class Background{
  float bgOpacity;
  int gridSpace = GRID_SPACE; //opacity of background and amount of space between grid lines
  int[] hgrid = new int[100];
  int[] vgrid = new int[100];
  int numVLines; 
  int numHLines; 
  int gridY;
  int gridX;


  //constructor
  Background(float bgo, int gs){
    bgOpacity = bgo;
    gridSpace = gs;
    numVLines = int(width/gridSpace);
    numHLines = int(height/gridSpace);
  }

  void display(){
    xyOffset();
    makeLineArrays();
    drawBackground();
    drawGrid();
    drawTray();
    drawTopTray();
  }

  void xyOffset(){
    gridY = gridSpace;  
    gridX = gridSpace;
  }

  void makeLineArrays(){
    for(int i=0; i<numHLines; i++){ //grid line array declaration
      hgrid[i] = gridY;
      gridY = gridY + gridSpace;
    }
    for(int i=0; i<numVLines; i++){
      vgrid[i] = gridX;
      gridX = gridX + gridSpace;
    }
  }

  void drawBackground(){
    fill(0, bgOpacity); //background color
    noStroke();
    rect(0,0, width, height);
  }

  void drawGrid(){
    stroke(34,48,188); //grid line color
    strokeWeight(.5); //grid line stroke
    for(int i = 0; i<numVLines; i++){
      line(vgrid[i],0, vgrid[i],height);
    }  
    for(int i = 0; i<numHLines; i++){
      line(0,hgrid[i], width,hgrid[i]);
    }
    drawThickerLines();
  }

  void drawTray(){
    fill(0);
    stroke(152,20,20);
    strokeWeight(5);
    rect(0,(height - (gridSpace*2)), width-1,(gridSpace*2));//draw the bottom tray
  }
  
  void drawTopTray(){
    fill(0);
    stroke(152,20,20);
    strokeWeight(5);
    rect(0, 0, width-1,(gridSpace*2));
  }
  
  void drawThickerLines(){
    strokeWeight(2);
    line(0,(height - (GRID_SPACE * 6)), width, (height - (GRID_SPACE * 6)));
    line(0,(height - (GRID_SPACE * 10)), width, (height - (GRID_SPACE * 10)));
    line(0,(height - (GRID_SPACE * 14)), width, (height - (GRID_SPACE * 14)));
    line(0,(height - (GRID_SPACE * 18)), width, (height - (GRID_SPACE * 18)));
  }
}