Internals: shuffling some sections, added index.

imgui_internal.h

@@ -9,15 +9,21 @@
 /*
 
 Index of this file:
-// Header mess
-// Forward declarations
-// STB libraries includes
-// Context pointer
-// Generic helpers
-// Flags, enums and data structures
-// Main imgui context
-// Tab bar, Tab item
-// Internal API
+
+// [SECTION] Header mess
+// [SECTION] Forward declarations
+// [SECTION] Context pointer
+// [SECTION] STB libraries includes
+// [SECTION] Macros
+// [SECTION] Generic helpers
+// [SECTION] ImDrawList support
+// [SECTION] Misc flags, enums and data structures
+// [SECTION] Settings support
+// [SECTION] ImGuiContext (main imgui context)
+// [SECTION] ImGuiWindowTempData, ImGuiWindow
+// [SECTION] Tab bar, Tab item
+// [SECTION] Internal API
+// [SECTION] Test Engine Hooks (imgui_test_engine)
 
 */
 
@@ -25,7 +31,7 @@ Index of this file:
 #ifndef IMGUI_DISABLE
 
 //-----------------------------------------------------------------------------
-// Header mess
+// [SECTION] Header mess
 //-----------------------------------------------------------------------------
 
 #ifndef IMGUI_VERSION
@@ -46,8 +52,8 @@ Index of this file:
 // Clang/GCC warnings with -Weverything
 #if defined(__clang__)
 #pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunused-function"        // for stb_textedit.h
-#pragma clang diagnostic ignored "-Wmissing-prototypes"     // for stb_textedit.h
+#pragma clang diagnostic ignored "-Wunused-function"    // for stb_textedit.h
+#pragma clang diagnostic ignored "-Wmissing-prototypes" // for stb_textedit.h
 #pragma clang diagnostic ignored "-Wold-style-cast"
 #if __has_warning("-Wzero-as-null-pointer-constant")
 #pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
@@ -57,20 +63,20 @@ Index of this file:
 #endif
 #elif defined(__GNUC__)
 #pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wpragmas"                  // warning: unknown option after '#pragma GCC diagnostic' kind
-#pragma GCC diagnostic ignored "-Wclass-memaccess"          // [__GNUC__ >= 8] warning: 'memset/memcpy' clearing/writing an object of type 'xxxx' with no trivial copy-assignment; use assignment or value-initialization instead
+#pragma GCC diagnostic ignored "-Wpragmas"              // warning: unknown option after '#pragma GCC diagnostic' kind
+#pragma GCC diagnostic ignored "-Wclass-memaccess"      // [__GNUC__ >= 8] warning: 'memset/memcpy' clearing/writing an object of type 'xxxx' with no trivial copy-assignment; use assignment or value-initialization instead
 #endif
 
 // Legacy defines
-#ifdef IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS                // Renamed in 1.74
+#ifdef IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS            // Renamed in 1.74
 #error Use IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS
 #endif
-#ifdef IMGUI_DISABLE_MATH_FUNCTIONS                         // Renamed in 1.74
+#ifdef IMGUI_DISABLE_MATH_FUNCTIONS                     // Renamed in 1.74
 #error Use IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS
 #endif
 
 //-----------------------------------------------------------------------------
-// Forward declarations
+// [SECTION] Forward declarations
 //-----------------------------------------------------------------------------
 
 struct ImBitVector;                 // Store 1-bit per value
@@ -115,8 +121,17 @@ typedef int ImGuiSliderFlags;           // -> enum ImGuiSliderFlags_        // F
 typedef int ImGuiTextFlags;             // -> enum ImGuiTextFlags_          // Flags: for TextEx()
 typedef int ImGuiTooltipFlags;          // -> enum ImGuiTooltipFlags_       // Flags: for BeginTooltipEx()
 
+//-----------------------------------------------------------------------------
+// [SECTION] Context pointer
+// See implementation of this variable in imgui.cpp for comments and details.
+//-----------------------------------------------------------------------------
+
+#ifndef GImGui
+extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
+#endif
+
 //-------------------------------------------------------------------------
-// STB libraries includes
+// [SECTION] STB libraries includes
 //-------------------------------------------------------------------------
 
 namespace ImStb
@@ -134,15 +149,7 @@ namespace ImStb
 } // namespace ImStb
 
 //-----------------------------------------------------------------------------
-// Context pointer
-//-----------------------------------------------------------------------------
-
-#ifndef GImGui
-extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
-#endif
-
-//-----------------------------------------------------------------------------
-// Macros
+// [SECTION] Macros
 //-----------------------------------------------------------------------------
 
