From 9dccd2988b725b3ba96faf719f9af419e42f5ba3 Mon Sep 17 00:00:00 2001
From: Joseph Walton-Rivers <joseph@walton-rivers.uk>
Date: Sun, 24 Apr 2022 18:05:08 +0100
Subject: [PATCH] add basic support for bullet integration
---
CMakeLists.txt | 1 +
demo/demo/main.cpp | 2 +
demo/demo/rollball.cpp | 4 +
fggl/CMakeLists.txt | 3 +
fggl/data/heightmap.cpp | 2 +-
fggl/phys/bullet/CMakeLists.txt | 11 +++
fggl/phys/bullet/simulation.cpp | 121 ++++++++++++++++++++++++++++
fggl/scenes/game.cpp | 9 ++-
include/fggl/ecs3/prototype/world.h | 19 +++++
include/fggl/ecs3/types.hpp | 7 +-
include/fggl/phys/bullet/bullet.hpp | 70 ++++++++++++++++
include/fggl/phys/bullet/types.hpp | 82 +++++++++++++++++++
include/fggl/phys/types.hpp | 52 ++++++++++++
include/fggl/scenes/game.hpp | 2 +
14 files changed, 382 insertions(+), 3 deletions(-)
create mode 100644 fggl/phys/bullet/CMakeLists.txt
create mode 100644 fggl/phys/bullet/simulation.cpp
create mode 100644 include/fggl/phys/bullet/bullet.hpp
create mode 100644 include/fggl/phys/bullet/types.hpp
create mode 100644 include/fggl/phys/types.hpp
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 18f5917..e1527a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,6 +27,7 @@ if (CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
glm/0.9.9.8
spdlog/1.10.0
freetype/2.11.1
+ bullet3/3.22a
GENERATORS
cmake_find_package
cmake_find_package_multi
diff --git a/demo/demo/main.cpp b/demo/demo/main.cpp
index 8d025d8..45846b3 100644
--- a/demo/demo/main.cpp
+++ b/demo/demo/main.cpp
@@ -33,6 +33,7 @@
#include "fggl/util/service.h"
#include "fggl/ecs3/types.hpp"
+#include "fggl/phys/bullet/bullet.hpp"
#include "fggl/scenes/menu.hpp"
@@ -98,6 +99,7 @@ int main(int argc, const char* argv[]) {
// load a bunch of modules to provide game functionality
//app.use<fggl::ecs3::ecsTypes>();
app.use<fggl::gfx::SceneUtils>();
+ app.use<fggl::phys::Bullet3>();
test_atlas_api();
diff --git a/demo/demo/rollball.cpp b/demo/demo/rollball.cpp
index 49396f6..4146ccd 100644
--- a/demo/demo/rollball.cpp
+++ b/demo/demo/rollball.cpp
@@ -67,6 +67,9 @@ static void setupPrefabs(fggl::ecs3::World& world, Prefabs& prefabs) {
prefabs.floor = world.create(true);
world.add<fggl::math::Transform>(prefabs.floor);
+ auto* rb = world.add<fggl::phys::RigidBody>(prefabs.floor);
+ rb->mass = fggl::phys::STATIC_MASS;
+
fggl::data::StaticMesh meshComponent;
meshComponent.pipeline = "phong";
@@ -82,6 +85,7 @@ static void setupPrefabs(fggl::ecs3::World& world, Prefabs& prefabs) {
// player (cube because my sphere function doesn't exist yet
prefabs.player = world.create(true);
world.add<fggl::math::Transform>(prefabs.player);
+ world.add<fggl::phys::RigidBody>(prefabs.player);
fggl::data::StaticMesh meshComponent;
meshComponent.pipeline = "phong";
diff --git a/fggl/CMakeLists.txt b/fggl/CMakeLists.txt
index 486ce21..0d34492 100644
--- a/fggl/CMakeLists.txt
+++ b/fggl/CMakeLists.txt
@@ -70,6 +70,9 @@ target_link_libraries(${PROJECT_NAME} PUBLIC freetype)
# Graphics backend
add_subdirectory(gfx)
+# physics integration
+add_subdirectory(phys/bullet)
+
# Debug backend
add_subdirectory(debug)
diff --git a/fggl/data/heightmap.cpp b/fggl/data/heightmap.cpp
index 72b9b78..525e886 100644
--- a/fggl/data/heightmap.cpp
+++ b/fggl/data/heightmap.cpp
@@ -99,7 +99,7 @@ namespace fggl::data {
for (std::size_t x = 0; x < data::heightMaxX - 1; x++) {
for (std::size_t z = 0; z < data::heightMaxZ; z++) {
for (int k=0; k < 2; k++) {
- int idx = (x+k) * data::heightMaxZ + z;
+ auto idx = (x+k) * data::heightMaxZ + z;
mesh.pushIndex(idx);
}
}
