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 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.
- 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 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 the result of interpreter
interp and
TCL_OK is returned
unless an error occurs, in which case
TCL_ERROR is returned and the
interpreter 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 the
interpreter
interp's result and returns
TCL_OK unless an error
occurs, in which case
TCL_ERROR is returned and the interpreter's
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 interpreter
interp's result and returns
TCL_OK
unless an error occurs, in which case
TCL_ERROR is returned and the
interpreter's 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 the result of interpreter
interp.
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
interpreter
interp's result and
TCL_OK is returned, unless an
error occurs, in which case
TCL_ERROR is returned and the interpreter's
result is overwritten with an error message.
KEYWORDS¶
bitmap, canvas, color, font, path, Postscript, stipple