godot/servers/physics_2d/step_2d_sw.cpp
PouleyKetchoupp 448c41a3e4 Godot Physics collisions and solver processed on threads
Use ThreadWorkPool to process physics step tasks in multiple threads. Collisions are all processed in parallel and solving impulses is
processed in parallel for rigid body islands.

Additional changes:
- Proper islands for soft bodies linked to active bodies
- All moving areas are on separate islands (can be parallelized)
- Fix inconsistencies with body islands (Kinematic bodies could link
bodies together or not depending on the processing order)
- Completely prevent static bodies to be active (it could cause islands
to be wrongly created and cause dangerous multi-threading operations as
well as inconsistencies in created islands)
- Apply impulses only on dynamic bodies to avoid unsafe multi-threaded
operations (static bodies can be on multiple islands)
- Removed inverted iterations when populating body islands, it's now
faster in regular order (maybe after fixing inconsistencies)
2021-04-26 18:26:00 -07:00

309 lines
10 KiB
C++

/*************************************************************************/
/* step_2d_sw.cpp */
/*************************************************************************/
/* 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). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
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/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/*************************************************************************/
#include "step_2d_sw.h"
#include "core/os/os.h"
#define BODY_ISLAND_COUNT_RESERVE 128
#define BODY_ISLAND_SIZE_RESERVE 512
#define ISLAND_COUNT_RESERVE 128
#define ISLAND_SIZE_RESERVE 512
#define CONSTRAINT_COUNT_RESERVE 1024
void Step2DSW::_populate_island(Body2DSW *p_body, LocalVector<Body2DSW *> &p_body_island, LocalVector<Constraint2DSW *> &p_constraint_island) {
p_body->set_island_step(_step);
if (p_body->get_mode() > PhysicsServer2D::BODY_MODE_KINEMATIC) {
// Only dynamic bodies are tested for activation.
p_body_island.push_back(p_body);
}
for (const List<Pair<Constraint2DSW *, int>>::Element *E = p_body->get_constraint_list().front(); E; E = E->next()) {
Constraint2DSW *constraint = (Constraint2DSW *)E->get().first;
if (constraint->get_island_step() == _step) {
continue; // Already processed.
}
constraint->set_island_step(_step);
p_constraint_island.push_back(constraint);
all_constraints.push_back(constraint);
for (int i = 0; i < constraint->get_body_count(); i++) {
if (i == E->get().second) {
continue;
}
Body2DSW *other_body = constraint->get_body_ptr()[i];
if (other_body->get_island_step() == _step) {
continue; // Already processed.
}
if (other_body->get_mode() == PhysicsServer2D::BODY_MODE_STATIC) {
continue; // Static bodies don't connect islands.
}
_populate_island(other_body, p_body_island, p_constraint_island);
}
}
}
void Step2DSW::_setup_contraint(uint32_t p_constraint_index, void *p_userdata) {
Constraint2DSW *constraint = all_constraints[p_constraint_index];
constraint->setup(delta);
}
void Step2DSW::_pre_solve_island(LocalVector<Constraint2DSW *> &p_constraint_island) const {
uint32_t constraint_count = p_constraint_island.size();
uint32_t valid_constraint_count = 0;
for (uint32_t constraint_index = 0; constraint_index < constraint_count; ++constraint_index) {
Constraint2DSW *constraint = p_constraint_island[constraint_index];
if (p_constraint_island[constraint_index]->pre_solve(delta)) {
// Keep this constraint for solving.
p_constraint_island[valid_constraint_count++] = constraint;
}
}
p_constraint_island.resize(valid_constraint_count);
}
void Step2DSW::_solve_island(uint32_t p_island_index, void *p_userdata) const {
const LocalVector<Constraint2DSW *> &constraint_island = constraint_islands[p_island_index];
for (int i = 0; i < iterations; i++) {
uint32_t constraint_count = constraint_island.size();
for (uint32_t constraint_index = 0; constraint_index < constraint_count; ++constraint_index) {
constraint_island[constraint_index]->solve(delta);
}
}
}
void Step2DSW::_check_suspend(LocalVector<Body2DSW *> &p_body_island) const {
bool can_sleep = true;
uint32_t body_count = p_body_island.size();
for (uint32_t body_index = 0; body_index < body_count; ++body_index) {
Body2DSW *body = p_body_island[body_index];
if (!body->sleep_test(delta)) {
can_sleep = false;
}
}
// Put all to sleep or wake up everyone.
for (uint32_t body_index = 0; body_index < body_count; ++body_index) {
Body2DSW *body = p_body_island[body_index];
bool active = body->is_active();
if (active == can_sleep) {
body->set_active(!can_sleep);
}
}
}
void Step2DSW::step(Space2DSW *p_space, real_t p_delta, int p_iterations) {
p_space->lock(); // can't access space during this
p_space->setup(); //update inertias, etc
