plugin checkpoint - multiple plugins and collision callbacks

16 files changed, 375 insertions, 46 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4ede1a9..0900da7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -198,3 +198,4 @@ add_dependencies(pke shaders)
 add_subdirectory(editor)
 add_subdirectory(runtime)
 add_subdirectory(test)
+add_subdirectory(example)
diff --git a/editor/editor.cpp b/editor/editor.cpp
index 5016070..db97802 100644
--- a/editor/editor.cpp
+++ b/editor/editor.cpp
@@ -696,6 +696,23 @@ void RecordImGuiUBO() {
 	ImGui::End();
 }
 
+bool RecordImGui_CallbackSelectModal(long &selectedIndex) {
+	bool returnValue = false;
+	if (ImGui::BeginPopupModal("CallbackSelect", nullptr, ImGuiWindowFlags_AlwaysAutoResize)) {
+		long count = 0;
+		auto *signatures = PkePlugin_GetSortedSignatures(count);
+		for (long i = 0; i < count; ++i) {
+			const CallbackSignature &sig = signatures[i];
+			if (ImGui::Selectable(sig, selectedIndex == i)) {
+				returnValue = true;
+				selectedIndex = i;
+			}
+		}
+		ImGui::EndPopup();
+	}
+	return returnValue;
+}
+
 void RecordImGuiModalCreateEntityType() {
 	if (ImGui::BeginPopupModal("CreateEntityType", nullptr, ImGuiWindowFlags_AlwaysAutoResize)) {
 		static char modelsDir[64];
@@ -835,6 +852,24 @@ void RecordImGui_CompGrBinds(bool readonly, CompGrBinds *component) {
 	ImGui::InputScalar("InstanceBufferMaxCount", ImGuiDataType_U32, &component->instanceBufferMaxCount, nullptr, nullptr, nullptr, ImGuiInputTextFlags_ReadOnly);
 	ImGui::InputScalar("Instance Count", ImGuiDataType_U32, &component->instanceCounter, nullptr, nullptr, nullptr, ImGuiInputTextFlags_ReadOnly);
 
+	static long index = -1;
+	if (ImGui::Button("Clear")) {
+		index = -1;
+		component->collisionCallback.name[0] = '\0';
+	}
+	ImGui::SameLine();
+	if (ImGui::Button("Change")) {
+		index = -1;
+		ImGui::OpenPopup("CallbackSelect");
+	}
+	ImGui::SameLine();
+	ImGui::Text("Collision Callback: '%s'", component->collisionCallback.name);
+	if (RecordImGui_CallbackSelectModal(index)) {
+		long x = 0;
+		memcpy(component->collisionCallback.name, PkePlugin_GetSortedSignatures(x)[index], 16);
+		PkePlugin_SetSignatureFunc(&component->collisionCallback);
+	}
+
 	ImGui::Spacing();
 }
 
@@ -868,6 +903,24 @@ void RecordImGui_CompInstPos(bool readonly, CompInstance *component) {
 	changed = ImGui::InputScalar("Phys - Collision Layer", ImGuiDataType_U16, &component->physicsLayer, nullptr, nullptr, nullptr, inputTextFlags) || changed;
 	changed = ImGui::InputScalar("Phys - Collision Mask", ImGuiDataType_U16, &component->physicsMask, nullptr, nullptr, nullptr, inputTextFlags) || changed;
 
+	static long index = -1;
+	if (ImGui::Button("Clear")) {
+		index = -1;
+		component->collisionCallback.name[0] = '\0';
+	}
+	ImGui::SameLine();
+	if (ImGui::Button("Change")) {
+		index = -1;
+		ImGui::OpenPopup("CallbackSelect");
+	}
+	ImGui::SameLine();
+	ImGui::Text("Collision Callback: '%s'", component->collisionCallback.name);
+	if (RecordImGui_CallbackSelectModal(index)) {
+		long x = 0;
+		memcpy(component->collisionCallback.name, PkePlugin_GetSortedSignatures(x)[index], 16);
+		PkePlugin_SetSignatureFunc(&component->collisionCallback);
+	}
+
 	ImGui::InputScalar("Phys - Rigid Body", ImGuiDataType_U64, &component->bt.rigidBody, nullptr, nullptr, "0x%016lX", ImGuiInputTextFlags_ReadOnly);
 	ImGui::InputScalar("Phys - Motion State", ImGuiDataType_U64, &component->bt.motionState, nullptr, nullptr, "0x%016lX", ImGuiInputTextFlags_ReadOnly);
 
