Interactive creation of a circle.
draw_circle produces the parameter for a circle created interactive by the user in the current window.
To create a circle you have to press the mouse button at the location which is used as the center of that circle. While keeping the mouse button pressed, the Radius's length can be modified through moving the mouse. After another mouse click in the created circle's center you can move it any desired. A click close to the circular arc "grips" the circle to modify the Radius. Pressing the right mousebutton terminates the procedure. After terminating the procedure the circle is not visible in the window any longer.
Row (output_control) |
circle.center.y -> integer |
barycenter's row index. |
Column (output_control) |
circle.center.x -> integer |
barycenter's column index. |
Radius (output_control) |
circle.radius -> integer |
Circle's radius. |
read_image(:Image:'affe':) > draw_circle(:::Row,Column,Radius) > circle(:Circle:Row,Column,Radius:) > reduce_domain(Image,Circle:GreyCircle::) > disp_image(GreyCircle:::).
draw_circle returns TRUE if a window is activated and if the needed drawing mode (see set_insert) is available. If necessary an exception is raised.
reduce_domain, disp_region, set_colored, set_line_width, set_draw, set_insert
circle, draw_rectangle1, draw_rectangle2, draw_polygon, set_insert