Merge branch 'master' into docking

# Conflicts:
#	examples/imgui_impl_sdl.cpp
#	imgui.cpp

docs/CHANGELOG.txt

@@ -124,6 +124,8 @@ Breaking Changes:
   documented (can only unreserve from the last reserve call). If you suspect you ever
   used that feature before, #define IMGUI_DEBUG_PARANOID in imconfig.h to catch existing
   calls. [@ShironekoBen]
+- Limiting Columns()/BeginColumns() api to 64 columns with an assert. While the current code
+  technically supports it, future code may not so we're putting the restriction ahead.
 - imgui_internal.h: changed ImRect() default constructor initializes all fields to 0.0f instead
   of (FLT_MAX,FLT_MAX,-FLT_MAX,-FLT_MAX). If you used ImRect::Add() to create bounding boxes by
   adding multiple points into it, you may need to fix your initial value.
@@ -138,6 +140,8 @@ Other Changes:
   selection, those new api can fill a gap. [@ShironekoBen]
 - Backends: GLFW, SDL, Win32, OSX, Allegro: Added support for ImGuiMouseCursor_NotAllowed. [@rokups]
 - Backends: GLFW: Added support for the missing mouse cursors newly added in GLFW 3.4+. [@rokups]
+- Backends: SDL: Wayland: use SDL_GetMouseState (because there is no global mouse state available
+  on Wayland). (#2800, #2802) [@NeroBurner]
 - Examples: Explicitly adding -DIMGUI_IMPL_OPENGL_LOADER_GL3W to Makefile to match linking
   settings (otherwise if another loader such as Glew is accessible, the opengl3 backend might
   automatically use it). [#2919, #2798]

examples/imgui_impl_sdl.cpp

@@ -20,6 +20,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2019-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2019-12-17: Inputs: On Wayland, use SDL_GetMouseState (because there is no global mouse state).
 //  2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor.
 //  2019-07-21: Inputs: Added mapping for ImGuiKey_KeyPadEnter.
 //  2019-04-23: Inputs: Added support for SDL_GameController (if ImGuiConfigFlags_NavEnableGamepad is set by user application).
@@ -72,6 +73,7 @@ static Uint64       g_Time = 0;
 static bool         g_MousePressed[3] = { false, false, false };
 static SDL_Cursor*  g_MouseCursors[ImGuiMouseCursor_COUNT] = {};
 static char*        g_ClipboardTextData = NULL;
+static bool         g_MouseCanUseGlobalState = true;
 
 // Forward Declarations
 static void ImGui_ImplSDL2_InitPlatformInterface(SDL_Window* window, void* sdl_gl_context);
@@ -191,6 +193,7 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, void* sdl_gl_context)
     io.GetClipboardTextFn = ImGui_ImplSDL2_GetClipboardText;
     io.ClipboardUserData = NULL;
 
+    // Load mouse cursors
     g_MouseCursors[ImGuiMouseCursor_Arrow] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_ARROW);
     g_MouseCursors[ImGuiMouseCursor_TextInput] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_IBEAM);
     g_MouseCursors[ImGuiMouseCursor_ResizeAll] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZEALL);
@@ -201,6 +204,9 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, void* sdl_gl_context)
     g_MouseCursors[ImGuiMouseCursor_Hand] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_HAND);
     g_MouseCursors[ImGuiMouseCursor_NotAllowed] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_NO);
 
+    // Check and store if we are on Wayland
+    g_MouseCanUseGlobalState = strncmp(SDL_GetCurrentVideoDriver(), "wayland", 7) != 0;
+
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = (void*)window;
@@ -291,6 +297,8 @@ static void ImGui_ImplSDL2_UpdateMousePosAndButtons()
 
 #if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE && !defined(__EMSCRIPTEN__) && !defined(__ANDROID__) && !(defined(__APPLE__) && TARGET_OS_IOS)
 
