Ech's Fractal 4+

I would like to ask a few questions.

1) How are you generating the fractal? Is it generating from an image or a formula?

2) Why is the quality so bad after a high zoom factor?

3) Is the quality decreasing because of the floating point numbers reach a limit?

If you would take a few minutes out of your time to awnser these questions, I would be happier to know why these problems occur.

Thank you for your question. :)
1) I generated the image from the formula. You can reference from the wiki page below.

https://en.m.wikipedia.org/wiki/Mandelbrot_set

2) 3) You got the point. To the higher zoom, it need to calculate the value at smaller scale of number that need more precision. At the limit of calculation ability of the device (phone), the rendered image will be broken. (In academy, they use the super computer to generate more precise fractal image)

Thank you for enjoying the app!

Let’s start with the two good points:
First, this is the only Mandelbrot set generator I found for the iPad which allows you the the iteration threshold. In other words, you can make your own choice between accuracy and speed.
Second, the author gives you a fair amount of control over the colors, so you can customize to your liking. Many other programs offer very limited color control.

The not-so-good, however, really hurts this application. The author sacrifices some screen space for a line of advertisement, which is downright rude for an application which can create beautiful images. The advertisement line just wrecks the picture. Another problem is the user interface. You zoom and pan using the familiar finger pinch and finger draw methods. That’s a poor fit for this application because it is very difficult to figure out what you’re going to end up with. This is particularly aggravating when using a relatively high iteration count, because of long delays involved in making the calculations. A better approach, used by other Mandelbrot set generators is to use a “rubber Band” rectangle around the zoom area. That way you can see exactly where you’re zooming.

Some included help would also be...helpful, particularly concerning the color options. Users who are not familiar with the Mandelbrot set may also appreciate some explanation of the iterations (depth) and how this will affect image quality and speed.

Thank you for the comment. I will consider to make this app more user-friendly in the future version. : )

nice but has significant flaw: you can zoom in and pan, but can't zoom out, you can only reset to the full image.

Thank you for your comment. What gesture will you suggest for the zoom out action? : )