Warp.pde

class Warp extends Routine {
  float r;
  float rofs;
  float warpSpeed;
  Routine subroutine;
  boolean warpHorizontal;
  boolean warpVertical;
  float warpFactor;

  public Warp() {
    this.subroutine = null;
    warpHorizontal = false;
    warpVertical = true;
    warpSpeed = 1;
    warpFactor = 1;
  }
  
  public Warp(Routine subroutine, boolean warpHorizontal, boolean warpVertical, float warpSpeed, float warpFactor) {
    this.subroutine = subroutine;
    this.warpHorizontal = warpHorizontal;
    this.warpVertical = warpVertical;
    this.warpSpeed = warpSpeed;
    this.warpFactor = warpFactor;
  }
  
  void setup(PApplet parent) {
    super.setup(parent);
    
    if (this.subroutine != null) {
      this.subroutine.setup(parent);
    }
  }
  
  void hshift(int y, int xofs) {
    if (xofs < 0) 
      xofs = width + xofs;

    PImage tmp = get(width-xofs,y,xofs,1);
    copy(0,y,width-xofs,1, xofs,y,width-xofs,1);    
    image(tmp,0,y);
  }

  void vshift(int x, int yofs) {
    if (yofs < 0) 
      yofs = height + yofs;

    PImage tmp = get(x,height-yofs,1,yofs);
    copy(x,0,1,height-yofs, x,yofs,1,height-yofs);    
    image(tmp,x,0);
  }

  void drawBackground() {
    if (subroutine != null) {
      subroutine.draw();
      
      if (subroutine.isDone) {
        newMode();
      }
    }
    else {
      background(0);
      fill(255);
      ellipseMode(CORNER);
      ellipse(0,0,width-1,height-1);
    }
  }
  
  void draw() {
    drawBackground();
    
    if (warpVertical) {
      for (int x=0; x<width; x++) {
        r = x*1.0/height*PI + rofs;
        vshift(x,int(sin(r)*(height*warpFactor)));
      }
      
      rofs += 0.0314 * warpSpeed;
    }

    if (warpHorizontal) {
      for (int y=0; y<height; y++) {
        r = y*1.0/width*PI + rofs;
        hshift(y,int(sin(r)*(width*warpFactor)));
      }
  
      rofs += 0.0314 * warpSpeed;
    }
  }
}