imgui_h.lua

--- ImGui Sincerely WIP
-- (Definitions)

--- @meta

-- [LuaBitOp](https://bitop.luajit.org/semantics.html)
local _band = bit.band

--- @class char          : integer
--- @class unsigned_char : integer

--- @alias ImS8 char
--- @alias ImU8 unsigned_char

--- @class ImU16 : integer
--- @class ImS16 : integer

--- @class ImU32 : integer
--- @class ImS32 : integer

--- @param val number
--- @return ImU8
function ImU8(val) return _band(val, 0xFF) end
--- @param val number
--- @return ImS8
function ImS8(val) return _band(val, 0xFF) - (_band(val, 0x80) ~= 0 and 0x100 or 0) end

--- @param val number
--- @return ImU16
function ImU16(val) return _band(val, 0xFFFF) end
--- @param val number
--- @return ImS16
function ImS16(val) return _band(val, 0xFFFF) - (_band(val, 0x8000) ~= 0 and 0x10000 or 0) end

--- @param val number
--- @return ImU32
function ImU32(val) return _band(val, 0xFFFFFFFF) end
--- @param val number
--- @return ImS32
function ImS32(val) return _band(val, 0xFFFFFFFF) end

--- @alias float          number
--- @class double : number

--- @alias int            integer
--- @alias unsigned_int   integer

--- @alias short          integer
--- @alias unsigned_short integer

--- @alias size_t unsigned_int

--- @alias ImWchar16 unsigned_short
--- @alias ImWchar   ImWchar16

--- @alias bool boolean

--- @alias ImGuiID unsigned_int

--- @alias ImTextureID integer

--- @alias ImGuiKeyChord int

--- @alias ImDrawIdx unsigned_int

IM_UNICODE_CODEPOINT_INVALID = 0xFFFD
IM_UNICODE_CODEPOINT_MAX     = 0xFFFF

IM_ALLOC = ImGui.MemAlloc
IM_FREE = ImGui.MemFree

---------------------------------------------------------------------------------------
-- [SECTION] METATABLE MANAGEMENT
---------------------------------------------------------------------------------------

--- File-scope metatable storage
local MT = {}

function ImGui.GetMetatables() return MT end

--- @param _EXPR any
--- @param _MSG  string?
function IM_ASSERT(_EXPR, _MSG) assert((_EXPR), _MSG) end

IM_ASSERT_PARANOID = IM_ASSERT

IM_DRAWLIST_TEX_LINES_WIDTH_MAX = 32
ImTextureID_Invalid = -1

--- @enum ImTextureFormat
ImTextureFormat = {
    RGBA32 = 0,
    Alpha8 = 1
}

--- @enum ImTextureStatus
ImTextureStatus = {
    OK          = 0,
    Destroyed   = 1,
    WantCreate  = 2,
    WantUpdates = 3,
    WantDestroy = 4
}

--- @enum ImFontAtlasFlags
ImFontAtlasFlags = {
    None               = 0,
    NoPowerOfTwoHeight = bit.lshift(1, 0),
    NoMouseCursors     = bit.lshift(1, 1),
    NoBakedLines       = bit.lshift(1, 2)
}

--- @class ImTextureRect
--- @field x unsigned_short
--- @field y unsigned_short
--- @field w unsigned_short
--- @field h unsigned_short

--- @param x? unsigned_short
--- @param y? unsigned_short
--- @param w? unsigned_short
--- @param h? unsigned_short
--- @return ImTextureRect
function ImTextureRect(x, y, w, h)
    return {
        x = x, y = y,
        w = w, h = h
    }
end

local rawget = rawget; local rawset = rawset

-- This structure supports indexing on string keys `x`, `y` and number keys 1, 2.
-- But note that the former is likely to be more expensive.
--- @class ImVec2
--- @operator add(ImVec2): ImVec2
--- @operator sub(ImVec2): ImVec2
--- @operator mul(number): ImVec2
--- @field [1] number
--- @field [2] number
--- @field x number
--- @field y number
MT.ImVec2 = {}

--- @param t ImVec2
--- @param k int
MT.ImVec2.__index = function(t, k)
    if     k == "x" then return rawget(t, 1)
    elseif k == "y" then return rawget(t, 2)
    end
end

--- @param t ImVec2
--- @param k int
--- @param v number
MT.ImVec2.__newindex = function(t, k, v)
    if     k == "x" then rawset(t, 1, v)
    elseif k == "y" then rawset(t, 2, v)
    end
end

--- @param x? number
--- @param y? number
--- @return ImVec2
--- @nodiscard
function ImVec2(x, y) return setmetatable({x or 0, y or 0}, MT.ImVec2) end

function MT.ImVec2.__add(lhs, rhs) return ImVec2(lhs[1] + rhs[1], lhs[2] + rhs[2]) end
function MT.ImVec2.__sub(lhs, rhs) return ImVec2(lhs[1] - rhs[1], lhs[2] - rhs[2]) end
function MT.ImVec2.__mul(lhs, rhs) return ImVec2(lhs[1] * rhs, lhs[2] * rhs) end
function MT.ImVec2.__eq(lhs, rhs) return lhs[1] == rhs[1] and lhs[2] == rhs[2] end

function MT.ImVec2:__tostring() return string.format("ImVec2(%g, %g)", self.x, self.y) end

--- @param dest ImVec2
--- @param src  ImVec2
function ImVec2_Copy(dest, src) dest[1] = src[1]; dest[2] = src[2] end

--- @param dest  ImVec2
--- @param src_x number
--- @param src_y number
function ImVec2_CopyV(dest, src_x, src_y) dest[1] = src_x; dest[2] = src_y end

--- @param lhs ImVec2
--- @param rhs ImVec2
function ImVec2_AddV(lhs, rhs) return lhs[1] + rhs[1], lhs[2] + rhs[2] end

--- @param lhs ImVec2
--- @param rhs ImVec2
function ImVec2_SubV(lhs, rhs) return lhs[1] - rhs[1], lhs[2] - rhs[2] end

--- @param v     ImVec2
--- @param add_x number
--- @param add_y number
function ImVec2_AddVA(v, add_x, add_y) return v[1] + add_x, v[2] + add_y end

--- @param v     ImVec2
--- @param sub_x number
--- @param sub_y number
function ImVec2_SubVA(v, sub_x, sub_y) return v[1] - sub_x, v[2] - sub_y end

--- @param lhs ImVec2
--- @param rhs number
function ImVec2_MulNV(lhs, rhs) return lhs[1] * rhs, lhs[2] * rhs end

--- @param lhs ImVec2
--- @param rhs ImVec2
--- @nodiscard
function ImVec2_MulComp(lhs, rhs) return ImVec2(lhs[1] * rhs[1], lhs[2] * rhs[2]) end

--- @param lhs ImVec2
--- @param rhs ImVec2
function ImVec2_MulCompV(lhs, rhs) return lhs[1] * rhs[1], lhs[2] * rhs[2] end

--- An inlined version of `ImVec2_Copy` currently for use in certain ImVector<ImVec2> `push_back`
--- @param t ImVec2[]
--- @param k int
--- @param v ImVec2
local function ImVec2_TCopy(t, k, v) local dest = t[k]; dest[1] = v[1]; dest[2] = v[2]; end

-- This structure supports indexing on string keys `x`, `y`, `z`, `w` and number keys 1, 2, 3, 4.
-- But note that the former is likely to be more expensive.
--- @class ImVec4
--- @operator add(ImVec4): ImVec4
--- @operator sub(ImVec4): ImVec4
--- @operator mul(number): ImVec4
--- @field [1] number
--- @field [2] number
--- @field [3] number
--- @field [4] number
--- @field x number
--- @field y number
--- @field z number
--- @field w number
MT.ImVec4 = {}

--- @param t ImVec4
--- @param k int
MT.ImVec4.__index = function(t, k)
    if     k == "x" then return rawget(t, 1)
    elseif k == "y" then return rawget(t, 2)
    elseif k == "z" then return rawget(t, 3)
    elseif k == "w" then return rawget(t, 4)
    end
end

--- @param t ImVec4
--- @param k int
--- @param v number
MT.ImVec4.__newindex = function(t, k, v)
    if     k == "x" then rawset(t, 1, v)
    elseif k == "y" then rawset(t, 2, v)
    elseif k == "z" then rawset(t, 3, v)
    elseif k == "w" then rawset(t, 4, v)
    end
end

--- @param x? number
--- @param y? number
--- @param z? number
--- @param w? number
--- @return ImVec4
--- @nodiscard
function ImVec4(x, y, z, w) return setmetatable({x or 0, y or 0, z or 0, w or 0}, MT.ImVec4) end

function MT.ImVec4.__add(lhs, rhs) return ImVec4(lhs[1] + rhs[1], lhs[2] + rhs[2], lhs[3] + rhs[3], lhs[4] + rhs[4]) end
function MT.ImVec4.__sub(lhs, rhs) return ImVec4(lhs[1] - rhs[1], lhs[2] - rhs[2], lhs[3] - rhs[3], lhs[4] - rhs[4]) end
function MT.ImVec4.__mul(lhs, rhs) return ImVec4(lhs[1] * rhs, lhs[2] * rhs, lhs[3] * rhs, lhs[4] * rhs) end
function MT.ImVec4.__eq(lhs, rhs) return lhs[1] == rhs[1] and lhs[2] == rhs[2] and lhs[3] == rhs[3] and lhs[4] == rhs[4] end

function MT.ImVec4:__tostring() return string.format("ImVec4(%g, %g, %g, %g)", self.x, self.y, self.z, self.w) end

--- @param dest ImVec4
--- @param src  ImVec4
function ImVec4_Copy(dest, src) dest[1] = src[1]; dest[2] = src[2]; dest[3] = src[3]; dest[4] = src[4] end

--- A compact ImVector clone
--- @class ImVector<T>
--- @field Data          T[] # 1-based table
--- @field Size          int # >= 0
--- @field _Constructor  function
--- @field _CopyFunc     function
MT.ImVector = {}

-- Support 1-based number key indexing while keep method accessing speed
--- @param t ImVector
--- @param k string|int
--- @return any
MT.ImVector.__index = function(t, k)
    return MT.ImVector[k] or t.Data[IM_ASSERT(k >= 1 and k <= t.Size) or k] -- if the mt access turns out nil, the k must be int index into Data
end

