//3 Dimension (pond ) to 2 dimension (line)===condensed dimension. //the moving dot is me.....
// shrinken square is a pond.
//when I move to outside of 100*100 dbn space, shape of the pond
//which I see looks like a line...( that is viewpoint ....)
repeat a 80 200
{
field (a-50) a (a-45) (a+5) 0
paper 100
field 10 30 110 130 20
smaller? a 125
{
field 30 35 90 (160-a) 50
}
notsmaller? a 125
{
field 30 35 90 35 50
}
}