Re: setrgbcolor with lineto/curveto

From	gernot.hoffmann@hs-emden-leer.de
Newsgroups	comp.lang.postscript
Subject	Re: setrgbcolor with lineto/curveto
Date	2012-06-16 11:00 -0700
Organization	http://groups.google.com
Message-ID	<4af5eb1e-4c3e-4586-bbc1-e833982dc80d@googlegroups.com> (permalink)
References	<jra5b7$mqu$1@reader1.panix.com>

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Posted once again.

Best regards --Gernot Hoffmann

----
%!PS-Adobe-3.0  EPSF-3.0
%%BoundingBox:  0 0 340 340
%%Creator:      Gernot Hoffmann
%%Title:        Color interpolation along Curve
%%CreationDate: June 15 / 2012

/mm {2.834646 mul} def	

% Bezier Reference:
% http://www.fho-emden.de/~hoffmann/bezier18122002.pdf
% page 2

% 4 control points

/p0x 1.0 def
/p0y 0.0 def

/p1x 1.0 def
/p1y 0.5 def

/p2x 0.5 def
/p2y 1.0 def

/p3x 0.0 def
/p3y 1.0 def

% Start and end color

/R0 0.0 def
/G0 0.5 def
/B0 0.0 def

/R3 1.0 def
/G3 0.5 def
/B3 0.0 def

/Coeff % coefficients see Ref. page 2 
{
/ax p3x p2x 3 mul sub p1x 3 mul add p0x sub def 
/bx p2x 3 mul p1x 6 mul sub p0x 3 mul add def
/cx p1x 3 mul p0x 3 mul sub def

/ay p3y p2y 3 mul sub p1y 3 mul add p0y sub def
/by p2y 3 mul p1y 6 mul sub p0y 3 mul add def
/cy p1y 3 mul p0y 3 mul sub def
} def

/Ipol % color interpolation
{/R R3 R0 sub t mul R0 add def
 /G G3 G0 sub t mul G0 add def
 /B B3 B0 sub t mul B0 add def
 R G B setrgbcolor
} def  

/Func % function, using Bezier by Horner scheme
{
/x ax t mul bx add t mul cx add t mul p0x add def
/y ay t mul by add t mul cy add t mul p0y add def
} def

100 mm 100 mm scale

0.1 0.1 translate

% black lines

0.001 setlinewidth
0 0 moveto 1 0 lineto stroke
0 0 moveto 0 1 lineto stroke

% black curve

0.04 setlinewidth
p0x p0y moveto
p1x p1y p2x p2y p3x p3y curveto stroke 

% color curve

0.02 setlinewidth

/N 100 def % e.g. 100 subdivisions
/dt 1 N div def

Coeff

/t 0 def
Func
N
{ 
 Ipol 
/t t dt add def 
 x y moveto
 Func 
 x y lineto stroke
} repeat 

showpage 
----

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Thread

setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-06-13 13:41 +0000
  Re: setrgbcolor with lineto/curveto Helge Blischke <h.blischke@acm.org> - 2012-06-13 16:16 +0200
    Re: setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-06-13 16:04 +0000
    Re: setrgbcolor with lineto/curveto Odysseus <odysseus1479-at@yahoo-dot.ca> - 2012-06-13 20:20 -0600
      Re: setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-06-14 04:05 +0000
      Re: setrgbcolor with lineto/curveto luser- -droog <mijoryx@yahoo.com> - 2012-06-16 14:45 -0700
  Re: setrgbcolor with lineto/curveto luser- -droog <mijoryx@yahoo.com> - 2012-06-13 16:20 -0700
    Re: setrgbcolor with lineto/curveto luser- -droog <mijoryx@yahoo.com> - 2012-06-13 17:16 -0700
      Re: setrgbcolor with lineto/curveto luser- -droog <mijoryx@yahoo.com> - 2012-06-13 17:36 -0700
        Re: setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-06-14 04:11 +0000
          Re: setrgbcolor with lineto/curveto luser- -droog <mijoryx@yahoo.com> - 2012-06-14 09:05 -0700
  Re: setrgbcolor with lineto/curveto gernot.hoffmann@hs-emden-leer.de - 2012-06-16 11:00 -0700
  Re: setrgbcolor with lineto/curveto gernot.hoffmann@hs-emden-leer.de - 2012-06-16 10:55 -0700
    Re: setrgbcolor with lineto/curveto gernot.hoffmann@hs-emden-leer.de - 2012-06-16 11:23 -0700
    Re: setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-06-19 07:00 +0000
      Re: setrgbcolor with lineto/curveto gernot.hoffmann@hs-emden-leer.de - 2012-06-19 00:34 -0700
        Re: setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-06-19 08:12 +0000
  Re: setrgbcolor with lineto/curveto John Deubert <john@acumentraining.com> - 2012-06-30 10:20 -0700
    Re: setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-07-04 03:07 +0000
      Re: setrgbcolor with lineto/curveto luser- -droog <mijoryx@yahoo.com> - 2012-07-05 16:24 -0700
        Re: setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-07-06 14:23 +0000
          Re: setrgbcolor with lineto/curveto JohnF <john@please.see.sig.for.email.com> - 2012-07-11 01:57 +0000
        Re: setrgbcolor with lineto/curveto tlvp <mPiOsUcB.EtLlLvEp@att.net> - 2012-07-11 01:08 -0400
          Re: setrgbcolor with lineto/curveto luser- -droog <mijoryx@yahoo.com> - 2012-07-12 03:12 -0700
            Re: setrgbcolor with lineto/curveto tlvp <mPiOsUcB.EtLlLvEp@att.net> - 2012-07-12 22:20 -0400

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