const float GRID_PIXEL = 75.0;
// how many frames to ignore when computing next iteration of game of life.
// Frame-Rate = fps/FRAME_INTERLACE
const int FRAME_INTERLACE = 10;

// pixelize
float pixelize(in float x)
{
    return floor(x * GRID_PIXEL)/GRID_PIXEL;
}

vec2 pixelize(in vec2 x)
{
    return floor(x * GRID_PIXEL)/GRID_PIXEL;
}