diff --git a/editor/main.cpp b/editor/main.cpp
index af0e66a..2dee016 100644
--- a/editor/main.cpp
+++ b/editor/main.cpp
@@ -23,10 +23,12 @@ int main(int argc, char *argv[]) {
 	{
 		pkeSettings.isSimulationPaused = true;
 		pkeSettings.isShowingEditor = true;
-		pkePlugin.OnInit = PkeEditor_Init;
-		pkePlugin.OnTick = PkeEditor_Tick;
-		pkePlugin.OnTeardown = PkeEditor_Teardown;
-		pkePlugin.OnImGuiRender = PkeEditor_RecordImGui;
+		LoadedPkePlugins.Push({
+			.OnInit = PkeEditor_Init,
+			.OnTick = PkeEditor_Tick,
+			.OnTeardown = PkeEditor_Teardown,
+			.OnImGuiRender = PkeEditor_RecordImGui,
+		});
 	}
 	// run
 	PkeArgs_Parse(argc, argv);
diff --git a/example/CMakeLists.txt b/example/CMakeLists.txt
new file mode 100644
index 0000000..a895b5d
--- /dev/null
+++ b/example/CMakeLists.txt
@@ -0,0 +1,14 @@
+project(pke_example VERSION 0.0)
+
+set(PKE_EDITOR_SOURCE_FILES
+	# example_export.h
+	example.hpp
+	example.cpp
+)
+
+add_library(pke_example
+	${PKE_EDITOR_SOURCE_FILES}
+)
+
+target_link_libraries(pke_example PUBLIC pke)
+target_include_directories(pke_example PUBLIC pke)
diff --git a/example/example.cpp b/example/example.cpp
new file mode 100644
index 0000000..b870806
--- /dev/null
+++ b/example/example.cpp
@@ -0,0 +1,27 @@
+
+#include "example.hpp"
+
+#include "components.hpp"
+
+void OnEntityTypeCollision(const EntityHandle &lhs, const EntityHandle &rhs) {
+	fprintf(stdout, "[Example::OnEntityTypeCollision] Called\n");
+}
+
+void OnEntityCollision(const EntityHandle &lhs, const EntityHandle &rhs) {
+	fprintf(stdout, "[Example::OnEntityCollision] Called\n");
+}
+
+void OnInit() {
+	PkeArray_Add(&pkePluginCallbacks, PkeCallback {
+		.name = "OnEntTypeColl",
+		.func = reinterpret_cast<void *>(OnEntityTypeCollision),
+	});
+	PkeArray_Add(&pkePluginCallbacks, PkeCallback {
+		.name = "OnEntColl",
+		.func = reinterpret_cast<void *>(OnEntityCollision),
+	});
+}
+
+PKEPluginInterface pkePluginInterface {
+	.OnInit = OnInit,
+};
diff --git a/example/example.hpp b/example/example.hpp
new file mode 100644
index 0000000..c64b3e9
--- /dev/null
+++ b/example/example.hpp
@@ -0,0 +1,14 @@
+#ifndef PKE_EXAMPLE_HPP
+#define PKE_EXAMPLE_HPP
+
+#include "plugins.hpp"
+
+// EXAMPLE_EXPORT void OnEntityTypeCollision(const EntityHandle &lhs, const EntityHandle &rhs);
+// void OnEntityTypeCollision(const EntityHandle &lhs, const EntityHandle &rhs);
+
+// EXAMPLE_EXPORT void OnEntityCollision(const EntityHandle &lhs, const EntityHandle &rhs);
+// void OnEntityCollision(const EntityHandle &lhs, const EntityHandle &rhs);
+
+extern PKEPluginInterface pkePluginInterface;
+
+#endif /* PKE_EXAMPLE_HPP */
diff --git a/example/example_export.h b/example/example_export.h
new file mode 100644
index 0000000..53bf208
--- /dev/null
+++ b/example/example_export.h
@@ -0,0 +1,42 @@
+
+#ifndef EXAMPLE_EXPORT_H
+#define EXAMPLE_EXPORT_H
+
+#ifdef EXAMPLE_STATIC_DEFINE
+#  define EXAMPLE_EXPORT
+#  define EXAMPLE_NO_EXPORT
+#else
+#  ifndef EXAMPLE_EXPORT
+#    ifdef extension_EXPORTS
+        /* We are building this library */
+#      define EXAMPLE_EXPORT extern "C" __attribute__((visibility("default")))
+#    else
+        /* We are using this library */
+#      define EXAMPLE_EXPORT __attribute__((visibility("default")))
+#    endif
+#  endif
+
+#  ifndef EXAMPLE_NO_EXPORT
+#    define EXAMPLE_NO_EXPORT __attribute__((visibility("hidden")))
+#  endif
+#endif
+
+#ifndef EXAMPLE_DEPRECATED
+#  define EXAMPLE_DEPRECATED __attribute__ ((__deprecated__))
+#endif
+
+#ifndef EXAMPLE_DEPRECATED_EXPORT
+#  define EXAMPLE_DEPRECATED_EXPORT EXAMPLE_EXPORT EXAMPLE_DEPRECATED
+#endif
+
+#ifndef EXAMPLE_DEPRECATED_NO_EXPORT
+#  define EXAMPLE_DEPRECATED_NO_EXPORT EXAMPLE_NO_EXPORT EXAMPLE_DEPRECATED
+#endif
+
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef EXAMPLE_NO_DEPRECATED
+#    define EXAMPLE_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* EXAMPLE_EXPORT_H */
diff --git a/src/components.hpp b/src/components.hpp
index e99481e..86c5727 100644
--- a/src/components.hpp
+++ b/src/components.hpp
@@ -4,6 +4,7 @@
 #include "dynamic-array.hpp"
 #include "macros.hpp"
 #include "physics.hpp"
+#include "plugins.hpp"
 
