• Draw Intro
• Arc
• Bezier
• Circle
• Ellispe
• Line
• Rectangles
• Polys
• Contact

There are several different Primitive commands that are capable of drawing circles beside Circle itself but at this time we are only going to discuss the actual Primitive Circle and how it works...

First thing you need to know is how many sets of Coordinates it takes to draw a circle. The Circle uses two and only two. The first set will set the Center of your circle. For example, if you wanted to place a circle in the center of an image of 400x400, the coordinates would be 200,200. 200 horizontal and 200 vertical where the two points meet is where the center will be. On the other hand the second set places where the edge of the circle will be located. On a 400x400 black background I used these coordinates: 200,200 75,50 for the example below.

As you can see, I placed a dot in the center for you to see. I also drew lines to show where 75 over and 50 down meet and where the edge of the circle will be placed.

Using the center of an image for the center of your circle is easy. But what would happen if you place the circle's center somewhere else? On the same 400x400 size background I placed the center at 150,300 and used the coordinate for the edge 30,100 in the color greenish blue. That one didn't quite hold the entire circle so I went back and changed the edge coordinates to 130,210 in gold. Take a look below.

The lines you see in the image represent the exact coordinates I used for the circles but instead used the Line Primitive in it's place. From the corner edge of the image I drew lines to show where 30,100 and 130,210 meet their circle's edge. If a circle you are drawing is off the edge of the background than you need to increase or decrease the edge coordinates( depending on where your center is) by going further over and down as I did when I went from 30,100 to 130,210. Work with it until you have what you want.

When choosing the edge coordinates I usually don't pass the center's location. Example a 400x400 background with the circle center at 200,200, I would use numbers for the edge lower that 200 over and 200 down. But what would happen if you did go past it, say maybe 300,300 for the edge? So lets see what happens. Look below.

Not what you expected, huh? It just changed from the left edge to the right. That simple. I hope this has helped you to understand how this Primitive works and you drawing circles and more circles. Enjoy!

Susanna M