Optimizing circle drawer

[Michael Zilber]

I'm making a game using a grid and I recently decided to make a circle drawer. After a bit of deep trig thinking I came up with a simple way to plot a circle:

for(int i=0; i<360; i++)
{
int x=(Math.cos(i)*radius)+xOffset, y=(Math.sine(i)*radius)+yOffset;
Grid.setColor(Color.black, x, y);
}

I get the circle just fine I just wanted to know of there was a more efficient way to increment i instead of going through all the angles.
I came up with a this: i+=45/(radius-2)
I've tried it out and it seems to work pretty well for smaller circles but I think (haven't had a chance to test) it might screw up with bigger circles. Does anyone know of this is the most efficient incrementation (or if it's right)?

[Tim Moores]

This should be of interest: http://www.gamedev.net/page/resources/_/technical/graphics-programming-and-theory/bresenhams-line-and-circle-algorithms-r767

[Michael Zilber]

Thanks for the quick reply. I'll have a look.