Method TableDrawBorders

src/external/imgui/imgui_tables.cpp:2642–2724

FIXME-TABLE: This is a mess, need to redesign how we render borders (as some are also done in TableEndRow)

// FIXME-TABLE: This is a mess, need to redesign how we render borders (as some are also done in TableEndRow)
void ImGui::TableDrawBorders(ImGuiTable* table)
{
    ImGuiWindow* inner_window = table->InnerWindow;
    if (!table->OuterWindow->ClipRect.Overlaps(table->OuterRect))
        return;

    ImDrawList* inner_drawlist = inner_window->DrawList;
    table->DrawSplitter->SetCurrentChannel(inner_drawlist, TABLE_DRAW_CHANNEL_BG0);
    inner_drawlist->PushClipRect(table->Bg0ClipRectForDrawCmd.Min, table->Bg0ClipRectForDrawCmd.Max, false);

    // Draw inner border and resizing feedback
    ImGuiTableInstanceData* table_instance = TableGetInstanceData(table, table->InstanceCurrent);
    const float border_size = TABLE_BORDER_SIZE;
    const float draw_y1 = ImMax(table->InnerRect.Min.y, (table->FreezeRowsCount >= 1 ? table->InnerRect.Min.y : table->WorkRect.Min.y) + table->AngledHeadersHeight) + ((table->Flags & ImGuiTableFlags_BordersOuterH) ? 1.0f : 0.0f);
    const float draw_y2_body = table->InnerRect.Max.y;
    const float draw_y2_head = table->IsUsingHeaders ? ImMin(table->InnerRect.Max.y, (table->FreezeRowsCount >= 1 ? table->InnerRect.Min.y : table->WorkRect.Min.y) + table_instance->LastTopHeadersRowHeight) : draw_y1;
    if (table->Flags & ImGuiTableFlags_BordersInnerV)
    {
        for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
        {
            if (!IM_BITARRAY_TESTBIT(table->EnabledMaskByDisplayOrder, order_n))
                continue;

            const int column_n = table->DisplayOrderToIndex[order_n];
            ImGuiTableColumn* column = &table->Columns[column_n];
            const bool is_hovered = (table->HoveredColumnBorder == column_n);
            const bool is_resized = (table->ResizedColumn == column_n) && (table->InstanceInteracted == table->InstanceCurrent);
            const bool is_resizable = (column->Flags & (ImGuiTableColumnFlags_NoResize | ImGuiTableColumnFlags_NoDirectResize_)) == 0;
            const bool is_frozen_separator = (table->FreezeColumnsCount == order_n + 1);
            if (column->MaxX > table->InnerClipRect.Max.x && !is_resized)
                continue;

            // Decide whether right-most column is visible
            if (column->NextEnabledColumn == -1 && !is_resizable)
                if ((table->Flags & ImGuiTableFlags_SizingMask_) != ImGuiTableFlags_SizingFixedSame || (table->Flags & ImGuiTableFlags_NoHostExtendX))
                    continue;
            if (column->MaxX <= column->ClipRect.Min.x) // FIXME-TABLE FIXME-STYLE: Assume BorderSize==1, this is problematic if we want to increase the border size..
                continue;

            // Draw in outer window so right-most column won't be clipped
            // Always draw full height border when being resized/hovered, or on the delimitation of frozen column scrolling.
            float draw_y2 = (is_hovered || is_resized || is_frozen_separator || (table->Flags & (ImGuiTableFlags_NoBordersInBody | ImGuiTableFlags_NoBordersInBodyUntilResize)) == 0) ? draw_y2_body : draw_y2_head;
            if (draw_y2 > draw_y1)
                inner_drawlist->AddLine(ImVec2(column->MaxX, draw_y1), ImVec2(column->MaxX, draw_y2), TableGetColumnBorderCol(table, order_n, column_n), border_size);
        }
    }

    // Draw outer border
    // FIXME: could use AddRect or explicit VLine/HLine helper?
    if (table->Flags & ImGuiTableFlags_BordersOuter)
    {
        // Display outer border offset by 1 which is a simple way to display it without adding an extra draw call
        // (Without the offset, in outer_window it would be rendered behind cells, because child windows are above their
        // parent. In inner_window, it won't reach out over scrollbars. Another weird solution would be to display part
        // of it in inner window, and the part that's over scrollbars in the outer window..)
        // Either solution currently won't allow us to use a larger border size: the border would clipped.
        const ImRect outer_border = table->OuterRect;
        const ImU32 outer_col = table->BorderColorStrong;