// Weave by John Clavin

void setup() {
  size(780, 482);
  frameRate(6);
  background(255);
  strokeCap(SQUARE);
  strokeWeight(14);
}

int rVert = int(random(50, 200));
int gVert = int(random(50, 200));
int bVert = int(random(50, 200));
int rHorz = int(random(50, 200));
int gHorz = int(random(50, 200));
int bHorz = int(random(50, 200));
boolean rVertDir = true;
boolean gVertDir = true;
boolean bVertDir = false;
boolean rHorzDir = false;
boolean gHorzDir = true;
boolean bHorzDir = false;

void draw() {
  rVertDir = directionChk(rVert, rVertDir);
  rVert = sequence(rVert, rVertDir);
  gVertDir = directionChk(gVert, gVertDir);
  gVert = sequence(gVert, gVertDir);
  bVertDir = directionChk(bVert, bVertDir); 
  bVert = sequence(bVert, bVertDir);   
  for(int x = 0; x <= width; x = x + 20) {
    stroke(rVert, gVert, bVert);
    line(x, 0, x, height);
  }

  rHorzDir = directionChk(rHorz, rHorzDir);
  rHorz = sequence(rHorz, rHorzDir);
  gHorzDir = directionChk(gHorz, gHorzDir); 
  gHorz = sequence(gHorz, gHorzDir);
  bHorzDir = directionChk(bHorz, bHorzDir); 
  bHorz = sequence(bHorz, bHorzDir); 
  for(int y = 0; y <= height; y = y + 40) {
    stroke(rHorz, gHorz, bHorz);
    int widthAcum1 = 0;
    int widthAcum2 = 0;
    line(0, y + 20, 13, y + 20);
    for(int index = 7; index <= width; index = index + 40) {
      widthAcum1 = index;
      widthAcum2 = widthAcum1 + 26;
      line(widthAcum1, y, widthAcum2, y);
      widthAcum1 = index + 20;
      widthAcum2 = widthAcum1 + 26;
      line(widthAcum1, y + 20, widthAcum2, y + 20);
    }
  }
}

int sequence(int number, boolean direction) {
  if(direction == true) {
    number = number + 1;
  }
  else {
    number = number - 1; 
  }
  return number;
}

boolean directionChk(int number, boolean direction) {
  if(3 > random(800))
    direction = !direction;
  if(number > 245)
    direction = false;
  if(number < 10)
    direction = true;
  return direction;  
}