Updated ImGui.

3rdparty/dear-imgui/imgui.cpp

@@ -37,9 +37,14 @@ DOCUMENTATION
   - Using gamepad/keyboard navigation controls.
 - API BREAKING CHANGES (read me when you update!)
 - FREQUENTLY ASKED QUESTIONS (FAQ), TIPS
+  - Where is the documentation?
+  - Which version should I get?
+  - Who uses Dear ImGui?
+  - Why the odd dual naming, "Dear ImGui" vs "ImGui"?
   - How can I tell whether to dispatch mouse/keyboard to imgui or to my application?
   - How can I display an image? What is ImTextureID, how does it works?
-  - How can I have multiple widgets with the same label or with an empty label? A primer on labels and the ID Stack.
+  - Why are multiple widgets reacting when I interact with a single one? How can I have
+    multiple widgets with the same label or with an empty label? A primer on labels and the ID Stack...
   - How can I use my own math types instead of ImVec2/ImVec4?
   - How can I load a different font than the default?
   - How can I easily use icons in my application?
@@ -552,6 +557,39 @@ CODE
  FREQUENTLY ASKED QUESTIONS (FAQ), TIPS
  ======================================
 
+ Q: Where is the documentation?
+ A: This library is poorly documented at the moment and expects of the user to be acquainted with C/C++.
+    - Run the examples/ and explore them.
+    - See demo code in imgui_demo.cpp and particularly the ImGui::ShowDemoWindow() function. 
+    - The demo covers most features of Dear ImGui, so you can read the code and see its output. 
+    - See documentation and comments at the top of imgui.cpp + effectively imgui.h.
+    - Dozens of standalone example applications using e.g. OpenGL/DirectX are provided in the examples/ 
+      folder to explain how to integrate Dear ImGui with your own engine/application.
+    - Your programming IDE is your friend, find the type or function declaration to find comments 
+      associated to it.
+
+ Q: Which version should I get?
+ A: I occasionally tag Releases (https://github.com/ocornut/imgui/releases) but it is generally safe 
+    and recommended to sync to master/latest. The library is fairly stable and regressions tend to be 
+    fixed fast when reported. You may also peak at the 'docking' branch which includes:
+    - Docking/Merging features (https://github.com/ocornut/imgui/issues/2109)
+    - Multi-viewport features (https://github.com/ocornut/imgui/issues/1542)
+    Many projects are using this branch and it is kept in sync with master regularly.
+
+ Q: Who uses Dear ImGui?
+ A: See "Quotes" (https://github.com/ocornut/imgui/wiki/Quotes) and
+    "Software using Dear ImGui" (https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) Wiki pages
+    for a list of games/software which are publicly known to use dear imgui. Please add yours if you can!
+
+ Q: Why the odd dual naming, "Dear ImGui" vs "ImGui"?
+ A: The library started its life as "ImGui" due to the fact that I didn't give it a proper name when 
+    when I released 1.0, and had no particular expectation that it would take off. However, the term IMGUI 
+    (immediate-mode graphical user interface) was coined before and is being used in variety of other 
+    situations (e.g. Unity uses it own implementation of the IMGUI paradigm). 
+    To reduce the ambiguity without affecting existing code bases, I have decided on an alternate, 
+    longer name "Dear ImGui" that people can use to refer to this specific library.
+    Please try to refer to this library as "Dear ImGui".
+
  Q: How can I tell whether to dispatch mouse/keyboard to imgui or to my application?
  A: You can read the 'io.WantCaptureMouse', 'io.WantCaptureKeyboard' and 'io.WantTextInput' flags from the ImGuiIO structure (e.g. if (ImGui::GetIO().WantCaptureMouse) { ... } )
     - When 'io.WantCaptureMouse' is set, imgui wants to use your mouse state, and you may want to discard/hide the inputs from the rest of your application.
@@ -653,8 +691,8 @@ CODE
 
     Finally, you may call ImGui::ShowMetricsWindow() to explore/visualize/understand how the ImDrawList are generated.
 
