collision callbacks

components/PlayerInput.cpp

@@ -1,14 +1,24 @@
 #include "PlayerInput.h"
-#include <goop/Input.h>
-#include <imgui.h>
 #include <GLFW/glfw3.h>
+#include <goop/Input.h>
 #include <goop/Physics.h>
+#include <imgui.h>
 #include <iostream>
 
 // Gets called when the game starts
 void PlayerInput::init()
 {
-    //...
+	auto& rb = getComponent<goop::RigidbodyComponent>();
+	rb.onCollisionEnter = [](goop::Entity other)
+	{
+		std::cout << "onCollisionEnter() << other: " << other.getComponent<goop::TagComponent>().tag
+				  << std::endl;
+	};
+	rb.onCollisionExit = [](goop::Entity other)
+	{
+		std::cout << "onCollisionExit() << other: " << other.getComponent<goop::TagComponent>().tag
+				  << std::endl;
+	};
 }
 
 // Gets called every frame
@@ -26,11 +36,11 @@ void PlayerInput::update(float dt)
 	{
 		auto& rb = getComponent<goop::RigidbodyComponent>();
 		goop::applyImpulse(rb, glm::vec3(0, 5.f, 0));
-		std::cout<<"pressed space"<<std::endl;
+		std::cout << "pressed space" << std::endl;
 	}
 	if (goop::isKeyReleased(ImGuiKey_Space))
 	{
-		std::cout<<"released space"<<std::endl;
+		std::cout << "released space" << std::endl;
 	}
 }
 
@@ -39,5 +49,5 @@ void PlayerInput::update(float dt)
 void PlayerInput::gui()
 {
 	// ImGui::Text("Hello from %s", name.c_str());
-    //...
+	//...
 }

editor/EditorApp.cpp

@@ -429,7 +429,8 @@ void EditorApp::gui()
 			}
 			if (!e.hasComponent<goop::RigidbodyComponent>() && ImGui::Button("Rigidbody"))
 			{
-				e.addComponent<goop::RigidbodyComponent>();
+				auto& rbc = e.addComponent<goop::RigidbodyComponent>();
+				rbc.entity = e;
 				if (goop::sys::gPhysics->isInitialized())
 				{
 					goop::sys::gPhysics->addRigidBody(&e.getComponent<goop::RigidbodyComponent>(),

goop/Components.h

@@ -48,13 +48,18 @@ struct RigidbodyComponent
 {
 	float mass;
 	float box[3];
-	RigidbodyComponent() : mass(1.0f)
+	bool isColliding = false;
+	std::function<void(goop::Entity)> onCollisionEnter = [](goop::Entity other) {};
+	std::function<void(goop::Entity)> onCollisionExit = [](goop::Entity other) {};
+	goop::Entity entity;
+	RigidbodyComponent() : mass(1.0f), entity(entt::null, nullptr)
 	{
 		box[0] = 1.0f;
 		box[1] = 1.0f;
 		box[2] = 1.0f;
 	}
-	RigidbodyComponent(float mass, float box[3]) : mass(mass)
+	RigidbodyComponent(float mass, float box[3])
+		: mass(mass), entity(goop::Entity(entt::null, nullptr))
 	{
 		memcpy(this->box, box, sizeof(float) * 3);
 	}

goop/Scene.cpp

@@ -79,7 +79,8 @@ void Scene::loadScene(nlohmann::json& startScene)
 			{
 				json& box = component["box"];
 				float size[3] = {box["x"], box["y"], box["z"]};
-				e.addComponent<goop::RigidbodyComponent>(component["mass"], size);
+				auto& rb = e.addComponent<goop::RigidbodyComponent>(component["mass"], size);
+				rb.entity = e;
 			}
 			else if (component["type"] == "camera")
 			{

goop/sys/platform/bullet/Physics_Bullet.cpp

@@ -1,5 +1,6 @@
 #include "Physics_Bullet.h"
 #include <glm/gtc/quaternion.hpp>
+#include <iostream>
 