--- @param t ImVector
--- @param k int
--- @param v any
MT.ImVector.__newindex = function(t, k, v)
    IM_ASSERT(k >= 1 and k <= t.Size)
    t.Data[k] = v
end

local _default_constructor = function() return nil end
local _default_copyfunc = function(t, k, v) t[k] = v end

local function _grow_capacity(v, sz) local new_capacity = (v.Capacity ~= 0) and (v.Capacity + v.Capacity / 2) or 8; return (new_capacity > sz) and new_capacity or sz; end

--- @param T?         function
--- @param COPY_FUNC? function
--- @return ImVector
--- @nodiscard
function ImVector(T, COPY_FUNC) return setmetatable({Data = {}, Size = 0, Capacity = 0, _Constructor = T or _default_constructor, _CopyFunc = COPY_FUNC or _default_copyfunc}, MT.ImVector) end

function MT.ImVector:push_back(value) if self.Size == self.Capacity then self:reserve(_grow_capacity(self, self.Size + 1)) end; self._CopyFunc(self.Data, self.Size + 1, value); self.Size = self.Size + 1; return value end
function MT.ImVector:pop_back() IM_ASSERT(self.Size > 0); self.Size = self.Size - 1; end
function MT.ImVector:push_front(value) if self.Size == 0 then self:push_back(value) else self:insert(1, value) end end
function MT.ImVector:clear() self.Size = 0 end
function MT.ImVector:clear_delete() for i = 1, self.Size do self.Data[i] = nil end self.Size = 0 end
function MT.ImVector:empty() return self.Size == 0 end
function MT.ImVector:back()   IM_ASSERT(self.Size > 0) return self.Data[self.Size] end
function MT.ImVector:erase(i) IM_ASSERT(i >= 1 and i <= self.Size) local removed = (table.remove(self.Data, i)) ~= nil self.Size = self.Size - 1 return removed end
local function _iter(v, i) i = i + 1 if i <= v.Size then return i, v.Data[i] end end
function MT.ImVector:iter() return _iter, self, 0 end
function MT.ImVector:find_index(value) for i = 1, self.Size do if self.Data[i] == value then return i end end return nil end
function MT.ImVector:erase_unsorted(index) IM_ASSERT(index >= 1 and index <= self.Size) local last_idx = self.Size if index ~= last_idx then self.Data[index] = self.Data[last_idx] end self.Data[last_idx] = nil self.Size = self.Size - 1 return true end
function MT.ImVector:find_erase(value) local idx = self:find_index(value) if idx then return self:erase(idx) end return false end
function MT.ImVector:find_erase_unsorted(value) local idx = self:find_index(value) if idx then return self:erase_unsorted(idx) end return false end

function MT.ImVector:reserve(new_capacity)
    if new_capacity <= self.Capacity then return end
    local new_data = IM_ALLOC(self._Constructor, self.Size + 1, new_capacity)
    if self.Data then
        ImStd.memmove(new_data, 1, self.Data, 1, self.Size)
        IM_FREE(self, "Data")
    end
    self.Data = new_data
    self.Capacity = new_capacity
end

function MT.ImVector:reserve_discard(new_capacity)
    if new_capacity <= self.Capacity then return end
    if self.Data then IM_FREE(self, "Data") end
    self.Data = IM_ALLOC(self._Constructor, 1, new_capacity)
    self.Capacity = new_capacity
end

function MT.ImVector:shrink(new_size) IM_ASSERT(new_size <= self.Size) self.Size = new_size end

function MT.ImVector:resize(new_size, v)
    if new_size > self.Capacity then self:reserve(_grow_capacity(self, new_size)) end
    if v ~= nil and new_size > self.Size then
        local data = self.Data
        for n = self.Size + 1, new_size do data[n] = v end
    end
    self.Size = new_size
end

function MT.ImVector:swap(other) self.Size, other.Size = other.Size, self.Size; self.Capacity, other.Capacity = other.Capacity, self.Capacity; self.Data, other.Data = other.Data, self.Data end
function MT.ImVector:contains(v) for i = 1, self.Size do if self.Data[i] == v then return true end end return false end

--- NOTE: This currently does not use type-aware copy!
function MT.ImVector:insert(pos, value) IM_ASSERT(pos >= 1 and pos <= self.Size + 1); if self.Size == self.Capacity then self:reserve(_grow_capacity(self, self.Size + 1)) end; for i = self.Size, pos, -1 do self.Data[i + 1] = self.Data[i] end self.Data[pos] = value self.Size = self.Size + 1 return value end

--- @nodiscard
function MT.ImVector:copy() local other = ImVector() other.Size = self.Size for i = 1, self.Size do other.Data[i] = self.Data[i] end return other end

-- Not keeping value-key records inside `ImVector`, instead just find it
--- @return int # 0-based index
function MT.ImVector:index_from_ptr(p)
    local data = self.Data
    local size = self.Size
    local mid = bit.rshift(size, 1)

    for i = size, mid + 1, -1 do if data[i] == p then return i - 1 end end
    for i =    1,     mid,  1 do if data[i] == p then return i - 1 end end

    --- @diagnostic disable-next-line
    IM_ASSERT(false, "index_from_ptr failed!")
end

--- @class ImDrawCmd
MT.ImDrawCmd = {}
MT.ImDrawCmd.__index = MT.ImDrawCmd

--- @return ImDrawCmd
--- @nodiscard
function ImDrawCmd()
    return setmetatable({
        ClipRect               = ImVec4(),
        TexRef                 = nil,
        VtxOffset              = 0,
        IdxOffset              = 0,
        ElemCount              = 0,
        UserCallback           = nil,
        UserCallbackData       = nil,
        UserCallbackDataSize   = 0,
        UserCallbackDataOffset = 0
    }, MT.ImDrawCmd)
end

--- @return ImTextureID
function MT.ImDrawCmd:GetTexID()
    local tex_id = (self.TexRef._TexData) and self.TexRef._TexData.TexID or self.TexRef._TexID
    if self.TexRef._TexData ~= nil then
        IM_ASSERT(tex_id ~= ImTextureID_Invalid, "ImDrawCmd is referring to ImTextureData that wasn't uploaded to graphics system. Backend must call ImTextureData::SetTexID() after handling ImTextureStatus_WantCreate request!")
    end
    return tex_id
end

--- @class ImDrawVert
--- @field [1] ImVec2 # pos
--- @field [2] ImVec2 # uv
--- @field [3] ImU32  # col

--- @return ImDrawVert
--- @nodiscard
function ImDrawVert() return { ImVec2(), ImVec2(), nil } end

--- @class ImDrawCmdHeader
--- @field ClipRect  ImVec4
--- @field TexRef    ImTextureRef
--- @field VtxOffset unsigned_int
MT.ImDrawCmdHeader = {}
MT.ImDrawCmdHeader.__index = MT.ImDrawCmdHeader

--- @return ImDrawCmdHeader
--- @nodiscard
function ImDrawCmdHeader()
    return setmetatable({
        ClipRect  = ImVec4(),
        TexRef    = nil,
        VtxOffset = 0
    }, MT.ImDrawCmdHeader)
end

--- @class ImDrawChannel
--- @field _CmdBuffer ImVector<ImDrawCmd>
--- @field _IdxBuffer ImVector<ImDrawIdx>

--- @return ImDrawChannel
--- @nodiscard
function ImDrawChannel()
    return {
        _CmdBuffer = ImVector(),
        _IdxBuffer = ImVector()
    }
end

--- @class ImDrawListSplitter
--- @field _Current  int
--- @field _Count    int
--- @field _Channels ImVector<ImDrawChannel>

--- @return ImDrawListSplitter
--- @nodiscard
function ImDrawListSplitter()
    return {
        _Current  = 0,
        _Count    = 0,
        _Channels = ImVector()
    }
end

--- @class ImDrawList
--- @field CmdBuffer         ImVector<ImDrawCmd>
--- @field IdxBuffer         ImVector<ImDrawIdx>
--- @field VtxBuffer         ImVector<ImDrawVert>
--- @field Flags             ImDrawListFlags
--- @field _VtxCurrentIdx    unsigned_int         # 1-based, generally == (VtxBuffer.Size + 1)
--- @field _Data             ImDrawListSharedData # Pointes to shared draw data
--- @field _VtxWritePtr      unsigned_int         # 1-based, points to the current writing index in VtxBuffer.Data
--- @field _IdxWritePtr      unsigned_int         # 1-based, points to the current writing index in IdxBuffer.Data
--- @field _Path             ImVector<ImVec2>     # current path building
--- @field _CmdHeader        ImDrawCmdHeader      # template of active commands. Fields should match those of CmdBuffer:back()
--- @field _Splitter         ImDrawListSplitter
--- @field _ClipRectStack    ImVector<ImVec4>
--- @field _TextureStack     ImVector<ImTextureRef>
--- @field _CallbacksDataBuf any
--- @field _FringeScale      float
--- @field _OwnerName        string
MT.ImDrawList = {}
MT.ImDrawList.__index = MT.ImDrawList

--- @param pos ImVec2
--- @param uv  ImVec2
--- @param col ImU32
function MT.ImDrawList:PrimWriteVtx(pos, uv, col)
    local vtx = self.VtxBuffer.Data[self._VtxWritePtr]
    ImVec2_Copy(vtx[1], pos)
    ImVec2_Copy(vtx[2], uv)
    vtx[3] = col
    self._VtxWritePtr = self._VtxWritePtr + 1
    self._VtxCurrentIdx = self._VtxCurrentIdx + 1
end

--- @param idx ImDrawIdx
function MT.ImDrawList:PrimWriteIdx(idx)
    self.IdxBuffer.Data[self._IdxWritePtr] = idx
    self._IdxWritePtr = self._IdxWritePtr + 1
end

--- @param pos ImVec2
--- @param uv  ImVec2
--- @param col ImU32
function MT.ImDrawList:PrimVtx(pos, uv, col)
    self:PrimWriteIdx(self._VtxCurrentIdx)
    self:PrimWriteVtx(pos, uv, col)
end

--- @param data? ImDrawListSharedData
--- @return ImDrawList
--- @nodiscard
function ImDrawList(data)
    --- @type ImDrawList
    local this = setmetatable({
        CmdBuffer = ImVector(),
        IdxBuffer = ImVector(),
        VtxBuffer = ImVector(ImDrawVert),
        Flags     = 0,

        _VtxCurrentIdx = 1,
        _Data          = nil,
        _VtxWritePtr   = 1,
        _IdxWritePtr   = 1,
        _Path          = ImVector(ImVec2, ImVec2_TCopy),
        _CmdHeader     = ImDrawCmdHeader(),
        _Splitter      = ImDrawListSplitter(),
        _ClipRectStack = ImVector(),
        _TextureStack  = ImVector(),
        _CallbacksDataBuf = nil,

