A Pattern Applet

Applet

Instructions

The two numbers that generate these patterns can be changed using the scroll bars. The vertical bar sets the multiplier and the higher horizontal one the offset. The lower horizontal scroll bar determines how many cells are drawn in the pattern.

Algorithm

The Algorithm for an N x N square pattern looks like;

   Set all cells to gray

   for x = 0 to N-1

      y = (x * multiplier + offset) % N

      cell (x,y) = blue
      cell (y, N - 1 - x) = blue
      cell (N - 1 - x, N - 1 - y) = blue
      cell (N - 1 - x, x) = blue

   next

Examples

What! You want examples? Just try it.