From 18d77b9da190cf0d68d8890a891cb1b033438b44 Mon Sep 17 00:00:00 2001
From: hikerstk <hikerstk@178a84e3-b1eb-0310-8ba1-8eac791a3b58>
Date: Sun, 9 Sep 2012 22:41:49 +0000
Subject: [PATCH] Improved handling of zippers: zippers will now be selected
 earlier (previously a kart needed 2.0 nitro in order to use a zipper), but
 won't be used if items to avoid are close by (since zipper make it harder to
 avoid them).

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@11571 178a84e3-b1eb-0310-8ba1-8eac791a3b58
---
 data/stk_config.xml                    |  3 ++
 src/karts/controller/ai_properties.cpp | 27 +++++++++--------
 src/karts/controller/ai_properties.hpp |  3 ++
 src/karts/controller/skidding_ai.cpp   | 42 +++++++++++++++++++++-----
 src/karts/controller/skidding_ai.hpp   |  4 +++
 5 files changed, 59 insertions(+), 20 deletions(-)

diff --git a/data/stk_config.xml b/data/stk_config.xml
index eeaa30798..15f1cd221 100644
--- a/data/stk_config.xml
+++ b/data/stk_config.xml
@@ -216,10 +216,13 @@
            to avoid hitting a bad item. If the distance is larger, it is
            assumed that there will be enough time to change steering
            direction.
+         straight-length-for-zipper is the minimum length a straight
+           section of the track should have in order to activate a zipper.
     -->
     <ai max-item-angle="0.7" max-item-angle-high-speed="0.3"
         time-full-steer="0.1"
         bad-item-closeness="6"
+        straight-length-for-zipper="35"
     />
 
     <!-- Slipstream: length: How far behind a kart slipstream works
diff --git a/src/karts/controller/ai_properties.cpp b/src/karts/controller/ai_properties.cpp
index eb865de96..9f11383ec 100644
--- a/src/karts/controller/ai_properties.cpp
+++ b/src/karts/controller/ai_properties.cpp
@@ -26,10 +26,11 @@ float AIProperties::UNDEFINED = -99.9f;
  */
 AIProperties::AIProperties()
 {
-    m_max_item_angle            = UNDEFINED;
-    m_max_item_angle_high_speed = UNDEFINED;
-    m_time_full_steer           = UNDEFINED;
-    m_bad_item_closeness_2      = UNDEFINED;
+    m_max_item_angle             = UNDEFINED;
+    m_max_item_angle_high_speed  = UNDEFINED;
+    m_time_full_steer            = UNDEFINED;
+    m_bad_item_closeness_2       = UNDEFINED;
+    m_straight_length_for_zipper = UNDEFINED;
 }   // AIProperties
 
 // ----------------------------------------------------------------------------
@@ -38,10 +39,11 @@ AIProperties::AIProperties()
  */
 void AIProperties::load(const XMLNode *ai_node)
 {
-    ai_node->get("max-item-angle",            &m_max_item_angle           );
-    ai_node->get("max-item-angle-high-speed", &m_max_item_angle_high_speed);
-    ai_node->get("time-full-steer",           &m_time_full_steer          );
-    ai_node->get("bad-item-closeness",        &m_bad_item_closeness_2     );
+    ai_node->get("max-item-angle",            &m_max_item_angle            );
+    ai_node->get("max-item-angle-high-speed", &m_max_item_angle_high_speed );
+    ai_node->get("time-full-steer",           &m_time_full_steer           );
+    ai_node->get("bad-item-closeness",        &m_bad_item_closeness_2      );
+    ai_node->get("straight-length-for-zipper",&m_straight_length_for_zipper);
 
     // We actually need the square of the distance later
     m_bad_item_closeness_2 *= m_bad_item_closeness_2;
@@ -59,10 +61,11 @@ void AIProperties::checkAllSet(const std::string &filename) const
         fprintf(stderr,"Missing default value for '%s' in '%s'.\n",    \
                 str_a,filename.c_str());exit(-1);                      \
     }
-    CHECK_NEG(m_max_item_angle,            "max-item-angle"           );
-    CHECK_NEG(m_max_item_angle_high_speed, "max-item-angle-high-speed");
-    CHECK_NEG(m_time_full_steer,           "time-full-steer"          );
-    CHECK_NEG(m_bad_item_closeness_2,      "bad-item-closeness"       );
+    CHECK_NEG(m_max_item_angle,            "max-item-angle"            );
+    CHECK_NEG(m_max_item_angle_high_speed, "max-item-angle-high-speed" );
+    CHECK_NEG(m_time_full_steer,           "time-full-steer"           );
+    CHECK_NEG(m_bad_item_closeness_2,      "bad-item-closeness"        );
+    CHECK_NEG(m_straight_length_for_zipper,"straight-length-for-zipper");
 
 }   // checkAllSet
 
diff --git a/src/karts/controller/ai_properties.hpp b/src/karts/controller/ai_properties.hpp
index 3c3d805ad..1a9dc9342 100644
--- a/src/karts/controller/ai_properties.hpp
+++ b/src/karts/controller/ai_properties.hpp
@@ -64,6 +64,9 @@ protected:
      *   of karts). */
     float m_time_full_steer;
 
+    /** Minimum length of a straight in order to activate a zipper. */
+    float m_straight_length_for_zipper;
+
 public:
 
