Internals: Menus: minor tidying up + renaming in ImGuiMenuColumns + removing extraneous offset field which is always zero + using smaller types.

sizeof() 36 -> 20

imgui.cpp

@@ -6266,7 +6266,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->DC.NavHasScroll = (window->ScrollMax.y > 0.0f);
 
         window->DC.MenuBarAppending = false;
-        window->DC.MenuColumns.Update(3, style.ItemSpacing.x, window_just_activated_by_user);
+        window->DC.MenuColumns.Update(style.ItemSpacing.x, window_just_activated_by_user);
         window->DC.TreeDepth = 0;
         window->DC.TreeJumpToParentOnPopMask = 0x00;
         window->DC.ChildWindows.resize(0);

imgui_demo.cpp

@@ -1168,7 +1168,7 @@ static void ShowDemoWindowWidgets()
         {
             static bool selected[10] = {};
 
-            if (ImGui::BeginTable("split1", 3, ImGuiTableFlags_Resizable | ImGuiTableFlags_NoSavedSettings))
+            if (ImGui::BeginTable("split1", 3, ImGuiTableFlags_Resizable | ImGuiTableFlags_NoSavedSettings | ImGuiTableFlags_Borders))
             {
                 for (int i = 0; i < 10; i++)
                 {
@@ -1179,8 +1179,8 @@ static void ShowDemoWindowWidgets()
                 }
                 ImGui::EndTable();
             }
-            ImGui::Separator();
-            if (ImGui::BeginTable("split2", 3, ImGuiTableFlags_Resizable | ImGuiTableFlags_NoSavedSettings))
+            ImGui::Spacing();
+            if (ImGui::BeginTable("split2", 3, ImGuiTableFlags_Resizable | ImGuiTableFlags_NoSavedSettings | ImGuiTableFlags_Borders))
             {
                 for (int i = 0; i < 10; i++)
                 {

imgui_internal.h

@@ -1035,14 +1035,15 @@ struct IMGUI_API ImGuiGroupData
 // Simple column measurement, currently used for MenuItem() only.. This is very short-sighted/throw-away code and NOT a generic helper.
 struct IMGUI_API ImGuiMenuColumns
 {
-    float       Spacing;
-    float       Width, NextWidth;
-    float       Pos[3], NextWidths[3];
+    ImU32       TotalWidth;
+    ImU32       NextTotalWidth;
+    ImU16       Spacing;
+    ImU16       Offsets[2];         // Offset of:         Shortcut, Check mark (locked in Update)
+    ImU16       Widths[3];          // Width of:   Label, Shortcut, Check mark (accumulator for current frame)
 
     ImGuiMenuColumns() { memset(this, 0, sizeof(*this)); }
-    void        Update(int count, float spacing, bool clear);
-    float       DeclColumns(float w0, float w1, float w2);
-    float       CalcExtraSpace(float avail_w) const;
+    void        Update(float spacing, bool window_reappearing);
+    float       DeclColumns(float w_label, float w_shortcut, float w_checkmark);
 };
 
 // Internal state of the currently focused/edited text input box

imgui_widgets.cpp

@@ -6591,38 +6591,32 @@ void ImGui::Value(const char* prefix, float v, const char* float_format)
 //-------------------------------------------------------------------------
 
 // Helpers for internal use
-void ImGuiMenuColumns::Update(int count, float spacing, bool clear)
+void ImGuiMenuColumns::Update(float spacing, bool window_reappearing)
 {
-    IM_ASSERT(count == IM_ARRAYSIZE(Pos));
-    IM_UNUSED(count);
-    Width = NextWidth = 0.0f;
-    Spacing = spacing;
-    if (clear)
-        memset(NextWidths, 0, sizeof(NextWidths));
-    for (int i = 0; i < IM_ARRAYSIZE(Pos); i++)
+    if (window_reappearing)
+        memset(Widths, 0, sizeof(Widths));
+    TotalWidth = NextTotalWidth = 0;
+    Spacing = (ImU16)spacing;
+    for (int i = 0; i < IM_ARRAYSIZE(Widths); i++)
     {
-        if (i > 0 && NextWidths[i] > 0.0f)
-            Width += Spacing;
-        Pos[i] = IM_FLOOR(Width);
-        Width += NextWidths[i];
-        NextWidths[i] = 0.0f;
+        if (i > 0 && Widths[i] > 0)
+            TotalWidth += Spacing;
+        if (i > 0)
+            Offsets[i - 1] = (ImU16)TotalWidth;
+        TotalWidth += Widths[i];
+        Widths[i] = 0;
     }
 }
 