 // Debug Logging
@@ -192,32 +199,50 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 #define IMGUI_CDECL
 #endif
 
+// Debug Tools
+// Use 'Metrics->Tools->Item Picker' to break into the call-stack of a specific item.
+#ifndef IM_DEBUG_BREAK
+#if defined(__clang__)
+#define IM_DEBUG_BREAK()    __builtin_debugtrap()
+#elif defined (_MSC_VER)
+#define IM_DEBUG_BREAK()    __debugbreak()
+#else
+#define IM_DEBUG_BREAK()    IM_ASSERT(0)    // It is expected that you define IM_DEBUG_BREAK() into something that will break nicely in a debugger!
+#endif
+#endif // #ifndef IM_DEBUG_BREAK
+
 //-----------------------------------------------------------------------------
-// Generic helpers
+// [SECTION] Generic helpers
 // Note that the ImXXX helpers functions are lower-level than ImGui functions.
 // ImGui functions or the ImGui context are never called/used from other ImXXX functions.
 //-----------------------------------------------------------------------------
-// - Helpers: Misc
+// - Helpers: Hashing
+// - Helpers: Sorting
 // - Helpers: Bit manipulation
 // - Helpers: String, Formatting
 // - Helpers: UTF-8 <> wchar conversions
 // - Helpers: ImVec2/ImVec4 operators
 // - Helpers: Maths
 // - Helpers: Geometry
-// - Helpers: Bit arrays
+// - Helper: ImVec1
+// - Helper: ImVec2ih
+// - Helper: ImRect
+// - Helper: ImBitArray
 // - Helper: ImBitVector
 // - Helper: ImPool<>
 // - Helper: ImChunkStream<>
 //-----------------------------------------------------------------------------
 
-// Helpers: Misc
-#define ImQsort         qsort
+// Helpers: Hashing
 IMGUI_API ImU32         ImHashData(const void* data, size_t data_size, ImU32 seed = 0);
 IMGUI_API ImU32         ImHashStr(const char* data, size_t data_size = 0, ImU32 seed = 0);
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
 static inline ImU32     ImHash(const void* data, int size, ImU32 seed = 0) { return size ? ImHashData(data, (size_t)size, seed) : ImHashStr((const char*)data, 0, seed); } // [moved to ImHashStr/ImHashData in 1.68]
 #endif
 
+// Helpers: Sorting
+#define ImQsort         qsort
+
 // Helpers: Color Blending
 IMGUI_API ImU32         ImAlphaBlendColors(ImU32 col_a, ImU32 col_b);
 
@@ -286,7 +311,6 @@ static inline ImU64         ImFileGetSize(ImFileHandle)
 static inline ImU64         ImFileRead(void*, ImU64, ImU64, ImFileHandle)           { return 0; }
 static inline ImU64         ImFileWrite(const void*, ImU64, ImU64, ImFileHandle)    { return 0; }
 #endif
-
 #ifndef IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS
 typedef FILE* ImFileHandle;
 IMGUI_API ImFileHandle      ImFileOpen(const char* filename, const char* mode);
@@ -354,7 +378,61 @@ IMGUI_API void       ImTriangleBarycentricCoords(const ImVec2& a, const ImVec2&
 inline float         ImTriangleArea(const ImVec2& a, const ImVec2& b, const ImVec2& c) { return ImFabs((a.x * (b.y - c.y)) + (b.x * (c.y - a.y)) + (c.x * (a.y - b.y))) * 0.5f; }
 IMGUI_API ImGuiDir   ImGetDirQuadrantFromDelta(float dx, float dy);
 
