Question

I would like it to display non-flickery animation like this awesome Linux command; sl

http://www.youtube.com/watch?v=9GyMZKWjcYU

I would appreciate a small & stupid example of say … a fly.

Thanks!

Answer 1

Just use Console.SetCursorPosition for moving the cursor to a certain position, then Console.Write a character. Before each frame you have to delete the previous one by overwriting it with spaces. Heres a little example I just built:

class Program
{
    static void Main(string[] args)
    {
        char[] chars = new char[] { '.', '-', '+', '^', '°', '*' };
        for (int i = 0; ; i++)
        {
            if (i != 0)
            {
                // Delete the previous char by setting it to a space
                Console.SetCursorPosition(6 - (i-1) % 6 - 1, Console.CursorTop);
                Console.Write(" ");
            }

            // Write the new char
            Console.SetCursorPosition(6 - i % 6 - 1, Console.CursorTop);
            Console.Write(chars[i % 6]);

            System.Threading.Thread.Sleep(100);
        }
    }
}

You could for instance take an animated gif, extract all single frames/images from it (see how to do that here), apply an ASCII transformation (how to do that is described here for example) and print these frame by frame like in the above code example.

Update

Just for fun, I implemented what I just described. Just try it out replacing @"C:\some_animated_gif.gif" with the path to some (not to large) animated gif. For example take an AJAX loader gif from here.

class Program
{
    static void Main(string[] args)
    {
        Image image = Image.FromFile(@"C:\some_animated_gif.gif");
        FrameDimension dimension = new FrameDimension(
                           image.FrameDimensionsList[0]);
        int frameCount = image.GetFrameCount(dimension);
        StringBuilder sb;

        // Remember cursor position
        int left = Console.WindowLeft, top = Console.WindowTop;

        char[] chars = { '#', '#', '@', '%', '=', '+', 
                         '*', ':', '-', '.', ' ' };
        for (int i = 0; ; i = (i + 1) % frameCount)
        {
            sb = new StringBuilder();
            image.SelectActiveFrame(dimension, i);

            for (int h = 0; h < image.Height; h++)
            {
                for (int w = 0; w < image.Width; w++)
                {
                    Color cl = ((Bitmap)image).GetPixel(w, h);
                    int gray = (cl.R + cl.G + cl.B) / 3;
                    int index = (gray * (chars.Length - 1)) / 255;

                    sb.Append(chars[index]);
                }
                sb.Append('\n');
            }

            Console.SetCursorPosition(left, top);
            Console.Write(sb.ToString());

            System.Threading.Thread.Sleep(100);
        }
    }
}