 #include <BulletDynamics/Dynamics/btRigidBody.h>
 #include <LinearMath/btDefaultMotionState.h>
@@ -65,6 +66,7 @@ struct CompGrBinds {
 	uint32_t instanceCounter = 0;
 	uint32_t instanceBufferMaxCount = 0;
 	VkDeviceSize instanceOffsets = 0;
+	PkeCallback collisionCallback{};
 };
 
 struct InstPos {
@@ -84,6 +86,7 @@ struct CompInstance {
 	PhysicsCollision physicsLayer = PhysicsCollision{1};
 	PhysicsCollision physicsMask = PhysicsCollision{1};
 	InstBt bt;
+	PkeCallback collisionCallback{};
 	bool isNeedingUpdated = false;
 };
 
diff --git a/src/ecs.cpp b/src/ecs.cpp
index 4580abe..c33caaa 100644
--- a/src/ecs.cpp
+++ b/src/ecs.cpp
@@ -327,6 +327,57 @@ void ECS_Tick_Late(double delta) {
 	}
 }
 
+void FindComponents(EntityHandle handle, Entity *&ent, CompInstance *&compInst, CompGrBinds *&grBinds) {
+	ECS_GetEntity_Inner(handle, ent);
+	if (ent == nullptr)
+		return;
+	GrBindsHandle grBindsHandle = ent->grBindsHandle;
+	if (ent->instanceHandle != InstanceHandle_MAX) {
+		compInst = &Comp_Instance_BucketContainer.buckets[ent->instanceHandle.bucketIndex].instances[ent->instanceHandle.itemIndex];
+		if (grBindsHandle == GrBindsHandle_MAX)
+			grBindsHandle = compInst->grBindsHandle;
+	}
+	if (grBindsHandle != GrBindsHandle_MAX) {
+		grBinds = &Comp_GrBinds_BucketContainer.buckets[grBindsHandle.bucketIndex].compGrBinds[grBindsHandle.itemIndex];
+	}
+}
+
+void ECS_HandleCollision(EntityHandle lhs, EntityHandle rhs) {
+	Entity *lhsEnt = nullptr;
+	CompInstance *lhsInst = nullptr;
+	CompGrBinds *lhsGrBinds = nullptr;
+	FindComponents(lhs, lhsEnt, lhsInst, lhsGrBinds);
+
+	Entity *rhsEnt = nullptr;
+	CompInstance *rhsInst = nullptr;
+	CompGrBinds *rhsGrBinds = nullptr;
+	FindComponents(rhs, rhsEnt, rhsInst, rhsGrBinds);
+
+	void (*lhsColFunc)(EntityHandle, EntityHandle) = nullptr;
+	void (*rhsColFunc)(EntityHandle, EntityHandle) = nullptr;
+
+	if (lhsInst && lhsInst->collisionCallback.func != nullptr) {
+		lhsColFunc = reinterpret_cast<void (*)(EntityHandle, EntityHandle)>(lhsInst->collisionCallback.func);
+	}
+	if (lhsColFunc == nullptr && lhsGrBinds && lhsGrBinds->collisionCallback.func) {
+		lhsColFunc = reinterpret_cast<void (*)(EntityHandle, EntityHandle)>(lhsGrBinds->collisionCallback.func);
+	}
+
+	if (rhsInst && rhsInst->collisionCallback.func != nullptr) {
+		rhsColFunc = reinterpret_cast<void (*)(EntityHandle, EntityHandle)>(rhsInst->collisionCallback.func);
+	}
+	if (rhsColFunc == nullptr && rhsGrBinds && rhsGrBinds->collisionCallback.func) {
+		rhsColFunc = reinterpret_cast<void (*)(EntityHandle, EntityHandle)>(rhsGrBinds->collisionCallback.func);
+	}
+
+	if (lhsColFunc) {
+		lhsColFunc(lhs, rhs);
+	}
+	if (rhsColFunc) {
+		rhsColFunc(lhs, rhs);
+	}
+}
+
 CompGrBinds &ECS_CreateGrBinds(EntityHandle entHandle) {
 	assert(entHandle != EntityHandle_MAX);
 
