1Tk_CanvasPs(3)               Tk Library Procedures              Tk_CanvasPs(3)
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NAME

8       Tk_CanvasPsY,   Tk_CanvasPsBitmap,  Tk_CanvasPsColor,  Tk_CanvasPsFont,
9       Tk_CanvasPsPath, Tk_CanvasPsStipple - utility procedures for generating
10       Postscript for canvases
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SYNOPSIS

13       #include <tk.h>
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15       double
16       Tk_CanvasPsY(canvas, canvasY)
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18       int
19       Tk_CanvasPsBitmap(interp, canvas, bitmap, x, y, width, height)
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21       int
22       Tk_CanvasPsColor(interp, canvas, colorPtr)
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24       int
25       Tk_CanvasPsFont(interp, canvas, tkFont)
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27       Tk_CanvasPsPath(interp, canvas, coordPtr, numPoints)
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29       int
30       Tk_CanvasPsStipple(interp, canvas, bitmap)
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ARGUMENTS

33       Tk_Canvas canvas (in)                A  token  that identifies a canvas
34                                            widget for which Postscript is be‐
35                                            ing generated.
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37       double canvasY (in)                  Y-coordinate  in  the space of the
38                                            canvas.
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40       Tcl_Interp *interp (in/out)          A Tcl interpreter;  Postscript  is
41                                            appended to its result, or the re‐
42                                            sult may be replaced with an error
43                                            message.
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45       Pixmap bitmap (in)                   Bitmap to use for generating Post‐
46                                            script.
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48       int x (in)                           X-coordinate within bitmap of left
49                                            edge of region to output.
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51       int y (in)                           Y-coordinate  within bitmap of top
52                                            edge of region to output.
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54       int width (in)                       Width of region of bitmap to  out‐
55                                            put, in pixels.
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57       int height (in)                      Height of region of bitmap to out‐
58                                            put, in pixels.
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60       XColor *colorPtr (in)                Information about color  value  to
61                                            set in Postscript.
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63       Tk_Font tkFont (in)                  Font for which Postscript is to be
64                                            generated.
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66       double *coordPtr (in)                Pointer to an array of coordinates
67                                            for  one  or more points specified
68                                            in canvas coordinates.  The  order
69                                            of  values  in coordPtr is x1, y1,
70                                            x2, y2, x3, y3, and so on.
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72       int numPoints (in)                   Number of points at coordPtr.
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DESCRIPTION

76       These procedures are called by canvas type managers to carry out common
77       functions  related  to  generating  Postscript.  Most of the procedures
78       take a canvas argument, which refers to a canvas widget for which Post‐
79       script is being generated.
80
81       Tk_CanvasPsY  takes as argument a y-coordinate in the space of a canvas
82       and returns the value that should be used for that point in  the  Post‐
83       script  currently  being  generated  for canvas.  Y coordinates require
84       transformation because Postscript uses an origin at the lower-left cor‐
85       ner  whereas X uses an origin at the upper-left corner.  Canvas x coor‐
86       dinates can be used directly in Postscript without transformation.
87
88       Tk_CanvasPsBitmap generates Postscript to describe a region of  a  bit‐
89       map.  The Postscript is generated in proper image data format for Post‐
90       script, i.e., as data between angle brackets, one bit per  pixel.   The
91       Postscript  is  appended to the result of interpreter interp and TCL_OK
92       is returned unless an error occurs, in which case TCL_ERROR is returned
93       and the interpreter result is overwritten with an error message.
94
95       Tk_CanvasPsColor  generates Postscript to set the current color to cor‐
96       respond to its colorPtr argument, taking into  account  any  color  map
97       specified  in the postscript command.  It appends the Postscript to the
98       interpreter interp's result and returns TCL_OK unless an error  occurs,
99       in  which  case  TCL_ERROR  is returned and the interpreter's result is
100       overwritten with an error message.
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102       Tk_CanvasPsFont generates Postscript that  sets  the  current  font  to
103       match  tkFont  as  closely as possible.  Tk_CanvasPsFont takes into ac‐
104       count any font map specified in the postscript command, and it does the
105       best  it  can  at  mapping X fonts to Postscript fonts.  It appends the
106       Postscript to interpreter interp's result and returns TCL_OK unless  an
107       error occurs, in which case TCL_ERROR is returned and the interpreter's
108       result is overwritten with an error message.
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110       Tk_CanvasPsPath generates Postscript to set the current path to the set
111       of  points  given  by coordPtr and numPoints.  It appends the resulting
112       Postscript to the result of interpreter interp.
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114       Tk_CanvasPsStipple generates Postscript that will fill the current path
115       in  stippled  fashion.   It  uses bitmap as the stipple pattern and the
116       current Postscript color;  ones in the stipple bitmap are drawn in  the
117       current  color, and zeroes are not drawn at all.  The Postscript is ap‐
118       pended to interpreter interp's result and TCL_OK is returned, unless an
119       error occurs, in which case TCL_ERROR is returned and the interpreter's
120       result is overwritten with an error message.
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KEYWORDS

123       bitmap, canvas, color, font, path, Postscript, stipple
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127Tk                                    4.0                       Tk_CanvasPs(3)
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