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
A token that identifies a canvas widget for which Postscript is being
generated. Y-coordinate in the space of the canvas. A Tcl inter-
preter; Postscript is appended to its result, or the result may be
replaced with an error message. Bitmap to use for generating Post-
script. X-coordinate within bitmap of left edge of region to output.
Y-coordinate within bitmap of top edge of region to output. Width of
region of bitmap to output, in pixels. Height of region of bitmap to
output, in pixels. Information about color value to set in Postscript.
Font for which Postscript is to be generated. 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.
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 Post-
script 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 Post-
script 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 bit-
map. The Postscript is generated in proper image data format for Post-
script, 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)
CanvPsY 8.5.4 - Generated Fri Aug 22 18:11:41 CDT 2008