+    if (g_MouseCanUseGlobalState)
+    {
         // SDL 2.0.4 and later has SDL_GetGlobalMouseState() and SDL_CaptureMouse()
         int mouse_x_global, mouse_y_global;
         SDL_GetGlobalMouseState(&mouse_x_global, &mouse_y_global);
@@ -312,6 +320,12 @@ static void ImGui_ImplSDL2_UpdateMousePosAndButtons()
                 io.MousePos = ImVec2((float)(mouse_x_global - window_x), (float)(mouse_y_global - window_y));
             }
         }
+    }
+    else
+    {
+        if (SDL_GetWindowFlags(g_Window) & SDL_WINDOW_INPUT_FOCUS)
+            io.MousePos = ImVec2((float)mouse_x_local, (float)mouse_y_local);
+    }
 
     // SDL_CaptureMouse() let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't e.g. trigger the OS window resize cursor.
     // The function is only supported from SDL 2.0.4 (released Jan 2016)

imgui.cpp

@@ -45,7 +45,8 @@ CODE
 // [SECTION] FORWARD DECLARATIONS
 // [SECTION] CONTEXT AND MEMORY ALLOCATORS
 // [SECTION] MAIN USER FACING STRUCTURES (ImGuiStyle, ImGuiIO)
-// [SECTION] MISC HELPERS/UTILITIES (Geometry, String, Format, Hash, File functions)
+// [SECTION] MISC HELPERS/UTILITIES (Geometry functions)
+// [SECTION] MISC HELPERS/UTILITIES (String, Format, Hash functions)
 // [SECTION] MISC HELPERS/UTILITIES (File functions)
 // [SECTION] MISC HELPERS/UTILITIES (ImText* functions)
 // [SECTION] MISC HELPERS/UTILITIES (Color functions)
@@ -364,6 +365,7 @@ CODE
  - 2019/XX/XX (1.XX) - Moved IME support functions from io.ImeSetInputScreenPosFn, io.ImeWindowHandle to the PlatformIO api.
 
 
+ - 2019/12/17 (1.75) - made Columns() limited to 64 columns by asserting above that limit. While the current code technically supports it, future code may not so we're putting the restriction ahead.
  - 2019/12/13 (1.75) - [imgui_internal.h] changed ImRect() default constructor initializes all fields to 0.0f instead of (FLT_MAX,FLT_MAX,-FLT_MAX,-FLT_MAX). If you used ImRect::Add() to create bounding boxes by adding multiple points into it, you may need to fix your initial value.
  - 2019/12/08 (1.75) - removed redirecting functions/enums that were marked obsolete in 1.53 (December 2017):
                        - ShowTestWindow()                    -> use ShowDemoWindow()
@@ -1143,9 +1145,77 @@ void ImGuiIO::ClearInputCharacters()
 }
 
 //-----------------------------------------------------------------------------
-// [SECTION] MISC HELPERS/UTILITIES (Geometry, String, Format, Hash, File functions)
+// [SECTION] MISC HELPERS/UTILITIES (Geometry functions)
 //-----------------------------------------------------------------------------
 
