class TGX11: public TVirtualX

 Default constructor.

 Normal Constructor.

 Copy constructor. Currently only used by TGX11TTF.

 Destructor.

 Initialize X11 system. Returns kFALSE in case of failure.

 Allocate color in colormap. If we are on an <= 8 plane machine
 we will use XAllocColor. If we are on a >= 15 (15, 16 or 24) plane
 true color machine we will calculate the pixel value using:
 for 15 and 16 bit true colors have 6 bits precision per color however
 only the 5 most significant bits are used in the color index.
 Except for 16 bits where green uses all 6 bits. I.e.:
   15 bits = rrrrrgggggbbbbb
   16 bits = rrrrrggggggbbbbb
 for 24 bits each r, g and b are represented by 8 bits.

 Since all colors are set with a max of 65535 (16 bits) per r, g, b
 we just right shift them by 10, 11 and 10 bits for 16 planes, and
 (10, 10, 10 for 15 planes) and by 8 bits for 24 planes.
 Returns kFALSE in case color allocation failed.

 Returns the current RGB value for the pixel in the XColor structure.

 Clear the pixmap pix.

 Clear current window.

 Delete current pixmap.

 Delete current window.

 Delete current window.

 Copy the pixmap wid at the position xpos, ypos in the current window.

 Copy area of current window in the pixmap pix.

 Draw a box.
 mode=0 hollow  (kHollow)
 mode=1 solid   (kSolid)

 Draw a cell array.
 x1,y1        : left down corner
 x2,y2        : right up corner
 nx,ny        : array size
 ic           : array

 Draw a cell array. The drawing is done with the pixel presicion
 if (X2-X1)/NX (or Y) is not a exact pixel number the position of
 the top rigth corner may be wrong.

 Fill area described by polygon.
 n         : number of points
 xy(2,n)   : list of points

 Draw a line.
 x1,y1        : begin of line
 x2,y2        : end of line

 Draw a line through all points.
 n         : number of points
 xy        : list of points

 Draw n markers with the current attributes at position x, y.
 n    : number of markers to draw
 xy   : x,y coordinates of markers

 Draw a text string using current font.
 mode       : drawing mode
 mode=0     : the background is not drawn (kClear)
 mode=1     : the background is drawn (kOpaque)
 x,y        : text position
 angle      : text angle
 mgn        : magnification factor
 text       : text string

 Find best visual, i.e. the one with the most planes and TrueColor or
 DirectColor. Sets fVisual, fDepth, fRootWin, fColormap, fBlackPixel
 and fWhitePixel.

 Check if visual is usable, if so set fVisual, fDepth, fColormap,
 fBlackPixel and fWhitePixel.

 Return character up vector.

 Return reference to internal color structure associated
 to color index cid.

 Return current window pointer. Protected method used by TGX11TTF.

 Return desired Graphics Context ("which" maps directly on gGCList[]).
 Protected method used by TGX11TTF.

 Query the double buffer value for the window wid.

 Return position and size of window wid.
 wid        : window identifier
 x,y        : window position (output)
 w,h        : window size (output)
 if wid < 0 the size of the display is returned

 Return hostname on which the display is opened.

 Return pixel value associated to specified ROOT color number.

 Get maximum number of planes.

 Get rgb values for color "index".

 Return the size of a character string.
 iw          : text width
 ih          : text height
 mess        : message

 Return the X11 window identifier.
 wid      : Workstation identifier (input)

 Move the window wid.
 wid  : Window identifier.
 x    : x new window position
 y    : y new window position

 Open the display. Return -1 if the opening fails, 0 when ok.

 Open a new pixmap.
 w,h : Width and height of the pixmap.

 Open window and return window number.
 Return -1 if window initialization fails.

 Register a window created by Qt as a ROOT window (like InitWindow()).

 Remove a window created by Qt (like CloseWindow1()).

 Query pointer position.
 ix       : X coordinate of pointer
 iy       : Y coordinate of pointer
 (both coordinates are relative to the origin of the root window)

 Remove the pixmap pix.

 Request Locator position.
 x,y       : cursor position at moment of button press (output)
 ctyp      : cursor type (input)
   ctyp=1 tracking cross
   ctyp=2 cross-hair
   ctyp=3 rubber circle
   ctyp=4 rubber band
   ctyp=5 rubber rectangle

 mode      : input mode
   mode=0 request
   mode=1 sample

 Request locator:
 return button number  1 = left is pressed
                       2 = middle is pressed
                       3 = right is pressed
        in sample mode:
                      11 = left is released
                      12 = middle is released
                      13 = right is released
                      -1 = nothing is pressed or released
                      -2 = leave the window
                    else = keycode (keyboard is pressed)

 Request a string.
 x,y         : position where text is displayed
 text        : text displayed (input), edited text (output)

 Request string:
 text is displayed and can be edited with Emacs-like keybinding
 return termination code (0 for ESC, 1 for RETURN)

 Rescale the window wid.
 wid  : Window identifier
 w    : Width
 h    : Heigth

 Resize a pixmap.
 wid : pixmap to be resized
 w,h : Width and height of the pixmap

 Resize the current window if necessary.

