The Importance of The Winding Rule

When I mention "The Winding Rule", you may think it has something to do with The Beatles song The Long and Winding Road. It might make for good listening while I try to explain, but they are completely unrelated.

When a curve is drawn as a vector graphic, the path can either be followed clockwise or counter-clockwise. Most of the time, it doesn't really matter to users. It can make a difference for those who are cutting some sort of material as it determines the path of the cutting device. If you want to change the direction, make sure to have the Shape tool selected in CorelDRAW and then click the Reverse Curve Direction on the Property Bar. I know, many of you are still asking why you should really care.

The reason it is so important is that it can determine whether combining two objects works the way you desire. For the simplest example possible, draw two concentric circles. Go ahead and convert them both to curves (Ctrl + Q). Now combine the two together (Ctrl + L) and you should end up with a donut. Mmmm, donuts!

I know, you still wonder why this is so important and we're getting there. Go ahead and Undo the combine (Ctrl + Z) so you have the two circles again. Select the inside circle with the Shape tool and reverse the curve direction using the button on the Property Bar. Now try combining the circles again and you'll most likely find that the hole was not cut out as before. I bet you can now understand the importance of the winding rule. Should you run into a situation where combining two objects isn't getting the result you desire, change the curve direction on one of them and I bet it find it works perfectly.