+ImVec2 ImBezierClosestPoint(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, int num_segments)
+{
+    IM_ASSERT(num_segments > 0); // Use ImBezierClosestPointCasteljau()
+    ImVec2 p_last = p1;
+    ImVec2 p_closest;
+    float p_closest_dist2 = FLT_MAX;
+    float t_step = 1.0f / (float)num_segments;
+    for (int i_step = 1; i_step <= num_segments; i_step++)
+    {
+        ImVec2 p_current = ImBezierCalc(p1, p2, p3, p4, t_step * i_step);
+        ImVec2 p_line = ImLineClosestPoint(p_last, p_current, p);
+        float dist2 = ImLengthSqr(p - p_line);
+        if (dist2 < p_closest_dist2)
+        {
+            p_closest = p_line;
+            p_closest_dist2 = dist2;
+        }
+        p_last = p_current;
+    }
+    return p_closest;
+}
+
+// Closely mimics PathBezierToCasteljau() in imgui_draw.cpp
+static void BezierClosestPointCasteljauStep(const ImVec2& p, ImVec2& p_closest, ImVec2& p_last, float& p_closest_dist2, float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4, float tess_tol, int level)
+{
+    float dx = x4 - x1;
+    float dy = y4 - y1;
+    float d2 = ((x2 - x4) * dy - (y2 - y4) * dx);
+    float d3 = ((x3 - x4) * dy - (y3 - y4) * dx);
+    d2 = (d2 >= 0) ? d2 : -d2;
+    d3 = (d3 >= 0) ? d3 : -d3;
+    if ((d2+d3) * (d2+d3) < tess_tol * (dx*dx + dy*dy))
+    {
+        ImVec2 p_current(x4, y4);
+        ImVec2 p_line = ImLineClosestPoint(p_last, p_current, p);
+        float dist2 = ImLengthSqr(p - p_line);
+        if (dist2 < p_closest_dist2)
+        {
+            p_closest = p_line;
+            p_closest_dist2 = dist2;
+        }
+        p_last = p_current;
+    }
+    else if (level < 10)
+    {
+        float x12 = (x1+x2)*0.5f,       y12 = (y1+y2)*0.5f;
+        float x23 = (x2+x3)*0.5f,       y23 = (y2+y3)*0.5f;
+        float x34 = (x3+x4)*0.5f,       y34 = (y3+y4)*0.5f;
+        float x123 = (x12+x23)*0.5f,    y123 = (y12+y23)*0.5f;
+        float x234 = (x23+x34)*0.5f,    y234 = (y23+y34)*0.5f;
+        float x1234 = (x123+x234)*0.5f, y1234 = (y123+y234)*0.5f;
+        BezierClosestPointCasteljauStep(p, p_closest, p_last, p_closest_dist2, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1);
+        BezierClosestPointCasteljauStep(p, p_closest, p_last, p_closest_dist2, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1);
+    }
+}
+
+// tess_tol is generally the same value you would find in ImGui::GetStyle().CurveTessellationTol
+// Because those ImXXX functions are lower-level than ImGui:: we cannot access this value automatically.
+ImVec2 ImBezierClosestPointCasteljau(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, float tess_tol)
+{
+    IM_ASSERT(tess_tol > 0.0f);
+    ImVec2 p_last = p1;
+    ImVec2 p_closest;
+    float p_closest_dist2 = FLT_MAX;
+    BezierClosestPointCasteljauStep(p, p_closest, p_last, p_closest_dist2, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, tess_tol, 0);
+    return p_closest;
+}
+
 ImVec2 ImLineClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& p)
 {
     ImVec2 ap = p - a;
@@ -1194,6 +1264,10 @@ ImVec2 ImTriangleClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c,
     return proj_ca;
 }
 
+//-----------------------------------------------------------------------------
+// [SECTION] MISC HELPERS/UTILITIES (String, Format, Hash functions)
+//-----------------------------------------------------------------------------
+
 // Consider using _stricmp/_strnicmp under Windows or strcasecmp/strncasecmp. We don't actually use either ImStricmp/ImStrnicmp in the codebase any more.
 int ImStricmp(const char* str1, const char* str2)
 {
@@ -1764,38 +1838,6 @@ void ImGui::ColorConvertHSVtoRGB(float h, float s, float v, float& out_r, float&
     }
 }
 
