checkpoint - physics is working but messy

5 files changed, 77 insertions, 4 deletions

diff --git a/src/components.hpp b/src/components.hpp
index 4d52e39..3e7521f 100644
--- a/src/components.hpp
+++ b/src/components.hpp
@@ -4,6 +4,9 @@
 #include "macros.hpp"
 #include "dynamic-array.hpp"
 
+#include <BulletCollision/CollisionShapes/btCollisionShape.h>
+#include <LinearMath/btDefaultMotionState.h>
+#include <BulletDynamics/Dynamics/btRigidBody.h>
 #include <glm/gtc/quaternion.hpp>
 #include <vulkan/vulkan_core.h>
 
@@ -63,6 +66,12 @@ struct CompInstance {
 	InstanceHandle instanceHandle = InstanceHandle_MAX;
 	uint64_t index = ECS_UNSET_VAL;
 	InstPos instPos;
+	struct {
+		btVector3 localInertia;
+		btCollisionShape *collisionShape;
+		btDefaultMotionState defaultMotionState;
+		btRigidBody *rigidBody;
+	} bt;
 	bool isNeedingUpdated = false;
 };
 
diff --git a/src/ecs.cpp b/src/ecs.cpp
index 3c5cbdb..831adfb 100644
--- a/src/ecs.cpp
+++ b/src/ecs.cpp
@@ -1,12 +1,18 @@
 
 #include "ecs.hpp"
 
+#include "game-settings.hpp"
 #include "memory.hpp"
 #include "vendor/glm_include.hpp"
 #include "window.hpp"
 
 #include <btBulletDynamicsCommon.h>
 
+#define GLM_TO_BULLET_VEC_3(vec) btVector3(vec.x, vec.y, vec.z)
+#define GLM_TO_BULLET_QUAT(quat) btQuaternion(quat.x, quat.y, quat.z, quat.w)
+#define BULLET_TO_GLM_VEC_3(vec) glm::vec3(vec.getX(), vec.getY(), vec.getZ())
+#define BULLET_TO_GLM_QUAT(qt)   glm::quat(qt.getW(), qt.getX(), qt.getY(), qt.getZ())
+
 TypeSafeInt_B(EntityHandle);
 const uint64_t maxBucketItemCount = 256;
 
@@ -178,6 +184,29 @@ void ECS_Tick_Early(double delta) {
 	entitiesMarkedForRemoval.Resize(0);
 }
 
+void ECS_Tick(double delta) {
+	if (btDynamicsWorld && pkeSettings.isSimulationPaused == false) {
+		auto physicsTickCount = btDynamicsWorld->stepSimulation(delta, 0);
+		if (physicsTickCount != 0) {
+			for (long b = 0; b <= Comp_Instance_BucketContainer.bucketCounter; ++b) {
+				auto &bkt = Comp_Instance_BucketContainer.buckets[b];
+				long count = Comp_Instance_BucketContainer.bucketCounter == b ? Comp_Instance_BucketContainer.itemCounter >> 32 : maxBucketItemCount;
+				for (uint32_t i = 0; i < count; ++i) {
+					auto &inst = bkt.instances[i];
+					btTransform trans;
+					inst.bt.defaultMotionState.getWorldTransform(trans);
+
+					InstPos instPos = inst.instPos;
+					instPos.pos = BULLET_TO_GLM_VEC_3(trans.getOrigin());
+					instPos.rot = BULLET_TO_GLM_QUAT(trans.getRotation());
+					// TODO add an _INNER since we have a reference to the object that this looks up
+					ECS_UpdateInstance(inst.entHandle, instPos, false);
+				}
+			}
+		}
+	}
+}
+
 struct InstanceBufferCopyChunk {
 	uint64_t startingIndex;
 	uint64_t endingIndex;
@@ -374,6 +403,22 @@ CompInstance &ECS_CreateInstance(EntityHandle entHandle, EntityHandle entityType
 	if (grBinds->instanceCounter > grBinds->instanceBufferMaxCount) {
 		EntitiesWithExcessInstances.Push(grBinds->entHandle);
 	}
+
+	if (btDynamicsWorld) {
+		comp->bt.localInertia = btVector3(0, 0, 0);
+		comp->bt.collisionShape = Pke_New<btBoxShape>(bulletBucket);
+		new (comp->bt.collisionShape) btBoxShape(GLM_TO_BULLET_VEC_3(comp->instPos.scale));
+		comp->bt.collisionShape->calculateLocalInertia(btScalar(1.f), comp->bt.localInertia);
+		btTransform transform;
+		transform.setIdentity();
+		transform.setOrigin(GLM_TO_BULLET_VEC_3(comp->instPos.pos));
+		comp->bt.defaultMotionState = btDefaultMotionState(transform);
+		comp->bt.rigidBody = Pke_New<btRigidBody>(bulletBucket);
+		new (comp->bt.rigidBody) btRigidBody(btScalar(1.f), &comp->bt.defaultMotionState, comp->bt.collisionShape, comp->bt.localInertia);
+		btDynamicsWorld->addRigidBody(comp->bt.rigidBody);
+		comp->bt.rigidBody->setUserPointer(reinterpret_cast<void *>(comp->entHandle));
+	}
+
 	return *comp;
 }
 
