stk-code_catmod/src/items/rubber_ball.hpp
hikerstk b9e4325560 Added 'early targeting': the rubber ball will align its relative position
to the center of the track according to the relative distance of its target
(more precisely: it will move the interpolation control points). This
results in the ball being better align when it switches to aim-directly-at-
target mode, meaning that the target-distance can be reduced, hopefully
reducing the frequency with which tunneling happens.


git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@10016 178a84e3-b1eb-0310-8ba1-8eac791a3b58
2011-10-18 20:14:03 +00:00

205 lines
8.5 KiB
C++

// $Id$
//
// SuperTuxKart - a fun racing game with go-kart
// Copyright (C) 2011 Joerg Henrichs
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 3
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#ifndef HEADER_RUBBER_BALL_HPP
#define HEADER_RUBBER_BALL_HPP
#include <irrString.h>
#include "items/flyable.hpp"
#include "tracks/track_sector.hpp"
class Kart;
class QuadGraph;
class SFXBase;
/**
* \ingroup items
*/
class RubberBall: public Flyable, public TrackSector
{
private:
/** Used in case of flyable debugging so that each output line gets
* a unique number for each ball. */
int m_id;
/** A class variable which stores the next id number to use. */
static int m_next_id;
/** A class variable to store the default interval size. */
static float m_st_interval;
/** A class variable to store the default squash duration. */
static float m_st_squash_duration;
/** A class variable to store the default squash slowdown. */
static float m_st_squash_slowdown;
/** If the ball is closer than this distance to the target, it will
* start to aim directly at the target (and not interpolate anymore). */
static float m_st_target_distance;
/** In somce track, e.g. subsea track, it is possible that the karts
* are on different parts of the track (different shortcuts), but
* still close to each other - because one of the parts is just
* on top of the other part. Therefore use the height as additional
* criteria to determine if a ball is close to its target. */
static float m_st_max_height_difference;
/** Distance between ball and target at which the ball will start to
* bounce faster (which makes more 'ping' sfx for the driver to
* hear it coming closer, but also higher probability to hit the
* target and not fly over it). */
static float m_st_fast_ping_distance;
/** The maximum angle the ball can change per second when being close
* to the taregt. If the target angle is small, it makes it much harder
* to hit the target, giving it some chances to escape. */
static float m_st_target_max_angle;
/** Each control point chosen must be at least this far away from
* the previous one. This gives smooth 'overall' interpolation
* even if the quads should be close to each other. */
static float m_st_min_interpolation_distance;
/** If the ball overtakes its target or starts to aim at the kart which
* originally shot the rubber ball, after this amount of time the
* ball will be deleted. */
static float m_st_delete_time;
/** This factor is used to influence how much the rubber ball should aim
* at its target early. It used the 'distance to center of track' of its
* target, and adjusts the interpolation control points to be more or
* less at the same (relative) distance from center. If the factor is
* 1, the rubber ball will aim to be at the same relative distance,
* if the factor is 0, the rubber ball will aim directly at the
* driveline points. A factor of 1 usually means that by the time
* the ball starts aiming directly at the target it is (nearly) on the
* same 'line', meaning it only has to go straight. On the other hand
* in a tunnel this might result in the ball being too far to the
* side, increasing the likelihood of the ball tunneling through
* (which can happen when the ball switches to aim-at-target mode,
* in a tight curve, so that the direct line to the target goes through
* a wall. */
static float m_st_early_target_factor;
/** A pointer to the target kart. */
const Kart *m_target;
/** The last graph node who's coordinates are stored in
* m_control_points[3]. */
int m_last_aimed_graph_node;
/** Keep the last two, current, and next aiming points
* for interpolation. */
Vec3 m_control_points[4];
/** Saves the previous location of the ball. This is needed if a ball
* should lose it target, and has to reinitialise the control points
* for the interpolation. */
Vec3 m_previous_xyz;
/** Estimated length of the spline between the control points
* 1 and 2. */
float m_length_cp_1_2;
/** Estimated length of the spline between the control points
* 2 and 3. */
float m_length_cp_2_3;
/** The parameter for the spline, m_t in [0,1]. This is not directly
* related to the time, since depending on the distance between
* the two control points different increments must be used for m_t.
* For example, if the distance is 10 m, and assuming a speed of
* 10 m/s for the ball, then each second must add '1' to m_t. If
* the distance on the other hand is 200 m, then 10/200 = 1/20 per
* second must be added (so that it takes 20 seconds to move from 0
* to 1). */
float m_t;
/** How much m_t must increase per second in order to maintain a
* constant speed, i.e. the speed of the ball divided by the
* distance between the control points. See m_t for more details. */
float m_t_increase;
/** How long it takes from one bounce of the ball to the next. */
float m_interval;
/** This flag is set if the target is within the fast ping distance. It
* will cause the rubber ball to decrese the jump height and intervall. */
bool m_fast_ping;
/** Distance to target. This is measured in terms of 'distance along
* track', but also takes the 3d distance and height difference into
* account (in case that the target is on a different part of the
* track) */
float m_distance_to_target;
/** This timer is used to determine the height depending on the time.
* It is always between 0 and m_interval. */
float m_height_timer;
/** If the ball overtakes its target or starts to aim at the kart which
* originally shot the rubber ball, after a certain amount of time the
* ball will be deleted. This timer tracks this time. If it is < 0
* it indicates that the ball is targeting another kart atm. */
float m_delete_timer;
/** The current maximum height of the ball. This value will be
* reduced if the ball gets closer to the target. */
float m_current_max_height;
/** Once the ball is close enough, it will aim for the kart. If the
* kart should be able to then increase the distance to the ball,
* the ball will be removed and the kart escapes. This boolean is
* used to keep track of the state of this ball. */
bool m_aiming_at_target;
/** A 'ping' sound effect to be played when the ball hits the ground. */
SFXBase *m_ping_sfx;
/** Sound effect to be played when a ball hits a kart. */
SFXBase *m_hit_sfx;
void computeTarget();
void updateDistanceToTarget();
unsigned int getSuccessorToHitTarget(unsigned int node_index,
float *f=NULL);
void getNextControlPoint();
float updateHeight();
void interpolate(Vec3 *next_xyz, float dt);
void moveTowardsTarget(Vec3 *next_xyz, float dt);
void initializeControlPoints(const Vec3 &xyz);
float getMaxTerrainHeight(const Vec3 &vertical_offset) const;
public:
RubberBall (Kart* kart);
virtual ~RubberBall();
static void init(const XMLNode &node, scene::IMesh *bowling);
virtual bool updateAndDelete(float dt);
virtual bool hit(Kart* kart, PhysicalObject* obj=NULL);
virtual const core::stringw getHitString(const Kart *kart) const;
// ------------------------------------------------------------------------
/** This object does not create an explosion, all affects on
* karts are handled by this hit() function. */
//virtual HitEffect *getHitEffect() const {return NULL; }
}; // RubberBall
#endif