        _FringeScale = 0,
        _OwnerName = nil
    }, MT.ImDrawList)

    this:_SetDrawListSharedData(data)

    return this
end

--- @class ImDrawData
--- @field Valid            bool
--- @field CmdListsCount    int
--- @field TotalIdxCount    int
--- @field TotalVtxCount    int
--- @field CmdLists         ImVector<ImDrawList>
--- @field DisplayPos       ImVec2
--- @field DisplaySize      ImVec2
--- @field FramebufferScale ImVec2
--- @field OwnerViewport    ImGuiViewport
--- @field Textures         ImVector<ImTextureData>
MT.ImDrawData = {}
MT.ImDrawData.__index = MT.ImDrawData

--- @return ImDrawData
function ImDrawData()
    --- @type ImDrawData
    local this = setmetatable({}, MT.ImDrawData)

    this.CmdLists = ImVector()
    this:Clear()

    return this
end

--- @class ImTextureData
--- @field UniqueID             int
--- @field Status               ImTextureStatus
--- @field BackendUserData      any
--- @field TexID                ImTextureID
--- @field Format               ImTextureFormat
--- @field Width                int
--- @field Height               int
--- @field BytesPerPixel        int
--- @field Pixels               unsigned_char[]
--- @field UsedRect             ImTextureRect
--- @field UpdateRect           ImTextureRect
--- @field Updates              ImVector<ImTextureRect>
--- @field UnusedFrames         int
--- @field RefCount             unsigned_short
--- @field UseColors            bool
--- @field WantDestroyNextFrame bool
MT.ImTextureData = {}
MT.ImTextureData.__index = MT.ImTextureData

--- @return ImTextureData
--- @nodiscard
function ImTextureData()
    --- @type ImTextureData
    local this = setmetatable({}, MT.ImTextureData)

    this.UniqueID             = 0
    this.Status               = ImTextureStatus.Destroyed
    this.BackendUserData      = nil
    this.TexID                = ImTextureID_Invalid
    this.Format               = 0
    this.Width                = 0
    this.Height               = 0
    this.BytesPerPixel        = 0
    this.Pixels               = nil
    this.UsedRect             = ImTextureRect()
    this.UpdateRect           = ImTextureRect()
    this.Updates              = ImVector()
    this.UnusedFrames         = 0
    this.RefCount             = 0
    this.UseColors            = false
    this.WantDestroyNextFrame = false

    return this
end

--- @param x int
--- @param y int
function MT.ImTextureData:GetPixelsAt(x, y)
    return self.Pixels, (x + y * self.Width) * self.BytesPerPixel + 1
end

function MT.ImTextureData:GetPitch() return self.Width * self.BytesPerPixel end
function MT.ImTextureData:GetTexID() return self.TexID end

--- @param tex_id ImTextureID
function MT.ImTextureData:SetTexID(tex_id) self.TexID = tex_id end

--- @param status ImTextureStatus
function MT.ImTextureData:SetStatus(status) self.Status = status if (status == ImTextureStatus.Destroyed and not self.WantDestroyNextFrame and self.Pixels ~= nil) then self.Status = ImTextureStatus.WantCreate end end

--- @class ImTextureRef
MT.ImTextureRef = {}
MT.ImTextureRef.__index = MT.ImTextureRef

--- @return ImTextureRef
--- @nodiscard
function ImTextureRef(tex_id)
    return setmetatable({
        _TexData = nil,
        _TexID   = tex_id or ImTextureID_Invalid
    }, MT.ImTextureRef)
end

--- @class ImFontBaked
--- @field IndexAdvanceX        ImVector<float>       # Glyphs->AdvanceX in a directly indexable way. Note that codepoint starts from 0, so IndexAdvanceX.Data[0 + 1] holds the advanceX of glyph at codepoint 0
--- @field FallbackAdvanceX     float
--- @field Size                 float
--- @field RasterizerDensity    float
--- @field IndexLookup          ImVector<ImU16>       # Index glyphs by Unicode codepoint. use IndexLookup.Data[codepoint + 1] for codepoint. Stores 1-based index!
--- @field Glyphs               ImVector<ImFontGlyph>
--- @field FallbackGlyphIndex   int                   # Initial value = -1, then becomes 1-based index if fallback char is set
--- @field Ascent               float
--- @field Descent              float
--- @field MetricsTotalSurface  unsigned_int
--- @field WantDestroy          bool
--- @field LoadNoFallback       bool
--- @field LoadNoRenderOnLayout bool
--- @field LastUsedFrame        int
--- @field BakedId              ImGuiID
--- @field OwnerFont            ImFont
--- @field FontLoaderDatas      any
MT.ImFontBaked = {}
MT.ImFontBaked.__index = MT.ImFontBaked

--- @return ImFontBaked
--- @nodiscard
function ImFontBaked()
    --- @type ImFontBaked
    local this = setmetatable({}, MT.ImFontBaked)

    this.IndexAdvanceX     = ImVector()
    this.FallbackAdvanceX  = 0
    this.Size              = 0
    this.RasterizerDensity = 0

    this.IndexLookup        = ImVector()
    this.Glyphs             = ImVector()
    this.FallbackGlyphIndex = -1

    this.Ascent               = 0
    this.Descent              = 0
    this.MetricsTotalSurface  = 0
    this.WantDestroy          = false
    this.LoadNoFallback       = false
    this.LoadNoRenderOnLayout = false
    this.LastUsedFrame        = 0
    this.BakedId              = 0
    this.OwnerFont            = nil
    this.FontLoaderDatas      = nil

    return this
end

--- @class ImFont
--- @field LastBaked                ImFontBaked
--- @field OwnerAtlas               ImFontAtlas
--- @field Flags                    ImFontFlags
--- @field CurrentRasterizerDensity float
--- @field FontId                   ImGuiID
--- @field LegacySize               float
--- @field Sources                  ImVector<ImFontConfig>
--- @field EllipsisChar             ImWchar
--- @field FallbackChar             ImWchar
--- @field Used8kPagesMap           ImU8[]                 # 1-based table
--- @field EllipsisAutoBake         bool
--- @field RemapPairs               table<ImGuiID, any>    # LUA: No ImGuiStorage
--- @field Scale                    float
MT.ImFont = {}
MT.ImFont.__index = MT.ImFont

function MT.ImFont:IsLoaded() return self.OwnerAtlas ~= nil end

--- @return ImFont
--- @nodiscard
function ImFont()
    --- @type ImFont
    local this = setmetatable({}, MT.ImFont)

    this.LastBaked                = nil
    this.OwnerAtlas               = nil
    this.Flags                    = 0
    this.CurrentRasterizerDensity = 0
    this.FontId           = 0
    this.LegacySize       = 0
    this.Sources          = ImVector()
    this.EllipsisChar     = 0
    this.FallbackChar     = 0
    this.Used8kPagesMap   = {}
    this.EllipsisAutoBake = false
    this.RemapPairs       = {}
    this.Scale            = 0

    return this
end

--- @class ImFontConfig
--- @field Name                 string
--- @field FontData             table
--- @field FontDataSize         int
--- @field FontDataOwnedByAtlas bool
--- @field MergeMode            bool
--- @field PixelSnapH           bool
--- @field OversampleH          ImS8
--- @field OversampleV          ImS8
--- @field EllipsisChar         ImWchar
--- @field SizePixels           float
--- @field GlyphRanges          ImWchar[]
--- @field GlyphExcludeRanges   ImWchar[]
--- @field GlyphOffset          ImVec2
--- @field GlyphMinAdvanceX     float
--- @field GlyphMaxAdvanceX     float
--- @field GlyphExtraAdvanceX   float
--- @field FontNo               ImU32
--- @field FontLoaderFlags      unsigned_int
--- @field RasterizerMultiply   float
--- @field RasterizerDensity    float
--- @field ExtraSizeScale       float
--- @field Flags                ImFontFlags
--- @field DstFont              ImFont
--- @field FontLoader           ImFontLoader
--- @field FontLoaderData       ImGui_ImplStbTrueType_FontSrcData|
MT.ImFontConfig = {}
MT.ImFontConfig.__index = MT.ImFontConfig

--- @return ImFontConfig
--- @nodiscard
function ImFontConfig()
    --- @type ImFontConfig
    local this = setmetatable({}, MT.ImFontConfig)

    this.Name                 = nil
    this.FontData             = nil
    this.FontDataSize         = 0
    this.FontDataOwnedByAtlas = true

    this.MergeMode          = false
    this.PixelSnapH         = false
    this.OversampleH        = 0
    this.OversampleV        = 0
    this.EllipsisChar       = 0
    this.SizePixels         = 0
    this.GlyphRanges        = nil
    this.GlyphExcludeRanges = nil
    this.GlyphOffset        = ImVec2()
    this.GlyphMinAdvanceX   = 0
    this.GlyphMaxAdvanceX   = FLT_MAX
    this.GlyphExtraAdvanceX = 0
    this.FontNo             = 0
    this.FontLoaderFlags    = 0
    this.RasterizerMultiply = 1.0
    this.RasterizerDensity  = 1.0
    this.ExtraSizeScale     = 1.0

    this.Flags          = 0
    this.DstFont        = nil
    this.FontLoader     = nil
    this.FontLoaderData = nil

    return this
end

--- @class ImFontAtlas
--- @field Flags               ImFontAtlasFlags
--- @field TexDesiredFormat    ImTextureFormat
--- @field TexGlyphPadding     int
--- @field TexMinWidth         int
--- @field TexMinHeight        int
--- @field TexMaxWidth         int
--- @field TexMaxHeight        int
--- @field TexRef              ImTextureRef
--- @field TexData             ImTextureData
--- @field TexList             ImVector<ImTextureData>
--- @field Locked              bool
--- @field RendererHasTextures bool
--- @field TexPixelsUseColors  bool
--- @field TexUvScale          ImVec2
--- @field TexUvWhitePixel     ImVec2
--- @field Fonts               ImVector<ImFont>
--- @field Sources             ImVector<ImFontConfig>
--- @field TexUvLines          ImVec4[]                       # 0-based table
--- @field TexNextUniqueID     int
--- @field FontNextUniqueID    int
--- @field DrawListSharedDatas ImVector<ImDrawListSharedData>
--- @field Builder             ImFontAtlasBuilder
--- @field FontLoader          ImFontLoader
--- @field FontLoaderName      string
--- @field FontLoaderData      any
--- @field FontLoaderFlags     unsigned_int
--- @field RefCount            int
--- @field OwnerContext        ImGuiContext
MT.ImFontAtlas = {}
MT.ImFontAtlas.__index = MT.ImFontAtlas

