Added radius rescaling to simple env

pettingzoo/mpe/_mpe_utils/simple_env.py

@@ -12,6 +12,7 @@
 from pettingzoo.utils.agent_selector import AgentSelector
 
 alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+DYNAMIC_RESCALING = True
 
 
 def make_env(raw_env):
@@ -116,6 +117,11 @@ def __init__(
  dtype=np.float32,
  )
 
+ # Get the original cam_range
+ # This will be used to scale the rendering
+ all_poses = [entity.state.p_pos for entity in self.world.entities]
+ self.original_cam_range = np.max(np.abs(np.array(all_poses)))
+
  self.steps = 0
 
  self.current_actions = [None] * self.num_agents
@@ -295,6 +301,10 @@ def draw(self):
  all_poses = [entity.state.p_pos for entity in self.world.entities]
  cam_range = np.max(np.abs(np.array(all_poses)))
 
+ # The scaling factor is used for dynamic rescaling of the rendering - a.k.a Zoom In/Zoom Out effect
+ # The 0.9 is a factor to keep the entities from appearing "too" out-of-bounds
+ scaling_factor = 0.9 * self.original_cam_range / cam_range
+
  # update geometry and text positions
  text_line = 0
  for e, entity in enumerate(self.world.entities):
@@ -309,11 +319,18 @@ def draw(self):
  y = (y / cam_range) * self.height // 2 * 0.9
  x += self.width // 2
  y += self.height // 2
+
+ # 350 is an arbitrary scale factor to get pygame to render similar sizes as pyglet
+ if DYNAMIC_RESCALING:
+ radius = entity.size * 350 * scaling_factor
+ else:
+ radius = entity.size * 350
+
  pygame.draw.circle(
- self.screen, entity.color * 200, (x, y), entity.size * 350
- ) # 350 is an arbitrary scale factor to get pygame to render similar sizes as pyglet
+ self.screen, entity.color * 200, (x, y), radius
+ ) 
  pygame.draw.circle(
- self.screen, (0, 0, 0), (x, y), entity.size * 350, 1
+ self.screen, (0, 0, 0), (x, y), radius, 1
  ) # borders
  assert (
  0 < x < self.width and 0 < y < self.height