-// Helpers: Bit arrays
+// Helper: ImVec1 (1D vector)
+// (this odd construct is used to facilitate the transition between 1D and 2D, and the maintenance of some branches/patches)
+struct ImVec1
+{
+    float   x;
+    ImVec1()         { x = 0.0f; }
+    ImVec1(float _x) { x = _x; }
+};
+
+// Helper: ImVec2ih (2D vector, half-size integer, for long-term packed storage)
+struct ImVec2ih
+{
+    short   x, y;
+    ImVec2ih()                           { x = y = 0; }
+    ImVec2ih(short _x, short _y)         { x = _x; y = _y; }
+    explicit ImVec2ih(const ImVec2& rhs) { x = (short)rhs.x; y = (short)rhs.y; }
+};
+
+// Helper: ImRect (2D axis aligned bounding-box)
+// NB: we can't rely on ImVec2 math operators being available here!
+struct IMGUI_API ImRect
+{
+    ImVec2      Min;    // Upper-left
+    ImVec2      Max;    // Lower-right
+
+    ImRect()                                        : Min(0.0f, 0.0f), Max(0.0f, 0.0f)  {}
+    ImRect(const ImVec2& min, const ImVec2& max)    : Min(min), Max(max)                {}
+    ImRect(const ImVec4& v)                         : Min(v.x, v.y), Max(v.z, v.w)      {}
+    ImRect(float x1, float y1, float x2, float y2)  : Min(x1, y1), Max(x2, y2)          {}
+
+    ImVec2      GetCenter() const                   { return ImVec2((Min.x + Max.x) * 0.5f, (Min.y + Max.y) * 0.5f); }
+    ImVec2      GetSize() const                     { return ImVec2(Max.x - Min.x, Max.y - Min.y); }
+    float       GetWidth() const                    { return Max.x - Min.x; }
+    float       GetHeight() const                   { return Max.y - Min.y; }
+    ImVec2      GetTL() const                       { return Min; }                   // Top-left
+    ImVec2      GetTR() const                       { return ImVec2(Max.x, Min.y); }  // Top-right
+    ImVec2      GetBL() const                       { return ImVec2(Min.x, Max.y); }  // Bottom-left
+    ImVec2      GetBR() const                       { return Max; }                   // Bottom-right
+    bool        Contains(const ImVec2& p) const     { return p.x     >= Min.x && p.y     >= Min.y && p.x     <  Max.x && p.y     <  Max.y; }
+    bool        Contains(const ImRect& r) const     { return r.Min.x >= Min.x && r.Min.y >= Min.y && r.Max.x <= Max.x && r.Max.y <= Max.y; }
+    bool        Overlaps(const ImRect& r) const     { return r.Min.y <  Max.y && r.Max.y >  Min.y && r.Min.x <  Max.x && r.Max.x >  Min.x; }
+    void        Add(const ImVec2& p)                { if (Min.x > p.x)     Min.x = p.x;     if (Min.y > p.y)     Min.y = p.y;     if (Max.x < p.x)     Max.x = p.x;     if (Max.y < p.y)     Max.y = p.y; }
+    void        Add(const ImRect& r)                { if (Min.x > r.Min.x) Min.x = r.Min.x; if (Min.y > r.Min.y) Min.y = r.Min.y; if (Max.x < r.Max.x) Max.x = r.Max.x; if (Max.y < r.Max.y) Max.y = r.Max.y; }
+    void        Expand(const float amount)          { Min.x -= amount;   Min.y -= amount;   Max.x += amount;   Max.y += amount; }
+    void        Expand(const ImVec2& amount)        { Min.x -= amount.x; Min.y -= amount.y; Max.x += amount.x; Max.y += amount.y; }
+    void        Translate(const ImVec2& d)          { Min.x += d.x; Min.y += d.y; Max.x += d.x; Max.y += d.y; }
+    void        TranslateX(float dx)                { Min.x += dx; Max.x += dx; }
+    void        TranslateY(float dy)                { Min.y += dy; Max.y += dy; }
+    void        ClipWith(const ImRect& r)           { Min = ImMax(Min, r.Min); Max = ImMin(Max, r.Max); }                   // Simple version, may lead to an inverted rectangle, which is fine for Contains/Overlaps test but not for display.
+    void        ClipWithFull(const ImRect& r)       { Min = ImClamp(Min, r.Min, r.Max); Max = ImClamp(Max, r.Min, r.Max); } // Full version, ensure both points are fully clipped.
+    void        Floor()                             { Min.x = IM_FLOOR(Min.x); Min.y = IM_FLOOR(Min.y); Max.x = IM_FLOOR(Max.x); Max.y = IM_FLOOR(Max.y); }
+    bool        IsInverted() const                  { return Min.x > Max.x || Min.y > Max.y; }
+};
+
+// Helper: ImBitArray
 inline bool          ImBitArrayTestBit(const ImU32* arr, int n)         { ImU32 mask = (ImU32)1 << (n & 31); return (arr[n >> 5] & mask) != 0; }
 inline void          ImBitArrayClearBit(ImU32* arr, int n)              { ImU32 mask = (ImU32)1 << (n & 31); arr[n >> 5] &= ~mask; }
 inline void          ImBitArraySetBit(ImU32* arr, int n)                { ImU32 mask = (ImU32)1 << (n & 31); arr[n >> 5] |= mask; }
@@ -431,7 +509,50 @@ struct IMGUI_API ImChunkStream
 };
 
