Type keys to set the boolean operator and create new shapes. Newer shapes will be drawn on top of older ones.
Use tab to cycle through the existing shapes. Drag or click to move the selected shape around the screen and the delete key to remove it if desired.
For triangles and quadrilaterals, use space to cycle through the angles when it is selected. A small white dot indicates the current angle.
a : AND (cyan)
o : OR (green)
n : NOT (red)
x : XOR (yellow)
r : rectangle
s : square
q : quadrilateral
e : ellipse
c : circle
t : triangle
del : remove selected
tab : cycle selected
arrow keys: expand/shrink shape
space : cycle corners