-ImU32 ImGui::GetColorU32(ImGuiCol idx, float alpha_mul)
-{
-    ImGuiStyle& style = GImGui->Style;
-    ImVec4 c = style.Colors[idx];
-    c.w *= style.Alpha * alpha_mul;
-    return ColorConvertFloat4ToU32(c);
-}
-
-ImU32 ImGui::GetColorU32(const ImVec4& col)
-{
-    ImGuiStyle& style = GImGui->Style;
-    ImVec4 c = col;
-    c.w *= style.Alpha;
-    return ColorConvertFloat4ToU32(c);
-}
-
-const ImVec4& ImGui::GetStyleColorVec4(ImGuiCol idx)
-{
-    ImGuiStyle& style = GImGui->Style;
-    return style.Colors[idx];
-}
-
-ImU32 ImGui::GetColorU32(ImU32 col)
-{
-    float style_alpha = GImGui->Style.Alpha;
-    if (style_alpha >= 1.0f)
-        return col;
-    ImU32 a = (col & IM_COL32_A_MASK) >> IM_COL32_A_SHIFT;
-    a = (ImU32)(a * style_alpha); // We don't need to clamp 0..255 because Style.Alpha is in 0..1 range.
-    return (col & ~IM_COL32_A_MASK) | (a << IM_COL32_A_SHIFT);
-}
-
 //-----------------------------------------------------------------------------
 // [SECTION] ImGuiStorage
 // Helper: Key->value storage
@@ -2253,10 +2295,42 @@ bool ImGuiListClipper::Step()
 
 //-----------------------------------------------------------------------------
 // [SECTION] RENDER HELPERS
-// Those (internal) functions are currently quite a legacy mess - their signature and behavior will change.
+// Some of those (internal) functions are currently quite a legacy mess - their signature and behavior will change.
 // Also see imgui_draw.cpp for some more which have been reworked to not rely on ImGui:: state.
 //-----------------------------------------------------------------------------
 
+ImU32 ImGui::GetColorU32(ImGuiCol idx, float alpha_mul)
+{
+    ImGuiStyle& style = GImGui->Style;
+    ImVec4 c = style.Colors[idx];
+    c.w *= style.Alpha * alpha_mul;
+    return ColorConvertFloat4ToU32(c);
+}
+
+ImU32 ImGui::GetColorU32(const ImVec4& col)
+{
+    ImGuiStyle& style = GImGui->Style;
+    ImVec4 c = col;
+    c.w *= style.Alpha;
+    return ColorConvertFloat4ToU32(c);
+}
+
+const ImVec4& ImGui::GetStyleColorVec4(ImGuiCol idx)
+{
+    ImGuiStyle& style = GImGui->Style;
+    return style.Colors[idx];
+}
+
+ImU32 ImGui::GetColorU32(ImU32 col)
+{
+    ImGuiStyle& style = GImGui->Style;
+    if (style.Alpha >= 1.0f)
+        return col;
+    ImU32 a = (col & IM_COL32_A_MASK) >> IM_COL32_A_SHIFT;
+    a = (ImU32)(a * style.Alpha); // We don't need to clamp 0..255 because Style.Alpha is in 0..1 range.
+    return (col & ~IM_COL32_A_MASK) | (a << IM_COL32_A_SHIFT);
+}
+
 const char* ImGui::FindRenderedTextEnd(const char* text, const char* text_end)
 {
     const char* text_display_end = text;

imgui.h

@@ -596,6 +596,7 @@ namespace ImGui
     // Columns
     // - You can also use SameLine(pos_x) to mimic simplified columns.
     // - The columns API is work-in-progress and rather lacking (columns are arguably the worst part of dear imgui at the moment!)
+    // - There is a maximum of 64 columns.
     // - By end of the 2019 we will expose a new 'Table' api which will replace columns.
     IMGUI_API void          Columns(int count = 1, const char* id = NULL, bool border = true);
     IMGUI_API void          NextColumn();                                                       // next column, defaults to current row or next row if the current row is finished
@@ -2042,7 +2043,7 @@ struct ImDrawList
     IMGUI_API void  AddText(const ImFont* font, float font_size, const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end = NULL, float wrap_width = 0.0f, const ImVec4* cpu_fine_clip_rect = NULL);
     IMGUI_API void  AddPolyline(const ImVec2* points, int num_points, ImU32 col, bool closed, float thickness);
     IMGUI_API void  AddConvexPolyFilled(const ImVec2* points, int num_points, ImU32 col); // Note: Anti-aliased filling requires points to be in clockwise order.
-    IMGUI_API void  AddBezierCurve(const ImVec2& pos0, const ImVec2& cp0, const ImVec2& cp1, const ImVec2& pos1, ImU32 col, float thickness, int num_segments = 0);
+    IMGUI_API void  AddBezierCurve(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, ImU32 col, float thickness, int num_segments = 0);
 
