Dirty PartitionBox

function PartitionBox(B: TBox; Rows, Cols: Integer): TBoxArray;
var
  idx,x,y,BoxW,BoxH: Integer;
begin
  SetLength(Result, (Cols+1)*(Rows+1));
  BoxW := (B.x2 - B.x1 + 1) div Cols;
  BoxH := (B.y2 - B.y1 + 1) div Rows;
  for y:=0 to Rows-1 do
    for x:=0 to Cols-1 do
    begin
      idx := (Y * Cols) + X;
      Result[idx].x1 := B.x1 + (BoxW * x);
      Result[idx].y1 := B.y1 + (BoxH * y);
      Result[idx].x2 := B.x1 + (BoxW * x) + BoxW-1;
      Result[idx].y2 := B.y1 + (BoxH * y) + BoxH-1;
    end;
end;