diff --git a/src/ecs.hpp b/src/ecs.hpp
index 7ac08e2..4deacaf 100644
--- a/src/ecs.hpp
+++ b/src/ecs.hpp
@@ -27,6 +27,8 @@ void ECS_MarkForRemoval(EntityHandle entHandle);
 uint64_t ECS_GetEntities_BucketCount();
 Entity *ECS_GetEntities(uint64_t bucketIndex, uint64_t &itemCount);
 
+void ECS_HandleCollision(EntityHandle lhs, EntityHandle rhs);
+
 CompGrBinds &ECS_CreateGrBinds(EntityHandle entHandle);
 CompGrBinds *ECS_GetGrBinds(EntityHandle entHandle);
 CompGrBinds *ECS_GetGrBinds(GrBindsHandle grBindsHandle);
diff --git a/src/game.cpp b/src/game.cpp
index 20e67a0..5df32a0 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -47,6 +47,7 @@ const char *PKE_FILE_INSTANCE_POS_SCALE = "InstPos::Scale: ";
 const char *PKE_FILE_INSTANCE_PHYSICS_MASS = "InstPos::Mass: ";
 const char *PKE_FILE_INSTANCE_PHYSICS_COLLISION_LAYER = "InstPos::CollisionLayer: ";
 const char *PKE_FILE_INSTANCE_PHYSICS_COLLISION_MASK = "InstPos::CollisionMask: ";
+const char *PKE_FILE_INSTANCE_COLLISION_CALLBACK_SIGNATURE = "Inst::CollisionCallbackSignature: ";
 
 const char *PKE_FILE_CAMERA_POS = "Cam::Pos: ";
 const char *PKE_FILE_CAMERA_ROT = "Cam::Rot: ";
@@ -141,6 +142,9 @@ void SerializeInstance(std::ofstream &stream, const CompInstance &comp) {
 	if (collisionMask != c.physicsMask) {
 		stream << PKE_FILE_INSTANCE_PHYSICS_COLLISION_MASK << static_cast<PhysicsCollision_T>(collisionMask) << std::endl;
 	}
+	if (comp.collisionCallback.name[0] != '\0') {
+		stream << PKE_FILE_INSTANCE_COLLISION_CALLBACK_SIGNATURE << comp.collisionCallback.name << std::endl;
+	}
 }
 
 void ParseCamera(LevelHandle levelHandle, std::ifstream &stream) {
@@ -238,6 +242,7 @@ void ParseInstance(EntityHandle parentEntHandle, std::ifstream &stream) {
 	instPos.posRot.setIdentity();
 	instPos.scale = btVector3(1, 1, 1);
 	instPos.mass = 1.f;
+	comp.collisionCallback.name[0] = '\0';
 	char entTypeCode[21];
 	memset(reinterpret_cast<void *>(entTypeCode), '\0', 21);
 	while (stream.getline(readLine, readLineLength)) {
@@ -255,6 +260,9 @@ void ParseInstance(EntityHandle parentEntHandle, std::ifstream &stream) {
 			auto entityHandle = ECS_CreateEntity(parentEntHandle);
 			auto &compInst = ECS_CreateInstance(entityHandle, et.entityHandle);
 
