g.Style.FramePadding.y = backup_padding_y;
    return pressed;
}

// Tip: use ImGui::PushID()/PopID() to push indices or pointers in the ID stack.
// Then you can keep 'str_id' empty or the same for all your buttons (instead of creating a string based on a non-string id)
bool ImGui::InvisibleButton(const char* str_id, const ImVec2& size_arg)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    // Cannot use zero-size for InvisibleButton(). Unlike Button() there is not way to fallback using the label size.
    IM_ASSERT(size_arg.x != 0.0f && size_arg.y != 0.0f);

    const ImGuiID id = window->GetID(str_id);
    ImVec2 size = CalcItemSize(size_arg, 0.0f, 0.0f);
    const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
    ItemSize(bb);
    if (!ItemAdd(bb, id))
        return false;

    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held);

    return pressed;
}

bool ImGui::ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size, ImGuiButtonFlags flags)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    ImGuiContext& g = *GImGui;
    const ImGuiID id = window->GetID(str_id);
    const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
    const float default_size = GetFrameHeight();
    ItemSize(bb, (size.y >= default_size) ? g.Style.FramePadding.y : 0.0f);
    if (!ItemAdd(bb, id))
        return false;

    if (window->DC.ItemFlags & ImGuiItemFlags_ButtonRepeat)
        flags |= ImGuiButtonFlags_Repeat;

    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held, flags);

    // Render
    const ImU32 col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
    RenderNavHighlight(bb, id);
    RenderFrame(bb.Min, bb.Max, col, true, g.Style.FrameRounding);
    RenderArrow(bb.Min + ImVec2(ImMax(0.0f, size.x - g.FontSize - g.Style.FramePadding.x), ImMax(0.0f, size.y - g.FontSize - g.Style.FramePadding.y)), dir);

    return pressed;
}

bool ImGui::ArrowButton(const char* str_id, ImGuiDir dir)
{
    float sz = GetFrameHeight();
    return ArrowButtonEx(str_id, dir, ImVec2(sz, sz), 0);
}

// Button to close a window
bool ImGui::CloseButton(ImGuiID id, const ImVec2& pos, float radius)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;

    // We intentionally allow interaction when clipped so that a mechanical Alt,Right,Validate sequence close a window.
    // (this isn't the regular behavior of buttons, but it doesn't affect the user much because navigation tends to keep items visible).
    const ImRect bb(pos - ImVec2(radius,radius), pos + ImVec2(radius,radius));
    bool is_clipped = !ItemAdd(bb, id);

    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held);
    if (is_clipped)
        return pressed;

    // Render
    ImVec2 center = bb.GetCenter();
    if (hovered)
        window->DrawList->AddCircleFilled(center, ImMax(2.0f, radius), GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : ImGuiCol_ButtonHovered), 9);

    float cross_extent = (radius * 0.7071f) - 1.0f;
    ImU32 cross_col = GetColorU32(ImGuiCol_Text);
    center -= ImVec2(0.5f, 0.5f);
    window->DrawList->AddLine(center + ImVec2(+cross_extent,+cross_extent), center + ImVec2(-cross_extent,-cross_extent), cross_col, 1.0f);
    window->DrawList->AddLine(center + ImVec2(+cross_extent,-cross_extent), center + ImVec2(-cross_extent,+cross_extent), cross_col, 1.0f);

    return pressed;
}

bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;

    ImRect bb(pos, pos + ImVec2(g.FontSize, g.FontSize) + g.Style.FramePadding * 2.0f);
    ItemAdd(bb, id);
    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_None);

    ImU32 col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
    if (hovered || held)
        window->DrawList->AddCircleFilled(bb.GetCenter() + ImVec2(0.0f, -0.5f), g.FontSize * 0.5f + 1.0f, col, 9);
    RenderArrow(bb.Min + g.Style.FramePadding, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);

    // Switch to moving the window after mouse is moved beyond the initial drag threshold
    if (IsItemActive() && IsMouseDragging())
        StartMouseMovingWindow(window);

    return pressed;
}

void ImGui::Image(ImTextureID user_texture_id, const ImVec2& size, const ImVec2& uv0, const ImVec2& uv1, const ImVec4& tint_col, const ImVec4& border_col)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;

    ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
    if (border_col.w > 0.0f)
        bb.Max += ImVec2(2, 2);
    ItemSize(bb);
    if (!ItemAdd(bb, 0))
        return;

    if (border_col.w > 0.0f)
    {
        window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(border_col), 0.0f);
        window->DrawList->AddImage(user_texture_id, bb.Min + ImVec2(1, 1), bb.Max - ImVec2(1, 1), uv0, uv1, GetColorU32(tint_col));
    }
    else
    {
        window->DrawList->AddImage(user_texture_id, bb.Min, bb.Max, uv0, uv1, GetColorU32(tint_col));
    }
}

// frame_padding < 0: uses FramePadding from style (default)
// frame_padding = 0: no framing
// frame_padding > 0: set framing size
// The color used are the button colors.
bool ImGui::ImageButton(ImTextureID user_texture_id, const ImVec2& size, const ImVec2& uv0, const ImVec2& uv1, int frame_padding, const ImVec4& bg_col, const ImVec4& tint_col)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;

    // Default to using texture ID as ID. User can still push string/integer prefixes.
    // We could hash the size/uv to create a unique ID but that would prevent the user from animating UV.
    PushID((void*)user_texture_id);
    const ImGuiID id = window->GetID("#image");
    PopID();

    const ImVec2 padding = (frame_padding >= 0) ? ImVec2((float)frame_padding, (float)frame_padding) : style.FramePadding;
    const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size + padding * 2);
    const ImRect image_bb(window->DC.CursorPos + padding, window->DC.CursorPos + padding + size);
    ItemSize(bb);
    if (!ItemAdd(bb, id))
        return false;

    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held);

    // Render
    const ImU32 col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
    RenderNavHighlight(bb, id);
    RenderFrame(bb.Min, bb.Max, col, true, ImClamp((float)ImMin(padding.x, padding.y), 0.0f, style.FrameRounding));
    if (bg_col.w > 0.0f)
        window->DrawList->AddRectFilled(image_bb.Min, image_bb.Max, GetColorU32(bg_col));
    window->DrawList->AddImage(user_texture_id, image_bb.Min, image_bb.Max, uv0, uv1, GetColorU32(tint_col));

    return pressed;
}

bool ImGui::Checkbox(const char* label, bool* v)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;
    const ImGuiID id = window->GetID(label);
    const ImVec2 label_size = CalcTextSize(label, NULL, true);

    const ImRect check_bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(label_size.y + style.FramePadding.y*2, label_size.y + style.FramePadding.y*2)); // We want a square shape to we use Y twice
    ItemSize(check_bb, style.FramePadding.y);

    ImRect total_bb = check_bb;
    if (label_size.x > 0)
        SameLine(0, style.ItemInnerSpacing.x);
    const ImRect text_bb(window->DC.CursorPos + ImVec2(0,style.FramePadding.y), window->DC.CursorPos + ImVec2(0,style.FramePadding.y) + label_size);
    if (label_size.x > 0)
    {
        ItemSize(ImVec2(text_bb.GetWidth(), check_bb.GetHeight()), style.FramePadding.y);
        total_bb = ImRect(ImMin(check_bb.Min, text_bb.Min), ImMax(check_bb.Max, text_bb.Max));
    }

    if (!ItemAdd(total_bb, id))
        return false;

    bool hovered, held;
    bool pressed = ButtonBehavior(total_bb, id, &hovered, &held);
    if (pressed)
    {
        *v = !(*v);
        MarkItemEdited(id);
    }

