UNIT:  GRAPH

    USES:  Plotting points, Line drawing, Stroke font text, turtle graphics,
           arcs, circles, patterns, and fills for many graphic adapters.

    GRAPHIC DRIVERS: CGA, MCGA, EGA, VGA, Hercules, AT & T 400, 3270 PC

                                  NOTE
    To compile a program that uses procedures or functions of the graph unit
    be sure to include the appropriate graphics driver and/or font driver in
    the default path.  The graph drivers are separate files with the (.BGI)
    extension and the font files are also separate files with the (.CHR)
    file extension.


    PROCEDURES/FUNCTIONS:

       Arc             : Draws an arc using (X,Y) as the center point.
       Bar             : Draws a bar using the current fill and color.
       Bar3D           : Draws a 3-D bar using the current fill and color.
       Circle          : Draws a circle.
       ClearDevice     : Clears and readies the currently selected output
                         device.
       ClearViewPort   : Clears the current viewport.
       CloseGraph      : Closes the graphic system.
       DetectGraph     : Determines the graphics driver and mode to use
                         through hardware checks.
       DrawPoly        : Draws a polygon using the current line style and
                         color.
       Ellipse         : Draws an ellipse using (X,Y) as the center point.
       FillPoly        : Fills a polygon using the current fill and color.
       FloodFill       : Fills a bounded area with the current flood pattern.
       GetArcCoords    : Returns information about the last arc command.
       GetAspectRatio  : Returns the effective resolution of the screen.
                         From this the aspect ration is computed. (Xasp, YAsp)
       GetBkColor      : Returns the current background color.
       GetColor        : Returns the current color used for drawing.
       GetFillSettings : Returns information about the current fill pattern
                         and color.
       GetGraphMode    : Returns the current graphic mode.
       GetImage        : Saves a specified image into a buffer.
       GetLineSettings : Returns information on the current line style,
                         pattern, size, and color.
       GetMaxX         : Returns the maximum X value of the current driver
                         and mode.
       GetMaxY         : Returns the maximum Y value of the current driver
                         and mode.
       GetPalette      : Returns information on the current palette.
       GetPixel        : Returns the pixel value of (X,Y).
       GetTextSettings : Returns information on the current text settings.
       GetViewSettings : Returns information on the current viewport.
       GetX            : Returns the X coordinate of the current position.
       GetY            : Returns the Y coordinate of the current position.
       GraphErrorMsg   : Returns the error message string for the specified
                         error message code (ErrorCode).
       GraphResult     : Returns the error value of the last graphics
                         operation.
       ImageSize       : Returns the size in bytes required to store a
                         specified rectangular area of the screen.
       InitGraph       : Initializes the graphic system.
       Line            : Draws a line.
       LineRel         : Draws a line a relative distance from the current
                         pointer.
       LineTo          : Draws a line from the current pointer to (X,Y).
       MoveRel         : Moves the current pointer a relative distance.
       MoveTo          : Moves the current pointer to (X,Y).
       OutText         : Outputs text to the current output device.
       OutTextXY       : Outputs text starting at (X,Y).
       PieSlice        : Draws a pie slice using (X,Y) as the center.
       PutImage        : Places a bitimage onto the screen.
       PutPixel        : Places a pixel at (X,Y).
       Rectangle       : Draws a rectangle.
       RestoreCrt      : Returns the CRT to the original mode detected at
                         startup.
       RestoreCrtMode  : Restores the screen mode detected before graphics
                         was initialized.
       SetActivePage   : Sets the active page.
       SetAllPalette   : Changes all palette colors.
       SetBkColor      : Sets the background color.
       SetColor        : Sets the color for drawing.
       SetFillPattern  : Selects the pattern used for filling.
       SetFillStyle    : Sets the pattern used for filling.
       SetGraphMode    : Sets the system into a specified graphics mode.
       SetLineStyle    : Sets the current line width and line style.
       SetPalette      : Changes a specified color palette.
       SetTextJustify  : Sets text justification.
       SetTextStyle    : Sets the text font, style, and size.
       SetViewPort     : Sets the currents window for graphics.
       SetVisualPage   : Sets the graphics page.
       TextHeight      : Returns the height of the text.
       TextWidth       : Returns the width of the text.



                                  NOTE
    Due to the complexities and variations of the procedures and functions
    of the graphics unit, only a brief listing will be given here.  For
    more information see the Turbo Pascal Reference manual, pages 309 - 323
    and chapter 27.