 //-----------------------------------------------------------------------------
-// Flags, enums and data structures
+// [SECTION] ImDrawList support
+//-----------------------------------------------------------------------------
+
+// ImDrawList: Helper function to calculate a circle's segment count given its radius and a "maximum error" value.
+#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN                     12
+#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX                     512
+#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(_RAD,_MAXERROR)    ImClamp((int)((IM_PI * 2.0f) / ImAcos(((_RAD) - (_MAXERROR)) / (_RAD))), IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX)
+
+// ImDrawList: You may set this to higher values (e.g. 2 or 3) to increase tessellation of fast rounded corners path.
+#ifndef IM_DRAWLIST_ARCFAST_TESSELLATION_MULTIPLIER
+#define IM_DRAWLIST_ARCFAST_TESSELLATION_MULTIPLIER             1
+#endif
+
+// Data shared between all ImDrawList instances
+// You may want to create your own instance of this if you want to use ImDrawList completely without ImGui. In that case, watch out for future changes to this structure.
+struct IMGUI_API ImDrawListSharedData
+{
+    ImVec2          TexUvWhitePixel;            // UV of white pixel in the atlas
+    ImFont*         Font;                       // Current/default font (optional, for simplified AddText overload)
+    float           FontSize;                   // Current/default font size (optional, for simplified AddText overload)
+    float           CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo()
+    float           CircleSegmentMaxError;      // Number of circle segments to use per pixel of radius for AddCircle() etc
+    ImVec4          ClipRectFullscreen;         // Value for PushClipRectFullscreen()
+    ImDrawListFlags InitialFlags;               // Initial flags at the beginning of the frame (it is possible to alter flags on a per-drawlist basis afterwards)
+
+    // [Internal] Lookup tables
+    ImVec2          ArcFastVtx[12 * IM_DRAWLIST_ARCFAST_TESSELLATION_MULTIPLIER];  // FIXME: Bake rounded corners fill/borders in atlas
+    ImU8            CircleSegmentCounts[64];    // Precomputed segment count for given radius (array index + 1) before we calculate it dynamically (to avoid calculation overhead)
+
+    ImDrawListSharedData();
+    void SetCircleSegmentMaxError(float max_error);
+};
+
+struct ImDrawDataBuilder
+{
+    ImVector<ImDrawList*>   Layers[2];           // Global layers for: regular, tooltip
+
+    void Clear()            { for (int n = 0; n < IM_ARRAYSIZE(Layers); n++) Layers[n].resize(0); }
+    void ClearFreeMemory()  { for (int n = 0; n < IM_ARRAYSIZE(Layers); n++) Layers[n].clear(); }
+    IMGUI_API void FlattenIntoSingleLayer();
+};
+
+//-----------------------------------------------------------------------------
+// [SECTION] Misc flags, enums and data structures
 //-----------------------------------------------------------------------------
 
 enum ImGuiButtonFlags_
@@ -662,59 +783,6 @@ enum ImGuiPopupPositionPolicy
     ImGuiPopupPositionPolicy_ComboBox
 };
 