    RenderNavHighlight(total_bb, id);
    RenderFrame(check_bb.Min, check_bb.Max, GetColorU32((held && hovered) ? ImGuiCol_FrameBgActive : hovered ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg), true, style.FrameRounding);
    if (*v)
    {
        const float check_sz = ImMin(check_bb.GetWidth(), check_bb.GetHeight());
        const float pad = ImMax(1.0f, (float)(int)(check_sz / 6.0f));
        RenderCheckMark(check_bb.Min + ImVec2(pad,pad), GetColorU32(ImGuiCol_CheckMark), check_bb.GetWidth() - pad*2.0f);
    }

    if (g.LogEnabled)
        LogRenderedText(&text_bb.Min, *v ? "[x]" : "[ ]");
    if (label_size.x > 0.0f)
        RenderText(text_bb.Min, label);

    return pressed;
}

bool ImGui::CheckboxFlags(const char* label, unsigned int* flags, unsigned int flags_value)
{
    bool v = ((*flags & flags_value) == flags_value);
    bool pressed = Checkbox(label, &v);
    if (pressed)
    {
        if (v)
            *flags |= flags_value;
        else
            *flags &= ~flags_value;
    }

    return pressed;
}

bool ImGui::RadioButton(const char* label, bool active)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;
    const ImGuiID id = window->GetID(label);
    const ImVec2 label_size = CalcTextSize(label, NULL, true);

    const ImRect check_bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(label_size.y + style.FramePadding.y*2-1, label_size.y + style.FramePadding.y*2-1));
    ItemSize(check_bb, style.FramePadding.y);

    ImRect total_bb = check_bb;
    if (label_size.x > 0)
        SameLine(0, style.ItemInnerSpacing.x);
    const ImRect text_bb(window->DC.CursorPos + ImVec2(0, style.FramePadding.y), window->DC.CursorPos + ImVec2(0, style.FramePadding.y) + label_size);
    if (label_size.x > 0)
    {
        ItemSize(ImVec2(text_bb.GetWidth(), check_bb.GetHeight()), style.FramePadding.y);
        total_bb.Add(text_bb);
    }

    if (!ItemAdd(total_bb, id))
        return false;

    ImVec2 center = check_bb.GetCenter();
    center.x = (float)(int)center.x + 0.5f;
    center.y = (float)(int)center.y + 0.5f;
    const float radius = check_bb.GetHeight() * 0.5f;

    bool hovered, held;
    bool pressed = ButtonBehavior(total_bb, id, &hovered, &held);
    if (pressed)
        MarkItemEdited(id);

    RenderNavHighlight(total_bb, id);
    window->DrawList->AddCircleFilled(center, radius, GetColorU32((held && hovered) ? ImGuiCol_FrameBgActive : hovered ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg), 16);
    if (active)
    {
        const float check_sz = ImMin(check_bb.GetWidth(), check_bb.GetHeight());
        const float pad = ImMax(1.0f, (float)(int)(check_sz / 6.0f));
        window->DrawList->AddCircleFilled(center, radius-pad, GetColorU32(ImGuiCol_CheckMark), 16);
    }

    if (style.FrameBorderSize > 0.0f)
    {
        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16, style.FrameBorderSize);
        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16, style.FrameBorderSize);
    }

    if (g.LogEnabled)
        LogRenderedText(&text_bb.Min, active ? "(x)" : "( )");
    if (label_size.x > 0.0f)
        RenderText(text_bb.Min, label);

    return pressed;
}

bool ImGui::RadioButton(const char* label, int* v, int v_button)
{
    const bool pressed = RadioButton(label, *v == v_button);
    if (pressed)
        *v = v_button;
    return pressed;
}

// size_arg (for each axis) < 0.0f: align to end, 0.0f: auto, > 0.0f: specified size
void ImGui::ProgressBar(float fraction, const ImVec2& size_arg, const char* overlay)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;

    ImVec2 pos = window->DC.CursorPos;
    ImRect bb(pos, pos + CalcItemSize(size_arg, CalcItemWidth(), g.FontSize + style.FramePadding.y*2.0f));
    ItemSize(bb, style.FramePadding.y);
    if (!ItemAdd(bb, 0))
        return;

    // Render
    fraction = ImSaturate(fraction);
    RenderFrame(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);
    bb.Expand(ImVec2(-style.FrameBorderSize, -style.FrameBorderSize));
    const ImVec2 fill_br = ImVec2(ImLerp(bb.Min.x, bb.Max.x, fraction), bb.Max.y);
    RenderRectFilledRangeH(window->DrawList, bb, GetColorU32(ImGuiCol_PlotHistogram), 0.0f, fraction, style.FrameRounding);

    // Default displaying the fraction as percentage string, but user can override it
    char overlay_buf[32];
    if (!overlay)
    {
        ImFormatString(overlay_buf, IM_ARRAYSIZE(overlay_buf), "%.0f%%", fraction*100+0.01f);
        overlay = overlay_buf;
    }

    ImVec2 overlay_size = CalcTextSize(overlay, NULL);
    if (overlay_size.x > 0.0f)
        RenderTextClipped(ImVec2(ImClamp(fill_br.x + style.ItemSpacing.x, bb.Min.x, bb.Max.x - overlay_size.x - style.ItemInnerSpacing.x), bb.Min.y), bb.Max, overlay, NULL, &overlay_size, ImVec2(0.0f,0.5f), &bb);
}

void ImGui::Bullet()
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;
    const float line_height = ImMax(ImMin(window->DC.CurrentLineSize.y, g.FontSize + g.Style.FramePadding.y*2), g.FontSize);
    const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(g.FontSize, line_height));
    ItemSize(bb);
    if (!ItemAdd(bb, 0))
    {
        SameLine(0, style.FramePadding.x*2);
        return;
    }

    // Render and stay on same line
    RenderBullet(bb.Min + ImVec2(style.FramePadding.x + g.FontSize*0.5f, line_height*0.5f));
    SameLine(0, style.FramePadding.x*2);
}

//-------------------------------------------------------------------------
// WIDGETS: Combo Box
// - BeginCombo()
// - EndCombo()
// - Combo()
//-------------------------------------------------------------------------

static float CalcMaxPopupHeightFromItemCount(int items_count)
{
    ImGuiContext& g = *GImGui;
    if (items_count <= 0)
        return FLT_MAX;
    return (g.FontSize + g.Style.ItemSpacing.y) * items_count - g.Style.ItemSpacing.y + (g.Style.WindowPadding.y * 2);
}

bool ImGui::BeginCombo(const char* label, const char* preview_value, ImGuiComboFlags flags)
{
    // Always consume the SetNextWindowSizeConstraint() call in our early return paths
    ImGuiContext& g = *GImGui;
    ImGuiCond backup_next_window_size_constraint = g.NextWindowData.SizeConstraintCond;
    g.NextWindowData.SizeConstraintCond = 0;