--- @return ImFontAtlas
--- @nodiscard
function ImFontAtlas()
    --- @type ImFontAtlas
    local this = setmetatable({}, MT.ImFontAtlas)

    this.Flags               = 0
    this.TexDesiredFormat    = ImTextureFormat.RGBA32
    this.TexGlyphPadding     = 1
    this.TexMinWidth         = 512
    this.TexMinHeight        = 128
    this.TexMaxWidth         = 8192
    this.TexMaxHeight        = 8192

    this.TexRef              = ImTextureRef()

    this.TexData             = nil

    this.TexList             = ImVector()
    this.Locked              = false
    this.RendererHasTextures = false
    this.TexPixelsUseColors  = nil
    this.TexUvScale          = nil
    this.TexUvWhitePixel     = nil
    this.Fonts               = ImVector()
    this.Sources             = ImVector()
    this.TexUvLines          = {} -- size = IM_DRAWLIST_TEX_LINES_WIDTH_MAX + 1
    this.TexNextUniqueID     = 1
    this.FontNextUniqueID    = 1
    this.DrawListSharedDatas = ImVector()
    this.Builder             = nil
    this.FontLoader          = nil
    this.FontLoaderName      = nil
    this.FontLoaderData      = nil
    this.FontLoaderFlags     = nil
    this.RefCount            = 0
    this.OwnerContext        = nil

    return this
end

--- @class ImFontAtlasRect
--- @field x   unsigned_short
--- @field y   unsigned_short
--- @field w   unsigned_short
--- @field h   unsigned_short
--- @field uv0 ImVec2
--- @field uv1 ImVec2

--- @alias ImFontAtlasRectId int

ImFontAtlasRectId_Invalid = -1

--- @return ImFontAtlasRect
--- @nodiscard
function ImFontAtlasRect()
    return {
        x = nil, y = nil,
        w = nil, h = nil,
        uv0 = ImVec2(),
        uv1 = ImVec2()
    }
end

--- @class ImFontGlyph
--- @field Colored   boolean
--- @field Visible   boolean
--- @field SourceIdx unsigned_int
--- @field Codepoint unsigned_int
--- @field AdvanceX  float
--- @field X0        float
--- @field Y0        float
--- @field X1        float
--- @field Y1        float
--- @field U0        float
--- @field V0        float
--- @field U1        float
--- @field V1        float
--- @field PackId    int

--- @return ImFontGlyph
--- @nodiscard
function ImFontGlyph()
    return {
        Colored   = false,
        Visible   = false,
        SourceIdx = 0,
        Codepoint = 0,
        AdvanceX  = 0,

        X0 = 0, Y0 = 0, X1 = 0, Y1 = 0,
        U0 = 0, V0 = 0, U1 = 0, V1 = 0,

        PackId = -1
    }
end

--- @class ImGuiKeyData
--- @field Down             bool
--- @field DownDuration     float
--- @field DownDurationPrev float
--- @field AnalogValue      float

--- @return ImGuiKeyData
--- @nodiscard
function ImGuiKeyData()
    return {
        Down             = false,
        DownDuration     = nil,
        DownDurationPrev = nil,
        AnalogValue      = nil
    }
end

--- @enum ImGuiConfigFlags
ImGuiConfigFlags = {
    None                = 0,
    NavEnableKeyboard   = bit.lshift(1, 0),  -- Master keyboard navigation enable flag. Enable full Tabbing + directional arrows + space/enter to activate
    NavEnableGamepad    = bit.lshift(1, 1),  -- Master gamepad navigation enable flag. Backend also needs to set ImGuiBackendFlags.HasGamepad
    NoMouse             = bit.lshift(1, 4),  -- Instruct dear imgui to disable mouse inputs and interactions
    NoMouseCursorChange = bit.lshift(1, 5),  -- Instruct backend to not alter mouse cursor shape and visibility. Use if the backend cursor changes are interfering with yours and you don't want to use SetMouseCursor() to change mouse cursor. You may want to honor requests from imgui by reading GetMouseCursor() yourself instead
    NoKeyboard          = bit.lshift(1, 6),  -- Instruct dear imgui to disable keyboard inputs and interactions. This is done by ignoring keyboard events and clearing existing states
    ViewportsEnable     = bit.lshift(1, 10),
    IsSRGB              = bit.lshift(1, 20), -- Application is SRGB-aware
    IsTouchScreen       = bit.lshift(1, 21)  -- Application is using a touch screen instead of a mouse
}

--- @class ImGuiIO
MT.ImGuiIO = {}
MT.ImGuiIO.__index = MT.ImGuiIO

--- @return ImGuiIO
function ImGuiIO()
    local this = {
        Ctx = nil,

        KeyCtrl  = false,
        KeyShift = false,
        KeyAlt   = false,
        KeySuper = false,

        KeyMods  = nil,

        BackendFlags = ImGuiBackendFlags.None,
        ConfigFlags  = ImGuiConfigFlags.None,
        DisplaySize = ImVec2(-1.0, -1.0),

        DeltaTime = 1.0 / 60.0,

        DisplayFramebufferScale = ImVec2(1.0, 1.0),

        MousePos = ImVec2(),
        MousePosPrev = ImVec2(),

        WantSetMousePos = false,

        MouseDelta = ImVec2(),

        MouseDown = {[0] = false, [1] = false, [2] = false},

        MouseWheel = 0,
        MouseWheelH = 0,

        MouseCtrlLeftAsRightClick = false,

        MouseWheelRequestAxisSwap = false,

        ConfigMacOSXBehaviors = false,
        ConfigNavCursorVisibleAuto = true,
        ConfigInputTrickleEventQueue = true,
        ConfigWindowsResizeFromEdges = true,

        ConfigViewportsNoAutoMerge = false,
        ConfigViewportsNoTaskBarIcon = false,
        ConfigViewportsNoDecoration = true,
        ConfigViewportsNoDefaultParent = true,
        ConfigViewportsPlatformFocusSetsImGuiFocus = true,

        MouseDrawCursor = false,

        MouseClicked          = {[0] = false, [1] = false, [2] = false},
        MouseReleased         = {[0] = false, [1] = false, [2] = false},
        MouseClickedCount     = {[0] =  0, [1] =  0, [2] =  0},
        MouseClickedLastCount = {[0] =  0, [1] =  0, [2] =  0},
        MouseDownDuration     = {[0] = -1, [1] = -1, [2] = -1},
        MouseDownDurationPrev = {[0] = -1, [1] = -1, [2] = -1},

        MouseDragMaxDistanceAbs = {[0] = ImVec2(), [1] = ImVec2(), [2] = ImVec2()},
        MouseDragMaxDistanceSqr = {[0] = 0, [1] = 0, [2] = 0},

        MouseDownOwned    = {[0] = nil, [1] = nil, [2] = nil},
        MouseDownOwnedUnlessPopupClose = {[0] = nil, [1] = nil, [2] = nil},
        MouseClickedTime  = {[0] = 0, [1] = 0, [2] = 0},
        MouseReleasedTime = {[0] = 0, [1] = 0, [2] = 0},
        MouseClickedPos   = {[0] = ImVec2(), [1] = ImVec2(), [2] = ImVec2()},

        MouseDoubleClicked = {[0] = false, [1] = false, [2] = false},

        MouseDoubleClickTime    = 0.30,
        MouseDoubleClickMaxDist = 6.0,
        MouseDragThreshold      = 6.0,
        KeyRepeatDelay          = 0.275,
        KeyRepeatRate           = 0.050,

        KeysData = {}, -- size = ImGuiKey.NamedKey_COUNT

        WantCaptureMouse    = nil,
        WantCaptureKeyboard = nil,
        WantTextInput       = nil,

        Framerate = 0,

        MetricsRenderWindows = 0,

        Fonts = nil,
        FontDefault = nil,

        BackendPlatformUserData = nil,
        BackendRendererUserData = nil,

        InputQueueCharacters = ImVector(),

        AppAcceptingEvents = true,
        InputQueueSurrogate = 0
    }

    for i = 0, ImGuiKey.NamedKey_COUNT - 1 do
        this.KeysData[i] = ImGuiKeyData()
    end

    return setmetatable(this, MT.ImGuiIO)
end

--- @class ImGuiPlatformImeData
--- @field WantVisible     bool
--- @field WantTextInput   bool
--- @field InputPos        ImVec2
--- @field InputLineHeight float
--- @field ViewportId      ImGuiID

--- @return ImGuiPlatformImeData
--- @nodiscard
function ImGuiPlatformImeData()
    return {
        WantVisible     = false,
        WantTextInput   = false,
        InputPos        = ImVec2(),
        InputLineHeight = 0.0,
        ViewportId      = 0
    }
end

--- @param dest ImGuiPlatformImeData
--- @param src  ImGuiPlatformImeData
function ImGuiPlatformImeData_Copy(dest, src)
    dest.WantVisible = src.WantVisible
    dest.WantTextInput = src.WantTextInput
    ImVec2_Copy(dest.InputPos, src.InputPos)
    dest.InputLineHeight = src.InputLineHeight
    dest.ViewportId = src.ViewportId
end

--- @param data1 ImGuiPlatformImeData
--- @param data2 ImGuiPlatformImeData
function ImGuiPlatformImeData_Compare(data1, data2)
    if data1.WantVisible ~= data2.WantVisible or
        data1.WantTextInput ~= data2.WantTextInput or
        data1.InputPos ~= data2.InputPos or
        data1.InputLineHeight ~= data2.InputLineHeight or
        data1.ViewportId ~= data2.ViewportId then
        return false
    end

    return true
end

--- @enum ImGuiMouseCursor
ImGuiMouseCursor = {
    None       = -1,
    Arrow      = 0,
    TextInput  = 1,
    ResizeAll  = 2,
    ResizeNS   = 3,
    ResizeEW   = 4,
    ResizeNESW = 5,
    ResizeNWSE = 6,
    Hand       = 7,
    Wait       = 8,
    Progress   = 9,
    NotAllowed = 10,
    COUNT      = 11
}

--- @enum ImGuiViewportFlags
ImGuiViewportFlags = {
    None                = 0,
    IsPlatformWindow    = bit.lshift(1, 0),
    IsPlatformMonitor   = bit.lshift(1, 1),
    OwnedByApp          = bit.lshift(1, 2),
    NoDecoration        = bit.lshift(1, 3),
    NoTaskBarIcon       = bit.lshift(1, 4),
    NoFocusOnAppearing  = bit.lshift(1, 5),
    NoFocusOnClick      = bit.lshift(1, 6),
    NoInputs            = bit.lshift(1, 7),
    NoRendererClear     = bit.lshift(1, 8),
    NoAutoMerge         = bit.lshift(1, 9),
    TopMost             = bit.lshift(1, 10),
    CanHostOtherWindows = bit.lshift(1, 11),

