Method DockNodeTreeSplit

imgui_tiny_app/imgui/imgui.cpp:20102–20144

//-----------------------------------------------------------------------------

void ImGui::DockNodeTreeSplit(ImGuiContext* ctx, ImGuiDockNode* parent_node, ImGuiAxis split_axis, int split_inheritor_child_idx, float split_ratio, ImGuiDockNode* new_node)
{
    ImGuiContext& g = *GImGui;
    IM_ASSERT(split_axis != ImGuiAxis_None);

    ImGuiDockNode* child_0 = (new_node && split_inheritor_child_idx != 0) ? new_node : DockContextAddNode(ctx, 0);
    child_0->ParentNode = parent_node;

    ImGuiDockNode* child_1 = (new_node && split_inheritor_child_idx != 1) ? new_node : DockContextAddNode(ctx, 0);
    child_1->ParentNode = parent_node;

    ImGuiDockNode* child_inheritor = (split_inheritor_child_idx == 0) ? child_0 : child_1;
    DockNodeMoveChildNodes(child_inheritor, parent_node);
    parent_node->ChildNodes[0] = child_0;
    parent_node->ChildNodes[1] = child_1;
    parent_node->ChildNodes[split_inheritor_child_idx]->VisibleWindow = parent_node->VisibleWindow;
    parent_node->SplitAxis = split_axis;
    parent_node->VisibleWindow = NULL;
    parent_node->AuthorityForPos = parent_node->AuthorityForSize = ImGuiDataAuthority_DockNode;

    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;
    child_0->SizeRef[split_axis] = ImTrunc(size_avail * split_ratio);
    child_1->SizeRef[split_axis] = ImTrunc(size_avail - child_0->SizeRef[split_axis]);

    DockNodeMoveWindows(parent_node->ChildNodes[split_inheritor_child_idx], parent_node);
    DockSettingsRenameNodeReferences(parent_node->ID, parent_node->ChildNodes[split_inheritor_child_idx]->ID);
    DockNodeUpdateHasCentralNodeChild(DockNodeGetRootNode(parent_node));
    DockNodeTreeUpdatePosSize(parent_node, parent_node->Pos, parent_node->Size);

    // Flags transfer (e.g. this is where we transfer the ImGuiDockNodeFlags_CentralNode property)
    child_0->SharedFlags = parent_node->SharedFlags & ImGuiDockNodeFlags_SharedFlagsInheritMask_;
    child_1->SharedFlags = parent_node->SharedFlags & ImGuiDockNodeFlags_SharedFlagsInheritMask_;
    child_inheritor->LocalFlags = parent_node->LocalFlags & ImGuiDockNodeFlags_LocalFlagsTransferMask_;
    parent_node->LocalFlags &= ~ImGuiDockNodeFlags_LocalFlagsTransferMask_;
    child_0->UpdateMergedFlags();
    child_1->UpdateMergedFlags();
    parent_node->UpdateMergedFlags();
    if (child_inheritor->IsCentralNode())
        DockNodeGetRootNode(parent_node)->CentralNode = child_inheritor;
}

void ImGui::DockNodeTreeMerge(ImGuiContext* ctx, ImGuiDockNode* parent_node, ImGuiDockNode* merge_lead_child)
{