class curveSegment {
  float xStart, yStart, xB1, yB1, xB2, yB2, xEnd, yEnd;
  float currentXStart, currentYStart, currentXB1, currentYB1, currentXB2, currentYB2, currentXEnd, currentYEnd;
  float percentCompleted1, percentCompleted2, percentCompleted3;
  float drift1XB1, drift1YB1, drift1XB2, drift1YB2;
  float drift2XB1, drift2YB1, drift2XB2, drift2YB2;
  float vel1XB1, vel1YB1, vel1XB2, vel1YB2;
  float vel2XB1, vel2YB1, vel2XB2, vel2YB2;
  color curveColor, currentColor, blackout, fadein;
  int behaviorMode, totalFrames1, framesCompleted1, totalFrames2, framesCompleted2, totalFrames3, framesCompleted3;
  /* current behavior modes:
  0 = not drawing
  1 = static drawing (or evolving bezier points) with fading color
  2 = drawing from beginning to end (transitioning to mode 1 at completion)
  3 = drawing from beginning to end (transitioning to mode 4 at completion)
  4 = "erasing" from beginning to end
  */
  
  curveSegment() {
    blackout = color(1, 1, 1, 1);
    fadein = color(10, 10, 10, 10);
    behaviorMode = 0;
  }
  
  void initialize(float xa, float ya, float xb, float yb, float xc, float yc, float xd, float yd, color cc) {
    xStart = xa;
    yStart = ya;
    xB1 = xb;
    yB1 = yb;
    xB2 = xc;
    yB2 = yc;
    xEnd = xd;
    yEnd = yd;
    currentXStart = xa;
    currentYStart = ya;
    currentXB1 = xa;
    currentYB1 = ya;
    currentXB2 = xd;
    currentYB2 = yd;
    currentXEnd = xa;
    currentYEnd = yb;
    curveColor = cc;
  }
  
  void paint() {
    switch(behaviorMode) {
      case 1: 
        stroke(currentColor);
        bezier(xStart, yStart, currentXB1, currentYB1, currentXB2, currentYB2, xEnd, yEnd);
        bezier(xStart, yStart, drift1XB1, drift1YB1, drift1XB2, drift1YB2, xEnd, yEnd);
        bezier(xStart, yStart, drift2XB1, drift2YB1, drift2XB2, drift2YB2, xEnd, yEnd);
        break;
      case 2:
      case 3:
        stroke(currentColor);
        bezier(xStart, yStart, currentXB1, currentYB1, currentXB2, currentYB2, currentXEnd, currentYEnd);
        break;
      case 4:
        stroke(currentColor);
        bezier(currentXStart, currentYStart, currentXB1, currentYB1, currentXB2, currentYB2, xEnd, yEnd);
        break;
      default: break;
    }
  }
        
  void update() {
    switch(behaviorMode) {
      case 2:
      case 3:
        if(percentCompleted1 < 1.0) {
          framesCompleted1 = framesCompleted1 + 1;
          percentCompleted1 = float(framesCompleted1) / totalFrames1;
          currentXB1 = lerp(xStart, xB1, percentCompleted1);
          currentYB1 = lerp(yStart, yB1, percentCompleted1);
          currentXB2 = lerp(xStart, xB2, percentCompleted1); // changed End to Start
          currentYB2 = lerp(yStart, yB2, percentCompleted1); // changed End to Start
          currentXEnd = lerp(xStart, xEnd, percentCompleted1);
          currentYEnd = lerp(yStart, yEnd, percentCompleted1);
          currentColor = curveColor;
        } else if(behaviorMode == 2) {
          behaviorMode = 1;
          drift1XB1 = currentXB1;
          drift1YB1 = currentYB1;
          drift1XB2 = currentXB2;
          drift1YB2 = currentYB2;
          drift2XB1 = currentXB1;
          drift2YB1 = currentYB1;
          drift2XB2 = currentXB2;
          drift2YB2 = currentYB2;
        } else if(behaviorMode == 3) {
          behaviorMode = 4;
        }
        break; 
      case 4:
        if(percentCompleted3 < 1.0) {
          framesCompleted3 = framesCompleted3 + 1;
          percentCompleted3 = float(framesCompleted3) / totalFrames3;
          currentXStart = lerp(xStart, xEnd, percentCompleted3);
          currentYStart = lerp(yStart, yEnd, percentCompleted3);
          currentXB1 = lerp(xB1, xEnd, percentCompleted3);
          currentYB1 = lerp(yB1, yEnd, percentCompleted3);
          currentXB2 = lerp(xB2, xEnd, percentCompleted3);
          currentYB2 = lerp(yB2, yEnd, percentCompleted3);
          currentColor = curveColor;
        } else {
          behaviorMode = 0;
        }
      break;
      case 1:
        if(percentCompleted2 < 1.0) {
          framesCompleted2 = framesCompleted2 + 1;
          percentCompleted2 = float(framesCompleted2) / totalFrames2;
          currentColor = lerpColor(curveColor, blackout, percentCompleted2);
          drift1XB1 = drift1XB1 + vel1XB1;
          drift1YB1 = drift1YB1 + vel1YB1;
          drift1XB2 = drift1XB2 + vel1XB2;
          drift1YB2 = drift1YB2 + vel1YB2;
          drift2XB1 = drift2XB1 + vel2XB1;
          drift2YB1 = drift2YB1 + vel2YB1;
          drift2XB2 = drift2XB2 + vel2XB2;
          drift2YB2 = drift2YB2 + vel2YB2;
        } else {
          behaviorMode = 0;
        }
        break;
      default: break;
    }   
  }
  
  void activate(int f1, int f2, float v1, float v2, int b) {
    framesCompleted1 = 0;
    framesCompleted2 = 0;
    framesCompleted3 = 0;
    percentCompleted1 = 0.0;
    percentCompleted2 = 0.0;
    percentCompleted3 = 0.0;
    totalFrames1 = f1;
    totalFrames2 = f2;
    totalFrames3 = f2;
    behaviorMode = b;
    currentColor = fadein;
    vel1XB1 = random(v1, v2);
    vel1YB1 = random(v1, v2);
    vel1XB2 = random(v1, v2);
    vel1YB2 = random(v1, v2);
    vel2XB1 = random(v1, v2);
    vel2YB1 = random(v1, v2);
    vel2XB2 = random(v1, v2);
    vel2YB2 = random(v1, v2);
  }
}