Docking: Added DockingSeparatorSize to style: amends (#3481, #4721, #2522)

Add ImGuiStyleVar_DockingSeparatorSize + misc Docking related comments.

docs/CHANGELOG.txt

@@ -97,6 +97,16 @@ Other changes:
   Note that Linux/Mac still have inconsistent support for multi-viewports. If you want to help see https://github.com/ocornut/imgui/issues/2117.
 
 
+-----------------------------------------------------------------------
+ VERSION 1.89.8 WIP (In Progress)
+-----------------------------------------------------------------------
+
+Docking+Viewports Branch:
+
+- Docking: added style.DockingSeparatorSize, ImGuiStyleVar_DockingSeparatorSize. Now
+  also scaled by style.ScaleAllSizes(). (#3481, #4721, #2522) [@PossiblyAShrub, @wobbier]
+
+
 -----------------------------------------------------------------------
  VERSION 1.89.7 (Released 2023-07-04)
 -----------------------------------------------------------------------

imgui.cpp

@@ -1184,7 +1184,7 @@ ImGuiStyle::ImGuiStyle()
     SeparatorTextPadding    = ImVec2(20.0f,3.f);// Horizontal offset of text from each edge of the separator + spacing on other axis. Generally small values. .y is recommended to be == FramePadding.y.
     DisplayWindowPadding    = ImVec2(19,19);    // Window position are clamped to be visible within the display area or monitors by at least this amount. Only applies to regular windows.
     DisplaySafeAreaPadding  = ImVec2(3,3);      // If you cannot see the edge of your screen (e.g. on a TV) increase the safe area padding. Covers popups/tooltips as well regular windows.
-    DockingSplitterSize     = 2.0f;             // Thickness of border/padding between docked windows
+    DockingSeparatorSize    = 2.0f;             // Thickness of resizing border between docked windows
     MouseCursorScale        = 1.0f;             // Scale software rendered mouse cursor (when io.MouseDrawCursor is enabled). May be removed later.
     AntiAliasedLines        = true;             // Enable anti-aliased lines/borders. Disable if you are really tight on CPU/GPU.
     AntiAliasedLinesUseTex  = true;             // Enable anti-aliased lines/borders using textures where possible. Require backend to render with bilinear filtering (NOT point/nearest filtering).
@@ -1228,6 +1228,7 @@ void ImGuiStyle::ScaleAllSizes(float scale_factor)
     TabRounding = ImFloor(TabRounding * scale_factor);
     TabMinWidthForCloseButton = (TabMinWidthForCloseButton != FLT_MAX) ? ImFloor(TabMinWidthForCloseButton * scale_factor) : FLT_MAX;
     SeparatorTextPadding = ImFloor(SeparatorTextPadding * scale_factor);
+    DockingSeparatorSize = ImFloor(DockingSeparatorSize * scale_factor);
     DisplayWindowPadding = ImFloor(DisplayWindowPadding * scale_factor);
     DisplaySafeAreaPadding = ImFloor(DisplaySafeAreaPadding * scale_factor);
     MouseCursorScale = ImFloor(MouseCursorScale * scale_factor);
@@ -3151,6 +3152,7 @@ static const ImGuiDataVarInfo GStyleVarInfo[] =
     { ImGuiDataType_Float, 1, (ImU32)IM_OFFSETOF(ImGuiStyle, SeparatorTextBorderSize) },// ImGuiStyleVar_SeparatorTextBorderSize
     { ImGuiDataType_Float, 2, (ImU32)IM_OFFSETOF(ImGuiStyle, SeparatorTextAlign) },     // ImGuiStyleVar_SeparatorTextAlign
     { ImGuiDataType_Float, 2, (ImU32)IM_OFFSETOF(ImGuiStyle, SeparatorTextPadding) },   // ImGuiStyleVar_SeparatorTextPadding
+    { ImGuiDataType_Float, 1, (ImU32)IM_OFFSETOF(ImGuiStyle, DockingSeparatorSize) },   // ImGuiStyleVar_DockingSeparatorSize
 };
 
