Hexagonal Pattern

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2 total messages Started by Arthur van Hoff Mon, 25 Jan 1993 12:34

#6496

Author: Arthur van Hoff
Date: Mon, 25 Jan 1993 12:34

81 lines
2125 bytes

Hi,

Here is a simple PdB program (the compiled PostScript is also
included) that draws an amazing hexagonal pattern resembling
that of the human retina.

	Arthur van Hoff

************************
Start of the PdB program
************************
#include <graphics.h>

#define RADIUS		25		/* Radius of fovia */
#define CIRCLES		30		/* The number of circles */
#define SEGMENTS	64		/* Segments on each circle */
#define FACTOR1		1.05		/* Scaling factor */
#define FACTOR2		(FACTOR1 * 0.995)

void main()
{
    float r1 = RADIUS, r2, r3;
    int n, i;

    clippath();
    fill(1);
    setgray(0);
    translate(250,250);

    for (n = 0 ; n < CIRCLES ; n++) {
	r3 = r1;
	r2 = r3 * FACTOR1;
	r1 = r2 * FACTOR2;

	for (i = 0 ; i < SEGMENTS ; i++) {
	    moveto(0,r1);
	    lineto(0,r2);
	    rotate(180 / SEGMENTS);
	    lineto(0,r3);
	    rotate(180 / SEGMENTS);
	    lineto(0,r2);
	}
	rotate(180 / SEGMENTS);
	stroke();
    }
}

extern "PostScript" {main};

************************
Verbatim compiler output
************************
/main {
  % --
  25 clippath 1 setgray fill 0 setgray 250 250 translate 30 {
    dup 1.05 mul exch 1 index 1.04475 mul 3 1 roll 64 {
      0 3 index moveto 0 2 index lineto 2.8125 rotate 0 1 index
      lineto 2.8125 rotate 0 2 index lineto
    } repeat
    pop pop 2.8125 rotate stroke
  } repeat
  pop
} def
%begin postscript section
main
%end

--

	Arthur van Hoff 
	The Turing Institute Limited
	36 North Hanover Street, 
	G1 2AD Glasgow, Scotland

	Tel: +44 41 552 8858 or +44 41 552 6400
	Fax: +44 41 552 2985
	Email: arthur@turing.com

	The opinions expressed in this message are not 
	necessarily those of The Turing Institute Limited.

Re: Hexagonal Pattern

#6501

Author: Allen B
Date: Mon, 25 Jan 1993 17:32

17 lines
1090 bytes

In article <ARTHUR.93Jan25122827@lurch.turing.ac.uk> arthur@turing.ac.uk  
(Arthur van Hoff) writes:
> Here is a simple PdB program (the compiled PostScript is also
> included) that draws an amazing hexagonal pattern resembling
> that of the human retina.

Wow, that is neat.  I haven't messed with PdB yet (I'm
pretty proficient the old-fashioned way :-) ), but I do
plan to.

Question: can you make it preface your file with a
bounding box so it looks like a good EPS document?  How
about DSC in general?  If it would do that, it'd make
incorporating your PdB programs into drawing programs
and such much easier.  Ease is the point, afterall. :-)

ab

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