    IsMinimized = bit.lshift(1, 12),
    IsFocused   = bit.lshift(1, 13)
}

--- @class ImGuiViewport
--- @field ID                    ImGuiID
--- @field Flags                 ImGuiViewportFlags
--- @field Pos                   ImVec2
--- @field Size                  ImVec2
--- @field FramebufferScale      ImVec2
--- @field WorkPos               ImVec2
--- @field WorkSize              ImVec2
--- @field DpiScale              float
--- @field ParentViewportId      ImGuiID
--- @field ParentViewport        ImGuiViewport
--- @field DrawData              ImDrawData
--- @field RendererUserData      any
--- @field PlatformUserData      any
--- @field PlatformHandle        any
--- @field PlatformHandleRaw     any
--- @field PlatformWindowCreated bool
--- @field PlatformRequestMove   bool
--- @field PlatformRequestResize bool
--- @field PlatformRequestClose  bool
MT.ImGuiViewport = {}
MT.ImGuiViewport.__index = MT.ImGuiViewport

function MT.ImGuiViewport:GetCenter()
    return ImVec2(self.Pos.x + self.Size.x * 0.5, self.Pos.y + self.Size.y * 0.5)
end

function MT.ImGuiViewport:GetWorkCenter()
    return ImVec2(self.WorkPos.x + self.WorkSize.x * 0.5, self.WorkPos.y + self.WorkSize.y * 0.5)
end

--- @return ImGuiViewport
--- @nodiscard
function ImGuiViewport()
    return setmetatable({
        ID       = 0,
        Flags    = 0,
        Pos      = ImVec2(),
        Size     = ImVec2(),
        FramebufferScale = ImVec2(),
        WorkPos  = ImVec2(),
        WorkSize = ImVec2(),
        DpiScale = 0,

        PlatformHandle = nil,
        PlatformHandleRaw = nil,
        PlatformWindowCreated = false
    }, MT.ImGuiViewport)
end

--- @class ImGuiPlatformIO
--- @field Platform_GetClipboardTextFn fun(ctx?: ImGuiContext): string
--- @field Platform_CreateWindow       fun(vp: ImGuiViewport)
--- @field Platform_OnChangedViewport  fun(vp: ImGuiViewport)
--- @field Monitors                    ImVector<ImGuiPlatformMonitor>
--- @field Textures                    ImVector<ImTextureData>
--- @field Viewports                   ImVector<ImGuiViewport>
MT.ImGuiPlatformIO = {}
MT.ImGuiPlatformIO.__index = MT.ImGuiPlatformIO

--- @return ImGuiPlatformIO
--- @nodiscard
function ImGuiPlatformIO()
    local this = {
        Platform_GetClipboardTextFn = nil,
        Platform_SetClipboardTextFn = nil,

        Platform_OpenInShellFn = nil,
        Platform_OpenInShellUserData = nil,

        Renderer_TextureMaxWidth = 0,
        Renderer_TextureMaxHeight = 0,

        Renderer_RenderState = nil,

        Monitors = ImVector(),
        Textures = ImVector(),
        Viewports = ImVector(),

        Platform_LocaleDecimalPoint = 46, -- '.'

        Platform_OnChangedViewport = nil,
    }

    return setmetatable(this, MT.ImGuiPlatformIO)
end

--- @class ImGuiPlatformMonitor
--- @field MainPos        ImVec2
--- @field MainSize       ImVec2
--- @field WorkPos        ImVec2
--- @field WorkSize       ImVec2
--- @field DpiScale       float
--- @field PlatformHandle any

--- @return ImGuiPlatformMonitor
--- @nodiscard
function ImGuiPlatformMonitor()
    return {
        MainPos  = ImVec2(0, 0),
        MainSize = ImVec2(0, 0),
        WorkPos  = ImVec2(0, 0),
        WorkSize = ImVec2(0, 0),
        DpiScale = 1.0,

        PlatformHandle = nil
    }
end

--- @enum ImGuiDir
ImGuiDir = {
    None  = -1,
    Left  = 0,
    Right = 1,
    Up    = 2,
    Down  = 3,
    COUNT = 4
}

--- @enum ImGuiMouseButton
ImGuiMouseButton = {
    Left   = 0,
    Right  = 1,
    Middle = 2,
    COUNT  = 5
}

--- @enum ImGuiWindowFlags
ImGuiWindowFlags = {
    None                      = 0,
    NoTitleBar                = bit.lshift(1, 0),
    NoResize                  = bit.lshift(1, 1),
    NoMove                    = bit.lshift(1, 2),
    NoScrollbar               = bit.lshift(1, 3),
    NoScrollWithMouse         = bit.lshift(1, 4),
    NoCollapse                = bit.lshift(1, 5),
    AlwaysAutoResize          = bit.lshift(1, 6),
    NoBackground              = bit.lshift(1, 7),
    NoSavedSettings           = bit.lshift(1, 8),
    NoMouseInputs             = bit.lshift(1, 9),
    MenuBar                   = bit.lshift(1, 10),
    HorizontalScrollbar       = bit.lshift(1, 11),
    NoFocusOnAppearing        = bit.lshift(1, 12),
    NoBringToFrontOnFocus     = bit.lshift(1, 13),
    AlwaysVerticalScrollbar   = bit.lshift(1, 14),
    AlwaysHorizontalScrollbar = bit.lshift(1, 15),
    NoNavInputs               = bit.lshift(1, 16),
    NoNavFocus                = bit.lshift(1, 17),
    UnsavedDocument           = bit.lshift(1, 18),
    NoDocking                 = bit.lshift(1, 19),
    DockNodeHost              = bit.lshift(1, 23),
    ChildWindow               = bit.lshift(1, 24),
    Tooltip                   = bit.lshift(1, 25),
    Popup                     = bit.lshift(1, 26),
    Modal                     = bit.lshift(1, 27),
    ChildMenu                 = bit.lshift(1, 28)
}

-- [Internal]
ImGuiWindowFlags.NoNav        = bit.bor(ImGuiWindowFlags.NoNavInputs, ImGuiWindowFlags.NoNavFocus)
ImGuiWindowFlags.NoDecoration = bit.bor(ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoScrollbar, ImGuiWindowFlags.NoCollapse)
ImGuiWindowFlags.NoInputs     = bit.bor(ImGuiWindowFlags.NoMouseInputs, ImGuiWindowFlags.NoNavInputs, ImGuiWindowFlags.NoNavFocus)

--- @enum ImGuiItemFlags
ImGuiItemFlags = {
    None              = 0,
    NoTabStop         = bit.lshift(1, 0),
    NoNav             = bit.lshift(1, 1),
    NoNavDefaultFocus = bit.lshift(1, 2),
    ButtonRepeat      = bit.lshift(1, 3),
    AutoClosePopups   = bit.lshift(1, 4),
    AllowDuplicateId  = bit.lshift(1, 5),
    Disabled          = bit.lshift(1, 6)
}

--- @enum ImGuiItemStatusFlags
ImGuiItemStatusFlags = {
    None             = 0,
    HoveredRect      = bit.lshift(1, 0),
    HasDisplayRect   = bit.lshift(1, 1),
    Edited           = bit.lshift(1, 2),
    ToggledSelection = bit.lshift(1, 3),
    ToggledOpen      = bit.lshift(1, 4),
    HasDeactivated   = bit.lshift(1, 5),
    Deactivated      = bit.lshift(1, 6),
    HoveredWindow    = bit.lshift(1, 7),
    Visible          = bit.lshift(1, 8),
    HasClipRect      = bit.lshift(1, 9),
    HasShortcut      = bit.lshift(1, 10),
    EditedInternal   = bit.lshift(1, 11)
}

--- @enum ImGuiChildFlags
ImGuiChildFlags = {
    None                   = 0,
    Borders                = bit.lshift(1, 0),
    AlwaysUseWindowPadding = bit.lshift(1, 1),
    ResizeX                = bit.lshift(1, 2),
    ResizeY                = bit.lshift(1, 3),
    AutoResizeX            = bit.lshift(1, 4),
    AutoResizeY            = bit.lshift(1, 5),
    AlwaysAutoResize       = bit.lshift(1, 6),
    FrameStyle             = bit.lshift(1, 7),
    NavFlattened           = bit.lshift(1, 8)
}

ImGuiChildFlags.ResizeBoth = bit.bor(ImGuiChildFlags.ResizeX, ImGuiChildFlags.ResizeY)
ImGuiChildFlags.ResizeXAndY = ImGuiChildFlags.ResizeBoth

--- @enum ImGuiNextItemDataFlags
ImGuiNextItemDataFlags = {
    None           = 0,
    HasWidth       = bit.lshift(1, 0),
    HasOpen        = bit.lshift(1, 1),
    HasShortcut    = bit.lshift(1, 2),
    HasRefVal      = bit.lshift(1, 3),
    HasStorageID   = bit.lshift(1, 4),
    HasColorMarker = bit.lshift(1, 5)
}

--- @enum ImDrawFlags
ImDrawFlags = {
    None                    = 0,
    RoundCornersTopLeft     = bit.lshift(1, 4),
    RoundCornersTopRight    = bit.lshift(1, 5),
    RoundCornersBottomLeft  = bit.lshift(1, 6),
    RoundCornersBottomRight = bit.lshift(1, 7),
    RoundCornersNone        = bit.lshift(1, 8),
    Closed                  = bit.lshift(1, 9)
}

ImDrawFlags.RoundCornersTop      = bit.bor(ImDrawFlags.RoundCornersTopLeft, ImDrawFlags.RoundCornersTopRight)
ImDrawFlags.RoundCornersBottom   = bit.bor(ImDrawFlags.RoundCornersBottomLeft, ImDrawFlags.RoundCornersBottomRight)
ImDrawFlags.RoundCornersLeft     = bit.bor(ImDrawFlags.RoundCornersBottomLeft, ImDrawFlags.RoundCornersTopLeft)
ImDrawFlags.RoundCornersRight    = bit.bor(ImDrawFlags.RoundCornersBottomRight, ImDrawFlags.RoundCornersTopRight)
ImDrawFlags.RoundCornersAll      = bit.bor(ImDrawFlags.RoundCornersTopLeft, ImDrawFlags.RoundCornersTopRight, ImDrawFlags.RoundCornersBottomLeft, ImDrawFlags.RoundCornersBottomRight)
ImDrawFlags.RoundCornersDefault_ = ImDrawFlags.RoundCornersAll
ImDrawFlags.RoundCornersMask_    = bit.bor(ImDrawFlags.RoundCornersAll, ImDrawFlags.RoundCornersNone)
ImDrawFlags.InvalidMask_         = 0x8000000F

