CIRCLE

Description

For use with graphics windows and graphicboxes, CIRCLE draws the outline of a circle shape with a radius r at the current pen position.

There are five graphics commands that draw shapes:

box

circle

ellipse

line

pie

Syntax

This command is NOT case sensitive.

Using literal values

1. #handle "circle r" - a graphics window
2. #handle.ext "circle r" - a graphic box

Using variable values

1. #handle "circle "; r
2. #handle.ext "circle "; r

r is the radius of the circle.

Hints

• Color & Size. Shapes are drawn with a pen color set by the color command and a line thickness set by the size command.
• Filled Shapes. You cannot draw a shape and then fill it with color. (The fill command is used to fill the graphics window with color). Instead, to make a shape filled with color, use the complimentary shapefilled commands:
  • boxfilled
  • circlefilled
  • ellipsefilled
  • piefilled

Example

An example of the command using a graphics window

nomainwin

    WindowWidth=400
    WindowHeight=300

    open "Draw Circle Demo" for graphics_nsb_nf as #g
    #g "trapclose [quit]"
    'put the pen down
    #g "down"
    'place pen at the center of the circle
    #g "place 100 150"
    'draw a circle with a radius of 63 pixels
    #g "circle 63"

    wait

[quit]
    close #g
    end

An example of the command using a graphicbox

nomainwin

    WindowWidth=400
    WindowHeight=300

    graphicbox #g.gb, 2, 2, 390, 270
    open "Draw Circle Demo" for graphics_nsb_nf as #g
    #g "trapclose [quit]"
    'put the pen down
    #g.gb "down"
    'set pen color and size for shape
    #g.gb "color blue; size 3"
    'set a point at the center of the circle
    #g.gb "set 100 150"
    'draw a circle with a radius of 63 pixels
    #g.gb "circle 63"

    wait

[quit]
    close #g
    end

An example combining four shape commands in a graphics window

     nomainwin

    WindowWidth=400
    WindowHeight=300

    open "All Shapes Demo" for graphics_nsb_nf as #g
    #g "trapclose [quit]"

    'put the pen down
    #g "down"
    'set the pen color and size
    #g "color blue; size 2"
    'place and draw a box
    #g "place 10 10; box 150 150"
    'place and draw a circle
    #g "place 80 80; circle 40"
    'place and draw an ellipse
    #g "place 200 200; ellipse 100 50"
    'change pen color and size
    #g "color red; size 1"
    'draw a line
    #g "line 10 10 200 200"
    #g "flush" 'make graphics stick
    wait

[quit]
    close #g
    end

Useful Procedures

' Place a useful function using this keyword here