From 9ec9b558e82b12be82072a12092390dc48ad707a Mon Sep 17 00:00:00 2001
From: Matthias Braun <matze@braunis.de>
Date: Sat, 20 May 2006 12:10:49 +0000
Subject: [PATCH] some comments about collision detection

SVN-Revision: 3551
---
 src/moving_object.hpp | 35 ++++++++++++++++++++++++++++++++---
 src/object/player.cpp |  5 ++---
 src/sector.hpp        | 20 +++++++++++++++++---
 3 files changed, 51 insertions(+), 9 deletions(-)

diff --git a/src/moving_object.hpp b/src/moving_object.hpp
index d18615f1b..2981829e9 100644
--- a/src/moving_object.hpp
+++ b/src/moving_object.hpp
@@ -30,15 +30,44 @@ class Sector;
 class CollisionGrid;
 
 enum CollisionGroup {
+  /** Objects in DISABLED group are not tested for collisions */
   COLGROUP_DISABLED,
+  /**
+   * "default" is moving object. MovingObjects get tested against all other
+   * objects and against other movingobjects
+   */
   COLGROUP_MOVING,
-  // moving object but don't collide against other moving objects
+  /**
+   * a Moving object, that is not tested against other MovingObjects (or other
+   * MovingOnlyStatic objects), but is tested against all other objects.
+   */
   COLGROUP_MOVING_ONLY_STATIC,
+  /**
+   * Doesn't move and isn't explicitely checked for collisions with other
+   * objects (but other objects might check with this)
+   * The difference to COLGROUP_TOUCHABLE is that we can do multiple
+   * collision response tests in a row which is needed for static object
+   * that tux walks on. The results for collisions with STATIC objects
+   * are also sorted by time (so that the first hit gets handled first).
+   *
+   * Use this for static obstacles
+   */
   COLGROUP_STATIC,
-  COLGROUP_MOVINGSTATIC,
+  /**
+   * Isn't explicitely checked for collisions with other objects. But other
+   * objects might check with this object.
+   * Difference to COLGROUP_STATIC is that collisions with this object are
+   * only tested once and collision response is typically not handled
+   *
+   * Use this for touchable things like spikes/areas or collectibles like
+   * coins
+   */
   COLGROUP_TOUCHABLE,
   
-  COLGROUP_TILEMAP /* not really used at the moment */
+  /**
+   * Should be used for tilemaps
+   */
+  COLGROUP_TILEMAP
 };
 
 /**
diff --git a/src/object/player.cpp b/src/object/player.cpp
index 14c20e3b0..80046081a 100644
--- a/src/object/player.cpp
+++ b/src/object/player.cpp
@@ -855,7 +855,7 @@ Player::collision(GameObject& other, const CollisionHit& hit)
 
   BadGuy* badguy = dynamic_cast<BadGuy*> (&other);
   if(badguy != NULL) {
-    if(safe_timer.started())
+    if(safe_timer.started() || invincible_timer.started())
       return FORCE_MOVE;
 
     return CONTINUE;
@@ -879,8 +879,7 @@ Player::kill(bool completely)
   if(dying || deactivated)
     return;
 
-  if(!completely && 
-      (safe_timer.get_timeleft() > 0 || invincible_timer.get_timeleft() > 0))
+  if(!completely && safe_timer.started() || invincible_timer.started())
     return;                          
   
   sound_manager->play("sounds/hurt.wav");
diff --git a/src/sector.hpp b/src/sector.hpp
index 7a973966d..7a7a7425e 100644
--- a/src/sector.hpp
+++ b/src/sector.hpp
@@ -156,14 +156,28 @@ private:
   void try_expose(GameObject* object);
   void try_unexpose(GameObject* object);
   
-  bool collision_static(MovingObject* object, const Vector& movement);
-  
   /** Checks for all possible collisions. And calls the
       collision_handlers, which the collision_objects provide for this
       case (or not). */
   void handle_collisions();
-  
+ 
+  /**
+   * Collision checks 2 objects against each other and does instant
+   * collision response handling in case of a collision
+   */
   void collision_object(MovingObject* object1, MovingObject* object2) const;
+
+  /**
+   * Does collision detection of an object against all other static
+   * objects (and the tilemap) in the level. Collisions are sorted
+   * and collision response against the first hit is done.
+   *
+   * returns true if the collision detection should be aborted for this object
+   * (because of ABORT_MOVE in the collision response)
+   */
+  bool collision_static(MovingObject* object, const Vector& movement);
+
+  
   GameObject* parse_object(const std::string& name, const lisp::Lisp& lisp);
 
   void fix_old_tiles();
-- 
2.11.0