Bresenham's Algorithm

With trigonometry functions such as sine and cosine, it is very easy to compute for the value of x and y for any given radius and teta.

We've all learned this from highschool and college class and it will not be tacked in this article. However, drawing a circle using these functions requires the usage of floating-point numbers which is slow, not to mention the typecasting from floating-point to integers as plotting a pixel requires such datatype.

The line equation represented by y = mx + b, is one of the most basic formulas in plotting a line. Where m represents the slope, x represents the value in horizontal coordinate and b represents the offset from y.

Suppose we have a line segment (x₁, y₁) to (x₂, y₂), the slope can be easily computed as (y₂ - y₁) / (x₂ - x₁) or to understand it better, we can read it as an increment in y for every step in x.

If you've always hated incrementing (or decrementing) float variables by some constant float within the range of -1 ≤ 0 ≤ 1, and increment ≠ 0, and wanted to implement a better approach by using integral data types (such as char, short, int, and long), then this article best describes the solution to your ordeal. Applications of this optimization vary from different fields of computer programming. One of which is Bersenham's Algorithm for drawing a line.