diff --git a/fggl/phys/bullet/CMakeLists.txt b/fggl/phys/bullet/CMakeLists.txt
new file mode 100644
index 0000000..54d35e5
--- /dev/null
+++ b/fggl/phys/bullet/CMakeLists.txt
@@ -0,0 +1,11 @@
+# bullet integration support
+
+find_package( Bullet REQUIRED )
+target_link_libraries(fggl PUBLIC Bullet::Bullet )
+
+#
+target_sources(fggl
+ PRIVATE
+ simulation.cpp
+)
+
diff --git a/fggl/phys/bullet/simulation.cpp b/fggl/phys/bullet/simulation.cpp
new file mode 100644
index 0000000..bfd1f1e
--- /dev/null
+++ b/fggl/phys/bullet/simulation.cpp
@@ -0,0 +1,121 @@
+/*
+ * ${license.title}
+ * Copyright (C) 2022 ${license.owner}
+ * ${license.mailto}
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "fggl/phys/bullet/types.hpp"
+
+namespace fggl::phys::bullet {
+
+ BulletPhysicsEngine::BulletPhysicsEngine(ecs3::World* world) : m_ecs(world), m_config(), m_world(nullptr) {
+ m_config.broadphase = new btDbvtBroadphase();
+ m_config.collisionConfiguration = new btDefaultCollisionConfiguration();
+ m_config.dispatcher = new btCollisionDispatcher(m_config.collisionConfiguration);
+ m_config.solver = new btSequentialImpulseConstraintSolver();
+
+ m_world = new btDiscreteDynamicsWorld(
+ m_config.dispatcher,
+ m_config.broadphase,
+ m_config.solver,
+ m_config.collisionConfiguration);
+ }
+
+ void BulletPhysicsEngine::step() {
+ checkForPhys();
+ m_world->stepSimulation(60.0f);
+ syncToECS();
+ }
+
+ static void build_motation_state(math::Transform* myState, BulletBody* btState) {
+ auto myPos = myState->origin();
+ btVector3 position{myPos.x, myPos.y, myPos.z};
+
+ auto myRot = myState->euler();
+ btQuaternion rotation;
+ rotation.setEulerZYX(myRot.x, myRot.y, myRot.z);
+ btState->motion = new btDefaultMotionState(btTransform(rotation, position));
+ }
+
+ void BulletPhysicsEngine::checkForPhys() {
+ // FIXME without reactive-based approaches this is very slow
+ auto entsWantPhys = m_ecs->findMatching<phys::RigidBody>();
+ for (auto ent : entsWantPhys) {
+ auto* btComp = m_ecs->get<BulletBody>(ent);
+ if ( btComp != nullptr ) {
+ // they are already in the simluation
+ continue;
+ }
+
+ btComp = m_ecs->add<BulletBody>(ent);
+ auto fgBody = m_ecs->get<phys::RigidBody>(ent);
+
+ // setup the starting motion state
+ auto* transform = m_ecs->get<math::Transform>(ent);
+ build_motation_state(transform, btComp);
+
+ // setup the construction information
+ // FIXME the world shouldn't be made only of unit spheres...
+ btSphereShape* shape = new btSphereShape(0.5f);
+ btRigidBody::btRigidBodyConstructionInfo bodyCI(
+ fgBody->mass,
+ btComp->motion,
+ shape
+ );
+ btComp->body = new btRigidBody(bodyCI);
+ m_world->addRigidBody(btComp->body);
+ }
+ }
+
+ void BulletPhysicsEngine::syncToECS() {
+ auto physEnts = m_ecs->findMatching<BulletBody>();
+ for (auto& ent : physEnts) {
+ auto* transform = m_ecs->get<math::Transform>(ent);
+ auto* physBody = m_ecs->get<BulletBody>(ent);
+
+ btTransform bTransform;
+ physBody->motion->getWorldTransform(bTransform);
+
+ // set calculate and set ecs position
+ auto& btPos = bTransform.getOrigin();
+ math::vec3 pos{btPos.x(), btPos.y(), btPos.z()};
+ transform->origin( pos );
+ }
+ }
+
+ BulletPhysicsEngine::~BulletPhysicsEngine() {
+ // clean up the rigid bodies
+ auto entRB = m_ecs->findMatching<BulletBody>();
+ for (auto& ent : entRB) {
+ auto* bulletBody = m_ecs->get<BulletBody>(ent);
+ delete bulletBody->motion;
+ m_world->removeCollisionObject(bulletBody->body);
+ delete bulletBody->body;
+ m_ecs->remove<BulletBody>(ent);
+ }
+
+ // delete the world
+ delete m_world;
+
+ // cleanup the configuration object
+ delete m_config.solver;
