Circle Tool
ALT-C
The "Circle Tool" is used for creating new circle layers. Click where you want the center of the circle to be, and drag to set the radius.
The "Circle tool" can also be used to create outline layers, region layers, curve gradient layers, and plant layers, each with approximately circular Splines.
The Tool Options Panel for the "Circle Tool" has checkboxes for each of the 5 types of layer (circle layer plus 4 spline layers) to select which layer type(s) will be created by the tool. It also has "Spline Points" which sets the number of Spline Points that will be used in the new Splines, and "Point Angle Offset" which determines where on the circumference of the circle the Spline Points will be.
Usage
Click on the canvas where you want to have the center of the circle and drag to obtain the desired radius value, and release the mouse button when you are done.
