Stop an if argument

hi everyone i'm here asking for your help i've been practicing codding on processing for a month now but i've come to met a big problem right now:

float w=10;   //haut
float x=14;  //haut
float y=10;   // bas
float z=24;  // bas



void setup() { 
frameRate(120);
size(600,600);
background (0);
stroke(255);
smooth();

}

void draw() {
println(frameCount);


line (w,x,y,z);
w=w+10;
x=x;
y=y+10;
z=z;
if ( (w>580) && ( y>580 ) && (frameCount<601)  ) { x=x+30;  w=10;   
z=z+30;      y=10;}

the thing is that i want the line to be a bit bended from the 601 frame

like that [1]: http://ift.tt/2filLss

thanks !