Tk_CanvasPsY(3tk)

Tk_CanvasPs(3)        Tk Library Procedures        Tk_CanvasPs(3)

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NAME

     Tk_CanvasPsY,      Tk_CanvasPsBitmap,      Tk_CanvasPsColor,
     Tk_CanvasPsFont, Tk_CanvasPsPath, Tk_CanvasPsStipple - util-
     ity 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  gen-
                                          erating 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.

Tk                      Last change: 4.0                        1

Tk_CanvasPs(3)        Tk Library Procedures        Tk_CanvasPs(3)

     int width (in)                       Width of region of bit-
                                          map  to output, in pix-
                                          els.

     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.
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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 coordi-
     nates can be used directly in Postscript without transforma-
     tion.

     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                      Last change: 4.0                        2

Tk_CanvasPs(3)        Tk Library Procedures        Tk_CanvasPs(3)

     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 map-
     ping 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                      Last change: 4.0                        3