// Random Movement 1D

// Display settings
int picLeft = 40;
int picTop = 40;
int picWidth = 300;
int picHeight = 300;

void setup(){
  size(700,400);
  background(204,204,182);
  framerate(60);
  loadFonts();
  drawTitle();
  stroke(153,153,153);
}
 
void loop(){
  drawPixels();
}

void drawPixels(){
  //draws the pixelarray on screen
  float valueX = 0, valueY = 0;
  int lineX, lineY;
  int v;
  // cleanup right area
  fill(204,204,182);
  rect(picLeft+310, picTop, picWidth, picHeight);
  
  // x loop
  for (int i=1; i<=picWidth; i++){ 
    if (i==picHeight){   lineX = picLeft + 1; // last col
    }else{               lineX = picLeft +i+1; // i-1 col
    } 
    // y loop
    for (int j=1; j<=picHeight; j++){
      // calculate new value from neighbour in x direction, add error
      if (j==picHeight){ lineY = picTop + 1; // last row
      }else{             lineY = picTop +j+1; // j-1 row
      }
      valueX = red(get(lineX, picTop + j)) + alter();
      valueY = red(get(picLeft + i, lineY)) + alter();
      //check boundaries of new values
      valueX = max(min(valueX,255),0); 
      valueY = max(min(valueY,255),0); 
      
      // calculate value for the pixel
      // mid value:
      v =roundme((valueX + valueY)/2);
      // extreme:
      //float difX = valueX;
      // float difY = valueY;
      //if(abs(difX) < abs(difY)){
      //  v = int(valueX);
      //}else{ 
      //  v = int(valueY);
      //}
      
      color c = color(v,v,v);
      set(picLeft+i, picTop + j, c);   
    }
    // draw level indicator;
  set(picLeft+310+i, picTop+picHeight-int(valueX), color(255,127,0));
  }
}
  
public float alter(){
   // gives an error value +-
  float n = random(50)-25;
  return(n);
}

void drawTitle(){
  // Text Caption
  fill(102,102,102);
  text("_random movement 2D", 495, 375); 
}

void loadFonts(){
  BFont Univers65; 
  Univers65 = loadFont("Univers65.vlw.gz"); 
  textFont(Univers65, 18); 
}

public int roundme(float i){
  // round correctly (unless i find the java round function)
  int ii = int(i);
  float r = i-ii;
  if (r <.5){ return ii;}
  else{ return ii+1;}
}