--- @enum ImDrawListFlags
ImDrawListFlags = {
    None                   = 0,
    AntiAliasedLines       = bit.lshift(1, 0),
    AntiAliasedLinesUseTex = bit.lshift(1, 1),
    AntiAliasedFill        = bit.lshift(1, 2),
    AllowVtxOffset         = bit.lshift(1, 3),
    TextNoPixelSnap        = bit.lshift(1, 4)
}

--- @enum ImFontFlags
ImFontFlags = {
    None            = 0,
    NoLoadError     = bit.lshift(1, 1),
    NoLoadGlyphs    = bit.lshift(1, 2),
    LockBakedSizes  = bit.lshift(1, 3),
    ImplicitRefSize = bit.lshift(1, 4)
}

--- @enum ImGuiMouseSource
ImGuiMouseSource = {
    Mouse       = 0,
    TouchScreen = 1,
    Pen         = 2,
    COUNT       = 3
}

--- @enum ImGuiCond
ImGuiCond = {
    None          = 0,                -- No condition (always set the variable), same as .Always
    Always        = bit.lshift(1, 0), -- No condition (always set the variable), same as .None
    Once          = bit.lshift(1, 1), -- Set the variable once per runtime session (only the first call will succeed)
    FirstUseEver  = bit.lshift(1, 2), -- Set the variable if the object/window has no persistently saved data (no entry in .ini file)
    Appearing     = bit.lshift(1, 3)  -- Set the variable if the object/window is appearing after being hidden/inactive (or the first time)
}

--- @enum ImGuiInputFlags
ImGuiInputFlags = {
    None                 = 0,
    Repeat               = bit.lshift(1, 0),
    RouteActive          = bit.lshift(1, 10),
    RouteFocused         = bit.lshift(1, 11),
    RouteGlobal          = bit.lshift(1, 12),
    RouteAlways          = bit.lshift(1, 13),
    RouteOverFocused     = bit.lshift(1, 14),
    RouteOverActive      = bit.lshift(1, 15),
    RouteUnlessBgFocused = bit.lshift(1, 16),
    RouteFromRootWindow  = bit.lshift(1, 17),
    Tooltip              = bit.lshift(1, 18)
}

--- @enum ImGuiButtonFlags
ImGuiButtonFlags = {
    None                          = 0,
    MouseButtonLeft               = bit.lshift(1, 0),
    MouseButtonRight              = bit.lshift(1, 1),
    MouseButtonMiddle             = bit.lshift(1, 2),
    EnableNav                     = bit.lshift(1, 3),
    PressedOnClick                = bit.lshift(1, 4),
    PressedOnClickRelease         = bit.lshift(1, 5),
    PressedOnClickReleaseAnywhere = bit.lshift(1, 6),
    PressedOnRelease              = bit.lshift(1, 7),
    PressedOnDoubleClick          = bit.lshift(1, 8),
    PressedOnDragDropHold         = bit.lshift(1, 9),
    FlattenChildren               = bit.lshift(1, 11),
    AllowOverlap                  = bit.lshift(1, 12),
    AlignTextBaseLine             = bit.lshift(1, 15),
    NoKeyModsAllowed              = bit.lshift(1, 16),
    NoHoldingActiveId             = bit.lshift(1, 17),
    NoNavFocus                    = bit.lshift(1, 18),
    NoHoveredOnFocus              = bit.lshift(1, 19),
    NoSetKeyOwner                 = bit.lshift(1, 20),
    NoTestKeyOwner                = bit.lshift(1, 21),
    NoFocus                       = bit.lshift(1, 22)
}

ImGuiButtonFlags.MouseButtonMask_  = bit.bor(ImGuiButtonFlags.MouseButtonLeft, ImGuiButtonFlags.MouseButtonRight, ImGuiButtonFlags.MouseButtonMiddle)
ImGuiButtonFlags.PressedOnMask_    = bit.bor(ImGuiButtonFlags.PressedOnClick, ImGuiButtonFlags.PressedOnClickRelease, ImGuiButtonFlags.PressedOnClickReleaseAnywhere, ImGuiButtonFlags.PressedOnRelease, ImGuiButtonFlags.PressedOnDoubleClick, ImGuiButtonFlags.PressedOnDragDropHold)
ImGuiButtonFlags.PressedOnDefault_ = ImGuiButtonFlags.PressedOnClickRelease
ImGuiButtonFlags.NoKeyModifiers    = ImGuiButtonFlags.NoKeyModsAllowed

--- @enum ImGuiStyleVar
ImGuiStyleVar = {
    Alpha                       = 0,
    DisabledAlpha               = 1,
    WindowPadding               = 2,
    WindowRounding              = 3,
    WindowBorderSize            = 4,
    WindowMinSize               = 5,
    WindowTitleAlign            = 6,
    ChildRounding               = 7,
    ChildBorderSize             = 8,
    PopupRounding               = 9,
    PopupBorderSize             = 10,
    FramePadding                = 11,
    FrameRounding               = 12,
    FrameBorderSize             = 13,
    ItemSpacing                 = 14,
    ItemInnerSpacing            = 15,
    IndentSpacing               = 16,
    CellPadding                 = 17,
    ScrollbarSize               = 18,
    ScrollbarRounding           = 19,
    ScrollbarPadding            = 20,
    GrabMinSize                 = 21,
    GrabRounding                = 22,
    ImageRounding               = 23,
    ImageBorderSize             = 24,
    TabRounding                 = 25,
    TabBorderSize               = 26,
    TabMinWidthBase             = 27,
    TabMinWidthShrink           = 28,
    TabBarBorderSize            = 29,
    TabBarOverlineSize          = 30,
    TableAngledHeadersAngle     = 31,
    TableAngledHeadersTextAlign = 32,
    TreeLinesSize               = 33,
    TreeLinesRounding           = 34,
    DragDropTargetRounding      = 35,
    ButtonTextAlign             = 36,
    SelectableTextAlign         = 37,
    SeparatorTextBorderSize     = 38,
    SeparatorTextAlign          = 39,
    SeparatorTextPadding        = 40,
    COUNT                       = 41
}

--- @enum ImGuiHoveredFlags
ImGuiHoveredFlags = {
    None                         = 0,
    ChildWindows                 = bit.lshift(1, 0),
    RootWindow                   = bit.lshift(1, 1),
    AnyWindow                    = bit.lshift(1, 2),
    NoPopupHierarchy             = bit.lshift(1, 3),
    AllowWhenBlockedByPopup      = bit.lshift(1, 5),
    AllowWhenBlockedByActiveItem = bit.lshift(1, 7),
    AllowWhenOverlappedByItem    = bit.lshift(1, 8),
    AllowWhenOverlappedByWindow  = bit.lshift(1, 9),
    AllowWhenDisabled            = bit.lshift(1, 10),
    NoNavOverride                = bit.lshift(1, 11),
    ForTooltip                   = bit.lshift(1, 12),
    Stationary                   = bit.lshift(1, 13),
    DelayNone                    = bit.lshift(1, 14),
    DelayShort                   = bit.lshift(1, 15),
    DelayNormal                  = bit.lshift(1, 16),
    NoSharedDelay                = bit.lshift(1, 17)
}

ImGuiHoveredFlags.AllowWhenOverlapped = bit.bor(ImGuiHoveredFlags.AllowWhenOverlappedByItem, ImGuiHoveredFlags.AllowWhenOverlappedByWindow)
ImGuiHoveredFlags.RectOnly            = bit.bor(ImGuiHoveredFlags.AllowWhenBlockedByPopup, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem, ImGuiHoveredFlags.AllowWhenOverlapped)
ImGuiHoveredFlags.RootAndChildWindows = bit.bor(ImGuiHoveredFlags.RootWindow, ImGuiHoveredFlags.ChildWindows)
ImGuiHoveredFlags.DelayMask_ = bit.bor(ImGuiHoveredFlags.DelayNone, ImGuiHoveredFlags.DelayShort, ImGuiHoveredFlags.DelayNormal, ImGuiHoveredFlags.NoSharedDelay)
ImGuiHoveredFlags.AllowedMaskForIsWindowHovered = bit.bor(ImGuiHoveredFlags.ChildWindows, ImGuiHoveredFlags.RootWindow, ImGuiHoveredFlags.AnyWindow, ImGuiHoveredFlags.NoPopupHierarchy, ImGuiHoveredFlags.AllowWhenBlockedByPopup, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem, ImGuiHoveredFlags.ForTooltip, ImGuiHoveredFlags.Stationary)
ImGuiHoveredFlags.AllowedMaskForIsItemHovered = bit.bor(ImGuiHoveredFlags.AllowWhenBlockedByPopup, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem, ImGuiHoveredFlags.AllowWhenOverlapped, ImGuiHoveredFlags.AllowWhenDisabled, ImGuiHoveredFlags.NoNavOverride, ImGuiHoveredFlags.ForTooltip, ImGuiHoveredFlags.Stationary, ImGuiHoveredFlags.DelayMask_)

--- @enum ImGuiKey
ImGuiKey = {
    None = 0,

    NamedKey_BEGIN = 512,

    Tab        = 512,
    LeftArrow  = 513,
    RightArrow = 514,
    UpArrow    = 515,
    DownArrow  = 516,
    PageUp     = 517,
    PageDown   = 518,
    Home       = 519,
    End        = 520,
    Insert     = 521,
    Delete     = 522,
    Backspace  = 523,
    Space      = 524,
    Enter      = 525,
    Escape     = 526,
    LeftCtrl   = 527, LeftShift  = 528, LeftAlt  = 529, LeftSuper  = 530,
    RightCtrl  = 531, RightShift = 532, RightAlt = 533, RightSuper = 534,
    Menu       = 535,

    -- 1 ~ 9
    K0 = 536, K1 = 537, K2 = 538, K3 = 539, K4 = 540, K5 = 541, K6 = 542, K7 = 543, K8 = 544, K9 = 545,

    A = 546, B = 547, C = 548, D = 549, E = 550, F = 551, G = 552, H = 553, I = 554, J = 555,
    K = 556, L = 557, M = 558, N = 559, O = 560, P = 561, Q = 562, R = 563, S = 564, T = 565,
    U = 566, V = 567, W = 568, X = 569, Y = 570, Z = 571,

