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LINE Statement Details
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LINE draws a line or box on the screen.
 
LINE [[STEP](x1,y1)] - [STEP](x2,y2) [,[color] [,[B[F]] [,style]]]
    ■ The argument color is the number of the color in which the line
      is drawn. See the ◄COLOR Statement Details►
      and ◄SCREEN Statement Details► for information
      about how to specify a color number in different screen modes.
    ■ The argument B draws a box with the points (x1,y1) and (x2,y2) as its
      diagonally opposite corners.
    ■ The argument BF draws a filled box in the selected color.
    ■ The argument style is a 16-bit integer mask used to put pixels on
      the screen.
 
Usage Notes
    ■ When coordinates specify a point that is not within the current
      viewport, the line segment to that point is drawn to the border
      of the viewpoint.
    ■ LINE reads the bits in style from left to right. If a bit is 0,
      then no point is plotted; if the bit is 1, a point is plotted.
      After plotting a point, LINE selects the next bit position in style.
    ■ Using the style argument is called "line styling."
    ■ Because a zero bit in style does not change the point on the screen,
      you may want to draw a background line before using styling so you
      can have a known background.
    ■ Style is used for normal lines and boxes, but has no effect on
      filled boxes.
    ■ STEP makes the specified coordinates relative to the most-recent
      point. For example, if the most-recent point referred to by the
      program were (10,10), the following would draw a line from (10,10)
      to the point with an x coordinate equal to 10 + 10 and a y coordinate
      equal to 10 + 5, or (20,15):
 
          LINE -STEP (10,5)
 
    ■ You can establish a new most-recent point by initializing the screen
      with the CLS and SCREEN statements. Using other graphics statements,
      (for example, PSET, PRESET, CIRCLE, or DRAW) will also establish a
      new most-recent point.
    ■ Variations of the STEP argument are shown below. For the following
      examples, assume that the last point plotted was (10,10):
 
        Statement                           Description
        ═════════════════════════════       ═════════════════════════════
        LINE -(50,50)                       Draws from (10,10) to (50,50)
        LINE -STEP(50,50)                   Draws from (10,10) to (60,60)
        LINE (25,25)-STEP(50,50)            Draws from (25,25) to (75,75)
        LINE STEP(25,25)-STEP(50,50)        Draws from (35,35) to (85,85)
        LINE STEP(25,25)-(50,50)            Draws from (35,35) to (50,50)