On 10/04/11 15:12, Tyler Leavitt wrote:
I've not had any real success using the formulas with [sin] and [cos]...
maybe I'm missing something here. The only solution that I've gotten to work
is the midpoint circle algorithm with Peter's patch.
A circle centered at the origin is implicitly[1] described by:
x^2 + y^2 = r^2
Rearranging this gives:
y = +/- sqrt(r^2 - x^2) for -r <= x <= r
Hopefully this more useful for your purposes than the parametric form:
(x,y) = (cos(t), sin(t)) for -PI <= t <= PI
Should be much simpler to implement than an optimized-for-integers
Bresenham-style implementation.
Relatedly[2] I like this function too:
f(x,t) = sqrt((t^2)+(x^2)*(2*t+1))-t for -1 <= x <= 1 and 0 <= t
[1] http://en.wikipedia.org/wiki/Circle#Cartesian_coordinates
[2] http://en.wikipedia.org/wiki/Conic_section
Claude
--
http://claudiusmaximus.goto10.org
_______________________________________________
[email protected] mailing list
UNSUBSCRIBE and account-management ->
http://lists.puredata.info/listinfo/pd-list
