CanvPsY

Tk_CanvasPs(3)               Tk Library Procedures              Tk_CanvasPs(3)



______________________________________________________________________________

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  out-
                                            put, in pixels.

       int            height      (in)      Height of region of bitmap to out-
                                            put, 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 cor-
       ner  whereas X uses an origin at the upper-left corner.  Canvas x coor-
       dinates 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 cor-
       respond 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 over-
       written with an error message.


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



Tk                                    4.0                       Tk_CanvasPs(3)