"Plotting" an equation I have an equation like
$$
(x - a)^2 + (y - b)^2 = r^2
$$
that represents a circle.
I need to "plot" it very basically with a programming language. Computer graphics coordinate generally use the "lower-right" quadrant of a Cartesian plane (0, 0 being top left).
I want my circle to have its center in (200, 200) and a radius of, say, 100. All measures given in pixels.
I need to do this step by step, within a loop. So, if the loop is 100 times, i need to know at each iteration at what x and y coordinate to draw a pixel. How to this? With my center and radius, the above equation is like this
$$
(x - 200)^2 + (y - 200)^2 = 1000
$$
but still I can't figure out how to express any "advancement" of my virtual plotting device. Thanks
EDIT
My question specifically asked for the equation of a circle, but it was just an example. I have the same problem with parabolas, sins...

Midpoint circle algorithm
