Intro
If you've ever drawn any kind of sprite you'll know that a large proportion of anything you draw is curves. The only thing is that they are damn hard to draw with just a pencil (or a pencil tool). Human hands aren't built for drawing curves, it's as simple as that. Sure you can use a Shape object on a programme, but these ellipses don't always do what you want them to.
Example
You have an isometric grid. You want to create a perfect ellipse that is 2 blocks long and one block wide. MMF, TGF or any paint programme won't easily allow you to do this...
To fathom what this article is about, you must first know what we are trying exactly to do. To create an ellipse, do you agree that there are 4 curves which join up to create this shape? Each curve occupies a quarter of the rectangle the ellipse is drawn in. First, mark off the halfway points of your oblong, splitting your oblong into quarters. Halfway points are very important to this whole article in fact, as soon you will see. Now, to make 1 curve (1 quadrant of the ellipse) we use a technique which can be best described as "drawing ever decreasing triangles".
*Please note I have used colours only for examples sake. You don't have to colour it all in fancy like I have done.
As you can see above, the bottom left orange quadrant has a red triangle in it. This triangle reaches halfway up the orange quadrant in either direction. This is a very important step. Whilst it is not vital that the triangle is exactly halfway up either side, it is preferred. Now, we continue to draw triangles, but of ever decreasing size.
*The second set of triangles in brown, the third set in almost black.
Notice the triangles almost form up to make a curve shape? But where are these triangles drawn from? Well, after the red triangle, I split up the part of the side remaining into half again. From this halfway point I drew a line to the midpoint of the hypotenuse (longest side), and ditto with the other remaining side. Then, I split the still remaining part into half again and drew a line from there to the hypotenuse of the second triangle (brown). After a while these triangles get so small it is worthless to draw anymore.
Here I have coloured all the triangles in the same colour, and copied and pasted onto the opposite side, then did the Triangles techniques with the other quadrants and voila! Notice that this looks almost perfect to the human eye, even though you have just drawn it usuing triangles! This takes practice though, so keep trying.
This is an example of what you can do using this technique. It's mostly useful for isometric or perspective drawing, when ellipses aren't of standard shape. This is not to say you can't use it for normal ellipses, or even circles.
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