+ Q: Why are multiple widgets reacting when I interact with a single one?
  Q: How can I have multiple widgets with the same label or with an empty label?
- Q: I have multiple widgets with the same label, and only the first one works. Why is that?
  A: A primer on labels and the ID Stack...
 
     Dear ImGui internally need to uniquely identify UI elements.

3rdparty/dear-imgui/imgui_internal.h

@@ -344,7 +344,8 @@ enum ImGuiSelectableFlagsPrivate_
     ImGuiSelectableFlags_NoHoldingActiveID  = 1 << 10,
     ImGuiSelectableFlags_PressedOnClick     = 1 << 11,
     ImGuiSelectableFlags_PressedOnRelease   = 1 << 12,
-    ImGuiSelectableFlags_DrawFillAvailWidth = 1 << 13
+    ImGuiSelectableFlags_DrawFillAvailWidth = 1 << 13,
+    ImGuiSelectableFlags_AllowItemOverlap   = 1 << 14
 };
 
 enum ImGuiSeparatorFlags_

3rdparty/dear-imgui/imgui_widgets.cpp

@@ -642,7 +642,7 @@ bool ImGui::ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size, ImGuiBu
     const ImGuiID id = window->GetID(str_id);
     const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
     const float default_size = GetFrameHeight();
-    ItemSize(bb, (size.y >= default_size) ? g.Style.FramePadding.y : 0.0f);
+    ItemSize(size, (size.y >= default_size) ? g.Style.FramePadding.y : 0.0f);
     if (!ItemAdd(bb, id))
         return false;
 
@@ -1040,8 +1040,9 @@ void ImGui::ProgressBar(float fraction, const ImVec2& size_arg, const char* over
     const ImGuiStyle& style = g.Style;
 
     ImVec2 pos = window->DC.CursorPos;
-    ImRect bb(pos, pos + CalcItemSize(size_arg, CalcItemWidth(), g.FontSize + style.FramePadding.y*2.0f));
-    ItemSize(bb, style.FramePadding.y);
+    ImVec2 size = CalcItemSize(size_arg, CalcItemWidth(), g.FontSize + style.FramePadding.y*2.0f);
+    ImRect bb(pos, pos + size);
+    ItemSize(size, style.FramePadding.y);
     if (!ItemAdd(bb, 0))
         return;
 
@@ -1114,7 +1115,7 @@ void ImGui::Dummy(const ImVec2& size)
         return;
 
     const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
-    ItemSize(bb);
+    ItemSize(size);
     ItemAdd(bb, 0);
 }
 
@@ -5275,7 +5276,7 @@ bool ImGui::Selectable(const char* label, bool selected, ImGuiSelectableFlags fl
     ImVec2 pos = window->DC.CursorPos;
     pos.y += window->DC.CurrentLineTextBaseOffset;
     ImRect bb_inner(pos, pos + size);
-    ItemSize(bb_inner);
+    ItemSize(size);
 
     // Fill horizontal space.
     ImVec2 window_padding = window->WindowPadding;
@@ -5322,6 +5323,8 @@ bool ImGui::Selectable(const char* label, bool selected, ImGuiSelectableFlags fl
     if (flags & ImGuiSelectableFlags_PressedOnRelease) button_flags |= ImGuiButtonFlags_PressedOnRelease;
     if (flags & ImGuiSelectableFlags_Disabled) button_flags |= ImGuiButtonFlags_Disabled;
     if (flags & ImGuiSelectableFlags_AllowDoubleClick) button_flags |= ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnDoubleClick;
+    if (flags & ImGuiSelectableFlags_AllowItemOverlap) button_flags |= ImGuiButtonFlags_AllowItemOverlap;
+
     if (flags & ImGuiSelectableFlags_Disabled)
         selected = false;
 
@@ -5337,6 +5340,9 @@ bool ImGui::Selectable(const char* label, bool selected, ImGuiSelectableFlags fl
     if (pressed)
         MarkItemEdited(id);
 
+    if (flags & ImGuiSelectableFlags_AllowItemOverlap)
+        SetItemAllowOverlap();
+
     // Render
     if (hovered || selected)
     {