+			strncpy(compInst.collisionCallback.name, comp.collisionCallback.name, 16);
+			PkePlugin_SetSignatureFunc(&compInst.collisionCallback);
+
 			compInst.physicsLayer = comp.physicsLayer;
 			compInst.physicsMask = comp.physicsMask;
 			btVector3 localInertia(0, 0, 0);
@@ -356,6 +364,11 @@ void ParseInstance(EntityHandle parentEntHandle, std::ifstream &stream) {
 			assert(result == STR2NUM_ERROR::SUCCESS);
 			continue;
 		}
+		if (strstr(readLine, PKE_FILE_INSTANCE_COLLISION_CALLBACK_SIGNATURE)) {
+			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_COLLISION_CALLBACK_SIGNATURE);
+			strncpy(comp.collisionCallback.name, readLine + prefixLen, 16);
+			continue;
+		}
 	}
 }
 
@@ -496,9 +509,11 @@ void Game_Tick(double delta) {
 	ECS_Tick(delta);
 	PkeInput_Tick(delta);
 
-	// TODO invoke external ticks here
-	if (pkePlugin.OnTick) {
-		pkePlugin.OnTick(delta);
+	const auto pluginCount = LoadedPkePlugins.Count();
+	for (long i = 0; i < pluginCount; ++i) {
+		if (LoadedPkePlugins[i].OnTick != nullptr) {
+			LoadedPkePlugins[i].OnTick(delta);
+		}
 	}
 
 	EntityType_Tick_Late(delta);
@@ -517,11 +532,14 @@ void Game_Main(PKEWindowProperties windowProps, const char *executablePath) {
 		CreateWindow(windowProps);
 		PkeInput_Init();
 		EntityType_Init();
-		if (pkeSettings.args.pluginPath) {
-			Pke_LoadPlugin(pkeSettings.args.pluginPath);
+		if (pkeSettings.args.pluginPath != nullptr) {
+			PkePlugin_Load(pkeSettings.args.pluginPath);
 		}
-		if (pkePlugin.OnInit) {
-			pkePlugin.OnInit();
+		const long pluginCount = LoadedPkePlugins.Count();
+		for (long i = 0; i < pluginCount; ++i) {
+			if (LoadedPkePlugins[i].OnInit != nullptr) {
+				LoadedPkePlugins[i].OnInit();
+			}
 		}
 		PkeProject_Load(pkeSettings.args.projectPath);
 
@@ -612,8 +630,11 @@ void Game_Main(PKEWindowProperties windowProps, const char *executablePath) {
 #ifndef NDEBUG
 	Pke_DebugPrint();
 #endif
-	if (pkePlugin.OnTeardown) {
-		pkePlugin.OnTeardown();
+	const auto pluginCount = LoadedPkePlugins.Count();
+	for (long i = 0; i < pluginCount; ++i) {
+		if (LoadedPkePlugins[i].OnTeardown) {
+			LoadedPkePlugins[i].OnTeardown();
+		}
 	}
 	Game_Teardown();
 	Event_Teardown();
diff --git a/src/physics.cpp b/src/physics.cpp
index e960059..4825955 100644
--- a/src/physics.cpp
+++ b/src/physics.cpp
@@ -3,6 +3,7 @@
 
 #include "components.hpp"
 #include "dynamic-array.hpp"
+#include "ecs.hpp"
 #include "game-settings.hpp"
 
 #include <LinearMath/btAlignedAllocator.h>
@@ -26,6 +27,11 @@ btCollisionDispatcher *btDispatcher = nullptr;
 btBroadphaseInterface *btBroadphase = nullptr;
 btConstraintSolver *btSolver = nullptr;
 
+struct EntityCollision {
+	EntityHandle a, b;
+};
+PkeArray<EntityCollision> collisionsThisTick{};
+
 void *pke_btAlignedAllocFunc(size_t size, int alignment) {
 	void *ptr = Pke_New(size, alignment, MemBkt_Bullet);
 	bulletAllocs->Push({ptr, size});
@@ -68,8 +74,25 @@ void pke_btFreeFunc(void *memBlock) {
 struct CollisionHandlerStruct : public btOverlapFilterCallback {
 	~CollisionHandlerStruct() override {}
 	bool needBroadphaseCollision(btBroadphaseProxy* proxy0, btBroadphaseProxy* proxy1) const override {
-		return (proxy0->m_collisionFilterGroup & proxy1->m_collisionFilterMask) ||
+		auto collided = (proxy0->m_collisionFilterGroup & proxy1->m_collisionFilterMask) |
 			(proxy1->m_collisionFilterGroup & proxy0->m_collisionFilterMask);
+		if (collided) {
+			const auto *col0 = static_cast<btCollisionObject *>(proxy0->m_clientObject);
+			const auto *col1 = static_cast<btCollisionObject *>(proxy1->m_clientObject);
+			if (col0 && col1) {
+				EntityHandle ent0{};
+				ent0.hash = reinterpret_cast<uint64_t>(col0->getUserPointer());
+				EntityHandle ent1{};
+				ent1.hash = reinterpret_cast<uint64_t>(col1->getUserPointer());
+				if (ent0 != EntityHandle_MAX && ent1 != EntityHandle_MAX) {
+					PkeArray_Add<EntityCollision>(&collisionsThisTick, {
+						.a = ent0,
+						.b = ent1,
+					});
+				}
+			}
+		}
+		return collided;
 	}
 } collisionHandlerStruct;
 
