Method TablePushBackgroundChannel

src/imgui/imgui_tables.cpp:2462–2472

Bg2 is used by Selectable (and possibly other widgets) to render to the background. Unlike our Bg0/1 channel which we uses for RowBg/CellBg/Borders and where we guarantee all shapes to be CPU-clipped, the Bg2 channel being widgets-facing will rely on regular ClipRect.

// Bg2 is used by Selectable (and possibly other widgets) to render to the background.
// Unlike our Bg0/1 channel which we uses for RowBg/CellBg/Borders and where we guarantee all shapes to be CPU-clipped, the Bg2 channel being widgets-facing will rely on regular ClipRect.
void ImGui::TablePushBackgroundChannel()
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    ImGuiTable* table = g.CurrentTable;

    // Optimization: avoid SetCurrentChannel() + PushClipRect()
    table->HostBackupInnerClipRect = window->ClipRect;
    SetWindowClipRectBeforeSetChannel(window, table->Bg2ClipRectForDrawCmd);
    table->DrawSplitter->SetCurrentChannel(window->DrawList, table->Bg2DrawChannelCurrent);
}

void ImGui::TablePopBackgroundChannel()
{