-// 1D vector (this odd construct is used to facilitate the transition between 1D and 2D, and the maintenance of some branches/patches)
-struct ImVec1
-{
-    float   x;
-    ImVec1()         { x = 0.0f; }
-    ImVec1(float _x) { x = _x; }
-};
-
-// 2D vector (half-size integer)
-struct ImVec2ih
-{
-    short   x, y;
-    ImVec2ih()                           { x = y = 0; }
-    ImVec2ih(short _x, short _y)         { x = _x; y = _y; }
-    explicit ImVec2ih(const ImVec2& rhs) { x = (short)rhs.x; y = (short)rhs.y; }
-};
-
-// 2D axis aligned bounding-box
-// NB: we can't rely on ImVec2 math operators being available here
-struct IMGUI_API ImRect
-{
-    ImVec2      Min;    // Upper-left
-    ImVec2      Max;    // Lower-right
-
-    ImRect()                                        : Min(0.0f, 0.0f), Max(0.0f, 0.0f)              {}
-    ImRect(const ImVec2& min, const ImVec2& max)    : Min(min), Max(max)                            {}
-    ImRect(const ImVec4& v)                         : Min(v.x, v.y), Max(v.z, v.w)                  {}
-    ImRect(float x1, float y1, float x2, float y2)  : Min(x1, y1), Max(x2, y2)                      {}
-
-    ImVec2      GetCenter() const                   { return ImVec2((Min.x + Max.x) * 0.5f, (Min.y + Max.y) * 0.5f); }
-    ImVec2      GetSize() const                     { return ImVec2(Max.x - Min.x, Max.y - Min.y); }
-    float       GetWidth() const                    { return Max.x - Min.x; }
-    float       GetHeight() const                   { return Max.y - Min.y; }
-    ImVec2      GetTL() const                       { return Min; }                   // Top-left
-    ImVec2      GetTR() const                       { return ImVec2(Max.x, Min.y); }  // Top-right
-    ImVec2      GetBL() const                       { return ImVec2(Min.x, Max.y); }  // Bottom-left
-    ImVec2      GetBR() const                       { return Max; }                   // Bottom-right
-    bool        Contains(const ImVec2& p) const     { return p.x     >= Min.x && p.y     >= Min.y && p.x     <  Max.x && p.y     <  Max.y; }
-    bool        Contains(const ImRect& r) const     { return r.Min.x >= Min.x && r.Min.y >= Min.y && r.Max.x <= Max.x && r.Max.y <= Max.y; }
-    bool        Overlaps(const ImRect& r) const     { return r.Min.y <  Max.y && r.Max.y >  Min.y && r.Min.x <  Max.x && r.Max.x >  Min.x; }
-    void        Add(const ImVec2& p)                { if (Min.x > p.x)     Min.x = p.x;     if (Min.y > p.y)     Min.y = p.y;     if (Max.x < p.x)     Max.x = p.x;     if (Max.y < p.y)     Max.y = p.y; }
-    void        Add(const ImRect& r)                { if (Min.x > r.Min.x) Min.x = r.Min.x; if (Min.y > r.Min.y) Min.y = r.Min.y; if (Max.x < r.Max.x) Max.x = r.Max.x; if (Max.y < r.Max.y) Max.y = r.Max.y; }
-    void        Expand(const float amount)          { Min.x -= amount;   Min.y -= amount;   Max.x += amount;   Max.y += amount; }
-    void        Expand(const ImVec2& amount)        { Min.x -= amount.x; Min.y -= amount.y; Max.x += amount.x; Max.y += amount.y; }
-    void        Translate(const ImVec2& d)          { Min.x += d.x; Min.y += d.y; Max.x += d.x; Max.y += d.y; }
-    void        TranslateX(float dx)                { Min.x += dx; Max.x += dx; }
-    void        TranslateY(float dy)                { Min.y += dy; Max.y += dy; }
-    void        ClipWith(const ImRect& r)           { Min = ImMax(Min, r.Min); Max = ImMin(Max, r.Max); }                   // Simple version, may lead to an inverted rectangle, which is fine for Contains/Overlaps test but not for display.
-    void        ClipWithFull(const ImRect& r)       { Min = ImClamp(Min, r.Min, r.Max); Max = ImClamp(Max, r.Min, r.Max); } // Full version, ensure both points are fully clipped.
-    void        Floor()                             { Min.x = IM_FLOOR(Min.x); Min.y = IM_FLOOR(Min.y); Max.x = IM_FLOOR(Max.x); Max.y = IM_FLOOR(Max.y); }
-    bool        IsInverted() const                  { return Min.x > Max.x || Min.y > Max.y; }
-};
-
 struct ImGuiDataTypeTempStorage
 {
     ImU8        Data[8];        // Can fit any data up to ImGuiDataType_COUNT
@@ -815,35 +883,6 @@ struct IMGUI_API ImGuiInputTextState
     void        SelectAll()                 { Stb.select_start = 0; Stb.cursor = Stb.select_end = CurLenW; Stb.has_preferred_x = 0; }
 };
 
