Greyscale Graphics CLI explanation

Want to make computer graphics demos, but don't know how to open a window? Don't have time to learn?

Use greyscale CLI graphics!

Here are 2 grey scales that work well on the terminal:

char greyscale[] = "$@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\\|()1{}[]?-_+~<>i!lI;:,\"^`'. ";
char short_greyscale[] = " .:-=+*#%@";

The larger greyscale is better for very detailed images while the short greyscale is more convincing.

Simply make your demo output a floating point number between 0 and 1 for every position, multiply it by strlen(greyscale), shorten it to an int and use it as an index to the array of characters. Write it out with printf() or std::cout if you're using C++. I recommend pushing out all lines of your graphics at once, by creating an array to hold your screen. Allocate it like this:

char screen[(screen_width + 1)  * (screen_height) + 1];

Initialize it like this:

screen[(screen_width + 1)  * (screen_height)]  = '\0';

for(int y = 0; y < screen_height; y++)

{

   screen[screen_width + (screen_width + 1) * y] = '\n';

}



When you want to write a float VAL which is between 0 and 1 to position (X, Y) in the screen, write to it like this:

screen[X + (screen_width + 1) * Y] = greyscale[VAL * (strlen(greyscale) - 1)];

Print it like this:

printf("\n%s",screen);

Or this:

std::cout << "\n" << screen << std::endl;

You now have everything you need to make amazing things using only ANSI C on the terminal. Go forth, and make me proud!