+ delete m_config.broadphase;
+ delete m_config.dispatcher;
+ delete m_config.collisionConfiguration;
+ }
+
+} // namespace fggl::phys::bullet
\ No newline at end of file
diff --git a/fggl/scenes/game.cpp b/fggl/scenes/game.cpp
index 623247d..0cf1717 100644
--- a/fggl/scenes/game.cpp
+++ b/fggl/scenes/game.cpp
@@ -24,6 +24,7 @@
#include "fggl/scenes/game.hpp"
#include "fggl/util/service.h"
+#include "fggl/phys/bullet/types.hpp"
namespace fggl::scenes {
@@ -36,10 +37,12 @@ namespace fggl::scenes {
fggl::AppState::activate();
// setup the scene
- m_world = std::make_unique<fggl::ecs3::World>(*m_owner.registry());
+ m_world = std::make_unique<ecs3::World>(*m_owner.registry());
+ m_phys = std::make_unique<phys::bullet::BulletPhysicsEngine>(m_world.get());
}
void Game::deactivate() {
+ m_phys.reset();
m_world.reset();
}
@@ -50,6 +53,10 @@ namespace fggl::scenes {
m_owner.change_state(m_previous);
}
}
+
+ if ( m_phys != nullptr ) {
+ m_phys->step();
+ }
}
void Game::render(fggl::gfx::Graphics &gfx) {
diff --git a/include/fggl/ecs3/prototype/world.h b/include/fggl/ecs3/prototype/world.h
index 26dba7a..75969c3 100644
--- a/include/fggl/ecs3/prototype/world.h
+++ b/include/fggl/ecs3/prototype/world.h
@@ -59,6 +59,11 @@ namespace fggl::ecs3::prototype {
return (C *) ptr;
}
+ template<typename C>
+ void remove(){
+ m_components.erase(Component<C>::typeID());
+ }
+
inline void *get(component_type_t t) {
return m_components.at(t);
}
@@ -215,6 +220,20 @@ namespace fggl::ecs3::prototype {
}
}
+ template<typename C>
+ void remove(entity_t entity_id) {
+ try {
+ auto &entity = m_entities.at(entity_id);
+ try {
+ return entity.remove<C>();
+ } catch ( std::out_of_range& e ) {
+ std::cerr << "entity " << entity_id << " does not have component "<< C::name << std::endl;
+ }
+ } catch ( std::out_of_range& e) {
+ std::cerr << "tried to delete component on entity that didn't exist, entity was: " << entity_id << std::endl;
+ }
+ }
+
void *get(entity_t entity_id, component_type_t t) {
auto &entity = m_entities.at(entity_id);
return entity.get(t);
diff --git a/include/fggl/ecs3/types.hpp b/include/fggl/ecs3/types.hpp
index 35b02f0..4a7ffc3 100644
--- a/include/fggl/ecs3/types.hpp
+++ b/include/fggl/ecs3/types.hpp
@@ -176,7 +176,12 @@ namespace fggl::ecs3 {
}
inline std::shared_ptr<fggl::ecs::ComponentBase> meta(component_type_t type_id) const {
- return m_types.at(type_id);
+ try {
+ return m_types.at(type_id);
+ } catch (std::out_of_range& err) {
+ std::cerr << "asked for metadata on type " << type_id << " but no such type is in the type system" << std::endl;
+ return nullptr;
+ }
}
inline component_type_t find(const char *name) const {
diff --git a/include/fggl/phys/bullet/bullet.hpp b/include/fggl/phys/bullet/bullet.hpp
new file mode 100644
index 0000000..e5d301f
--- /dev/null
+++ b/include/fggl/phys/bullet/bullet.hpp
@@ -0,0 +1,70 @@
+/*
+ * ${license.title}
+ * Copyright (C) 2022 ${license.owner}
+ * ${license.mailto}
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+//
+// Created by webpigeon on 24/04/22.
+//
+
+#ifndef FGGL_PHYS_BULLET_BULLET_HPP
+#define FGGL_PHYS_BULLET_BULLET_HPP
+
+#include "fggl/ecs3/module/module.h"
+
+#include "fggl/phys/types.hpp"
+#include "fggl/phys/bullet/types.hpp"
+
+namespace fggl::phys::bullet {
+
+ /**
+ * Bullet integration module.
+ *
+ * This provides the ability for FGGL to use bullet as a physics backened. Bullet is mature, stable physics
+ * engine which makes it suitable for most use cases. For use with FGGL there is a reasonable amount of copying
+ * back and forth to keep the two states in sync.
