Misc Post #2: Bezier Curves in Relation to the Pen Tool

In my pen tool blog post I said how I was interested in learning the code behind the pen tool.  I initially thought that the pen tool used splines. Splines are a piecewise functions that when connected with other polynomials produce smooth lines. In other words if you have a bunch of points the goal is to have a splines that will connect through them with smooth curves. I got the idea of splines from my course CS 370 (numerical computation). It seemed that when the pen tool would go around a circular edge it would automatically bend to the correct shape. After some research I found out that the pen tool does use splines. But it's a special type of spline called a Bezier curve. So a normal splines would be made up of different polynomials, but with a Bezier splines you have one continuous polynomial.

So the pen tool use a Bezier curve with 2 anchor points that allow adjustments to the vector.  I found this pretty cool.