Tk_CanvasPsY(3Tk)Tk_CanvasPsY(3Tk)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, fontStructPtr)
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.
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Tk_CanvasPsY(3Tk)Tk_CanvasPsY(3Tk)
int height (in) Height of region of bitmap to
output, in pixels.
XColor *colorPtr (in) Information about color value
to set in Postscript.
XFontStruct *fontStructPtr (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_CanvasY 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
fontStructPtr 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
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Tk_CanvasPsY(3Tk)Tk_CanvasPsY(3Tk)
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
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