gtk:bitset-add-rectangle (bitset start width height stride)

bitset -- a gtk:bitset instance
start -- an unsigned integer for the first value to add
width -- an unsigned integer for the width of the rectangle
height -- an unsigned integer for the height of the rectangle
stride -- an unsigned integer for the row stride of the grid

Interprets the values as a 2-dimensional boolean grid with the given stride and inside that grid, adds a rectangle with the given width and height. This funtion is equivalent to:

(dotimes (i height)
  (gtk:bitset-add-range bitset (+ (* i stride) start) width))