     // Image primitives
     // - Read FAQ to understand what ImTextureID is.
@@ -2060,7 +2061,7 @@ struct ImDrawList
     inline    void  PathStroke(ImU32 col, bool closed, float thickness = 1.0f)  { AddPolyline(_Path.Data, _Path.Size, col, closed, thickness); _Path.Size = 0; }
     IMGUI_API void  PathArcTo(const ImVec2& center, float radius, float a_min, float a_max, int num_segments = 10);
     IMGUI_API void  PathArcToFast(const ImVec2& center, float radius, int a_min_of_12, int a_max_of_12);                                            // Use precomputed angles for a 12 steps circle
-    IMGUI_API void  PathBezierCurveTo(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, int num_segments = 0);
+    IMGUI_API void  PathBezierCurveTo(const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, int num_segments = 0);
     IMGUI_API void  PathRect(const ImVec2& rect_min, const ImVec2& rect_max, float rounding = 0.0f, ImDrawCornerFlags rounding_corners = ImDrawCornerFlags_All);
 
     // Advanced

imgui_draw.cpp

@@ -913,6 +913,17 @@ void ImDrawList::PathArcTo(const ImVec2& center, float radius, float a_min, floa
     }
 }
 
+ImVec2 ImBezierCalc(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, float t)
+{
+    float u = 1.0f - t;
+    float w1 = u*u*u;
+    float w2 = 3*u*u*t;
+    float w3 = 3*u*t*t;
+    float w4 = t*t*t;
+    return ImVec2(w1*p1.x + w2*p2.x + w3*p3.x + w4*p4.x, w1*p1.y + w2*p2.y + w3*p3.y + w4*p4.y);
+}
+
+// Closely mimics BezierClosestPointCasteljauStep() in imgui.cpp
 static void PathBezierToCasteljau(ImVector<ImVec2>* path, float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4, float tess_tol, int level)
 {
     float dx = x4 - x1;
@@ -933,7 +944,6 @@ static void PathBezierToCasteljau(ImVector<ImVec2>* path, float x1, float y1, fl
         float x123 = (x12+x23)*0.5f,    y123 = (y12+y23)*0.5f;
         float x234 = (x23+x34)*0.5f,    y234 = (y23+y34)*0.5f;
         float x1234 = (x123+x234)*0.5f, y1234 = (y123+y234)*0.5f;
-
         PathBezierToCasteljau(path, x1,y1,        x12,y12,    x123,y123,  x1234,y1234, tess_tol, level+1);
         PathBezierToCasteljau(path, x1234,y1234,  x234,y234,  x34,y34,    x4,y4,       tess_tol, level+1);
     }
@@ -944,22 +954,13 @@ void ImDrawList::PathBezierCurveTo(const ImVec2& p2, const ImVec2& p3, const ImV
     ImVec2 p1 = _Path.back();
     if (num_segments == 0)
     {
-        // Auto-tessellated
+        PathBezierToCasteljau(&_Path, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, _Data->CurveTessellationTol, 0); // Auto-tessellated
-        PathBezierToCasteljau(&_Path, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, _Data->CurveTessellationTol, 0);
     }
     else
     {
         float t_step = 1.0f / (float)num_segments;
         for (int i_step = 1; i_step <= num_segments; i_step++)
-        {
+            _Path.push_back(ImBezierCalc(p1, p2, p3, p4, t_step * i_step));
-            float t = t_step * i_step;
-            float u = 1.0f - t;
-            float w1 = u*u*u;
-            float w2 = 3*u*u*t;
-            float w3 = 3*u*t*t;
-            float w4 = t*t*t;
-            _Path.push_back(ImVec2(w1*p1.x + w2*p2.x + w3*p3.x + w4*p4.x, w1*p1.y + w2*p2.y + w3*p3.y + w4*p4.y));
-        }
     }
 }
 
