Re: [Swarm-Support] question about coloring of the background, and leaving paths

[Paul E Johnson]

Rex Oleson wrote:
> Actually I have 2 seperate questions, but they might be related to each other.
>
> 1)
>   I was wondering how you go about leaving a trail behind and agent. To 
> demonstrate where he has been? I know I could do this by leaving an object and 
> setting the color of that object appropriately, but that seem like a lot of 
> work. I know also that in the termite program and a few others they appear to 
> use another.
>
> 2) 
>   Is there a way to set the background color of the simulation screen, instead of the standard black?

Here's a method from an observer swarm that rewrites each of NOFSPACES 
rasters with color 1 from the colormap you define.  Schedule that before 
you write on the raster and it will do what you want.

- eraseRaster
{
  // A method that overrides the default
  // black background for raster and paints
  // the raster white instead
  int i;
  for (i=0; i < NOFSPACES; i++)
    {
      [[rasters atOffset: i] fillRectangleX0: 0
                             Y0: 0
                             X1: [[modelSwarm getMDSpace] getMaxDim: 0]
                             Y1:  [[modelSwarm getMDSpace] getMaxDim: 1]
                             Color: 1];
    }
  return self;
}


If you erase the raster every time, then you will have to redraw the 
paths of your creatures every time.  In the past, I have found this 
works.  Create an object that can draw itself on the screen, and every 
time an agent goes somewhere, it creates one of these objects and puts 
it in a list.  Then redraw the list at each timestep.

Here's a method from a model swarm that draws objects in a voterList 
(which is the same everytime) as well as the "winnerList", a collection 
of objects that gets bigger each time a winner is chosen.  If you do it 
this way, you can customize the "draw objects" by having them put 
pixmaps on the screen saying "agent 1 started here" and so forth.

// This sweeps through the object that we want to draw
// themselves on the rasters, and it tells them to draw themselves.
- drawAgents
{
  id index;
  id anObject;
  index = [voterList begin: self];
  for ( anObject = [index next]; [index getLoc]==Member; 
anObject=[index next])
    {
      [anObject drawSelfOn: observerSwarm];//??last argument unnecessary
    }
  [index drop];

  index = [winnerList begin: self];
  for ( anObject = [index next]; [index getLoc]==Member; 
anObject=[index next])
    {
      [anObject drawSelfOn: observerSwarm];
    }
  [index drop];

  return self;
}


--
Paul E. Johnson                       email: address@hidden
Dept. of Political Science            http://lark.cc.ku.edu/~pauljohn
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