    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    IM_ASSERT((flags & (ImGuiComboFlags_NoArrowButton | ImGuiComboFlags_NoPreview)) != (ImGuiComboFlags_NoArrowButton | ImGuiComboFlags_NoPreview)); // Can't use both flags together

    const ImGuiStyle& style = g.Style;
    const ImGuiID id = window->GetID(label);

    const float arrow_size = (flags & ImGuiComboFlags_NoArrowButton) ? 0.0f : GetFrameHeight();
    const ImVec2 label_size = CalcTextSize(label, NULL, true);
    const float w = (flags & ImGuiComboFlags_NoPreview) ? arrow_size : CalcItemWidth();
    const ImRect frame_bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(w, label_size.y + style.FramePadding.y*2.0f));
    const ImRect total_bb(frame_bb.Min, frame_bb.Max + ImVec2(label_size.x > 0.0f ? style.ItemInnerSpacing.x + label_size.x : 0.0f, 0.0f));
    ItemSize(total_bb, style.FramePadding.y);
    if (!ItemAdd(total_bb, id, &frame_bb))
        return false;

    bool hovered, held;
    bool pressed = ButtonBehavior(frame_bb, id, &hovered, &held);
    bool popup_open = IsPopupOpen(id);

    const ImRect value_bb(frame_bb.Min, frame_bb.Max - ImVec2(arrow_size, 0.0f));
    const ImU32 frame_col = GetColorU32(hovered ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg);
    RenderNavHighlight(frame_bb, id);
    if (!(flags & ImGuiComboFlags_NoPreview))
        window->DrawList->AddRectFilled(frame_bb.Min, ImVec2(frame_bb.Max.x - arrow_size, frame_bb.Max.y), frame_col, style.FrameRounding, ImDrawCornerFlags_Left);
    if (!(flags & ImGuiComboFlags_NoArrowButton))
    {
        window->DrawList->AddRectFilled(ImVec2(frame_bb.Max.x - arrow_size, frame_bb.Min.y), frame_bb.Max, GetColorU32((popup_open || hovered) ? ImGuiCol_ButtonHovered : ImGuiCol_Button), style.FrameRounding, (w <= arrow_size) ? ImDrawCornerFlags_All : ImDrawCornerFlags_Right);
        RenderArrow(ImVec2(frame_bb.Max.x - arrow_size + style.FramePadding.y, frame_bb.Min.y + style.FramePadding.y), ImGuiDir_Down);
    }
    RenderFrameBorder(frame_bb.Min, frame_bb.Max, style.FrameRounding);
    if (preview_value != NULL && !(flags & ImGuiComboFlags_NoPreview))
        RenderTextClipped(frame_bb.Min + style.FramePadding, value_bb.Max, preview_value, NULL, NULL, ImVec2(0.0f,0.0f));
    if (label_size.x > 0)
        RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label);

    if ((pressed || g.NavActivateId == id) && !popup_open)
    {
        if (window->DC.NavLayerCurrent == 0)
            window->NavLastIds[0] = id;
        OpenPopupEx(id);
        popup_open = true;
    }

    if (!popup_open)
        return false;

    if (backup_next_window_size_constraint)
    {
        g.NextWindowData.SizeConstraintCond = backup_next_window_size_constraint;
        g.NextWindowData.SizeConstraintRect.Min.x = ImMax(g.NextWindowData.SizeConstraintRect.Min.x, w);
    }
    else
    {
        if ((flags & ImGuiComboFlags_HeightMask_) == 0)
            flags |= ImGuiComboFlags_HeightRegular;
        IM_ASSERT(ImIsPowerOfTwo(flags & ImGuiComboFlags_HeightMask_));    // Only one
        int popup_max_height_in_items = -1;
        if (flags & ImGuiComboFlags_HeightRegular)     popup_max_height_in_items = 8;
        else if (flags & ImGuiComboFlags_HeightSmall)  popup_max_height_in_items = 4;
        else if (flags & ImGuiComboFlags_HeightLarge)  popup_max_height_in_items = 20;
        SetNextWindowSizeConstraints(ImVec2(w, 0.0f), ImVec2(FLT_MAX, CalcMaxPopupHeightFromItemCount(popup_max_height_in_items)));
    }

    char name[16];
    ImFormatString(name, IM_ARRAYSIZE(name), "##Combo_%02d", g.CurrentPopupStack.Size); // Recycle windows based on depth

    // Peak into expected window size so we can position it
    if (ImGuiWindow* popup_window = FindWindowByName(name))
        if (popup_window->WasActive)
        {
            ImVec2 size_expected = CalcWindowExpectedSize(popup_window);
            if (flags & ImGuiComboFlags_PopupAlignLeft)
                popup_window->AutoPosLastDirection = ImGuiDir_Left;
            ImRect r_outer = GetWindowAllowedExtentRect(popup_window);
            ImVec2 pos = FindBestWindowPosForPopupEx(frame_bb.GetBL(), size_expected, &popup_window->AutoPosLastDirection, r_outer, frame_bb, ImGuiPopupPositionPolicy_ComboBox);
            SetNextWindowPos(pos);
        }

    // Horizontally align ourselves with the framed text
    ImGuiWindowFlags window_flags = ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_Popup | ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoSavedSettings;
    PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(style.FramePadding.x, style.WindowPadding.y));
    bool ret = Begin(name, NULL, window_flags);
    PopStyleVar();
    if (!ret)
    {
        EndPopup();
        IM_ASSERT(0);   // This should never happen as we tested for IsPopupOpen() above
        return false;
    }
    return true;
}

void ImGui::EndCombo()
{
    EndPopup();
}

// Getter for the old Combo() API: const char*[]
static bool Items_ArrayGetter(void* data, int idx, const char** out_text)
{
    const char* const* items = (const char* const*)data;
    if (out_text)
        *out_text = items[idx];
    return true;
}

// Getter for the old Combo() API: "item1\0item2\0item3\0"
static bool Items_SingleStringGetter(void* data, int idx, const char** out_text)
{
    // FIXME-OPT: we could pre-compute the indices to fasten this. But only 1 active combo means the waste is limited.
    const char* items_separated_by_zeros = (const char*)data;
    int items_count = 0;
    const char* p = items_separated_by_zeros;
    while (*p)
    {
        if (idx == items_count)
            break;
        p += strlen(p) + 1;
        items_count++;
    }
    if (!*p)
        return false;
    if (out_text)
        *out_text = p;
    return true;
}

// Old API, prefer using BeginCombo() nowadays if you can.
bool ImGui::Combo(const char* label, int* current_item, bool (*items_getter)(void*, int, const char**), void* data, int items_count, int popup_max_height_in_items)
{
    ImGuiContext& g = *GImGui;

    // Call the getter to obtain the preview string which is a parameter to BeginCombo()
    const char* preview_value = NULL;
    if (*current_item >= 0 && *current_item < items_count)
        items_getter(data, *current_item, &preview_value);

    // The old Combo() API exposed "popup_max_height_in_items". The new more general BeginCombo() API doesn't have/need it, but we emulate it here.
    if (popup_max_height_in_items != -1 && !g.NextWindowData.SizeConstraintCond)
        SetNextWindowSizeConstraints(ImVec2(0,0), ImVec2(FLT_MAX, CalcMaxPopupHeightFromItemCount(popup_max_height_in_items)));

    if (!BeginCombo(label, preview_value, ImGuiComboFlags_None))
        return false;

