size(200, 200);
background(255);
noFill();
stroke(0);
int x1 = 0;
int x2 = width;
int y = 0;
int counter = 0;
int lineNum = 10;
int lineGap = height/lineNum;

while (counter<10){
line(x1,y,x2,y);
y=y+lineGap;
counter = counter+1;
}