iterations = p_iterations;
delta = p_delta;
const SelfList<Body2DSW>::List *body_list = &p_space->get_active_body_list();
/* INTEGRATE FORCES */
uint64_t profile_begtime = OS::get_singleton()->get_ticks_usec();
uint64_t profile_endtime = 0;
int active_count = 0;
const SelfList<Body2DSW> *b = body_list->first();
while (b) {
b->self()->integrate_forces(p_delta);
b = b->next();
active_count++;
}
p_space->set_active_objects(active_count);
{ //profile
profile_endtime = OS::get_singleton()->get_ticks_usec();
p_space->set_elapsed_time(Space2DSW::ELAPSED_TIME_INTEGRATE_FORCES, profile_endtime - profile_begtime);
profile_begtime = profile_endtime;
}
/* GENERATE CONSTRAINT ISLANDS FOR MOVING AREAS */
uint32_t island_count = 0;
const SelfList<Area2DSW>::List &aml = p_space->get_moved_area_list();
while (aml.first()) {
for (const Set<Constraint2DSW *>::Element *E = aml.first()->self()->get_constraints().front(); E; E = E->next()) {
Constraint2DSW *constraint = E->get();
if (constraint->get_island_step() == _step) {
continue;
}
constraint->set_island_step(_step);
// Each constraint can be on a separate island for areas as there's no solving phase.
++island_count;
if (constraint_islands.size() < island_count) {
constraint_islands.resize(island_count);
}
LocalVector<Constraint2DSW *> &constraint_island = constraint_islands[island_count - 1];
constraint_island.clear();
all_constraints.push_back(constraint);
constraint_island.push_back(constraint);
}
p_space->area_remove_from_moved_list((SelfList<Area2DSW> *)aml.first()); //faster to remove here
}
/* GENERATE CONSTRAINT ISLANDS FOR ACTIVE RIGID BODIES */
b = body_list->first();
uint32_t body_island_count = 0;
while (b) {
Body2DSW *body = b->self();
if (body->get_island_step() != _step) {
++body_island_count;
if (body_islands.size() < body_island_count) {
body_islands.resize(body_island_count);
}
LocalVector<Body2DSW *> &body_island = body_islands[body_island_count - 1];
body_island.clear();
body_island.reserve(BODY_ISLAND_SIZE_RESERVE);
++island_count;
if (constraint_islands.size() < island_count) {
constraint_islands.resize(island_count);
}
LocalVector<Constraint2DSW *> &constraint_island = constraint_islands[island_count - 1];
constraint_island.clear();
constraint_island.reserve(ISLAND_SIZE_RESERVE);
_populate_island(body, body_island, constraint_island);
if (body_island.is_empty()) {
--body_island_count;
}
if (constraint_island.is_empty()) {
--island_count;
}
}
b = b->next();
}
p_space->set_island_count((int)island_count);
{ //profile
profile_endtime = OS::get_singleton()->get_ticks_usec();
p_space->set_elapsed_time(Space2DSW::ELAPSED_TIME_GENERATE_ISLANDS, profile_endtime - profile_begtime);
profile_begtime = profile_endtime;
}
/* SETUP CONSTRAINTS / PROCESS COLLISIONS */
uint32_t total_contraint_count = all_constraints.size();
work_pool.do_work(total_contraint_count, this, &Step2DSW::_setup_contraint, nullptr);
{ //profile
profile_endtime = OS::get_singleton()->get_ticks_usec();
p_space->set_elapsed_time(Space2DSW::ELAPSED_TIME_SETUP_CONSTRAINTS, profile_endtime - profile_begtime);
profile_begtime = profile_endtime;
}
/* PRE-SOLVE CONSTRAINT ISLANDS */
// Warning: This doesn't run on threads, because it involves thread-unsafe processing.
for (uint32_t island_index = 0; island_index < island_count; ++island_index) {
_pre_solve_island(constraint_islands[island_index]);
}
/* SOLVE CONSTRAINT ISLANDS */
// Warning: _solve_island modifies the constraint islands for optimization purpose,
// their content is not reliable after these calls and shouldn't be used anymore.
if (island_count > 1) {
work_pool.do_work(island_count, this, &Step2DSW::_solve_island, nullptr);
} else if (island_count > 0) {
_solve_island(0);
}
{ //profile
profile_endtime = OS::get_singleton()->get_ticks_usec();
p_space->set_elapsed_time(Space2DSW::ELAPSED_TIME_SOLVE_CONSTRAINTS, profile_endtime - profile_begtime);
profile_begtime = profile_endtime;
}
/* INTEGRATE VELOCITIES */
b = body_list->first();
while (b) {
const SelfList<Body2DSW> *n = b->next();
b->self()->integrate_velocities(p_delta);
b = n; // in case it shuts itself down
}
/* SLEEP / WAKE UP ISLANDS */
for (uint32_t island_index = 0; island_index < body_island_count; ++island_index) {
_check_suspend(body_islands[island_index]);
}
{ //profile
profile_endtime = OS::get_singleton()->get_ticks_usec();
p_space->set_elapsed_time(Space2DSW::ELAPSED_TIME_INTEGRATE_VELOCITIES, profile_endtime - profile_begtime);
//profile_begtime=profile_endtime;
}
all_constraints.clear();
p_space->update();
p_space->unlock();
_step++;
}
Step2DSW::Step2DSW() {
_step = 1;
body_islands.reserve(BODY_ISLAND_COUNT_RESERVE);
constraint_islands.reserve(ISLAND_COUNT_RESERVE);
all_constraints.reserve(CONSTRAINT_COUNT_RESERVE);
work_pool.init();
}
Step2DSW::~Step2DSW() {
work_pool.finish();
}