-// Windows data saved in imgui.ini file
-// Because we never destroy or rename ImGuiWindowSettings, we can store the names in a separate buffer easily.
-// (this is designed to be stored in a ImChunkStream buffer, with the variable-length Name following our structure)
-struct ImGuiWindowSettings
-{
-    ImGuiID     ID;
-    ImVec2ih    Pos;
-    ImVec2ih    Size;
-    bool        Collapsed;
-    bool        WantApply;      // Set when loaded from .ini data (to enable merging/loading .ini data into an already running context)
-
-    ImGuiWindowSettings()       { ID = 0; Pos = Size = ImVec2ih(0, 0); Collapsed = WantApply = false; }
-    char* GetName()             { return (char*)(this + 1); }
-};
-
-struct ImGuiSettingsHandler
-{
-    const char* TypeName;       // Short description stored in .ini file. Disallowed characters: '[' ']'
-    ImGuiID     TypeHash;       // == ImHashStr(TypeName)
-    void        (*ClearAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler);                                // Clear all settings data
-    void        (*ApplyAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler);                                // Read: Called after reading (in registration order)
-    void*       (*ReadOpenFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, const char* name);              // Read: Called when entering into a new ini entry e.g. "[Window][Name]"
-    void        (*ReadLineFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, void* entry, const char* line); // Read: Called for every line of text within an ini entry
-    void        (*WriteAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, ImGuiTextBuffer* out_buf);      // Write: Output every entries into 'out_buf'
-    void*       UserData;
-
-    ImGuiSettingsHandler() { memset(this, 0, sizeof(*this)); }
-};
-
 // Storage for current popup stack
 struct ImGuiPopupData
 {
@@ -902,45 +941,6 @@ struct ImGuiColumns
     }
 };
 
-// ImDrawList: Helper function to calculate a circle's segment count given its radius and a "maximum error" value.
-#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN                     12
-#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX                     512
-#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(_RAD,_MAXERROR)    ImClamp((int)((IM_PI * 2.0f) / ImAcos(((_RAD) - (_MAXERROR)) / (_RAD))), IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX)
-
-// ImDrawList: You may set this to higher values (e.g. 2 or 3) to increase tessellation of fast rounded corners path.
-#ifndef IM_DRAWLIST_ARCFAST_TESSELLATION_MULTIPLIER
-#define IM_DRAWLIST_ARCFAST_TESSELLATION_MULTIPLIER             1
-#endif
-
-// Data shared between all ImDrawList instances
-// You may want to create your own instance of this if you want to use ImDrawList completely without ImGui. In that case, watch out for future changes to this structure.
-struct IMGUI_API ImDrawListSharedData
-{
-    ImVec2          TexUvWhitePixel;            // UV of white pixel in the atlas
-    ImFont*         Font;                       // Current/default font (optional, for simplified AddText overload)
-    float           FontSize;                   // Current/default font size (optional, for simplified AddText overload)
-    float           CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo()
-    float           CircleSegmentMaxError;      // Number of circle segments to use per pixel of radius for AddCircle() etc
-    ImVec4          ClipRectFullscreen;         // Value for PushClipRectFullscreen()
-    ImDrawListFlags InitialFlags;               // Initial flags at the beginning of the frame (it is possible to alter flags on a per-drawlist basis afterwards)
-
-    // [Internal] Lookup tables
-    ImVec2          ArcFastVtx[12 * IM_DRAWLIST_ARCFAST_TESSELLATION_MULTIPLIER];  // FIXME: Bake rounded corners fill/borders in atlas
-    ImU8            CircleSegmentCounts[64];    // Precomputed segment count for given radius (array index + 1) before we calculate it dynamically (to avoid calculation overhead)
-
-    ImDrawListSharedData();
-    void SetCircleSegmentMaxError(float max_error);
-};
-
-struct ImDrawDataBuilder
-{
-    ImVector<ImDrawList*>   Layers[2];           // Global layers for: regular, tooltip
-
-    void Clear()            { for (int n = 0; n < IM_ARRAYSIZE(Layers); n++) Layers[n].resize(0); }
-    void ClearFreeMemory()  { for (int n = 0; n < IM_ARRAYSIZE(Layers); n++) Layers[n].clear(); }
-    IMGUI_API void FlattenIntoSingleLayer();
-};
-
 struct ImGuiNavMoveResult
 {
     ImGuiWindow*    Window;             // Best candidate window
@@ -1010,27 +1010,56 @@ struct ImGuiNextItemData
     inline void ClearFlags()    { Flags = ImGuiNextItemDataFlags_None; } // Also cleared manually by ItemAdd()!
 };
 
