godot/servers/physics_2d/body_2d_sw.h
PouleyKetchoupp 9c9e528e3e Fix point gravity calculation
Removing the + 1 in point gravity formula when using distance scale to
make it more accurate for standard gravitation.

Fixes precession in orbits for games using gravitation.

Also moved gravity calculation to area to use it for both rigid bodies
and soft bodies in 3D (same change in 2D for consistency).

Co-authored-by: Ryan Peach <ryan.peach@keysight.com>
2021-08-24 09:32:28 -07:00

419 lines
16 KiB
C++

/*************************************************************************/
/* body_2d_sw.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
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#ifndef BODY_2D_SW_H
#define BODY_2D_SW_H
#include "area_2d_sw.h"
#include "collision_object_2d_sw.h"
#include "core/templates/list.h"
#include "core/templates/pair.h"
#include "core/templates/vset.h"
class Constraint2DSW;
class Body2DSW : public CollisionObject2DSW {
PhysicsServer2D::BodyMode mode;
Vector2 biased_linear_velocity;
real_t biased_angular_velocity;
Vector2 linear_velocity;
real_t angular_velocity;
real_t linear_damp;
real_t angular_damp;
real_t gravity_scale;
real_t mass;
real_t inertia;
real_t bounce;
real_t friction;
real_t _inv_mass;
real_t _inv_inertia;
bool user_inertia;
Vector2 gravity;
real_t area_linear_damp;
real_t area_angular_damp;
real_t still_time;
Vector2 applied_force;
real_t applied_torque;
SelfList<Body2DSW> active_list;
SelfList<Body2DSW> inertia_update_list;
SelfList<Body2DSW> direct_state_query_list;
VSet<RID> exceptions;
PhysicsServer2D::CCDMode continuous_cd_mode;
bool omit_force_integration;
bool active;
bool can_sleep;
bool first_time_kinematic;
bool first_integration;
void _update_inertia();
virtual void _shapes_changed();
Transform2D new_transform;
List<Pair<Constraint2DSW *, int>> constraint_list;
struct AreaCMP {
Area2DSW *area;
int refCount;
_FORCE_INLINE_ bool operator==(const AreaCMP &p_cmp) const { return area->get_self() == p_cmp.area->get_self(); }
_FORCE_INLINE_ bool operator<(const AreaCMP &p_cmp) const { return area->get_priority() < p_cmp.area->get_priority(); }
_FORCE_INLINE_ AreaCMP() {}
_FORCE_INLINE_ AreaCMP(Area2DSW *p_area) {
area = p_area;
refCount = 1;
}
};
Vector<AreaCMP> areas;
struct Contact {
Vector2 local_pos;
Vector2 local_normal;
real_t depth;
int local_shape;
Vector2 collider_pos;
int collider_shape;
ObjectID collider_instance_id;
RID collider;
Vector2 collider_velocity_at_pos;
};
Vector<Contact> contacts; //no contacts by default
int contact_count;
struct ForceIntegrationCallback {
Callable callable;
Variant callback_udata;
};
ForceIntegrationCallback *fi_callback;
uint64_t island_step;
_FORCE_INLINE_ void _compute_area_gravity_and_damping(const Area2DSW *p_area);
friend class PhysicsDirectBodyState2DSW; // i give up, too many functions to expose
public:
void set_force_integration_callback(const Callable &p_callable, const Variant &p_udata = Variant());
_FORCE_INLINE_ void add_area(Area2DSW *p_area) {
int index = areas.find(AreaCMP(p_area));
if (index > -1) {
areas.write[index].refCount += 1;
} else {
areas.ordered_insert(AreaCMP(p_area));
}
}
_FORCE_INLINE_ void remove_area(Area2DSW *p_area) {
int index = areas.find(AreaCMP(p_area));
if (index > -1) {
areas.write[index].refCount -= 1;
if (areas[index].refCount < 1) {
areas.remove(index);
}
}
}
_FORCE_INLINE_ void set_max_contacts_reported(int p_size) {
contacts.resize(p_size);
contact_count = 0;
if (mode == PhysicsServer2D::BODY_MODE_KINEMATIC && p_size) {
set_active(true);
}
}
_FORCE_INLINE_ int get_max_contacts_reported() const { return contacts.size(); }
_FORCE_INLINE_ bool can_report_contacts() const { return !contacts.is_empty(); }