    // Display items
    // FIXME-OPT: Use clipper (but we need to disable it on the appearing frame to make sure our call to SetItemDefaultFocus() is processed)
    bool value_changed = false;
    for (int i = 0; i < items_count; i++)
    {
        PushID((void*)(intptr_t)i);
        const bool item_selected = (i == *current_item);
        const char* item_text;
        if (!items_getter(data, i, &item_text))
            item_text = "*Unknown item*";
        if (Selectable(item_text, item_selected))
        {
            value_changed = true;
            *current_item = i;
        }
        if (item_selected)
            SetItemDefaultFocus();
        PopID();
    }

    EndCombo();
    return value_changed;
}

// Combo box helper allowing to pass an array of strings.
bool ImGui::Combo(const char* label, int* current_item, const char* const items[], int items_count, int height_in_items)
{
    const bool value_changed = Combo(label, current_item, Items_ArrayGetter, (void*)items, items_count, height_in_items);
    return value_changed;
}

// Combo box helper allowing to pass all items in a single string literal holding multiple zero-terminated items "item1\0item2\0" 
bool ImGui::Combo(const char* label, int* current_item, const char* items_separated_by_zeros, int height_in_items)
{
    int items_count = 0;
    const char* p = items_separated_by_zeros;       // FIXME-OPT: Avoid computing this, or at least only when combo is open
    while (*p)
    {
        p += strlen(p) + 1;
        items_count++;
    }
    bool value_changed = Combo(label, current_item, Items_SingleStringGetter, (void*)items_separated_by_zeros, items_count, height_in_items);
    return value_changed;
}

//-------------------------------------------------------------------------
// WIDGETS: Data Type and Data Formatting Helpers [Internal]
// - PatchFormatStringFloatToInt()
// - DataTypeFormatString()
// - DataTypeApplyOp()
// - DataTypeApplyOpFromText()
// - GetMinimumStepAtDecimalPrecision
// - RoundScalarWithFormat<>()
//-------------------------------------------------------------------------


//-------------------------------------------------------------------------
// WIDGETS: Drags
// - DragBehaviorT<>() [Internal]
// - DragBehavior() [Internal]
// - DragScalar()
// - DragScalarN()
// - DragFloat()
// - DragFloat2()
// - DragFloat3()
// - DragFloat4()
// - DragFloatRange2()
// - DragInt()
// - DragInt2()
// - DragInt3()
// - DragInt4()
// - DragIntRange2()
//-------------------------------------------------------------------------


//-------------------------------------------------------------------------
// WIDGETS: Sliders
// - SliderBehaviorT<>() [Internal]
// - SliderBehavior() [Internal]
// - SliderScalar()
// - SliderScalarN()
// - SliderFloat()
// - SliderFloat2()
// - SliderFloat3()
// - SliderFloat4()
// - SliderAngle()
// - SliderInt()
// - SliderInt2()
// - SliderInt3()
// - SliderInt4()
// - VSliderScalar()
// - VSliderFloat()
// - VSliderInt()
//-------------------------------------------------------------------------


















//-------------------------------------------------------------------------
// WIDGETS: Inputs (_excepted InputText_)
// - ImParseFormatFindStart()
// - ImParseFormatFindEnd()
// - ImParseFormatTrimDecorations()
// - ImParseFormatPrecision()
// - InputScalarAsWidgetReplacement() [Internal]
// - InputScalar()
// - InputScalarN()
// - InputFloat()
// - InputFloat2()
// - InputFloat3()
// - InputFloat4()
// - InputInt()
// - InputInt2()
// - InputInt3()
// - InputInt4()
// - InputDouble()
//-------------------------------------------------------------------------

















//-------------------------------------------------------------------------
// WIDGETS: InputText
// - InputText()
// - InputTextMultiline()
// - InputTextEx() [Internal]
//-------------------------------------------------------------------------


//-------------------------------------------------------------------------
// WIDGETS: Color Editor / Picker
// - ColorEdit3()
// - ColorEdit4()
// - ColorPicker3()
// - RenderColorRectWithAlphaCheckerboard() [Internal]
// - ColorPicker4()
// - ColorButton()
// - SetColorEditOptions()
// - ColorTooltip() [Internal]
// - ColorEditOptionsPopup() [Internal]
// - ColorPickerOptionsPopup() [Internal]
//-------------------------------------------------------------------------


//-------------------------------------------------------------------------
// WIDGETS: Trees
// - TreeNode()
// - TreeNodeV()
// - TreeNodeEx()
// - TreeNodeExV()
// - TreeNodeBehavior() [Internal]  
// - TreePush()
// - TreePop()
// - TreeAdvanceToLabelPos()
// - GetTreeNodeToLabelSpacing()
// - SetNextTreeNodeOpen()
// - CollapsingHeader()
//-------------------------------------------------------------------------


//-------------------------------------------------------------------------
// WIDGETS: Selectables
// - Selectable()
//-------------------------------------------------------------------------


//-------------------------------------------------------------------------
// WIDGETS: List Box
// - ListBox()
// - ListBoxHeader()
// - ListBoxFooter()
//-------------------------------------------------------------------------

// FIXME: Rename to BeginListBox()
// Helper to calculate the size of a listbox and display a label on the right.
// Tip: To have a list filling the entire window width, PushItemWidth(-1) and pass an empty label "##empty"
bool ImGui::ListBoxHeader(const char* label, const ImVec2& size_arg)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    const ImGuiStyle& style = GetStyle();
    const ImGuiID id = GetID(label);
    const ImVec2 label_size = CalcTextSize(label, NULL, true);

    // Size default to hold ~7 items. Fractional number of items helps seeing that we can scroll down/up without looking at scrollbar.
    ImVec2 size = CalcItemSize(size_arg, CalcItemWidth(), GetTextLineHeightWithSpacing() * 7.4f + style.ItemSpacing.y);
    ImVec2 frame_size = ImVec2(size.x, ImMax(size.y, label_size.y));
    ImRect frame_bb(window->DC.CursorPos, window->DC.CursorPos + frame_size);
    ImRect bb(frame_bb.Min, frame_bb.Max + ImVec2(label_size.x > 0.0f ? style.ItemInnerSpacing.x + label_size.x : 0.0f, 0.0f));
    window->DC.LastItemRect = bb; // Forward storage for ListBoxFooter.. dodgy.

    BeginGroup();
    if (label_size.x > 0)
        RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label);

    BeginChildFrame(id, frame_bb.GetSize());
    return true;
}

// FIXME: Rename to BeginListBox()
bool ImGui::ListBoxHeader(const char* label, int items_count, int height_in_items)
{
    // Size default to hold ~7 items. Fractional number of items helps seeing that we can scroll down/up without looking at scrollbar.
    // We don't add +0.40f if items_count <= height_in_items. It is slightly dodgy, because it means a dynamic list of items will make the widget resize occasionally when it crosses that size.
    // I am expecting that someone will come and complain about this behavior in a remote future, then we can advise on a better solution.
    if (height_in_items < 0)
        height_in_items = ImMin(items_count, 7);
    float height_in_items_f = height_in_items < items_count ? (height_in_items + 0.40f) : (height_in_items + 0.00f);

    // We include ItemSpacing.y so that a list sized for the exact number of items doesn't make a scrollbar appears. We could also enforce that by passing a flag to BeginChild().
    ImVec2 size;
    size.x = 0.0f;
    size.y = GetTextLineHeightWithSpacing() * height_in_items_f + GetStyle().ItemSpacing.y;
    return ListBoxHeader(label, size);
}