          AIProperties();
diff --git a/src/karts/controller/skidding_ai.cpp b/src/karts/controller/skidding_ai.cpp
index 69d34731e..280f8ecd2 100644
--- a/src/karts/controller/skidding_ai.cpp
+++ b/src/karts/controller/skidding_ai.cpp
@@ -23,7 +23,7 @@
 //to 2 in main.cpp with quickstart and run supertuxkart with the arg -N.
 #ifdef DEBUG
    // Enable AeI graphical debugging
-#  undef AI_DEBUG
+#  define AI_DEBUG
    // Shows left and right lines when using new findNonCrashing function
 #  undef AI_DEBUG_NEW_FIND_NON_CRASHING
    // Show the predicted turn circles
@@ -31,7 +31,7 @@
    // Show the heading of the kart
 #  undef AI_DEBUG_KART_HEADING
    // Shows line from kart to its aim point
-#  undef AI_DEBUG_KART_AIM
+#  define AI_DEBUG_KART_AIM
 #endif
 
 #include "karts/controller/skidding_ai.hpp"
@@ -196,12 +196,13 @@ SkiddingAI::SkiddingAI(AbstractKart *kart)
     m_curve[CURVE_QG]        = new ShowCurve(0.5f, 0.5f, 
                                    irr::video::SColor(128,   0, 128,   0));
 #ifdef AI_DEBUG_KART_AIM
+    irr::video::SColor c1;
     if(m_item_behaviour == ITEM_COLLECT_PRIORITY)
-        c = irr::video::SColor(128,   0,   0, 128);
+        c1 = irr::video::SColor(128,   0,   0, 128);
     else
-        c = irr::video::SColor(128,   0, 128,   0);
+        c1 = irr::video::SColor(128,   0, 128,   0);
 
-    m_curve[CURVE_AIM]       = new ShowCurve(0.5f, 0.5f, c);
+    m_curve[CURVE_AIM]       = new ShowCurve(0.5f, 0.5f, c1);
 #endif
 #endif
 
@@ -240,6 +241,7 @@ void SkiddingAI::reset()
     m_curve_center               = Vec3(0,0,0);
     m_current_track_direction    = GraphNode::DIR_STRAIGHT;
     m_item_to_collect            = NULL;
+    m_avoid_item_close           = false;
 
     AIBaseController::reset();
     m_track_node               = QuadGraph::UNKNOWN_SECTOR;
@@ -392,11 +394,12 @@ void SkiddingAI::update(float dt)
             handleNitroAndZipper();
     }
     // If we are supposed to use nitro, but have a zipper, 
-    // use the zipper instead
+    // use the zipper instead (unless there are items to avoid cloe by)
     if(m_controls->m_nitro && 
         m_kart->getPowerup()->getType()==PowerupManager::POWERUP_ZIPPER && 
         m_kart->getSpeed()>1.0f && 
-        m_kart->getSpeedIncreaseTimeLeft(MaxSpeed::MS_INCREASE_ZIPPER)<=0)
+        m_kart->getSpeedIncreaseTimeLeft(MaxSpeed::MS_INCREASE_ZIPPER)<=0 &&
+        !m_avoid_item_close)
     {
         // Make sure that not all AI karts use the zipper at the same
         // time in time trial at start up, so during the first 5 seconds
@@ -626,7 +629,7 @@ void SkiddingAI::handleItemCollectionAndAvoidance(Vec3 *aim_point,
         if(node==last_node) break;
     }   // while (distance < max_item_lookahead_distance)
 
-
+    m_avoid_item_close = items_to_avoid.size()>0;
 
     core::line2df line_to_target(aim_point->getX(), 
                                  aim_point->getZ(),
@@ -1396,6 +1399,11 @@ void SkiddingAI::handleNitroAndZipper()
           m_item_tactic==IT_TEN_SECONDS                                    ) )
         return;
 
+    // If there are items to avoid close, and we only have zippers, don't
+    // use them (since this make it harder to avoid items).
+    if(m_avoid_item_close &&
+        (m_kart->getEnergy()==0|| m_nitro_level==NITRO_NONE) )
+        return;
     // If a parachute or anvil is attached, the nitro doesn't give much
     // benefit. Better wait till later.
     const bool has_slowdown_attachment = 
@@ -1459,6 +1467,24 @@ void SkiddingAI::handleNitroAndZipper()
         return;
     }
     
+    if(m_kart->getPowerup()->getType()==PowerupManager::POWERUP_ZIPPER &&
+        m_kart->getSpeed()>1.0f && 
+        m_kart->getSpeedIncreaseTimeLeft(MaxSpeed::MS_INCREASE_ZIPPER)<=0)
+    {
+        GraphNode::DirectionType dir;
+        unsigned int last;
+        const GraphNode &gn = QuadGraph::get()->getNode(m_track_node);
+        gn.getDirectionData(m_successor_index[m_track_node], &dir, &last);
+        if(dir==GraphNode::DIR_STRAIGHT)
+        {
+            float diff = QuadGraph::get()->getDistanceFromStart(last)
+                       - QuadGraph::get()->getDistanceFromStart(m_track_node);
+            if(diff<0) diff+=World::getWorld()->getTrack()->getTrackLength();
+            if(diff>m_ai_properties->m_straight_length_for_zipper)
+                m_controls->m_fire = true;
+        }
+        
+    }
 }   // handleNitroAndZipper
 
 //-----------------------------------------------------------------------------
diff --git a/src/karts/controller/skidding_ai.hpp b/src/karts/controller/skidding_ai.hpp
index 26fa8884a..8fe7339c4 100644
--- a/src/karts/controller/skidding_ai.hpp
+++ b/src/karts/controller/skidding_ai.hpp
@@ -146,6 +146,10 @@ private:
     /** If set an item that the AI should aim for. */
     const Item *m_item_to_collect;
 
+    /** True if items to avoid are close by. Used to avoid using zippers
+     *  (which would make it more difficult to avoid items). */
+    bool m_avoid_item_close;
+
     /** True if the new findNonCrashingPoint2 function should be used. */
     bool m_use_new_aim_point_selection;