_FORCE_INLINE_ void add_contact(const Vector2 &p_local_pos, const Vector2 &p_local_normal, real_t p_depth, int p_local_shape, const Vector2 &p_collider_pos, int p_collider_shape, ObjectID p_collider_instance_id, const RID &p_collider, const Vector2 &p_collider_velocity_at_pos);
_FORCE_INLINE_ void add_exception(const RID &p_exception) { exceptions.insert(p_exception); }
_FORCE_INLINE_ void remove_exception(const RID &p_exception) { exceptions.erase(p_exception); }
_FORCE_INLINE_ bool has_exception(const RID &p_exception) const { return exceptions.has(p_exception); }
_FORCE_INLINE_ const VSet<RID> &get_exceptions() const { return exceptions; }
_FORCE_INLINE_ uint64_t get_island_step() const { return island_step; }
_FORCE_INLINE_ void set_island_step(uint64_t p_step) { island_step = p_step; }
_FORCE_INLINE_ void add_constraint(Constraint2DSW *p_constraint, int p_pos) { constraint_list.push_back({ p_constraint, p_pos }); }
_FORCE_INLINE_ void remove_constraint(Constraint2DSW *p_constraint, int p_pos) { constraint_list.erase({ p_constraint, p_pos }); }
const List<Pair<Constraint2DSW *, int>> &get_constraint_list() const { return constraint_list; }
_FORCE_INLINE_ void clear_constraint_list() { constraint_list.clear(); }
_FORCE_INLINE_ void set_omit_force_integration(bool p_omit_force_integration) { omit_force_integration = p_omit_force_integration; }
_FORCE_INLINE_ bool get_omit_force_integration() const { return omit_force_integration; }
_FORCE_INLINE_ void set_linear_velocity(const Vector2 &p_velocity) { linear_velocity = p_velocity; }
_FORCE_INLINE_ Vector2 get_linear_velocity() const { return linear_velocity; }
_FORCE_INLINE_ void set_angular_velocity(real_t p_velocity) { angular_velocity = p_velocity; }
_FORCE_INLINE_ real_t get_angular_velocity() const { return angular_velocity; }
_FORCE_INLINE_ void set_biased_linear_velocity(const Vector2 &p_velocity) { biased_linear_velocity = p_velocity; }
_FORCE_INLINE_ Vector2 get_biased_linear_velocity() const { return biased_linear_velocity; }
_FORCE_INLINE_ void set_biased_angular_velocity(real_t p_velocity) { biased_angular_velocity = p_velocity; }
_FORCE_INLINE_ real_t get_biased_angular_velocity() const { return biased_angular_velocity; }
_FORCE_INLINE_ void apply_central_impulse(const Vector2 &p_impulse) {
linear_velocity += p_impulse * _inv_mass;
}
_FORCE_INLINE_ void apply_impulse(const Vector2 &p_impulse, const Vector2 &p_position = Vector2()) {
linear_velocity += p_impulse * _inv_mass;
angular_velocity += _inv_inertia * p_position.cross(p_impulse);
}
_FORCE_INLINE_ void apply_torque_impulse(real_t p_torque) {
angular_velocity += _inv_inertia * p_torque;
}
_FORCE_INLINE_ void apply_bias_impulse(const Vector2 &p_impulse, const Vector2 &p_position = Vector2()) {
biased_linear_velocity += p_impulse * _inv_mass;
biased_angular_velocity += _inv_inertia * p_position.cross(p_impulse);
}
void set_active(bool p_active);
_FORCE_INLINE_ bool is_active() const { return active; }
_FORCE_INLINE_ void wakeup() {
if ((!get_space()) || mode == PhysicsServer2D::BODY_MODE_STATIC || mode == PhysicsServer2D::BODY_MODE_KINEMATIC) {
return;
}
set_active(true);
}
void set_param(PhysicsServer2D::BodyParameter p_param, real_t);
real_t get_param(PhysicsServer2D::BodyParameter p_param) const;
void set_mode(PhysicsServer2D::BodyMode p_mode);
PhysicsServer2D::BodyMode get_mode() const;
void set_state(PhysicsServer2D::BodyState p_state, const Variant &p_variant);
Variant get_state(PhysicsServer2D::BodyState p_state) const;
void set_applied_force(const Vector2 &p_force) { applied_force = p_force; }
Vector2 get_applied_force() const { return applied_force; }
void set_applied_torque(real_t p_torque) { applied_torque = p_torque; }