// FIXME: Rename to EndListBox()
void ImGui::ListBoxFooter()
{
    ImGuiWindow* parent_window = GetCurrentWindow()->ParentWindow;
    const ImRect bb = parent_window->DC.LastItemRect;
    const ImGuiStyle& style = GetStyle();

    EndChildFrame();

    // Redeclare item size so that it includes the label (we have stored the full size in LastItemRect)
    // We call SameLine() to restore DC.CurrentLine* data
    SameLine();
    parent_window->DC.CursorPos = bb.Min;
    ItemSize(bb, style.FramePadding.y);
    EndGroup();
}

bool ImGui::ListBox(const char* label, int* current_item, const char* const items[], int items_count, int height_items)
{
    const bool value_changed = ListBox(label, current_item, Items_ArrayGetter, (void*)items, items_count, height_items);
    return value_changed;
}

bool ImGui::ListBox(const char* label, int* current_item, bool (*items_getter)(void*, int, const char**), void* data, int items_count, int height_in_items)
{
    if (!ListBoxHeader(label, items_count, height_in_items))
        return false;

    // Assume all items have even height (= 1 line of text). If you need items of different or variable sizes you can create a custom version of ListBox() in your code without using the clipper.
    ImGuiContext& g = *GImGui;
    bool value_changed = false;
    ImGuiListClipper clipper(items_count, GetTextLineHeightWithSpacing()); // We know exactly our line height here so we pass it as a minor optimization, but generally you don't need to.
    while (clipper.Step())
        for (int i = clipper.DisplayStart; i < clipper.DisplayEnd; i++)
        {
            const bool item_selected = (i == *current_item);
            const char* item_text;
            if (!items_getter(data, i, &item_text))
                item_text = "*Unknown item*";

            PushID(i);
            if (Selectable(item_text, item_selected))
            {
                *current_item = i;
                value_changed = true;
            }
            if (item_selected)
                SetItemDefaultFocus();
            PopID();
        }
    ListBoxFooter();
    if (value_changed)
        MarkItemEdited(g.CurrentWindow->DC.LastItemId);

    return value_changed;
}

//-------------------------------------------------------------------------
// WIDGETS: Data Plotting
// - PlotEx() [Internal]
// - PlotLines()
// - PlotHistogram()
//-------------------------------------------------------------------------

void ImGui::PlotEx(ImGuiPlotType plot_type, const char* label, float (*values_getter)(void* data, int idx), void* data, int values_count, int values_offset, const char* overlay_text, float scale_min, float scale_max, ImVec2 graph_size)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;

    const ImVec2 label_size = CalcTextSize(label, NULL, true);
    if (graph_size.x == 0.0f)
        graph_size.x = CalcItemWidth();
    if (graph_size.y == 0.0f)
        graph_size.y = label_size.y + (style.FramePadding.y * 2);

    const ImRect frame_bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(graph_size.x, graph_size.y));
    const ImRect inner_bb(frame_bb.Min + style.FramePadding, frame_bb.Max - style.FramePadding);
    const ImRect total_bb(frame_bb.Min, frame_bb.Max + ImVec2(label_size.x > 0.0f ? style.ItemInnerSpacing.x + label_size.x : 0.0f, 0));
    ItemSize(total_bb, style.FramePadding.y);
    if (!ItemAdd(total_bb, 0, &frame_bb))
        return;
    const bool hovered = ItemHoverable(inner_bb, 0);

    // Determine scale from values if not specified
    if (scale_min == FLT_MAX || scale_max == FLT_MAX)
    {
        float v_min = FLT_MAX;
        float v_max = -FLT_MAX;
        for (int i = 0; i < values_count; i++)
        {
            const float v = values_getter(data, i);
            v_min = ImMin(v_min, v);
            v_max = ImMax(v_max, v);
        }
        if (scale_min == FLT_MAX)
            scale_min = v_min;
        if (scale_max == FLT_MAX)
            scale_max = v_max;
    }

    RenderFrame(frame_bb.Min, frame_bb.Max, GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);

    if (values_count > 0)
    {
        int res_w = ImMin((int)graph_size.x, values_count) + ((plot_type == ImGuiPlotType_Lines) ? -1 : 0);
        int item_count = values_count + ((plot_type == ImGuiPlotType_Lines) ? -1 : 0);

        // Tooltip on hover
        int v_hovered = -1;
        if (hovered)
        {
            const float t = ImClamp((g.IO.MousePos.x - inner_bb.Min.x) / (inner_bb.Max.x - inner_bb.Min.x), 0.0f, 0.9999f);
            const int v_idx = (int)(t * item_count);
            IM_ASSERT(v_idx >= 0 && v_idx < values_count);

            const float v0 = values_getter(data, (v_idx + values_offset) % values_count);
            const float v1 = values_getter(data, (v_idx + 1 + values_offset) % values_count);
            if (plot_type == ImGuiPlotType_Lines)
                SetTooltip("%d: %8.4g\n%d: %8.4g", v_idx, v0, v_idx+1, v1);
            else if (plot_type == ImGuiPlotType_Histogram)
                SetTooltip("%d: %8.4g", v_idx, v0);
            v_hovered = v_idx;
        }

        const float t_step = 1.0f / (float)res_w;
        const float inv_scale = (scale_min == scale_max) ? 0.0f : (1.0f / (scale_max - scale_min));

        float v0 = values_getter(data, (0 + values_offset) % values_count);
        float t0 = 0.0f;
        ImVec2 tp0 = ImVec2( t0, 1.0f - ImSaturate((v0 - scale_min) * inv_scale) );                       // Point in the normalized space of our target rectangle
        float histogram_zero_line_t = (scale_min * scale_max < 0.0f) ? (-scale_min * inv_scale) : (scale_min < 0.0f ? 0.0f : 1.0f);   // Where does the zero line stands

        const ImU32 col_base = GetColorU32((plot_type == ImGuiPlotType_Lines) ? ImGuiCol_PlotLines : ImGuiCol_PlotHistogram);
        const ImU32 col_hovered = GetColorU32((plot_type == ImGuiPlotType_Lines) ? ImGuiCol_PlotLinesHovered : ImGuiCol_PlotHistogramHovered);

        for (int n = 0; n < res_w; n++)
        {
            const float t1 = t0 + t_step;
            const int v1_idx = (int)(t0 * item_count + 0.5f);
            IM_ASSERT(v1_idx >= 0 && v1_idx < values_count);
            const float v1 = values_getter(data, (v1_idx + values_offset + 1) % values_count);
            const ImVec2 tp1 = ImVec2( t1, 1.0f - ImSaturate((v1 - scale_min) * inv_scale) );

            // NB: Draw calls are merged together by the DrawList system. Still, we should render our batch are lower level to save a bit of CPU.
            ImVec2 pos0 = ImLerp(inner_bb.Min, inner_bb.Max, tp0);
            ImVec2 pos1 = ImLerp(inner_bb.Min, inner_bb.Max, (plot_type == ImGuiPlotType_Lines) ? tp1 : ImVec2(tp1.x, histogram_zero_line_t));
            if (plot_type == ImGuiPlotType_Lines)
            {
                window->DrawList->AddLine(pos0, pos1, v_hovered == v1_idx ? col_hovered : col_base);
            }
            else if (plot_type == ImGuiPlotType_Histogram)
            {
                if (pos1.x >= pos0.x + 2.0f)
                    pos1.x -= 1.0f;
                window->DrawList->AddRectFilled(pos0, pos1, v_hovered == v1_idx ? col_hovered : col_base);
            }

            t0 = t1;
            tp0 = tp1;
        }
    }

    // Text overlay
    if (overlay_text)
        RenderTextClipped(ImVec2(frame_bb.Min.x, frame_bb.Min.y + style.FramePadding.y), frame_bb.Max, overlay_text, NULL, NULL, ImVec2(0.5f,0.0f));

    if (label_size.x > 0.0f)
        RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, inner_bb.Min.y), label);
}

struct ImGuiPlotArrayGetterData
{
    const float* Values;
    int Stride;