@@ -102,7 +125,12 @@ void Physics_Init() {
 int32_t Physics_Tick(double delta) {
 	if (pkeSettings.isSimulationPaused == true)
 		return 0;
-	return BtDynamicsWorld->stepSimulation(delta, 1);
+	PkeArray_SoftReset(&collisionsThisTick);
+	auto tickCount = BtDynamicsWorld->stepSimulation(delta, 1);
+	for (long i = 0; i < collisionsThisTick.next; ++i) {
+		ECS_HandleCollision(collisionsThisTick.data[i].a, collisionsThisTick.data[i].b);
+	}
+	return tickCount;
 }
 
 void Physics_Teardown() {
diff --git a/src/plugins.cpp b/src/plugins.cpp
index bfd2e9b..5b0b817 100644
--- a/src/plugins.cpp
+++ b/src/plugins.cpp
@@ -1,22 +1,24 @@
 
-#include "macros.hpp"
 #include "plugins.hpp"
 
-#include <cstdio>
-#include <dlfcn.h>
+#include "array.hpp"
+#include "macros.hpp"
 
-PKEPluginInterface pkePlugin{};
+#include <cassert>
+#include <cstdio>
+#include <cstring>
 
-void *loadedPlugin = nullptr;
+#ifdef WIN32
+	// TODO
+#else
+	#include <dlfcn.h>
+#endif
 
-void Pke_UpdatePlugin(const PKEPluginInterface &plugin) {
-	pkePlugin.OnInit = plugin.OnInit;
-	pkePlugin.OnTick = plugin.OnTick;
-	pkePlugin.OnTeardown = plugin.OnTeardown;
-	pkePlugin.OnImGuiRender = plugin.OnImGuiRender;
-}
+DynArray<PKEPluginInterface> LoadedPkePlugins;
+PkeArray<PkeCallback> pkePluginCallbacks;
+PkeArray<CallbackSignature> sortedSignatures;
 
-void Pke_LoadPlugin(const char *path) {
+void PkePlugin_Load(const char *path) {
 	if (path == nullptr || path == CAFE_BABE(void)) {
 		return;
 	}
@@ -33,19 +35,43 @@ void Pke_LoadPlugin(const char *path) {
 		dlclose(extension);
 		return;
 	}
-	Pke_UpdatePlugin(*interface);
-	loadedPlugin = interface;
+	interface->pluginHandle = extension;
+	LoadedPkePlugins.Push(*interface);
+}
+
+PkeCallback *PkePlugin_FindSignature(const CallbackSignature &sig) {
+	for (long i = 0; i < pkePluginCallbacks.next; ++i) {
+		if (strncmp(sig, pkePluginCallbacks.data[i].name, 16) == 0) {
+			return &pkePluginCallbacks.data[i];
+		}
+	}
+	return nullptr;
 }
 