 const ImGuiDataVarInfo* ImGui::GetStyleVarInfo(ImGuiStyleVar idx)
@@ -15294,7 +15296,7 @@ void ImGui::DockContextEndFrame(ImGuiContext* ctx)
             if (node->LastFrameActive == g.FrameCount && node->IsVisible && node->HostWindow && node->IsLeafNode() && !node->IsBgDrawnThisFrame)
             {
                 ImRect bg_rect(node->Pos + ImVec2(0.0f, GetFrameHeight()), node->Pos + node->Size);
-                ImDrawFlags bg_rounding_flags = CalcRoundingFlagsForRectInRect(bg_rect, node->HostWindow->Rect(), g.Style.DockingSplitterSize);
+                ImDrawFlags bg_rounding_flags = CalcRoundingFlagsForRectInRect(bg_rect, node->HostWindow->Rect(), g.Style.DockingSeparatorSize);
                 node->HostWindow->DrawList->ChannelsSetCurrent(DOCKING_HOST_DRAW_CHANNEL_BG);
                 node->HostWindow->DrawList->AddRectFilled(bg_rect.Min, bg_rect.Max, node->LastBgColor, node->HostWindow->WindowRounding, bg_rounding_flags);
             }
@@ -16767,7 +16769,7 @@ static void ImGui::DockNodeUpdateTabBar(ImGuiDockNode* node, ImGuiWindow* host_w
     if (is_focused)
         node->LastFrameFocused = g.FrameCount;
     ImU32 title_bar_col = GetColorU32(host_window->Collapsed ? ImGuiCol_TitleBgCollapsed : is_focused ? ImGuiCol_TitleBgActive : ImGuiCol_TitleBg);
-    ImDrawFlags rounding_flags = CalcRoundingFlagsForRectInRect(title_bar_rect, host_window->Rect(), g.Style.DockingSplitterSize);
+    ImDrawFlags rounding_flags = CalcRoundingFlagsForRectInRect(title_bar_rect, host_window->Rect(), g.Style.DockingSeparatorSize);
     host_window->DrawList->AddRectFilled(title_bar_rect.Min, title_bar_rect.Max, title_bar_col, host_window->WindowRounding, rounding_flags);
 
     // Docking/Collapse button
@@ -17249,7 +17251,7 @@ static void ImGui::DockNodePreviewDockRender(ImGuiWindow* host_window, ImGuiDock
             overlay_rect.Min.y += GetFrameHeight();
         if (data->SplitDir != ImGuiDir_None || data->IsCenterAvailable)
             for (int overlay_n = 0; overlay_n < overlay_draw_lists_count; overlay_n++)
-                overlay_draw_lists[overlay_n]->AddRectFilled(overlay_rect.Min, overlay_rect.Max, overlay_col_main, host_window->WindowRounding, CalcRoundingFlagsForRectInRect(overlay_rect, host_window->Rect(), g.Style.DockingSplitterSize));
+                overlay_draw_lists[overlay_n]->AddRectFilled(overlay_rect.Min, overlay_rect.Max, overlay_col_main, host_window->WindowRounding, CalcRoundingFlagsForRectInRect(overlay_rect, host_window->Rect(), g.Style.DockingSeparatorSize));
     }
 
     // Display tab shape/label preview unless we are splitting node (it generally makes the situation harder to read)
@@ -17366,7 +17368,7 @@ void ImGui::DockNodeTreeSplit(ImGuiContext* ctx, ImGuiDockNode* parent_node, ImG
     parent_node->VisibleWindow = NULL;
     parent_node->AuthorityForPos = parent_node->AuthorityForSize = ImGuiDataAuthority_DockNode;
 
-    float size_avail = (parent_node->Size[split_axis] - g.Style.DockingSplitterSize);
+    float size_avail = (parent_node->Size[split_axis] - g.Style.DockingSeparatorSize);
     size_avail = ImMax(size_avail, g.Style.WindowMinSize[split_axis] * 2.0f);
     IM_ASSERT(size_avail > 0.0f); // If you created a node manually with DockBuilderAddNode(), you need to also call DockBuilderSetNodeSize() before splitting.
     child_0->SizeRef = child_1->SizeRef = parent_node->Size;
@@ -17447,6 +17449,7 @@ void ImGui::DockNodeTreeUpdatePosSize(ImGuiDockNode* node, ImVec2 pos, ImVec2 si
 {
     // During the regular dock node update we write to all nodes.
     // 'only_write_to_single_node' is only set when turning a node visible mid-frame and we need its size right-away.
+    ImGuiContext& g = *GImGui;
     const bool write_to_node = only_write_to_single_node == NULL || only_write_to_single_node == node;
     if (write_to_node)
     {
@@ -17469,8 +17472,7 @@ void ImGui::DockNodeTreeUpdatePosSize(ImGuiDockNode* node, ImVec2 pos, ImVec2 si
 
     if (child_0_is_or_will_be_visible && child_1_is_or_will_be_visible)
     {
-        ImGuiContext& g = *GImGui;
-        const float spacing = g.Style.DockingSplitterSize;
+        const float spacing = g.Style.DockingSeparatorSize;
         const ImGuiAxis axis = (ImGuiAxis)node->SplitAxis;
         const float size_avail = ImMax(size[axis] - spacing, 0.0f);
 

