Circle code

[chump1708]

Can anyone give me an idea for drawing a circle without making use of
any floating point computations?
Thanks
Prasad

 

[Vladimir S. Oka]

Can anyone give me an idea for drawing a circle without making use of
any floating point computations?
Thanks
Prasad

Asking in comp.programming is possibly a better idea.

If you try to implement this in C, and have questions, you can always
come back here.

Cheers

Vladimir

 

[CBFalconer]

Can anyone give me an idea for drawing a circle without making
use of any floating point computations?

Sure. Take compass, insert pencil in pencil holder, place pointy
end on desired circle center, adjust compass for appropriate
radius, and spin it.

What was your question about the C language?

--
"If you want to post a followup via groups.google.com, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers." - Keith Thompson
More details at: <http://cfaj.freeshell.org/google/>

 

[Roberto Waltman]

Can anyone give me an idea for drawing a
circle without making use of any floating
point computations?

This is not a C language question.
Try asking in "comp.graphics.algorithms",
and/or search for "Bresenham’s Algorithm"

Roberto Waltman

[ Please reply to the group, ]
[ return address is invalid. ]

 

[Default User]

Can anyone give me an idea for drawing a circle without making use of
any floating point computations?

Why? That seems a fairly useless thing to do.



Brian

 

[Mike Wahler]

Can anyone give me an idea for drawing a circle without making use of
any floating point computations?
Thanks
Prasad

Use a compass and a pencil.

I used no floating point calculations in
conceiving or presenting this idea.

-Mike

 

[tedu]

If you try to implement this in C, and have questions, you can always
come back here.

this C program draws one circle without any fp:

#include <stdio.h>
int main(int argc, char **argv) {
printf("o\n");
}

 

[Ico]

Can anyone give me an idea for drawing a circle without making use of
any floating point computations?
Thanks
Prasad

Solution #1:
------------

#include <stdio.h>

int main(void)
{
putchar('O');
}

Solution #2:
------------

#include <stdio.h>

int main(int i, char **v)
{
int c='\n',_=-c,y;
for(y=i-c;putc((_*_<c*c-y*y)?0x2a:040,stdout),_<=c;++_);
return((puts("")&&c>y)?main(++i,v):i^i);
}

 

[Googmeister]

Here's the LOGO / differential geometry solution:

repeat
go forward 1 unit
turn right 1 unit

 

[Vladimir S. Oka]

this C program draws one circle without any fp:

This program is not correct C:

#include <stdio.h>
int main(int argc, char **argv) {
printf("o\n");

return 0;

}

Also I was not the OP.

Cheers

Vladimir

 

[Vladimir S. Oka]

Here's the LOGO / differential geometry solution:

repeat
go forward 1 unit
turn right 1 unit

Apart from the original question not being asked by me at all, this is
now way off topic in comp.lang.c! Please trim your cross-posts to
comp.programing only.

Cheers

Vladimir

 

[tedu]

This program is not correct C:


return 0;

i was hoping the on-topic requirements here were loose enough to
squeeze a little c99 into the group.

Also I was not the OP.

that post isn't visible to me, which is why i quoted the original
author as well.

 

[Vladimir S. Oka]

i was hoping the on-topic requirements here were loose enough to
squeeze a little c99 into the group.

You're right about the C99. I guess I'll get used to it when there's
more compilers supporting it. I still think that it's good practice to
have something returned from a function that does have a return value.

that post isn't visible to me, which is why i quoted the original
author as well.

Sorry for jumping the gun.

Cheers

Vladimir

 

[Rod Pemberton]

Can anyone give me an idea for drawing a circle without making use of
any floating point computations?
Thanks
Prasad

32 seconds with Google returned this excellent page:
http://www.cs.unc.edu/~mcmillan/comp136/Lecture7/circle.html


Rod Pemberton

 

[Keith Thompson]

Why? That seems a fairly useless thing to do.

It could be very useful for a graphics program running on a system
where integer arithmetic is significantly faster than floating-point
arithmetic. (That doesn't make it topical here, of course.)

 

[Chris McDonald]

32 seconds with Google returned this excellent page:
http://www.cs.unc.edu/~mcmillan/comp136/Lecture7/circle.html

No wonder the OP couldn't find his homework solution using Google -
that page doesn't even use the word 'float'.

 

[Chris F.A. Johnson]

Can anyone give me an idea for drawing a circle without making use of
any floating point computations?

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[])
{
long radius = 100, point;
if ( argc > 1 ) radius = strtol(argv[1],NULL,10);
point = radius + 18;
printf( "%!\n%d %d %d 0 360 arc stroke showpage\n", point, point, radius);
return 0;
}

 

[Jordan Abel]

Solution #1:
------------

#include <stdio.h>

int main(void)
{
putchar('O');
}

You need to also output a newline, otherwise the output might never
show. In particular, my system's interactive shell prints a carriage
return and overwrites an unterminated last line of output with its
prompt. Other systems may not flush an unterminated last line to the
output device at all.

 

[Ico]

You need to also output a newline, otherwise the output might never
show. In particular, my system's interactive shell prints a carriage
return and overwrites an unterminated last line of output with its
prompt. Other systems may not flush an unterminated last line to the
output device at all.

Yes, you are completely right. I guess my suggesions are just bad
examples for the OP's homework.

 

[Richard Bos]

this C program draws one circle without any fp:

#include <stdio.h>
int main(int argc, char **argv) {
printf("o\n");
}

Whether that draws a true circle or only an approximation is
implementation-dependent. On non-Western or oddly configured systems it
could even result in a completely different drawing.

Richard