-void Pke_UnloadPlugin() {
-	pkePlugin = {
-		.OnInit = nullptr,
-		.OnTick= nullptr,
-		.OnTeardown= nullptr,
-		.OnImGuiRender= nullptr,
-	};
-	if (loadedPlugin != nullptr && loadedPlugin != CAFE_BABE(void)) {
-		dlclose(loadedPlugin);
-		loadedPlugin = CAFE_BABE(void);
+void PkePlugin_SetSignatureFunc(PkeCallback *sig) {
+	assert(sig != nullptr);
+	if (sig->name[0] == '\0') {
+		return;
+	}
+	auto *registeredSig = PkePlugin_FindSignature(sig->name);
+	if (registeredSig == nullptr) {
+		fprintf(stdout, "[WARN] [PkePlugin_SetSignatureFunc] Failed to find configured signature: '%s'\n", sig->name);
+		return;
+	}
+	sig->func = registeredSig->func;
+}
+
+int pstrncmp(const void* a, const void* b)
+{
+	return strncmp(static_cast<const CallbackSignature *>(a)[0], static_cast<const CallbackSignature *>(b)[0], 16);
+}
+CallbackSignature *PkePlugin_GetSortedSignatures(long &count) {
+	if (sortedSignatures.next != pkePluginCallbacks.next) {
+		while (sortedSignatures.next != pkePluginCallbacks.next) {
+			PkeArray_Add(&sortedSignatures, pkePluginCallbacks.data[sortedSignatures.next].name);
+		}
+		qsort(sortedSignatures.data, sortedSignatures.next, sizeof(CallbackSignature), pstrncmp);
 	}
+	count = sortedSignatures.next;
+	return sortedSignatures.data;
 }
diff --git a/src/plugins.hpp b/src/plugins.hpp
index 2f34c12..64c19f0 100644
--- a/src/plugins.hpp
+++ b/src/plugins.hpp
@@ -1,16 +1,32 @@
 #ifndef PKE_PLUGINS_HPP
 #define PKE_PLUGINS_HPP
 
+#include "array.hpp"
+#include "dynamic-array.hpp"
+
 struct PKEPluginInterface {
+	// for internal use only
+	void *pluginHandle = nullptr;
 	void (*OnInit)() = nullptr;
 	void (*OnTick)(double delta) = nullptr;
 	void (*OnTeardown)() = nullptr;
 	void (*OnImGuiRender)() = nullptr;
 };
 
-extern PKEPluginInterface pkePlugin;
+using CallbackSignature = char[16];
+struct PkeCallback {
+	// the 16 char signature(name) of a function
+	CallbackSignature name = {'\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0'};
+	// the address of the function to call - populated on startup
+	void *func = nullptr;
+};
+
+extern DynArray<PKEPluginInterface> LoadedPkePlugins;
+extern PkeArray<PkeCallback> pkePluginCallbacks;
 
-void Pke_LoadPlugin(const char *path);
-void Pke_UnloadPlugin();
+void PkePlugin_Load(const char *path);
+PkeCallback *PkePlugin_FindSignature(const CallbackSignature &sig);
+void PkePlugin_SetSignatureFunc(PkeCallback *sig);
+CallbackSignature *PkePlugin_GetSortedSignatures(long &count);
 
 #endif /* PKE_PLUGINS_HPP */
diff --git a/src/project.cpp b/src/project.cpp
index e5b5583..08c7c2a 100644
--- a/src/project.cpp
+++ b/src/project.cpp
@@ -27,6 +27,7 @@ const char* const PKE_PROJ_FILE_ENTITY_TYPE_MODELS_DIR = "ModelsDir: ";
 const char* const PKE_PROJ_FILE_ENTITY_TYPE_MODEL_FILE = "ModelFile: ";
 const char* const PKE_PROJ_FILE_ENTITY_TYPE_ENTITY_TYPE_CODE = "EntityTypeCode: ";
 const char* const PKE_PROJ_FILE_ENTITY_TYPE_ENTITY_HANDLE = "EntityHandle: ";
+const char* const PKE_PROJ_FILE_ENTITY_TYPE_COLLISION_CALLBACK_SIGNATURE = "CollisionCallbackSignature: ";
 const char* const PKE_PROJ_FILE_ENTITY_TYPE_STARTING_INSTANCE_COUNT = "StartingInstanceCount: ";
 const char* const PKE_PROJ_FILE_ENTITY_TYPE_IMPORTER_GLTF_ACCESSOR_INDEX_VERTEX = "Importer_GLTF::AccessorIndexVertex: ";
 const char* const PKE_PROJ_FILE_ENTITY_TYPE_IMPORTER_GLTF_ACCESSOR_INDEX_NORMAL = "Importer_GLTF::AccessorIndexNormal: ";
@@ -61,6 +62,7 @@ void Proj_SerializeEntityType(std::ofstream &stream, const EntityType &et) {
 	char handleStr[19] = { '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0' };
 	snprintf(handleStr, 19, "0x%016lX", et.entityHandle.hash);
 	EntityType e{};
+	CompGrBinds *grBinds = ECS_GetGrBinds(et.entityHandle);
 	if (et.modelsDir != e.modelsDir)
 		stream << PKE_PROJ_FILE_ENTITY_TYPE_MODELS_DIR << et.modelsDir << std::endl;
 	if (et.modelFile != e.modelFile)
@@ -69,6 +71,11 @@ void Proj_SerializeEntityType(std::ofstream &stream, const EntityType &et) {
 		stream << PKE_PROJ_FILE_ENTITY_TYPE_ENTITY_TYPE_CODE << et.entityTypeCode << std::endl;
 	if (et.entityHandle != e.entityHandle)
 		stream << PKE_PROJ_FILE_ENTITY_TYPE_ENTITY_HANDLE << handleStr << std::endl;
+	if (grBinds) {
+		if (grBinds->collisionCallback.name[0] != '\0') {
+			stream << PKE_PROJ_FILE_ENTITY_TYPE_COLLISION_CALLBACK_SIGNATURE << grBinds->collisionCallback.name << std::endl;
+		}
+	}
 	if (et.startingInstanceCount != e.startingInstanceCount)
 		stream << PKE_PROJ_FILE_ENTITY_TYPE_STARTING_INSTANCE_COUNT << et.startingInstanceCount << std::endl;
 	if (et.Importer_GLTF.AccessorIndexVertex != e.Importer_GLTF.AccessorIndexVertex)
@@ -126,6 +133,8 @@ void Proj_ParseProjectSettings(std::ifstream &stream) {
 */
 