+struct ImGuiShrinkWidthItem
+{
+    int         Index;
+    float       Width;
+};
+
+struct ImGuiPtrOrIndex
+{
+    void*       Ptr;            // Either field can be set, not both. e.g. Dock node tab bars are loose while BeginTabBar() ones are in a pool.
+    int         Index;          // Usually index in a main pool.
+
+    ImGuiPtrOrIndex(void* ptr)  { Ptr = ptr; Index = -1; }
+    ImGuiPtrOrIndex(int index)  { Ptr = NULL; Index = index; }
+};
+
 //-----------------------------------------------------------------------------
-// Tab bar, Tab item
+// [SECTION] Settings support
 //-----------------------------------------------------------------------------
 
-struct ImGuiShrinkWidthItem
+// Windows data saved in imgui.ini file
+// Because we never destroy or rename ImGuiWindowSettings, we can store the names in a separate buffer easily.
+// (this is designed to be stored in a ImChunkStream buffer, with the variable-length Name following our structure)
+struct ImGuiWindowSettings
 {
-    int             Index;
-    float           Width;
+    ImGuiID     ID;
+    ImVec2ih    Pos;
+    ImVec2ih    Size;
+    bool        Collapsed;
+    bool        WantApply;      // Set when loaded from .ini data (to enable merging/loading .ini data into an already running context)
+
+    ImGuiWindowSettings()       { ID = 0; Pos = Size = ImVec2ih(0, 0); Collapsed = WantApply = false; }
+    char* GetName()             { return (char*)(this + 1); }
 };
 
-struct ImGuiPtrOrIndex
+struct ImGuiSettingsHandler
 {
-    void*           Ptr;                // Either field can be set, not both. e.g. Dock node tab bars are loose while BeginTabBar() ones are in a pool.
-    int             Index;              // Usually index in a main pool.
+    const char* TypeName;       // Short description stored in .ini file. Disallowed characters: '[' ']'
+    ImGuiID     TypeHash;       // == ImHashStr(TypeName)
+    void        (*ClearAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler);                                // Clear all settings data
+    void        (*ApplyAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler);                                // Read: Called after reading (in registration order)
+    void*       (*ReadOpenFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, const char* name);              // Read: Called when entering into a new ini entry e.g. "[Window][Name]"
+    void        (*ReadLineFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, void* entry, const char* line); // Read: Called for every line of text within an ini entry
+    void        (*WriteAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, ImGuiTextBuffer* out_buf);      // Write: Output every entries into 'out_buf'
+    void*       UserData;
 
-    ImGuiPtrOrIndex(void* ptr)          { Ptr = ptr; Index = -1; }
-    ImGuiPtrOrIndex(int index)          { Ptr = NULL; Index = index; }
+    ImGuiSettingsHandler() { memset(this, 0, sizeof(*this)); }
 };
 
 //-----------------------------------------------------------------------------
-// Main Dear ImGui context
+// [SECTION] ImGuiContext (main imgui context)
 //-----------------------------------------------------------------------------
 
 struct ImGuiContext
@@ -1386,7 +1415,7 @@ struct ImGuiContext
 };
 
 //-----------------------------------------------------------------------------
-// ImGuiWindow
+// [SECTION] ImGuiWindowTempData, ImGuiWindow
 //-----------------------------------------------------------------------------
 
 // Transient per-window data, reset at the beginning of the frame. This used to be called ImGuiDrawContext, hence the DC variable name in ImGuiWindow.
@@ -1580,12 +1609,12 @@ public:
     ImGuiID     GetIDFromRectangle(const ImRect& r_abs);
 