    ImGuiPlotArrayGetterData(const float* values, int stride) { Values = values; Stride = stride; }
};

static float Plot_ArrayGetter(void* data, int idx)
{
    ImGuiPlotArrayGetterData* plot_data = (ImGuiPlotArrayGetterData*)data;
    const float v = *(const float*)(const void*)((const unsigned char*)plot_data->Values + (size_t)idx * plot_data->Stride);
    return v;
}

void ImGui::PlotLines(const char* label, const float* values, int values_count, int values_offset, const char* overlay_text, float scale_min, float scale_max, ImVec2 graph_size, int stride)
{
    ImGuiPlotArrayGetterData data(values, stride);
    PlotEx(ImGuiPlotType_Lines, label, &Plot_ArrayGetter, (void*)&data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size);
}

void ImGui::PlotLines(const char* label, float (*values_getter)(void* data, int idx), void* data, int values_count, int values_offset, const char* overlay_text, float scale_min, float scale_max, ImVec2 graph_size)
{
    PlotEx(ImGuiPlotType_Lines, label, values_getter, data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size);
}

void ImGui::PlotHistogram(const char* label, const float* values, int values_count, int values_offset, const char* overlay_text, float scale_min, float scale_max, ImVec2 graph_size, int stride)
{
    ImGuiPlotArrayGetterData data(values, stride);
    PlotEx(ImGuiPlotType_Histogram, label, &Plot_ArrayGetter, (void*)&data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size);
}

void ImGui::PlotHistogram(const char* label, float (*values_getter)(void* data, int idx), void* data, int values_count, int values_offset, const char* overlay_text, float scale_min, float scale_max, ImVec2 graph_size)
{
    PlotEx(ImGuiPlotType_Histogram, label, values_getter, data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size);
}

//-------------------------------------------------------------------------
// WIDGETS: Value() helpers
// - Value()
//-------------------------------------------------------------------------

void ImGui::Value(const char* prefix, bool b)
{
    Text("%s: %s", prefix, (b ? "true" : "false"));
}

void ImGui::Value(const char* prefix, int v)
{
    Text("%s: %d", prefix, v);
}

void ImGui::Value(const char* prefix, unsigned int v)
{
    Text("%s: %d", prefix, v);
}

void ImGui::Value(const char* prefix, float v, const char* float_format)
{
    if (float_format)
    {
        char fmt[64];
        ImFormatString(fmt, IM_ARRAYSIZE(fmt), "%%s: %s", float_format);
        Text(fmt, prefix, v);
    }
    else
    {
        Text("%s: %.3f", prefix, v);
    }
}

//-------------------------------------------------------------------------
// WIDGETS: Menus
// - ImGuiMenuColumns
// - BeginMainMenuBar()
// - EndMainMenuBar()
// - BeginMenuBar()
// - EndMenuBar()
// - BeginMenu()
// - EndMenu()
// - MenuItem()
//-------------------------------------------------------------------------

// Helpers for internal use
ImGuiMenuColumns::ImGuiMenuColumns()
{
    Count = 0;
    Spacing = Width = NextWidth = 0.0f;
    memset(Pos, 0, sizeof(Pos));
    memset(NextWidths, 0, sizeof(NextWidths));
}

void ImGuiMenuColumns::Update(int count, float spacing, bool clear)
{
    IM_ASSERT(Count <= IM_ARRAYSIZE(Pos));
    Count = count;
    Width = NextWidth = 0.0f;
    Spacing = spacing;
    if (clear) memset(NextWidths, 0, sizeof(NextWidths));
    for (int i = 0; i < Count; i++)
    {
        if (i > 0 && NextWidths[i] > 0.0f)
            Width += Spacing;
        Pos[i] = (float)(int)Width;
        Width += NextWidths[i];
        NextWidths[i] = 0.0f;
    }
}

float ImGuiMenuColumns::DeclColumns(float w0, float w1, float w2) // not using va_arg because they promote float to double
{
    NextWidth = 0.0f;
    NextWidths[0] = ImMax(NextWidths[0], w0);
    NextWidths[1] = ImMax(NextWidths[1], w1);
    NextWidths[2] = ImMax(NextWidths[2], w2);
    for (int i = 0; i < 3; i++)
        NextWidth += NextWidths[i] + ((i > 0 && NextWidths[i] > 0.0f) ? Spacing : 0.0f);
    return ImMax(Width, NextWidth);
}

float ImGuiMenuColumns::CalcExtraSpace(float avail_w)
{
    return ImMax(0.0f, avail_w - Width);
}

// For the main menu bar, which cannot be moved, we honor g.Style.DisplaySafeAreaPadding to ensure text can be visible on a TV set.
bool ImGui::BeginMainMenuBar()
{
    ImGuiContext& g = *GImGui;
    g.NextWindowData.MenuBarOffsetMinVal = ImVec2(g.Style.DisplaySafeAreaPadding.x, ImMax(g.Style.DisplaySafeAreaPadding.y - g.Style.FramePadding.y, 0.0f));
    SetNextWindowPos(g.Viewports[0]->Pos);
    SetNextWindowSize(ImVec2(g.Viewports[0]->Size.x, g.NextWindowData.MenuBarOffsetMinVal.y + g.FontBaseSize + g.Style.FramePadding.y));
    PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
    PushStyleVar(ImGuiStyleVar_WindowMinSize, ImVec2(0,0));
    ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_MenuBar;
    bool is_open = Begin("##MainMenuBar", NULL, window_flags) && BeginMenuBar();
    PopStyleVar(2);
    g.NextWindowData.MenuBarOffsetMinVal = ImVec2(0.0f, 0.0f);
    if (!is_open)
    {
        End();
        return false;
    }
    return true;
}

void ImGui::EndMainMenuBar()
{
    EndMenuBar();

    // When the user has left the menu layer (typically: closed menus through activation of an item), we restore focus to the previous window
    ImGuiContext& g = *GImGui;
    if (g.CurrentWindow == g.NavWindow && g.NavLayer == 0)
        FocusFrontMostActiveWindowIgnoringOne(g.NavWindow);

    End();
}

bool ImGui::BeginMenuBar()
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;
    if (!(window->Flags & ImGuiWindowFlags_MenuBar))
        return false;

    IM_ASSERT(!window->DC.MenuBarAppending);
    BeginGroup(); // Backup position on layer 0
    PushID("##menubar");

