// // SuperTuxKart - a fun racing game with go-kart // Copyright (C) 2011-2015 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 #include "items/flyable.hpp" #include "tracks/track_sector.hpp" class AbstractKart; 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; /** Timer before another rubber ball can be picked up. This is to ensure * that there are not too many rubber balls on the track in races with many * karts. */ static int m_ticks_between_balls; /** 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 AbstractKart *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; /** To simplify code this stores the previous height above terrain * used. */ float m_previous_height; /** 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; /** This variable counts how often a ball tunneled (in consecutive * frames). If a ball tunnels a certain number of times, it is * considered stuck and will be removed. */ unsigned int m_tunnel_count; /** A 'ping' sound effect to be played when the ball hits the ground. */ SFXBase *m_ping_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 getTunnelHeight(const Vec3 &next_xyz, const float vertical_offset) const; bool checkTunneling(); public: RubberBall (AbstractKart* kart); virtual ~RubberBall(); static void init(const XMLNode &node, scene::IMesh *rubberball); virtual bool updateAndDelete(float dt); virtual bool hit(AbstractKart* kart, PhysicalObject* obj=NULL); virtual void setAnimation(AbstractKartAnimation *animation); // ------------------------------------------------------------------------ /** Returns time (in ticks) between rubberballs, to avoid that in games * with many karts too many rubber balls are in play at the same time. */ static int getTicksBetweenRubberBalls() { return m_ticks_between_balls; } // ------------------------------------------------------------------------ /** 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