real_t get_applied_torque() const { return applied_torque; }
_FORCE_INLINE_ void add_central_force(const Vector2 &p_force) {
applied_force += p_force;
}
_FORCE_INLINE_ void add_force(const Vector2 &p_force, const Vector2 &p_position = Vector2()) {
applied_force += p_force;
applied_torque += p_position.cross(p_force);
}
_FORCE_INLINE_ void add_torque(real_t p_torque) {
applied_torque += p_torque;
}
_FORCE_INLINE_ void set_continuous_collision_detection_mode(PhysicsServer2D::CCDMode p_mode) { continuous_cd_mode = p_mode; }
_FORCE_INLINE_ PhysicsServer2D::CCDMode get_continuous_collision_detection_mode() const { return continuous_cd_mode; }
void set_space(Space2DSW *p_space);
void update_inertias();
_FORCE_INLINE_ real_t get_inv_mass() const { return _inv_mass; }
_FORCE_INLINE_ real_t get_inv_inertia() const { return _inv_inertia; }
_FORCE_INLINE_ real_t get_friction() const { return friction; }
_FORCE_INLINE_ Vector2 get_gravity() const { return gravity; }
_FORCE_INLINE_ real_t get_bounce() const { return bounce; }
_FORCE_INLINE_ real_t get_linear_damp() const { return linear_damp; }
_FORCE_INLINE_ real_t get_angular_damp() const { return angular_damp; }
void integrate_forces(real_t p_step);
void integrate_velocities(real_t p_step);
_FORCE_INLINE_ Vector2 get_velocity_in_local_point(const Vector2 &rel_pos) const {
return linear_velocity + Vector2(-angular_velocity * rel_pos.y, angular_velocity * rel_pos.x);
}
_FORCE_INLINE_ Vector2 get_motion() const {
if (mode > PhysicsServer2D::BODY_MODE_KINEMATIC) {
return new_transform.get_origin() - get_transform().get_origin();
} else if (mode == PhysicsServer2D::BODY_MODE_KINEMATIC) {
return get_transform().get_origin() - new_transform.get_origin(); //kinematic simulates forward
}
return Vector2();
}
void call_queries();
void wakeup_neighbours();
bool sleep_test(real_t p_step);
Body2DSW();
~Body2DSW();
};
//add contact inline
void Body2DSW::add_contact(const Vector2 &p_local_pos, const Vector2 &p_local_normal, real_t p_depth, int p_local_shape, const Vector2 &p_collider_pos, int p_collider_shape, ObjectID p_collider_instance_id, const RID &p_collider, const Vector2 &p_collider_velocity_at_pos) {
int c_max = contacts.size();
if (c_max == 0) {
return;
}
Contact *c = contacts.ptrw();
int idx = -1;
if (contact_count < c_max) {
idx = contact_count++;
} else {
real_t least_depth = 1e20;
int least_deep = -1;
for (int i = 0; i < c_max; i++) {
if (i == 0 || c[i].depth < least_depth) {
least_deep = i;
least_depth = c[i].depth;
}
}
if (least_deep >= 0 && least_depth < p_depth) {
idx = least_deep;
}
if (idx == -1) {
return; //none least deepe than this
}
}
c[idx].local_pos = p_local_pos;
c[idx].local_normal = p_local_normal;
c[idx].depth = p_depth;
c[idx].local_shape = p_local_shape;
c[idx].collider_pos = p_collider_pos;
c[idx].collider_shape = p_collider_shape;
c[idx].collider_instance_id = p_collider_instance_id;
c[idx].collider = p_collider;
c[idx].collider_velocity_at_pos = p_collider_velocity_at_pos;
}
class PhysicsDirectBodyState2DSW : public PhysicsDirectBodyState2D {
GDCLASS(PhysicsDirectBodyState2DSW, PhysicsDirectBodyState2D);
public:
static PhysicsDirectBodyState2DSW *singleton;
Body2DSW *body;
real_t step;
virtual Vector2 get_total_gravity() const override { return body->gravity; } // get gravity vector working on this body space/area
virtual real_t get_total_angular_damp() const override { return body->area_angular_damp; } // get density of this body space/area
virtual real_t get_total_linear_damp() const override { return body->area_linear_damp; } // get density of this body space/area
virtual real_t get_inverse_mass() const override { return body->get_inv_mass(); } // get the mass