    // We don't clip with current window clipping rectangle as it is already set to the area below. However we clip with window full rect.
    // We remove 1 worth of rounding to Max.x to that text in long menus and small windows don't tend to display over the lower-right rounded area, which looks particularly glitchy.
    ImRect bar_rect = window->MenuBarRect();
    ImRect clip_rect(ImFloor(bar_rect.Min.x + 0.5f), ImFloor(bar_rect.Min.y + window->WindowBorderSize + 0.5f), ImFloor(ImMax(bar_rect.Min.x, bar_rect.Max.x - window->WindowRounding) + 0.5f), ImFloor(bar_rect.Max.y + 0.5f));
    clip_rect.ClipWith(window->OuterRectClipped);
    PushClipRect(clip_rect.Min, clip_rect.Max, false);

    window->DC.CursorPos = ImVec2(bar_rect.Min.x + window->DC.MenuBarOffset.x, bar_rect.Min.y + window->DC.MenuBarOffset.y);
    window->DC.LayoutType = ImGuiLayoutType_Horizontal;
    window->DC.NavLayerCurrent++;
    window->DC.NavLayerCurrentMask <<= 1;
    window->DC.MenuBarAppending = true;
    AlignTextToFramePadding();
    return true;
}

void ImGui::EndMenuBar()
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return;
    ImGuiContext& g = *GImGui;

    // Nav: When a move request within one of our child menu failed, capture the request to navigate among our siblings.
    if (NavMoveRequestButNoResultYet() && (g.NavMoveDir == ImGuiDir_Left || g.NavMoveDir == ImGuiDir_Right) && (g.NavWindow->Flags & ImGuiWindowFlags_ChildMenu))
    {
        ImGuiWindow* nav_earliest_child = g.NavWindow;
        while (nav_earliest_child->ParentWindow && (nav_earliest_child->ParentWindow->Flags & ImGuiWindowFlags_ChildMenu))
            nav_earliest_child = nav_earliest_child->ParentWindow;
        if (nav_earliest_child->ParentWindow == window && nav_earliest_child->DC.ParentLayoutType == ImGuiLayoutType_Horizontal && g.NavMoveRequestForward == ImGuiNavForward_None)
        {
            // To do so we claim focus back, restore NavId and then process the movement request for yet another frame.
            // This involve a one-frame delay which isn't very problematic in this situation. We could remove it by scoring in advance for multiple window (probably not worth the hassle/cost)
            IM_ASSERT(window->DC.NavLayerActiveMaskNext & 0x02); // Sanity check
            FocusWindow(window);
            SetNavIDWithRectRel(window->NavLastIds[1], 1, window->NavRectRel[1]);
            g.NavLayer = 1;
            g.NavDisableHighlight = true; // Hide highlight for the current frame so we don't see the intermediary selection.
            g.NavMoveRequestForward = ImGuiNavForward_ForwardQueued;
            NavMoveRequestCancel();
        }
    }

    IM_ASSERT(window->Flags & ImGuiWindowFlags_MenuBar);
    IM_ASSERT(window->DC.MenuBarAppending);
    PopClipRect();
    PopID();
    window->DC.MenuBarOffset.x = window->DC.CursorPos.x - window->MenuBarRect().Min.x; // Save horizontal position so next append can reuse it. This is kinda equivalent to a per-layer CursorPos.
    window->DC.GroupStack.back().AdvanceCursor = false;
    EndGroup(); // Restore position on layer 0
    window->DC.LayoutType = ImGuiLayoutType_Vertical;
    window->DC.NavLayerCurrent--;
    window->DC.NavLayerCurrentMask >>= 1;
    window->DC.MenuBarAppending = false;
}

bool ImGui::BeginMenu(const char* label, bool enabled)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;
    const ImGuiID id = window->GetID(label);

    ImVec2 label_size = CalcTextSize(label, NULL, true);

    bool pressed;
    bool menu_is_open = IsPopupOpen(id);
    bool menuset_is_open = !(window->Flags & ImGuiWindowFlags_Popup) && (g.OpenPopupStack.Size > g.CurrentPopupStack.Size && g.OpenPopupStack[g.CurrentPopupStack.Size].OpenParentId == window->IDStack.back());
    ImGuiWindow* backed_nav_window = g.NavWindow;
    if (menuset_is_open)
        g.NavWindow = window;  // Odd hack to allow hovering across menus of a same menu-set (otherwise we wouldn't be able to hover parent)

    // The reference position stored in popup_pos will be used by Begin() to find a suitable position for the child menu (using FindBestWindowPosForPopup).
    ImVec2 popup_pos, pos = window->DC.CursorPos;
    if (window->DC.LayoutType == ImGuiLayoutType_Horizontal)
    {
        // Menu inside an horizontal menu bar
        // Selectable extend their highlight by half ItemSpacing in each direction.
        // For ChildMenu, the popup position will be overwritten by the call to FindBestWindowPosForPopup() in Begin()
        popup_pos = ImVec2(pos.x - window->WindowPadding.x, pos.y - style.FramePadding.y + window->MenuBarHeight());
        window->DC.CursorPos.x += (float)(int)(style.ItemSpacing.x * 0.5f);
        PushStyleVar(ImGuiStyleVar_ItemSpacing, style.ItemSpacing * 2.0f);
        float w = label_size.x;
        pressed = Selectable(label, menu_is_open, ImGuiSelectableFlags_NoHoldingActiveID | ImGuiSelectableFlags_PressedOnClick | ImGuiSelectableFlags_DontClosePopups | (!enabled ? ImGuiSelectableFlags_Disabled : 0), ImVec2(w, 0.0f));
        PopStyleVar();
        window->DC.CursorPos.x += (float)(int)(style.ItemSpacing.x * (-1.0f + 0.5f)); // -1 spacing to compensate the spacing added when Selectable() did a SameLine(). It would also work to call SameLine() ourselves after the PopStyleVar().
    }
    else
    {
        // Menu inside a menu
        popup_pos = ImVec2(pos.x, pos.y - style.WindowPadding.y);
        float w = window->MenuColumns.DeclColumns(label_size.x, 0.0f, (float)(int)(g.FontSize * 1.20f)); // Feedback to next frame
        float extra_w = ImMax(0.0f, GetContentRegionAvail().x - w);
        pressed = Selectable(label, menu_is_open, ImGuiSelectableFlags_NoHoldingActiveID | ImGuiSelectableFlags_PressedOnClick | ImGuiSelectableFlags_DontClosePopups | ImGuiSelectableFlags_DrawFillAvailWidth | (!enabled ? ImGuiSelectableFlags_Disabled : 0), ImVec2(w, 0.0f));
        if (!enabled) PushStyleColor(ImGuiCol_Text, g.Style.Colors[ImGuiCol_TextDisabled]);
        RenderArrow(pos + ImVec2(window->MenuColumns.Pos[2] + extra_w + g.FontSize * 0.30f, 0.0f), ImGuiDir_Right);
        if (!enabled) PopStyleColor();
    }

    const bool hovered = enabled && ItemHoverable(window->DC.LastItemRect, id);
    if (menuset_is_open)
        g.NavWindow = backed_nav_window;