+ */
+ struct BulletModule : ecs3::Module {
+ public:
+ BulletModule() = default;
+
+ [[nodiscard]]
+ std::string name() const override {
+ return "phys::Bullet3";
+ }
+
+ void onLoad(ecs3::ModuleManager &manager, ecs3::TypeRegistry &types) override {
+ // dependencies
+ types.make<phys::RigidBody>();
+
+ // my types
+ types.make<phys::bullet::BulletBody>();
+ }
+
+ };
+
+} // namespace fggl::phys::bullet
+
+namespace fggl::phys {
+
+ // allows using fggl::phys::Bullet3 as the module name
+ using Bullet3 = bullet::BulletModule;
+
+} // namespace fggl::phys
+
+#endif //FGGL_PHYS_BULLET_BULLET_HPP
diff --git a/include/fggl/phys/bullet/types.hpp b/include/fggl/phys/bullet/types.hpp
new file mode 100644
index 0000000..31d9a94
--- /dev/null
+++ b/include/fggl/phys/bullet/types.hpp
@@ -0,0 +1,82 @@
+/*
+ * ${license.title}
+ * Copyright (C) 2022 ${license.owner}
+ * ${license.mailto}
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+//
+// Created by webpigeon on 24/04/22.
+//
+
+#ifndef FGGL_PHYS_BULLET_TYPES_HPP
+#define FGGL_PHYS_BULLET_TYPES_HPP
+
+#include "fggl/ecs3/ecs.hpp"
+#include "fggl/phys/types.hpp"
+
+#include <bullet/btBulletDynamicsCommon.h>
+#include <bullet/btBulletCollisionCommon.h>
+
+namespace fggl::phys::bullet {
+
+ struct BulletConfiguration {
+ btBroadphaseInterface* broadphase;
+ btCollisionConfiguration* collisionConfiguration;
+ btDispatcher* dispatcher;
+ btConstraintSolver* solver;
+ };
+
+ /**
+ * Bullet component.
+ */
+ struct BulletBody {
+ constexpr static const char* name = "phys::bullet::body";
+ btMotionState* motion;
+ btRigidBody* body;
+ };
+
+ /**
+ * Bullet physics engine implementation.
+ *
+ * This wraps the bullet physics world and provides the systems needed for integrating it into our ECS. The state
+ * is responsible for creating and manging this object.
+ */
+ class BulletPhysicsEngine : public PhysicsEngine {
+ public:
+ explicit BulletPhysicsEngine(ecs3::World* world);
+ ~BulletPhysicsEngine() override;
+
+ void step() override;
+ private:
+ ecs3::World* m_ecs;
+ BulletConfiguration m_config;
+ btDiscreteDynamicsWorld* m_world;
+
+ /**
+ * Check for ECS components which aren't in the physics world and add them.
+ */
+ void checkForPhys();
+
+ /**
+ * Sync the bullet world state back to the ECS.
+ */
+ void syncToECS();
+ };
+
+} // namespace fggl::phys::bullet
+
+#endif //FGGL_PHYS_BULLET_TYPES_HPP
diff --git a/include/fggl/phys/types.hpp b/include/fggl/phys/types.hpp
new file mode 100644
index 0000000..8ae73b6
--- /dev/null
+++ b/include/fggl/phys/types.hpp
@@ -0,0 +1,52 @@
+/*
+ * ${license.title}
+ * Copyright (C) 2022 ${license.owner}
+ * ${license.mailto}
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+//
+// Created by webpigeon on 24/04/22.
+//
+
+#ifndef FGGL_PHYS_TYPES_HPP
+#define FGGL_PHYS_TYPES_HPP
+
+namespace fggl::phys {
+ constexpr float STATIC_MASS = 0.0F;
+
+ struct RigidBody {
+ constexpr static const char* name = "phys::Body";
+ float mass = 1.0F;
+ };
+
+ class PhysicsEngine {
+ public:
+ PhysicsEngine() = default;
+ virtual ~PhysicsEngine() = default;
+
+ // no copy and no move
+ PhysicsEngine(PhysicsEngine&) = delete;
+ PhysicsEngine(PhysicsEngine&&) = delete;
+ PhysicsEngine& operator=(PhysicsEngine&) = delete;
+ PhysicsEngine& operator=(PhysicsEngine&&) = delete;
+
+ virtual void step() = 0;
+ };
+
+} // namespace fggl::phys
+
+#endif //FGGL_PHYS_TYPES_HPP
diff --git a/include/fggl/scenes/game.hpp b/include/fggl/scenes/game.hpp
index fa9cafc..509388f 100644
--- a/include/fggl/scenes/game.hpp
+++ b/include/fggl/scenes/game.hpp
@@ -26,6 +26,7 @@
#define FGGL_SCENES_GAME_HPP
#include "fggl/app.hpp"
+#include "fggl/phys/types.hpp"
namespace fggl::scenes {
@@ -52,6 +53,7 @@ namespace fggl::scenes {
private:
std::shared_ptr<input::Input> m_input;
std::unique_ptr<ecs3::World> m_world;
+ std::unique_ptr<phys::PhysicsEngine> m_phys;
std::string m_previous = "menu";
};
--
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