NAME

       Tk_CanvasPsY, Tk_CanvasPsBitmap, Tk_CanvasPsColor, Tk_CanvasPsFont, Tk_CanvasPsPath, Tk_CanvasPsStipple -
       utility procedures for generating Postscript for canvases

SYNOPSIS

       #include <tk.h>

       double
       Tk_CanvasPsY(canvas, canvasY)

       int
       Tk_CanvasPsBitmap(interp, canvas, bitmap, x, y, width, height)

       int
       Tk_CanvasPsColor(interp, canvas, colorPtr)

       int
       Tk_CanvasPsFont(interp, canvas, tkFont)

       Tk_CanvasPsPath(interp, canvas, coordPtr, numPoints)

       int
       Tk_CanvasPsStipple(interp, canvas, bitmap)

ARGUMENTS

       Tk_Canvas      canvas      (in)      A  token  that  identifies  a  canvas widget for which Postscript is
                                            being generated.

       double         canvasY     (in)      Y-coordinate in the space of the canvas.

       Tcl_Interp     *interp     (in/out)  A Tcl interpreter;  Postscript is appended to  its  result,  or  the
                                            result may be replaced with an error message.

       Pixmap         bitmap      (in)      Bitmap to use for generating Postscript.

       int            x           (in)      X-coordinate within bitmap of left edge of region to output.

       int            y           (in)      Y-coordinate within bitmap of top edge of region to output.

       int            width       (in)      Width of region of bitmap to output, in pixels.

       int            height      (in)      Height of region of bitmap to output, in pixels.

       XColor         *colorPtr   (in)      Information about color value to set in Postscript.

       Tk_Font        tkFont      (in)      Font for which Postscript is to be generated.

       double         *coordPtr   (in)      Pointer  to an array of coordinates for one or more points specified
                                            in canvas coordinates.  The order of values in coordPtr is  x1,  y1,
                                            x2, y2, x3, y3, and so on.

       int            numPoints   (in)      Number of points at coordPtr.
_________________________________________________________________

DESCRIPTION

       These  procedures  are called by canvas type managers to carry out common functions related to generating
       Postscript.  Most of the procedures take a canvas argument, which refers to a  canvas  widget  for  which
       Postscript is being generated.

       Tk_CanvasPsY  takes as argument a y-coordinate in the space of a canvas and returns the value that should
       be used for that point in the Postscript currently being generated for  canvas.   Y  coordinates  require
       transformation because Postscript uses an origin at the lower-left corner whereas X uses an origin at the
       upper-left corner.  Canvas x coordinates can be used directly in Postscript without transformation.

       Tk_CanvasPsBitmap  generates Postscript to describe a region of a bitmap.  The Postscript is generated in
       proper image data format for Postscript, i.e., as data between angle brackets, one bit  per  pixel.   The
       Postscript  is  appended  to  interp->result and TCL_OK is returned unless an error occurs, in which case
       TCL_ERROR is returned and interp->result is overwritten with an error message.

       Tk_CanvasPsColor generates Postscript to set the current color to correspond to  its  colorPtr  argument,
       taking  into  account  any  color  map specified in the postscript command.  It appends the Postscript to
       interp->result and returns TCL_OK unless an error  occurs,  in  which  case  TCL_ERROR  is  returned  and
       interp->result is overwritten with an error message.

       Tk_CanvasPsFont  generates  Postscript that sets the current font to match tkFont as closely as possible.
       Tk_CanvasPsFont takes into account any font map specified in the postscript command, and it does the best
       it can at mapping X fonts to Postscript fonts.  It appends the Postscript to interp->result  and  returns
       TCL_OK unless an error occurs, in which case TCL_ERROR is returned and interp->result is overwritten with
       an error message.

       Tk_CanvasPsPath  generates  Postscript to set the current path to the set of points given by coordPtr and
       numPoints.  It appends the resulting Postscript to interp->result.

       Tk_CanvasPsStipple generates Postscript that will fill the current path in  stippled  fashion.   It  uses
       bitmap  as the stipple pattern and the current Postscript color;  ones in the stipple bitmap are drawn in
       the current color, and zeroes are not drawn at all.  The Postscript is  appended  to  interp->result  and
       TCL_OK  is  returned,  unless  an error occurs, in which case TCL_ERROR is returned and interp->result is
       overwritten with an error message.

KEYWORDS

       bitmap, canvas, color, font, path, Postscript, stipple

Tk                                                     4.0                                      Tk_CanvasPs(3tk)