    bool want_open = false, want_close = false;
    if (window->DC.LayoutType == ImGuiLayoutType_Vertical) // (window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu))
    {
        // Implement http://bjk5.com/post/44698559168/breaking-down-amazons-mega-dropdown to avoid using timers, so menus feels more reactive.
        bool moving_within_opened_triangle = false;
        if (g.HoveredWindow == window && g.OpenPopupStack.Size > g.CurrentPopupStack.Size && g.OpenPopupStack[g.CurrentPopupStack.Size].ParentWindow == window && !(window->Flags & ImGuiWindowFlags_MenuBar))
        {
            if (ImGuiWindow* next_window = g.OpenPopupStack[g.CurrentPopupStack.Size].Window)
            {
                ImRect next_window_rect = next_window->Rect();
                ImVec2 ta = g.IO.MousePos - g.IO.MouseDelta;
                ImVec2 tb = (window->Pos.x < next_window->Pos.x) ? next_window_rect.GetTL() : next_window_rect.GetTR();
                ImVec2 tc = (window->Pos.x < next_window->Pos.x) ? next_window_rect.GetBL() : next_window_rect.GetBR();
                float extra = ImClamp(ImFabs(ta.x - tb.x) * 0.30f, 5.0f, 30.0f); // add a bit of extra slack.
                ta.x += (window->Pos.x < next_window->Pos.x) ? -0.5f : +0.5f;   // to avoid numerical issues
                tb.y = ta.y + ImMax((tb.y - extra) - ta.y, -100.0f);            // triangle is maximum 200 high to limit the slope and the bias toward large sub-menus // FIXME: Multiply by fb_scale?
                tc.y = ta.y + ImMin((tc.y + extra) - ta.y, +100.0f);
                moving_within_opened_triangle = ImTriangleContainsPoint(ta, tb, tc, g.IO.MousePos);
                //window->DrawList->PushClipRectFullScreen(); window->DrawList->AddTriangleFilled(ta, tb, tc, moving_within_opened_triangle ? IM_COL32(0,128,0,128) : IM_COL32(128,0,0,128)); window->DrawList->PopClipRect(); // Debug
            }
        }

        want_close = (menu_is_open && !hovered && g.HoveredWindow == window && g.HoveredIdPreviousFrame != 0 && g.HoveredIdPreviousFrame != id && !moving_within_opened_triangle);
        want_open = (!menu_is_open && hovered && !moving_within_opened_triangle) || (!menu_is_open && hovered && pressed);

        if (g.NavActivateId == id)
        {
            want_close = menu_is_open;
            want_open = !menu_is_open;
        }
        if (g.NavId == id && g.NavMoveRequest && g.NavMoveDir == ImGuiDir_Right) // Nav-Right to open
        {
            want_open = true;
            NavMoveRequestCancel();
        }
    }
    else
    {
        // Menu bar
        if (menu_is_open && pressed && menuset_is_open) // Click an open menu again to close it
        {
            want_close = true;
            want_open = menu_is_open = false;
        }
        else if (pressed || (hovered && menuset_is_open && !menu_is_open)) // First click to open, then hover to open others
        {
            want_open = true;
        }
        else if (g.NavId == id && g.NavMoveRequest && g.NavMoveDir == ImGuiDir_Down) // Nav-Down to open
        {
            want_open = true;
            NavMoveRequestCancel();
        }
    }

    if (!enabled) // explicitly close if an open menu becomes disabled, facilitate users code a lot in pattern such as 'if (BeginMenu("options", has_object)) { ..use object.. }'
        want_close = true;
    if (want_close && IsPopupOpen(id))
        ClosePopupToLevel(g.CurrentPopupStack.Size);

    if (!menu_is_open && want_open && g.OpenPopupStack.Size > g.CurrentPopupStack.Size)
    {
        // Don't recycle same menu level in the same frame, first close the other menu and yield for a frame.
        OpenPopup(label);
        return false;
    }

    menu_is_open |= want_open;
    if (want_open)
        OpenPopup(label);

    if (menu_is_open)
    {
        // Sub-menus are ChildWindow so that mouse can be hovering across them (otherwise top-most popup menu would steal focus and not allow hovering on parent menu)
        SetNextWindowPos(popup_pos, ImGuiCond_Always);
        ImGuiWindowFlags flags = ImGuiWindowFlags_ChildMenu | ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_NoNavFocus;
        if (window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu))
            flags |= ImGuiWindowFlags_ChildWindow;
        menu_is_open = BeginPopupEx(id, flags); // menu_is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
    }

    return menu_is_open;
}

void ImGui::EndMenu()
{
    // Nav: When a left move request _within our child menu_ failed, close the menu.
    // A menu doesn't close itself because EndMenuBar() wants the catch the last Left<>Right inputs.
    // However, it means that with the current code, a BeginMenu() from outside another menu or a menu-bar won't be closable with the Left direction.
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    if (g.NavWindow && g.NavWindow->ParentWindow == window && g.NavMoveDir == ImGuiDir_Left && NavMoveRequestButNoResultYet() && window->DC.LayoutType == ImGuiLayoutType_Vertical)
    {
        ClosePopupToLevel(g.OpenPopupStack.Size - 1);
        NavMoveRequestCancel();
    }

    EndPopup();
}

bool ImGui::MenuItem(const char* label, const char* shortcut, bool selected, bool enabled)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    ImGuiContext& g = *GImGui;
    ImGuiStyle& style = g.Style;
    ImVec2 pos = window->DC.CursorPos;
    ImVec2 label_size = CalcTextSize(label, NULL, true);

    ImGuiSelectableFlags flags = ImGuiSelectableFlags_PressedOnRelease | (enabled ? 0 : ImGuiSelectableFlags_Disabled);
    bool pressed;
    if (window->DC.LayoutType == ImGuiLayoutType_Horizontal)
    {
        // Mimic the exact layout spacing of BeginMenu() to allow MenuItem() inside a menu bar, which is a little misleading but may be useful
        // Note that in this situation we render neither the shortcut neither the selected tick mark
        float w = label_size.x;
        window->DC.CursorPos.x += (float)(int)(style.ItemSpacing.x * 0.5f);
        PushStyleVar(ImGuiStyleVar_ItemSpacing, style.ItemSpacing * 2.0f);
        pressed = Selectable(label, false, flags, ImVec2(w, 0.0f));
        PopStyleVar();
        window->DC.CursorPos.x += (float)(int)(style.ItemSpacing.x * (-1.0f + 0.5f)); // -1 spacing to compensate the spacing added when Selectable() did a SameLine(). It would also work to call SameLine() ourselves after the PopStyleVar().
    }
    else
    {
        ImVec2 shortcut_size = shortcut ? CalcTextSize(shortcut, NULL) : ImVec2(0.0f, 0.0f);
        float w = window->MenuColumns.DeclColumns(label_size.x, shortcut_size.x, (float)(int)(g.FontSize * 1.20f)); // Feedback for next frame
        float extra_w = ImMax(0.0f, GetContentRegionAvail().x - w);
        pressed = Selectable(label, false, flags | ImGuiSelectableFlags_DrawFillAvailWidth, ImVec2(w, 0.0f));
        if (shortcut_size.x > 0.0f)
        {
            PushStyleColor(ImGuiCol_Text, g.Style.Colors[ImGuiCol_TextDisabled]);
            RenderText(pos + ImVec2(window->MenuColumns.Pos[1] + extra_w, 0.0f), shortcut, NULL, false);
            PopStyleColor();
        }
        if (selected)
            RenderCheckMark(pos + ImVec2(window->MenuColumns.Pos[2] + extra_w + g.FontSize * 0.40f, g.FontSize * 0.134f * 0.5f), GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled), g.FontSize  * 0.866f);
    }
    return pressed;
}

bool ImGui::MenuItem(const char* label, const char* shortcut, bool* p_selected, bool enabled)
{
    if (MenuItem(label, shortcut, p_selected ? *p_selected : false, enabled))
    {
        if (p_selected)
            *p_selected = !*p_selected;
        return true;
    }
    return false;
}