ellipse
Entity: predicate

draw_chord
Entity: predicate

draw_pie
Entity: predicate

draw_arc
Entity: predicate

Usage:
ellipse(X1, Y1, X2, Y2)

Draws an ellipse bounded by the rectangle with the upper left corner ( X1,Y1 ) and the lower right corner ( X2,Y2 ). The border line is drawn using the current pen , and the ellipse is filled using the current brush .

Usage:
draw_chord(X1, Y1, X2, Y2, Px, Py, Qx, Qy)

Usage:
draw_pie(X1, Y1, X2, Y2, Px, Py, Qx, Qy)

Usage:
draw_arc(X1, Y1, X2, Y2, Px, Py, Qx, Qy)

These predicates draw a chord, a pie and an arc respectively. First four arguments give ellipse bounded by the rectangle with the upper left corner ( X1,Y1 ) and the lower right corner ( X2,Y2 ). The next four arguments give two radial's endpoints ( P and Q ). If the P and Q are the same then an ellipse will be drawn. If you want the other part of the figure (not the one drawn) then replace P and Q . The border line is drawn using the current pen , and the figure is filled (only for chord and pie ) using the current brush.

All these predicates fail if any of their arguments is not a number.

Example:

?-window(_, _, win_func(_), "Ellipse demo", 100, 100, 200, 200).

win_func(paint):-ellipse(0,0,200,200).

See also:

rect
line