Defines the screen coordinates within which graphics can be displayed.
VIEW [ [SCREEN ] (x1,y1)-(x2,y2) [, [ fill_color] [, border_present]]]
VIEW allows you to restrict graphics output to specific coordinates on the screen. Coordinates outside this range are not drawn.
The keyword SCREEN states that graphics coordinates are relative to the screen, not to the viewport.
xl and yl are the coordinates of one comer of the viewport; x2 and y2 are the coordinates of the opposite comer.
fill_color specifies the color with which to fill the viewport.
border_present is any numeric expression that, when present, directs VIEW to draw a border around the viewport.
If you omit all arguments, VIEW sets the viewport to the entire screen.
The SCREEN and RUN statements set the viewport back to the entire screen.
SCREEN 1
VIEW (0, 0)-(20, 20), 1, 2
LINE (10, 10)-(100, 100)