 Select window to which subsequent output is directed.

 Set character up vector.

 Turn off the clipping for the window wid.

 Set clipping region for the window wid.
 wid        : Window indentifier
 x,y        : origin of clipping rectangle
 w,h        : size of clipping rectangle;

 Set the foreground color in GC.

 Set the cursor.

 Set the double buffer on/off on window wid.
 wid  : Window identifier.
        999 means all the opened windows.
 mode : 1 double buffer is on
        0 double buffer is off

 Turn double buffer mode off.

 Turn double buffer mode on.

 Set the drawing mode.
 mode : drawing mode
   mode=1 copy
   mode=2 xor
   mode=3 invert
   mode=4 set the suitable mode for cursor echo according to
          the vendor

 Set color index for fill areas.

 Set fill area style.
 fstyle   : compound fill area interior style
    fstyle = 1000*interiorstyle + styleindex

 Set fill area style index.

 Set input on or off.

 Set color index for lines.

 Set line type.
 n         : length of dash list
 dash(n)   : dash segment lengths

 if n <= 0 use solid lines
 if n >  0 use dashed lines described by DASH(N)
    e.g. N=4,DASH=(6,3,1,3) gives a dashed-dotted line with dash length 6
    and a gap of 7 between dashes

 Set line style.

 Set line width.
 width   : line width in pixels

 Set color index for markers.

 Set marker size index.
 msize  : marker scale factor

 Set marker type.
 type      : marker type
 n         : length of marker description
 xy        : list of points describing marker shape

 if n == 0 marker is a single point
 if TYPE == 0 marker is hollow circle of diameter N
 if TYPE == 1 marker is filled circle of diameter N
 if TYPE == 2 marker is a hollow polygon describe by line XY
 if TYPE == 3 marker is a filled polygon describe by line XY
 if TYPE == 4 marker is described by segmented line XY
   e.g. TYPE=4,N=4,XY=(-3,0,3,0,0,-3,0,3) sets a plus shape of 7x7 pixels

 Set marker style.

 Set opacity of a window. This image manipulation routine works
 by adding to a percent amount of neutral to each pixels RGB.
 Since it requires quite some additional color map entries is it
 only supported on displays with more than > 8 color planes (> 256
 colors).

 Collect in orgcolors all different original image colors.

 Get RGB values for orgcolors, add percent neutral to the RGB and
 allocate fNewColors.

 Returns index in orgcolors (and fNewColors) for pixel.

 Set color intensities for given color index.
 cindex     : color index
 r,g,b      : red, green, blue intensities between 0.0 and 1.0

 Set text alignment.
 txalh   : horizontal text alignment
 txalv   : vertical text alignment

 Set color index for text.

 Set text font to specified name.
 mode       : loading flag
 mode=0     : search if the font exist (kCheck)
 mode=1     : search the font and load it if it exists (kLoad)
 font       : font name

 Set text font to specified name. This function returns 0 if
 the specified font is found, 1 if not.

 Set current text font number.

 Set current text size.

 Set synchronisation on or off.
 mode : synchronisation on/off
    mode=1  on
    mode<>0 off

 Update display.
 mode : (1) update
        (0) sync

 Synchronise client and server once (not permanent).
 Copy the pixmap gCws->fDrawing on the window gCws->fWindow
 if the double buffer is on.

 Set pointer position.
 ix       : New X coordinate of pointer
 iy       : New Y coordinate of pointer
 Coordinates are relative to the origin of the window id
 or to the origin of the current window if id == 0.

 Write the pixmap wid in the bitmap file pxname.
 wid         : Pixmap address
 w,h         : Width and height of the pixmap.
 lenname     : pixmap name length
 pxname      : pixmap name

 Returns in R G B the ncol colors of the palette used by the image.
 The image pixels are changed to index values in these R G B arrays.
 This produces a colormap with only the used colors (so even on displays
 with more than 8 planes we will be able to create GIF's when the image
 contains no more than 256 different colors). If it does contain more
 colors we will have to use GIFquantize to reduce the number of colors.
 The R G B arrays must be deleted by the caller.

 Writes the current window into GIF file. Returns 1 in case of success,
 0 otherwise.

 Draw image.

 If id is NULL - loads the specified gif file at position [x0,y0] in the
 current window. Otherwise creates pixmap from gif file

 Returns an array of pixels created from a part of drawable (defined by x, y, w, h)
 in format:
 b1, g1, r1, 0,  b2, g2, r2, 0 ... bn, gn, rn, 0 ..

 Pixels are numbered from left to right and from top to bottom.
 By default all pixels from the whole drawable are returned.

 Note that return array is 32-bit aligned

 create pixmap from RGB data. RGB data is in format :
 b1, g1, r1, 0,  b2, g2, r2, 0 ... bn, gn, rn, 0 ..

 Pixels are numbered from left to right and from top to bottom.
 Note that data must be 32-bit aligned

 Register pixmap created by gVirtualGL
 w,h : Width and height of the pixmap.
register new pixmap

Private methods used for GUI

 needed by TGX11TTF

Methods used for GUI