Tk_CanvasPsY(3Tk)					     Tk_CanvasPsY(3Tk)

NAME    [Toc]    [Back]

     Tk_CanvasPsY, Tk_CanvasPsBitmap, Tk_CanvasPsColor,	Tk_CanvasPsFont,
     Tk_CanvasPsPath, Tk_CanvasPsStipple - utility procedures for generating
     Postscript	for canvases

SYNOPSIS    [Toc]    [Back]

     #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    [Toc]    [Back]

     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    [Toc]    [Back]

     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    [Toc]    [Back]

     bitmap, canvas, color, font, path,	Postscript, stipple


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