virtual real_t get_inverse_inertia() const override { return body->get_inv_inertia(); } // get density of this body space
virtual void set_linear_velocity(const Vector2 &p_velocity) override { body->set_linear_velocity(p_velocity); }
virtual Vector2 get_linear_velocity() const override { return body->get_linear_velocity(); }
virtual void set_angular_velocity(real_t p_velocity) override { body->set_angular_velocity(p_velocity); }
virtual real_t get_angular_velocity() const override { return body->get_angular_velocity(); }
virtual void set_transform(const Transform2D &p_transform) override { body->set_state(PhysicsServer2D::BODY_STATE_TRANSFORM, p_transform); }
virtual Transform2D get_transform() const override { return body->get_transform(); }
virtual Vector2 get_velocity_at_local_position(const Vector2 &p_position) const override { return body->get_velocity_in_local_point(p_position); }
virtual void add_central_force(const Vector2 &p_force) override { body->add_central_force(p_force); }
virtual void add_force(const Vector2 &p_force, const Vector2 &p_position = Vector2()) override { body->add_force(p_force, p_position); }
virtual void add_torque(real_t p_torque) override { body->add_torque(p_torque); }
virtual void apply_central_impulse(const Vector2 &p_impulse) override { body->apply_central_impulse(p_impulse); }
virtual void apply_impulse(const Vector2 &p_impulse, const Vector2 &p_position = Vector2()) override { body->apply_impulse(p_impulse, p_position); }
virtual void apply_torque_impulse(real_t p_torque) override { body->apply_torque_impulse(p_torque); }
virtual void set_sleep_state(bool p_enable) override { body->set_active(!p_enable); }
virtual bool is_sleeping() const override { return !body->is_active(); }
virtual int get_contact_count() const override { return body->contact_count; }
virtual Vector2 get_contact_local_position(int p_contact_idx) const override {
ERR_FAIL_INDEX_V(p_contact_idx, body->contact_count, Vector2());
return body->contacts[p_contact_idx].local_pos;
}
virtual Vector2 get_contact_local_normal(int p_contact_idx) const override {
ERR_FAIL_INDEX_V(p_contact_idx, body->contact_count, Vector2());
return body->contacts[p_contact_idx].local_normal;
}
virtual int get_contact_local_shape(int p_contact_idx) const override {
ERR_FAIL_INDEX_V(p_contact_idx, body->contact_count, -1);
return body->contacts[p_contact_idx].local_shape;
}
virtual RID get_contact_collider(int p_contact_idx) const override {
ERR_FAIL_INDEX_V(p_contact_idx, body->contact_count, RID());
return body->contacts[p_contact_idx].collider;
}
virtual Vector2 get_contact_collider_position(int p_contact_idx) const override {
ERR_FAIL_INDEX_V(p_contact_idx, body->contact_count, Vector2());
return body->contacts[p_contact_idx].collider_pos;
}
virtual ObjectID get_contact_collider_id(int p_contact_idx) const override {
ERR_FAIL_INDEX_V(p_contact_idx, body->contact_count, ObjectID());
return body->contacts[p_contact_idx].collider_instance_id;
}
virtual int get_contact_collider_shape(int p_contact_idx) const override {
ERR_FAIL_INDEX_V(p_contact_idx, body->contact_count, 0);
return body->contacts[p_contact_idx].collider_shape;
}
virtual Variant get_contact_collider_shape_metadata(int p_contact_idx) const override;
virtual Vector2 get_contact_collider_velocity_at_position(int p_contact_idx) const override {
ERR_FAIL_INDEX_V(p_contact_idx, body->contact_count, Vector2());
return body->contacts[p_contact_idx].collider_velocity_at_pos;
}
virtual PhysicsDirectSpaceState2D *get_space_state() override;
virtual real_t get_step() const override { return step; }
PhysicsDirectBodyState2DSW() {
singleton = this;
body = nullptr;
}
};
#endif // BODY_2D_SW_H