-float ImGuiMenuColumns::DeclColumns(float w0, float w1, float w2) // not using va_arg because they promote float to double
-{
-    NextWidth = 0.0f;
-    NextWidths[0] = ImMax(NextWidths[0], w0);
-    NextWidths[1] = ImMax(NextWidths[1], w1);
-    NextWidths[2] = ImMax(NextWidths[2], w2);
-    for (int i = 0; i < IM_ARRAYSIZE(Pos); i++)
-        NextWidth += NextWidths[i] + ((i > 0 && NextWidths[i] > 0.0f) ? Spacing : 0.0f);
-    return ImMax(Width, NextWidth);
-}
-
-float ImGuiMenuColumns::CalcExtraSpace(float avail_w) const
+float ImGuiMenuColumns::DeclColumns(float w_label, float w_shortcut, float w_checkmark)
 {
-    return ImMax(0.0f, avail_w - Width);
+    Widths[0] = ImMax(Widths[0], (ImU16)w_label);
+    Widths[1] = ImMax(Widths[1], (ImU16)w_shortcut);
+    Widths[2] = ImMax(Widths[2], (ImU16)w_checkmark);
+    NextTotalWidth = 0;
+    for (int i = 0; i < IM_ARRAYSIZE(Widths); i++)
+        NextTotalWidth += Widths[i] + ((i > 0 && Widths[i] > 0) ? Spacing : 0);
+    return (float)ImMax(TotalWidth, NextTotalWidth);
 }
 
 // FIXME: Provided a rectangle perhaps e.g. a BeginMenuBarEx() could be used anywhere..
@@ -6835,7 +6829,7 @@ bool ImGui::BeginMenu(const char* label, bool enabled)
         float extra_w = ImMax(0.0f, GetContentRegionAvail().x - min_w);
         pressed = Selectable(label, menu_is_open, ImGuiSelectableFlags_NoHoldingActiveID | ImGuiSelectableFlags_SelectOnClick | ImGuiSelectableFlags_DontClosePopups | ImGuiSelectableFlags_SpanAvailWidth | (!enabled ? ImGuiSelectableFlags_Disabled : 0), ImVec2(min_w, 0.0f));
         ImU32 text_col = GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled);
-        RenderArrow(window->DrawList, pos + ImVec2(window->DC.MenuColumns.Pos[2] + extra_w + g.FontSize * 0.30f, 0.0f), text_col, ImGuiDir_Right);
+        RenderArrow(window->DrawList, pos + ImVec2(window->DC.MenuColumns.Offsets[1] + extra_w + g.FontSize * 0.30f, 0.0f), text_col, ImGuiDir_Right);
     }
 
     const bool hovered = enabled && ItemHoverable(window->DC.LastItemRect, id);
@@ -6988,11 +6982,11 @@ bool ImGui::MenuItem(const char* label, const char* shortcut, bool selected, boo
         if (shortcut_w > 0.0f)
         {
             PushStyleColor(ImGuiCol_Text, g.Style.Colors[ImGuiCol_TextDisabled]);
-            RenderText(pos + ImVec2(window->DC.MenuColumns.Pos[1] + extra_w, 0.0f), shortcut, NULL, false);
+            RenderText(pos + ImVec2(window->DC.MenuColumns.Offsets[0] + extra_w, 0.0f), shortcut, NULL, false);
             PopStyleColor();
         }
         if (selected)
-            RenderCheckMark(window->DrawList, pos + ImVec2(window->DC.MenuColumns.Pos[2] + extra_w + g.FontSize * 0.40f, g.FontSize * 0.134f * 0.5f), GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled), g.FontSize  * 0.866f);
+            RenderCheckMark(window->DrawList, pos + ImVec2(window->DC.MenuColumns.Offsets[1] + extra_w + g.FontSize * 0.40f, g.FontSize * 0.134f * 0.5f), GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled), g.FontSize  * 0.866f);
     }
 
     IMGUI_TEST_ENGINE_ITEM_INFO(window->DC.LastItemId, label, window->DC.LastItemStatusFlags | ImGuiItemStatusFlags_Checkable | (selected ? ImGuiItemStatusFlags_Checked : 0));