class TPDF: public TVirtualPS

 Default PDF constructor

 Initialize the PDF interface

  fname : PDF file name
  wtype : PDF workstation type. Not used in the PDF driver. But as TPDF
          inherits from TVirtualPS it should be kept. Anyway it is not
          necessary to specify this parameter at creation time because it
          has a default value (which is ignore in the PDF case).

 Default PDF destructor

 Begin the Cell Array painting

 Paint the Cell Array

 End the Cell Array painting

 Close a PDF file

 Draw a Box

 Draw a Frame around a box

 mode = -1  box looks as it is behind the screen
 mode =  1  box looks as it is in front of the screen
 border is the border size in already precomputed PDF units
 dark  is the color for the dark part of the frame
 light is the color for the light part of the frame

 Draw Fill area with hatch styles

 Draw Fill area with hatch styles

 Draw a PolyLine

  Draw a polyline through  the points xy.
  If NN=1 moves only to point x,y.
  If NN=0 the x,y are  written  in the PDF file
     according to the current transformation.
  If NN>0 the line is clipped as a line.
  If NN<0 the line is clipped as a fill area.

 Draw a PolyLine in NDC space

  Draw a polyline through the points xy.
  If NN=1 moves only to point x,y.
  If NN=0 the x,y are  written in the PDF file
     according to the current transformation.
  If NN>0 the line is clipped as a line.
  If NN<0 the line is clipped as a fill area.

 Draw markers at the n WC points xw, yw

 Draw markers at the n WC points xw, yw

 Draw a PolyLine

  Draw a polyline through the points xw,yw.
  If nn=1 moves only to point xw,yw.
  If nn=0 the XW(1) and YW(1) are  written  in the PDF file
          according to the current NT.
  If nn>0 the line is clipped as a line.
  If nn<0 the line is clipped as a fill area.

 Draw a PolyLine

 Draw a polyline through  the points xw,yw.
 If nn=1 moves only to point xw,yw.
 If nn=0 the xw(1) and YW(1) are  written  in the PDF file
         according to the current NT.
 If nn>0 the line is clipped as a line.
 If nn<0 the line is clipped as a fill area.

 Font encoding

 Draw a line to a new position

 Move to a new position

 Create a new object in the PDF file

 Start a new PDF page.

 Deactivate an already open PDF file

 Activate an already open PDF file

 Open a PDF file

 Patterns encoding

 Output the string str in the output buffer

 Fast version of Print

 Set the range for the paper in centimetres

 Set the alpha channel value.

 Set color with its color index.

 Set color with its R G B components:

  r: % of red in [0,1]
  g: % of green in [0,1]
  b: % of blue in [0,1]

 Set color index for fill areas

 Set the fill patterns (1 to 25) for fill areas

 Set color index for lines

 Change the line style

 linestyle = 2 dashed
           = 3 dotted
           = 4 dash-dotted
           = else solid (1 in is used most of the time)

 Change the line width

 Set color index for markers.

 Set color index for text

 Draw text

 xx: x position of the text
 yy: y position of the text
 chars: text to be drawn

 Write a string of characters in NDC

 Convert U from NDC coordinate to PDF

 Convert V from NDC coordinate to PDF

 Convert X from world coordinate to PDF

 Convert Y from world coordinate to PDF

 Write the buffer in a compressed way

 Write a Real number to the file.
 This method overwrites TVirtualPS::WriteReal. Some PDF reader like
 Acrobat do not work when a PDF file contains reals with exponent. This
 method writes the real number "z" using the format "%f" instead of the
 format "%g" when writing it with "%g" generates a number with exponent.