Cannon: Use the cannon's and badguy's bounding boxes to calculate the starting position.

The previous code assumed width of no more than 32 pixels to work correctly.
mathnerd314's change in revision 6530 widened that a bit, but could only be
considered a dirty hack. This change should work for arbitrary badguy widths,
moving narrow badguys (Short Fuse, for example) closer to the Cannon when shot
to the left.

git-svn-id: http://supertux.lethargik.org/svn/supertux/trunk/supertux@6542 837edb03-e0f3-0310-88ca-d4d4e8b29345

diff --git a/src/badguy/dispenser.cpp b/src/badguy/dispenser.cpp
index 19ac634..a3db52a 100644 (file)
--- a/src/badguy/dispenser.cpp
+++ b/src/badguy/dispenser.cpp
@@ -200,22 +200,42 @@ Dispenser::launch_badguy()
       return;
     }
 
-    GameObject* badguy_object = NULL;
-
     try {
+      GameObject *game_object;
+      MovingObject *moving_object;
       Vector spawnpoint;
+      Rectf object_bbox;
+
+      /* Need to allocate the badguy first to figure out its bounding box. */
+      game_object = ObjectFactory::instance().create(badguy, get_pos(), launchdir);
+      if (game_object == NULL)
+        throw std::runtime_error("Creating " + badguy + " object failed.");
+
+      moving_object = dynamic_cast<MovingObject *> (game_object);
+      if (moving_object == NULL)
+        throw std::runtime_error(badguy + " is not a moving object.");
 
-      if (type == "dropper")
-        spawnpoint = Vector(get_pos().x, get_pos().y+get_bbox().get_height()+8);
-      else if (type == "cannon")
-        spawnpoint = Vector(get_pos().x + (launchdir == LEFT ? -32 : get_bbox().get_width()+3), get_pos().y);
-      else if (type == "rocketlauncher")
-        spawnpoint = Vector(get_pos().x + (launchdir == LEFT ? -32 : get_bbox().get_width()+3), get_pos().y);
+      object_bbox = moving_object->get_bbox ();
+
+      if (type == "dropper") {
+        spawnpoint = get_anchor_pos (get_bbox (), ANCHOR_BOTTOM);
+        spawnpoint.x -= 0.5 * object_bbox.get_width ();
+      }
+      else if ((type == "cannon") || (type == "rocketlauncher")) {
+        spawnpoint = get_pos (); /* top-left corner of the cannon */
+        if (launchdir == LEFT)
+          spawnpoint.x -= object_bbox.get_width () + 1;
+        else
+          spawnpoint.x += get_bbox ().get_width () + 1;
+      }
 
-      badguy_object = ObjectFactory::instance().create(badguy, spawnpoint, launchdir);
+      /* Now we set the real spawn position */
+      log_debug << "Cannong bbox: " << get_bbox () << std::endl;
+      log_debug << "Badguy width: " << object_bbox.get_width () << std::endl;
+      log_debug << "New badguy's spawnpoint: " << spawnpoint << std::endl;
+      moving_object->set_pos (spawnpoint);
 
-      if (badguy_object)
-        Sector::current()->add_object(badguy_object);
+      Sector::current()->add_object(moving_object);
     } catch(std::exception& e) {
       log_warning << "Error dispensing badguy: " << e.what() << std::endl;
       return;