 void Proj_ParseEntityType(std::ifstream &stream) {
+	CallbackSignature collisionSig;
+	collisionSig[0] = '\0';
 	EntityType et{};
 	while (stream.getline(projReadLine, projReadLineLength)) {
 		if (strcmp(PKE_PROJ_FILE_OBJ_END, projReadLine) == 0) {
@@ -136,6 +145,11 @@ void Proj_ParseEntityType(std::ifstream &stream) {
 			et.entityHandle = ECS_CreateEntity();
 			EntityType_Load(et);
 			GlobalEntityTypes.Push(et);
+			CompGrBinds *grBinds = ECS_GetGrBinds(et.entityHandle);
+			if (grBinds) {
+				strncpy(grBinds->collisionCallback.name, collisionSig, 16);
+				PkePlugin_SetSignatureFunc(&grBinds->collisionCallback);
+			}
 			return;
 		}
 		if (strstr(projReadLine, PKE_PROJ_FILE_ENTITY_TYPE_MODELS_DIR)) {
@@ -171,6 +185,11 @@ void Proj_ParseEntityType(std::ifstream &stream) {
 			assert(result == STR2NUM_ERROR::SUCCESS);
 			continue;
 		}
+		if (strstr(projReadLine, PKE_PROJ_FILE_ENTITY_TYPE_COLLISION_CALLBACK_SIGNATURE)) {
+			uint64_t prefixLen = strlen(PKE_PROJ_FILE_ENTITY_TYPE_COLLISION_CALLBACK_SIGNATURE);
+			memcpy(collisionSig, projReadLine + prefixLen, 16);
+			continue;
+		}
 		if (strstr(projReadLine, PKE_PROJ_FILE_ENTITY_TYPE_STARTING_INSTANCE_COUNT)) {
 			uint64_t prefixLen = strlen(PKE_PROJ_FILE_ENTITY_TYPE_STARTING_INSTANCE_COUNT);
 			STR2NUM_ERROR result = str2num(et.startingInstanceCount, projReadLine + prefixLen);
diff --git a/src/window.cpp b/src/window.cpp
index f9b6ff2..e7d4506 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -2428,13 +2428,23 @@ void RecordCommandBuffer(VkCommandBuffer commandBuffer, uint32_t imageIndex) {
 	vkCmdDraw(commandBuffer, 3, 1, 0, 0);
 
 	// ImGui
-	if (pkePlugin.OnImGuiRender) {
+	const auto count = LoadedPkePlugins.Count();
+	bool any = false;
+	for (long i = 0; i < count; ++i) {
+		if (LoadedPkePlugins[i].OnImGuiRender != nullptr) {
+			any = true;
+			break;
+		}
+	}
+	if (any) {
 		ImGui_ImplVulkan_NewFrame();
 		ImGui_ImplGlfw_NewFrame();
 		ImGui::NewFrame();
-
-		pkePlugin.OnImGuiRender();
-
+		for (long i = 0; i < count; ++i) {
+			if (LoadedPkePlugins[i].OnImGuiRender != nullptr) {
+				LoadedPkePlugins[i].OnImGuiRender();
+			}
+		}
 		ImGui::Render();
 		auto drawData = ImGui::GetDrawData();
 		const bool isMinimized = drawData->DisplaySize.x <= 0.0f || drawData->DisplaySize.y <= 0.0f;