Tk_CanvasPsY(3) Tk (4.0) Tk_CanvasPsY(3)
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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
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Tk_CanvasPsY(3) Tk (4.0) Tk_CanvasPsY(3)
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.
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.
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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_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
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Tk_CanvasPsY(3) Tk (4.0) Tk_CanvasPsY(3)
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 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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