    F1  = 572, F2  = 573, F3  = 574, F4  = 575, F5  = 576, F6  = 577,
    F7  = 578, F8  = 579, F9  = 580, F10 = 581, F11 = 582, F12 = 583,
    F13 = 584, F14 = 585, F15 = 586, F16 = 587, F17 = 588, F18 = 589,
    F19 = 590, F20 = 591, F21 = 592, F22 = 593, F23 = 594, F24 = 595,

    Apostrophe     = 596,
    Comma          = 597,
    Minus          = 598,
    Period         = 599,
    Slash          = 600,
    Semicolon      = 601,
    Equal          = 602,
    LeftBracket    = 603,
    Backslash      = 604,
    RightBracket   = 605,
    GraveAccent    = 606,
    CapsLock       = 607,
    ScrollLock     = 608,
    NumLock        = 609,
    PrintScreen    = 610,
    Pause          = 611,
    Keypad0        = 612,
    Keypad1        = 613,
    Keypad2        = 614,
    Keypad3        = 615,
    Keypad4        = 616,
    Keypad5        = 617,
    Keypad6        = 618,
    Keypad7        = 619,
    Keypad8        = 620,
    Keypad9        = 621,
    KeypadDecimal  = 622,
    KeypadDivide   = 623,
    KeypadMultiply = 624,
    KeypadSubtract = 625,
    KeypadAdd      = 626,
    KeypadEnter    = 627,
    KeypadEqual    = 628,
    AppBack        = 629,
    AppForward     = 630,
    Oem102         = 631,

    GamepadStart       = 632,
    GamepadBack        = 633,
    GamepadFaceLeft    = 634,
    GamepadFaceRight   = 635,
    GamepadFaceUp      = 636,
    GamepadFaceDown    = 637,
    GamepadDpadLeft    = 638,
    GamepadDpadRight   = 639,
    GamepadDpadUp      = 640,
    GamepadDpadDown    = 641,
    GamepadL1          = 642,
    GamepadR1          = 643,
    GamepadL2          = 644,
    GamepadR2          = 645,
    GamepadL3          = 646,
    GamepadR3          = 647,
    GamepadLStickLeft  = 648,
    GamepadLStickRight = 649,
    GamepadLStickUp    = 650,
    GamepadLStickDown  = 651,
    GamepadRStickLeft  = 652,
    GamepadRStickRight = 653,
    GamepadRStickUp    = 654,
    GamepadRStickDown  = 655,

    MouseLeft = 656, MouseRight = 657, MouseMiddle = 658, MouseX1 = 659, MouseX2 = 660, MouseWheelX = 661, MouseWheelY = 662,

    ReservedForModCtrl = 663, ReservedForModShift = 664, ReservedForModAlt = 665, ReservedForModSuper = 666,

    NamedKey_END = 667
}

ImGuiKey.NamedKey_COUNT = ImGuiKey.NamedKey_END - ImGuiKey.NamedKey_BEGIN

ImGuiMod_None  = 0
ImGuiMod_Ctrl  = bit.lshift(1, 12)
ImGuiMod_Shift = bit.lshift(1, 13)
ImGuiMod_Alt   = bit.lshift(1, 14)
ImGuiMod_Super = bit.lshift(1, 15)
ImGuiMod_Mask_ = 0xF000

--- @enum ImGuiCol
ImGuiCol = {
    Text                      = 0,
    TextDisabled              = 1,
    WindowBg                  = 2,
    ChildBg                   = 3,
    PopupBg                   = 4,
    Border                    = 5,
    BorderShadow              = 6,
    FrameBg                   = 7,
    FrameBgHovered            = 8,
    FrameBgActive             = 9,
    TitleBg                   = 10,
    TitleBgActive             = 11,
    TitleBgCollapsed          = 12,
    MenuBarBg                 = 13,
    ScrollbarBg               = 14,
    ScrollbarGrab             = 15,
    ScrollbarGrabHovered      = 16,
    ScrollbarGrabActive       = 17,
    CheckMark                 = 18,
    CheckboxSelectedBg        = 19,
    SliderGrab                = 20,
    SliderGrabActive          = 21,
    Button                    = 22,
    ButtonHovered             = 23,
    ButtonActive              = 24,
    Header                    = 25,
    HeaderHovered             = 26,
    HeaderActive              = 27,
    Separator                 = 28,
    SeparatorHovered          = 29,
    SeparatorActive           = 30,
    ResizeGrip                = 31,
    ResizeGripHovered         = 32,
    ResizeGripActive          = 33,
    InputTextCursor           = 34,
    TabHovered                = 35,
    Tab                       = 36,
    TabSelected               = 37,
    TabSelectedOverline       = 38,
    TabDimmed                 = 39,
    TabDimmedSelected         = 40,
    TabDimmedSelectedOverline = 41,
    PlotLines                 = 42,
    PlotLinesHovered          = 43,
    PlotHistogram             = 44,
    PlotHistogramHovered      = 45,
    TableHeaderBg             = 46,
    TableBorderStrong         = 47,
    TableBorderLight          = 48,
    TableRowBg                = 49,
    TableRowBgAlt             = 50,
    TextLink                  = 51,
    TextSelectedBg            = 52,
    TreeLines                 = 53,
    DragDropTarget            = 54,
    DragDropTargetBg          = 55,
    UnsavedMarker             = 56,
    NavCursor                 = 57,
    NavWindowingHighlight     = 58,
    NavWindowingDimBg         = 59,
    ModalWindowDimBg          = 60,
    COUNT                     = 61
}

--- @enum ImGuiBackendFlags
ImGuiBackendFlags = {
    None                  = 0,
    HasGamepad            = bit.lshift(1, 0),
    HasMouseCursors       = bit.lshift(1, 1),
    HasSetMousePos        = bit.lshift(1, 2),
    RendererHasVtxOffset  = bit.lshift(1, 3),
    RendererHasTextures   = bit.lshift(1, 4),

    -- [BETA] Multi-Viewports
    RendererHasViewports    = bit.lshift(1, 10),
    PlatformHasViewports    = bit.lshift(1, 11),
    HasMouseHoveredViewport = bit.lshift(1, 12),
    HasParentViewport       = bit.lshift(1, 13)
}

--- @enum ImGuiDragDropFlags
ImGuiDragDropFlags = {
    None                     = 0,
    SourceNoPreviewTooltip   = bit.lshift(1, 0),
    SourceNoDisableHover     = bit.lshift(1, 1),
    SourceNoHoldToOpenOthers = bit.lshift(1, 2),
    SourceAllowNullID        = bit.lshift(1, 3),
    SourceExtern             = bit.lshift(1, 4),
    PayloadAutoExpire        = bit.lshift(1, 5),
    PayloadNoCrossContext    = bit.lshift(1, 6),
    PayloadNoCrossProcess    = bit.lshift(1, 7),
    AcceptBeforeDelivery     = bit.lshift(1, 10),
    AcceptNoDrawDefaultRect  = bit.lshift(1, 11),
    AcceptNoPreviewTooltip   = bit.lshift(1, 12),
    AcceptDrawAsHovered      = bit.lshift(1, 13)
}

ImGuiDragDropFlags.AcceptPeekOnly = bit.bor(ImGuiDragDropFlags.AcceptBeforeDelivery, ImGuiDragDropFlags.AcceptNoDrawDefaultRect)

--- Note that `S64` and `U64` are not supported
--- @enum ImGuiDataType
ImGuiDataType = {
    S8     = 0, -- signed char / char
    U8     = 1, -- unsigned char
    S16    = 2, -- short
    U16    = 3, -- unsigned short
    S32    = 4, -- int
    U32    = 5, -- unsigned int
    Float  = 6, -- float
    Double = 7, -- double
    Bool   = 8, -- bool (provided for user convenience, not supported by scalar widgets)
    String = 9, -- string (provided for user convenience, not supported by scalar widgets)
    COUNT  = 10
}

IM_COL32_R_SHIFT = 0
IM_COL32_G_SHIFT = 8
IM_COL32_B_SHIFT = 16
IM_COL32_A_SHIFT = 24
IM_COL32_A_MASK  = 0xFF000000

--- @param R ImU32
--- @param G ImU32
--- @param B ImU32
--- @param A ImU32
IM_COL32             = function(R, G, B, A) return (bit.bor(bit.lshift(A, IM_COL32_A_SHIFT), bit.lshift(B, IM_COL32_B_SHIFT), bit.lshift(G, IM_COL32_G_SHIFT), bit.lshift(R, IM_COL32_R_SHIFT))) end
IM_COL32_WHITE       = IM_COL32(255, 255, 255, 255)
IM_COL32_BLACK       = IM_COL32(0, 0, 0, 255)
IM_COL32_BLACK_TRANS = IM_COL32(0, 0, 0, 0)

--- @enum ImGuiPopupFlags
ImGuiPopupFlags = {
    None                    = 0,
    MouseButtonLeft         = bit.lshift(1, 2),
    MouseButtonRight        = bit.lshift(2, 2),
    MouseButtonMiddle       = bit.lshift(3, 2),
    NoReopen                = bit.lshift(1, 5),
    NoOpenOverExistingPopup = bit.lshift(1, 7),
    NoOpenOverItems         = bit.lshift(1, 8),
    AnyPopupId              = bit.lshift(1, 10),
    AnyPopupLevel           = bit.lshift(1, 11)
}

ImGuiPopupFlags.AnyPopup          = bit.bor(ImGuiPopupFlags.AnyPopupId, ImGuiPopupFlags.AnyPopupLevel)
ImGuiPopupFlags.MouseButtonShift_ = 2
ImGuiPopupFlags.MouseButtonMask_  = 0x0C
ImGuiPopupFlags.InvalidMask_      = 0x03

--- @enum ImGuiComboFlags
ImGuiComboFlags = {
    None            = 0,
    PopupAlignLeft  = bit.lshift(1, 0),
    HeightSmall     = bit.lshift(1, 1),
    HeightRegular   = bit.lshift(1, 2),
    HeightLarge     = bit.lshift(1, 3),
    HeightLargest   = bit.lshift(1, 4),
    NoArrowButton   = bit.lshift(1, 5),
    NoPreview       = bit.lshift(1, 6),
    WidthFitPreview = bit.lshift(1, 7)
}

ImGuiComboFlags.HeightMask_ = bit.bor(ImGuiComboFlags.HeightSmall, ImGuiComboFlags.HeightRegular, ImGuiComboFlags.HeightLarge, ImGuiComboFlags.HeightLargest)
ImGuiComboFlags.CustomPreview = bit.lshift(1, 20)