@@ -1134,13 +1135,14 @@ void ImDrawList::AddNgonFilled(const ImVec2& center, float radius, ImU32 col, in
     PathFillConvex(col);
 }
 
-void ImDrawList::AddBezierCurve(const ImVec2& pos0, const ImVec2& cp0, const ImVec2& cp1, const ImVec2& pos1, ImU32 col, float thickness, int num_segments)
+// Cubic Bezier takes 4 controls points
+void ImDrawList::AddBezierCurve(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, ImU32 col, float thickness, int num_segments)
 {
     if ((col & IM_COL32_A_MASK) == 0)
         return;
 
-    PathLineTo(pos0);
+    PathLineTo(p1);
-    PathBezierCurveTo(cp0, cp1, pos1, num_segments);
+    PathBezierCurveTo(p2, p3, p4, num_segments);
     PathStroke(col, false, thickness);
 }
 

imgui_internal.h

@@ -203,6 +203,8 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 
 //-----------------------------------------------------------------------------
 // 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: Bit manipulation
@@ -349,6 +351,9 @@ static inline float  ImLinearSweep(float current, float target, float speed)
 static inline ImVec2 ImMul(const ImVec2& lhs, const ImVec2& rhs)                { return ImVec2(lhs.x * rhs.x, lhs.y * rhs.y); }
 
 // Helpers: Geometry
+IMGUI_API ImVec2     ImBezierCalc(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, float t);                                         // Cubic Bezier
+IMGUI_API ImVec2     ImBezierClosestPoint(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, int num_segments);       // For curves with explicit number of segments
+IMGUI_API ImVec2     ImBezierClosestPointCasteljau(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, float tess_tol);// For auto-tessellated curves you can use tess_tol = style.CurveTessellationTol
 IMGUI_API ImVec2     ImLineClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& p);
 IMGUI_API bool       ImTriangleContainsPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p);
 IMGUI_API ImVec2     ImTriangleClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p);

imgui_widgets.cpp

@@ -1266,21 +1266,14 @@ void ImGui::SeparatorEx(ImGuiSeparatorFlags flags)
         // We don't provide our width to the layout so that it doesn't get feed back into AutoFit
         const ImRect bb(ImVec2(x1, window->DC.CursorPos.y), ImVec2(x2, window->DC.CursorPos.y + thickness_draw));
         ItemSize(ImVec2(0.0f, thickness_layout));
-        if (!ItemAdd(bb, 0))
+        const bool item_visible = ItemAdd(bb, 0);
-        {
+        if (item_visible)
-            if (columns)
         {
-                PopColumnsBackground();
-                columns->LineMinY = window->DC.CursorPos.y;
-            }
-            return;
-        }
-
             // Draw
             window->DrawList->AddLine(bb.Min, ImVec2(bb.Max.x, bb.Min.y), GetColorU32(ImGuiCol_Separator));
             if (g.LogEnabled)
                 LogRenderedText(&bb.Min, "--------------------------------");
-
+        }
         if (columns)
         {
             PopColumnsBackground();
@@ -7528,7 +7521,7 @@ void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiColumnsFlag
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = GetCurrentWindow();
 
-    IM_ASSERT(columns_count >= 1);
+    IM_ASSERT(columns_count >= 1 && columns_count <= 64);   // Maximum 64 columns
     IM_ASSERT(window->DC.CurrentColumns == NULL);           // Nested columns are currently not supported
 
     // Acquire storage for the columns set