imgui.h

@@ -819,9 +819,9 @@ namespace ImGui
     // - Drag from window menu button (upper-left button) to undock an entire node (all windows).
     // - When io.ConfigDockingWithShift == true, you instead need to hold SHIFT to _enable_ docking/undocking.
     // About dockspaces:
-    // - Use DockSpace() to create an explicit dock node _within_ an existing window. See Docking demo for details.
     // - Use DockSpaceOverViewport() to create an explicit dock node covering the screen or a specific viewport.
-    //   This is often used with ImGuiDockNodeFlags_PassthruCentralNode.
+    //   This is often used with ImGuiDockNodeFlags_PassthruCentralNode to make it transparent.
+    // - Use DockSpace() to create an explicit dock node _within_ an existing window. See Docking demo for details.
     // - Important: Dockspaces need to be submitted _before_ any window they can host. Submit it early in your frame!
     // - Important: Dockspaces need to be kept alive if hidden, otherwise windows docked into it will be undocked.
     //   e.g. if you have multiple tabs with a dockspace inside each tab: submit the non-visible dockspaces with ImGuiDockNodeFlags_KeepAliveOnly.
@@ -1723,6 +1723,7 @@ enum ImGuiStyleVar_
     ImGuiStyleVar_SeparatorTextBorderSize,// float  SeparatorTextBorderSize
     ImGuiStyleVar_SeparatorTextAlign,  // ImVec2    SeparatorTextAlign
     ImGuiStyleVar_SeparatorTextPadding,// ImVec2    SeparatorTextPadding
+    ImGuiStyleVar_DockingSeparatorSize,// float     DockingSeparatorSize
     ImGuiStyleVar_COUNT
 };
 
@@ -1992,7 +1993,7 @@ struct ImGuiStyle
     ImVec2      SeparatorTextPadding;       // Horizontal offset of text from each edge of the separator + spacing on other axis. Generally small values. .y is recommended to be == FramePadding.y.
     ImVec2      DisplayWindowPadding;       // Window position are clamped to be visible within the display area or monitors by at least this amount. Only applies to regular windows.
     ImVec2      DisplaySafeAreaPadding;     // If you cannot see the edges of your screen (e.g. on a TV) increase the safe area padding. Apply to popups/tooltips as well regular windows. NB: Prefer configuring your TV sets correctly!
-    float       DockingSplitterSize;        // Thickness of border/padding between docked windows
+    float       DockingSeparatorSize;       // Thickness of resizing border between docked windows
     float       MouseCursorScale;           // Scale software rendered mouse cursor (when io.MouseDrawCursor is enabled). We apply per-monitor DPI scaling over this scale. May be removed later.
     bool        AntiAliasedLines;           // Enable anti-aliased lines/borders. Disable if you are really tight on CPU/GPU. Latched at the beginning of the frame (copied to ImDrawList).
     bool        AntiAliasedLinesUseTex;     // Enable anti-aliased lines/borders using textures where possible. Require backend to render with bilinear filtering (NOT point/nearest filtering). Latched at the beginning of the frame (copied to ImDrawList).

imgui_demo.cpp

@@ -6379,7 +6379,7 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             ImGui::SliderFloat("LogSliderDeadzone", &style.LogSliderDeadzone, 0.0f, 12.0f, "%.0f");
 
             ImGui::SeparatorText("Docking");
-            ImGui::SliderFloat("DockingSplitterSize", &style.DockingSplitterSize, 0.0f, 12.0f, "%.0f");
+            ImGui::SliderFloat("DockingSplitterSize", &style.DockingSeparatorSize, 0.0f, 12.0f, "%.0f");
 
             ImGui::SeparatorText("Tooltips");
             for (int n = 0; n < 2; n++)
@@ -7953,18 +7953,20 @@ static void ShowExampleAppCustomRendering(bool* p_open)
 // your own implicit "Debug##2" window after calling DockSpace() and leave it in the window stack for anyone to use.
 void ShowExampleAppDockSpace(bool* p_open)
 {
-    // If you strip some features of, this demo is pretty much equivalent to calling DockSpaceOverViewport()!
-    // In most cases you should be able to just call DockSpaceOverViewport() and ignore all the code below!
-    // In this specific demo, we are not using DockSpaceOverViewport() because:
-    // - we allow the host window to be floating/moveable instead of filling the viewport (when opt_fullscreen == false)
-    // - we allow the host window to have padding (when opt_padding == true)
-    // - we have a local menu bar in the host window (vs. you could use BeginMainMenuBar() + DockSpaceOverViewport() in your code!)
-    // TL;DR; this demo is more complicated than what you would normally use.
-    // If we removed all the options we are showcasing, this demo would become:
+    // READ THIS !!!
+    // TL;DR; this demo is more complicated than what most users you would normally use.
+    // If we remove all options we are showcasing, this demo would become:
     //     void ShowExampleAppDockSpace()
     //     {
     //         ImGui::DockSpaceOverViewport(ImGui::GetMainViewport());
     //     }
+    // In most cases you should be able to just call DockSpaceOverViewport() and ignore all the code below!
+    // In this specific demo, we are not using DockSpaceOverViewport() because:
+    // - (1) we allow the host window to be floating/moveable instead of filling the viewport (when opt_fullscreen == false)
+    // - (2) we allow the host window to have padding (when opt_padding == true)
+    // - (3) we expose many flags and need a way to have them visible.
+    // - (4) we have a local menu bar in the host window (vs. you could use BeginMainMenuBar() + DockSpaceOverViewport()
+    //      in your code, but we don't here because we allow the window to be floating)
 
     static bool opt_fullscreen = true;
     static bool opt_padding = false;