--- @enum ImGuiSelectableFlags
ImGuiSelectableFlags = {
    None              = 0,
    NoAutoClosePopups = bit.lshift(1, 0),
    SpanAllColumns    = bit.lshift(1, 1),
    AllowDoubleClick  = bit.lshift(1, 2),
    Disabled          = bit.lshift(1, 3),
    AllowOverlap      = bit.lshift(1, 4),
    Highlight         = bit.lshift(1, 5),
    SelectOnNav       = bit.lshift(1, 6),

    NoHoldingActiveID    = bit.lshift(1, 20),
    SelectOnClick        = bit.lshift(1, 22),
    SelectOnRelease      = bit.lshift(1, 23),
    SpanAvailWidth       = bit.lshift(1, 24),
    SetNavIdOnHover      = bit.lshift(1, 25),
    NoPadWithHalfSpacing = bit.lshift(1, 26),
    NoSetKeyOwner        = bit.lshift(1, 27),
}

-- Flags for ColorEdit3() / ColorEdit4() / ColorPicker3() / ColorPicker4() / ColorButton()
--- @enum ImGuiColorEditFlags
ImGuiColorEditFlags = {
    None           = 0,
    NoAlpha        = bit.lshift(1, 1),
    NoPicker       = bit.lshift(1, 2),
    NoOptions      = bit.lshift(1, 3),
    NoSmallPreview = bit.lshift(1, 4),
    NoInputs       = bit.lshift(1, 5),
    NoTooltip      = bit.lshift(1, 6),
    NoLabel        = bit.lshift(1, 7),
    NoSidePreview  = bit.lshift(1, 8),
    NoDragDrop     = bit.lshift(1, 9),
    NoBorder       = bit.lshift(1, 10),
    NoColorMarkers = bit.lshift(1, 11),

    -- Alpha preview
    AlphaOpaque      = bit.lshift(1, 12),
    AlphaNoBg        = bit.lshift(1, 13),
    AlphaPreviewHalf = bit.lshift(1, 14),

    -- User Options (right-click on widget to change some of them)
    AlphaBar       = bit.lshift(1, 18),
    HDR            = bit.lshift(1, 19),
    DisplayRGB     = bit.lshift(1, 20),
    DisplayHSV     = bit.lshift(1, 21),
    DisplayHex     = bit.lshift(1, 22),
    Uint8          = bit.lshift(1, 23),
    Float          = bit.lshift(1, 24),
    PickerHueBar   = bit.lshift(1, 25),
    PickerHueWheel = bit.lshift(1, 26),
    InputRGB       = bit.lshift(1, 27),
    InputHSV       = bit.lshift(1, 28)
}

ImGuiColorEditFlags.DefaultOptions_ = bit.bor(ImGuiColorEditFlags.Uint8, ImGuiColorEditFlags.DisplayRGB, ImGuiColorEditFlags.InputRGB, ImGuiColorEditFlags.PickerHueBar)

ImGuiColorEditFlags.AlphaMask_ = bit.bor(
    ImGuiColorEditFlags.NoAlpha,
    ImGuiColorEditFlags.AlphaOpaque,
    ImGuiColorEditFlags.AlphaNoBg,
    ImGuiColorEditFlags.AlphaPreviewHalf
)

ImGuiColorEditFlags.DisplayMask_ = bit.bor(
    ImGuiColorEditFlags.DisplayRGB,
    ImGuiColorEditFlags.DisplayHSV,
    ImGuiColorEditFlags.DisplayHex
)

ImGuiColorEditFlags.DataTypeMask_ = bit.bor(
    ImGuiColorEditFlags.Uint8,
    ImGuiColorEditFlags.Float
)

ImGuiColorEditFlags.PickerMask_ = bit.bor(
    ImGuiColorEditFlags.PickerHueWheel,
    ImGuiColorEditFlags.PickerHueBar
)

ImGuiColorEditFlags.InputMask_ = bit.bor(
    ImGuiColorEditFlags.InputRGB,
    ImGuiColorEditFlags.InputHSV
)

--- @enum ImGuiSliderFlags
ImGuiSliderFlags = {
    None            = 0,
    Logarithmic     = bit.lshift(1, 5),
    NoRoundToFormat = bit.lshift(1, 6),
    NoInput         = bit.lshift(1, 7),
    WrapAround      = bit.lshift(1, 8),
    ClampOnInput    = bit.lshift(1, 9),
    ClampZeroRange  = bit.lshift(1, 10),
    NoSpeedTweaks   = bit.lshift(1, 11),
    ColorMarkers    = bit.lshift(1, 12),
    InvalidMask_    = 0x7000000F,
}

ImGuiSliderFlags.AlwaysClamp = bit.bor(ImGuiSliderFlags.ClampOnInput, ImGuiSliderFlags.ClampZeroRange)

ImGuiSliderFlags.Vertical = bit.lshift(1, 20)
ImGuiSliderFlags.ReadOnly = bit.lshift(1, 21)

--- @class ImGuiWindowClass
--- @field ClassId                    ImGuiID
--- @field ParentViewportId           ImGuiID
--- @field FocusRouteParentWindowId   ImGuiID
--- @field ViewportFlagsOverrideSet   ImGuiViewportFlags
--- @field ViewportFlagsOverrideClear ImGuiViewportFlags

--- @return ImGuiWindowClass
--- @nodiscard
function ImGuiWindowClass()
    return {
        ClassId                    = 0,
        ParentViewportId           = 0xFFFFFFFF,
        FocusRouteParentWindowId   = 0,
        ViewportFlagsOverrideSet   = 0,
        ViewportFlagsOverrideClear = 0,

        TabItemFlagsOverrideSet  = 0,
        DockNodeFlagsOverrideSet = 0,
        DockingAlwaysTabBar      = false,
        DockingAllowUnclassed    = true
    }
end

--- @enum ImGuiInputTextFlags
ImGuiInputTextFlags = {
    None = 0,

    -- Basic filters (also see ImGuiInputTextFlags.CallbackCharFilter)
    CharsDecimal     = bit.lshift(1, 0),
    CharsHexadecimal = bit.lshift(1, 1),
    CharsScientific  = bit.lshift(1, 2),
    CharsUppercase   = bit.lshift(1, 3),
    CharsNoBlank     = bit.lshift(1, 4),

    -- Inputs
    AllowTabInput       = bit.lshift(1, 5),
    EnterReturnsTrue    = bit.lshift(1, 6),
    EscapeClearsAll     = bit.lshift(1, 7),
    CtrlEnterForNewLine = bit.lshift(1, 8),

    -- Other options
    ReadOnly           = bit.lshift(1, 9),
    Password           = bit.lshift(1, 10),
    AlwaysOverwrite    = bit.lshift(1, 11),
    AutoSelectAll      = bit.lshift(1, 12),
    ParseEmptyRefVal   = bit.lshift(1, 13),
    DisplayEmptyRefVal = bit.lshift(1, 14),
    NoHorizontalScroll = bit.lshift(1, 15),
    NoUndoRedo         = bit.lshift(1, 16),

    -- Elide display / Alignment
    ElideLeft = bit.lshift(1, 17),

    -- Callback features
    CallbackCompletion = bit.lshift(1, 18),
    CallbackHistory    = bit.lshift(1, 19),
    CallbackAlways     = bit.lshift(1, 20),
    CallbackCharFilter = bit.lshift(1, 21),
    CallbackResize     = bit.lshift(1, 22),
    CallbackEdit       = bit.lshift(1, 23),

    -- Multi-line Word-Wrapping [BETA]
    WordWrap = bit.lshift(1, 24),

    -- [Internal]
    Multiline            = bit.lshift(1, 26),
    TempInput            = bit.lshift(1, 27),
    LocalizeDecimalPoint = bit.lshift(1, 28),
}

--- @class ImGuiInputTextCallbackData

--- @return ImGuiInputTextCallbackData
function ImGuiInputTextCallbackData()
    return {}
end

--- @alias ImGuiInputTextCallback fun(data: ImGuiInputTextCallbackData)

--- @alias ImGuiMemAllocFunc fun(T: function, start_idx: int, end_idx: int, userdata: any): table
--- @alias ImGuiMemFreeFunc fun(owner: table, field: string, userdata: any)

--- @alias ImDrawCallback fun(parent_list: ImDrawList, cmd: ImDrawCmd)

--- @enum ImGuiTreeNodeFlags
ImGuiTreeNodeFlags = {
    None                 = 0,
    Selected             = bit.lshift(1, 0),
    Framed               = bit.lshift(1, 1),
    AllowOverlap         = bit.lshift(1, 2),
    NoTreePushOnOpen     = bit.lshift(1, 3),
    NoAutoOpenOnLog      = bit.lshift(1, 4),
    DefaultOpen          = bit.lshift(1, 5),
    OpenOnDoubleClick    = bit.lshift(1, 6),
    OpenOnArrow          = bit.lshift(1, 7),
    Leaf                 = bit.lshift(1, 8),
    Bullet               = bit.lshift(1, 9),
    FramePadding         = bit.lshift(1, 10),
    SpanAvailWidth       = bit.lshift(1, 11),
    SpanFullWidth        = bit.lshift(1, 12),
    SpanLabelWidth       = bit.lshift(1, 13),
    SpanAllColumns       = bit.lshift(1, 14),
    LabelSpanAllColumns  = bit.lshift(1, 15),
    NavLeftJumpsToParent = bit.lshift(1, 17),
    DrawLinesNone        = bit.lshift(1, 18),
    DrawLinesFull        = bit.lshift(1, 19),
    DrawLinesToNodes     = bit.lshift(1, 20),

    NoNavFocus                 = bit.lshift(1, 27),
    ClipLabelForTrailingButton = bit.lshift(1, 28),
    UpsideDownArrow            = bit.lshift(1, 29),
}

ImGuiTreeNodeFlags.CollapsingHeader = bit.bor(ImGuiTreeNodeFlags.Framed, ImGuiTreeNodeFlags.NoTreePushOnOpen, ImGuiTreeNodeFlags.NoAutoOpenOnLog)

ImGuiTreeNodeFlags.OpenOnMask_ = bit.bor(ImGuiTreeNodeFlags.OpenOnDoubleClick, ImGuiTreeNodeFlags.OpenOnArrow)
ImGuiTreeNodeFlags.DrawLinesMask_ = bit.bor(ImGuiTreeNodeFlags.DrawLinesNone, ImGuiTreeNodeFlags.DrawLinesFull, ImGuiTreeNodeFlags.DrawLinesToNodes)

--- @enum ImGuiTableFlags
ImGuiTableFlags = {
    None = 0,
}