     // We don't use g.FontSize because the window may be != g.CurrentWidow.
-    ImRect      Rect() const                { return ImRect(Pos.x, Pos.y, Pos.x+Size.x, Pos.y+Size.y); }
-    float       CalcFontSize() const        { ImGuiContext& g = *GImGui; float scale = g.FontBaseSize * FontWindowScale; if (ParentWindow) scale *= ParentWindow->FontWindowScale; return scale; }
-    float       TitleBarHeight() const      { ImGuiContext& g = *GImGui; return (Flags & ImGuiWindowFlags_NoTitleBar) ? 0.0f : CalcFontSize() + g.Style.FramePadding.y * 2.0f; }
-    ImRect      TitleBarRect() const        { return ImRect(Pos, ImVec2(Pos.x + SizeFull.x, Pos.y + TitleBarHeight())); }
-    float       MenuBarHeight() const       { ImGuiContext& g = *GImGui; return (Flags & ImGuiWindowFlags_MenuBar) ? DC.MenuBarOffset.y + CalcFontSize() + g.Style.FramePadding.y * 2.0f : 0.0f; }
-    ImRect      MenuBarRect() const         { float y1 = Pos.y + TitleBarHeight(); return ImRect(Pos.x, y1, Pos.x + SizeFull.x, y1 + MenuBarHeight()); }
+    ImRect      Rect() const            { return ImRect(Pos.x, Pos.y, Pos.x+Size.x, Pos.y+Size.y); }
+    float       CalcFontSize() const    { ImGuiContext& g = *GImGui; float scale = g.FontBaseSize * FontWindowScale; if (ParentWindow) scale *= ParentWindow->FontWindowScale; return scale; }
+    float       TitleBarHeight() const  { ImGuiContext& g = *GImGui; return (Flags & ImGuiWindowFlags_NoTitleBar) ? 0.0f : CalcFontSize() + g.Style.FramePadding.y * 2.0f; }
+    ImRect      TitleBarRect() const    { return ImRect(Pos, ImVec2(Pos.x + SizeFull.x, Pos.y + TitleBarHeight())); }
+    float       MenuBarHeight() const   { ImGuiContext& g = *GImGui; return (Flags & ImGuiWindowFlags_MenuBar) ? DC.MenuBarOffset.y + CalcFontSize() + g.Style.FramePadding.y * 2.0f : 0.0f; }
+    ImRect      MenuBarRect() const     { float y1 = Pos.y + TitleBarHeight(); return ImRect(Pos.x, y1, Pos.x + SizeFull.x, y1 + MenuBarHeight()); }
 };
 
 // Backup and restore just enough data to be able to use IsItemHovered() on item A after another B in the same window has overwritten the data.
@@ -1602,7 +1631,7 @@ struct ImGuiItemHoveredDataBackup
 };
 
 //-----------------------------------------------------------------------------
-// Tab bar, tab item
+// [SECTION] Tab bar, Tab item
 //-----------------------------------------------------------------------------
 
 // Extend ImGuiTabBarFlags_
@@ -1672,8 +1701,8 @@ struct ImGuiTabBar
 };
 
 //-----------------------------------------------------------------------------
-// Internal API
-// No guarantee of forward compatibility here.
+// [SECTION] Internal API
+// No guarantee of forward compatibility here!
 //-----------------------------------------------------------------------------
 
 namespace ImGui
@@ -1944,19 +1973,10 @@ IMGUI_API void              ImFontAtlasBuildFinish(ImFontAtlas* atlas);
 IMGUI_API void              ImFontAtlasBuildMultiplyCalcLookupTable(unsigned char out_table[256], float in_multiply_factor);
 IMGUI_API void              ImFontAtlasBuildMultiplyRectAlpha8(const unsigned char table[256], unsigned char* pixels, int x, int y, int w, int h, int stride);
 
-// Debug Tools
-// Use 'Metrics->Tools->Item Picker' to break into the call-stack of a specific item.
-#ifndef IM_DEBUG_BREAK
-#if defined(__clang__)
-#define IM_DEBUG_BREAK()    __builtin_debugtrap()
-#elif defined (_MSC_VER)
-#define IM_DEBUG_BREAK()    __debugbreak()
-#else
-#define IM_DEBUG_BREAK()    IM_ASSERT(0)    // It is expected that you define IM_DEBUG_BREAK() into something that will break nicely in a debugger!
-#endif
-#endif // #ifndef IM_DEBUG_BREAK
+//-----------------------------------------------------------------------------
+// [SECTION] Test Engine Hooks (imgui_test_engine)
+//-----------------------------------------------------------------------------
 
-// Test Engine Hooks (imgui_tests)
 //#define IMGUI_ENABLE_TEST_ENGINE
 #ifdef IMGUI_ENABLE_TEST_ENGINE
 extern void                 ImGuiTestEngineHook_PreNewFrame(ImGuiContext* ctx);