 #ifdef GOOP_PHYSICS_BULLET
 const std::unique_ptr<goop::sys::Physics> goop::sys::gPhysics =
@@ -79,6 +80,58 @@ void Physics_Bullet::simulate(float dt)
 		glm::vec3 euler =
 			glm::degrees(glm::eulerAngles(glm::quat(rot.w(), rot.x(), rot.y(), rot.z())));
 		transforms[rbc]->rotation = euler;
+
+		// check entry and exit of collisions
+		int numManifolds = dynamicsWorld->getDispatcher()->getNumManifolds();
+		for (int i = 0; i < numManifolds; i++)
+		{
+			btPersistentManifold* contactManifold =
+				dynamicsWorld->getDispatcher()->getManifoldByIndexInternal(i);
+			const btCollisionObject* obA = contactManifold->getBody0();
+			const btCollisionObject* obB = contactManifold->getBody1();
+
+			if (obA == rb || obB == rb)
+			{
+				int numContacts = contactManifold->getNumContacts();
+				// find other rbc
+				RigidbodyComponent* otherRbc = nullptr;
+				if (obA == rb)
+				{
+					for (auto& [rbc, rb] : rigidBodies)
+					{
+						if (rb == obB)
+						{
+							otherRbc = rbc;
+							break;
+						}
+					}
+				}
+				else
+				{
+					for (auto& [rbc, rb] : rigidBodies)
+					{
+						if (rb == obA)
+						{
+							otherRbc = rbc;
+							break;
+						}
+					}
+				}
+				if (numContacts > 0)
+				{
+					if (!rbc->isColliding)
+					{
+						rbc->isColliding = true;
+						rbc->onCollisionEnter(otherRbc->entity);
+					}
+				}
+				else if (rbc->isColliding)
+				{
+					rbc->isColliding = false;
+					rbc->onCollisionExit(otherRbc->entity);
+				}
+			}
+		}
 	}
 }
 
@@ -131,4 +184,3 @@ void Physics_Bullet::applyImpulse(RigidbodyComponent* rbc, glm::vec3 impulse)
 {
 	rigidBodies[rbc]->applyCentralImpulse(btVector3(impulse.x, impulse.y, impulse.z));
 }
-

imgui.ini

@@ -11,13 +11,13 @@ DockId=0x00000006,0
 
 [Window][Viewport]
 Pos=262,27
-Size=1735,1469
+Size=603,1435
 Collapsed=0
 DockId=0x00000003,0
 
 [Window][Inspector]
-Pos=1999,27
-Size=249,1469
+Pos=867,27
+Size=249,1435
 Collapsed=0
 DockId=0x00000004,0
 
@@ -27,7 +27,7 @@ Collapsed=0
 
 [Window][Dockspace]
 Pos=0,19
-Size=2256,1485
+Size=1124,1451
 Collapsed=0
 
 [Window][Example: Log]
@@ -54,12 +54,12 @@ Collapsed=0
 
 [Window][Scene]
 Pos=8,27
-Size=252,1469
+Size=252,1435
 Collapsed=0
 DockId=0x00000007,0
 
 [Docking][Data]
-DockSpace         ID=0x33675C32 Window=0x5B816B74 Pos=8,27 Size=2240,1469 Split=Y
+DockSpace         ID=0x33675C32 Window=0x5B816B74 Pos=10,59 Size=1108,1435 Split=Y
   DockNode        ID=0x00000001 Parent=0x33675C32 SizeRef=1954,445 Split=X Selected=0x13926F0B
     DockNode      ID=0x00000005 Parent=0x00000001 SizeRef=1806,941 Split=X Selected=0x13926F0B
       DockNode    ID=0x00000007 Parent=0x00000005 SizeRef=252,1435 Selected=0xE192E354