@@ -392,7 +437,7 @@ CompInstance *ECS_GetInstance(EntityHandle entHandle) {
 	return inst;
 }
 
-void ECS_UpdateInstance(EntityHandle entHandle, const InstPos &instPos) {
+void ECS_UpdateInstance(EntityHandle entHandle, const InstPos &instPos, bool overridePhysics) {
 	Entity *ent = nullptr;
 	ECS_GetEntity_Inner(entHandle, ent);
 
@@ -404,10 +449,25 @@ void ECS_UpdateInstance(EntityHandle entHandle, const InstPos &instPos) {
 	auto i = Buckets_GetItemIndex(instanceHandle_t);
 	auto *inst = &Comp_Instance_BucketContainer.buckets[b].instances[i];
 
+	if (overridePhysics == false
+			&& instPos.pos == inst->instPos.pos
+			&& instPos.rot == inst->instPos.rot
+			&& instPos.scale == inst->instPos.scale) {
+		return;
+	}
+
 	inst->instPos.pos = instPos.pos;
 	inst->instPos.rot = instPos.rot;
 	inst->instPos.scale = instPos.scale;
 	inst->isNeedingUpdated = true;
+
+	if (overridePhysics == true && btDynamicsWorld) {
+		btTransform transform;
+		transform.setIdentity();
+		transform.setOrigin(GLM_TO_BULLET_VEC_3(inst->instPos.pos));
+		transform.setRotation(GLM_TO_BULLET_QUAT(inst->instPos.rot));
+		inst->bt.rigidBody->setWorldTransform(transform);
+	}
 }
 
 uint64_t ECS_GetInstances_BucketCount() {
diff --git a/src/ecs.hpp b/src/ecs.hpp
index 49d947c..480ba0c 100644
--- a/src/ecs.hpp
+++ b/src/ecs.hpp
@@ -20,6 +20,7 @@ static struct {
 void ECS_Init();
 void ECS_Teardown();
 void ECS_Tick_Early(double delta);
+void ECS_Tick(double delta);
 void ECS_Tick_Late(double delta);
 EntityHandle ECS_CreateEntity(EntityHandle parentEntHandle = EntityHandle{EntityHandle_T{0xFFFFFFFFFFFFFFFF}});
 void ECS_MarkForRemoval(EntityHandle entHandle);
@@ -33,7 +34,7 @@ CompGrBinds *ECS_GetGrBinds(uint64_t bucketIndex, uint64_t &itemCount);
 
 CompInstance &ECS_CreateInstance(EntityHandle entHandle, EntityHandle entityTypeEntityHandle);
 CompInstance *ECS_GetInstance(EntityHandle entHandle);
-void ECS_UpdateInstance(EntityHandle entHandle, const InstPos &instPos);
+void ECS_UpdateInstance(EntityHandle entHandle, const InstPos &instPos, bool overridePhysics = false);
 uint64_t ECS_GetInstances_BucketCount();
 CompInstance *ECS_GetInstances(uint64_t bucketIndex, uint64_t &itemCount);
 
diff --git a/src/game-settings.hpp b/src/game-settings.hpp
index c42b917..1131e6d 100644
--- a/src/game-settings.hpp
+++ b/src/game-settings.hpp
@@ -9,6 +9,7 @@ struct GameSettings {
 	bool isGamePaused = false;
 	bool isShowingEditor = true;
 	bool isRenderingDebug = false;
+	bool isSimulationPaused = false;
 	std::chrono::steady_clock steadyClock;
 	int64_t targetFPS = 144;
 	int64_t minFPS = 20;
diff --git a/src/game.cpp b/src/game.cpp
index e921b2f..a1ba28b 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -247,7 +247,7 @@ void ParseInstance(std::ifstream &stream) {
 			const auto &et = GlobalEntityTypes[existingEntityTypeIndex];
 			auto entityHandle = ECS_CreateEntity();
 			ECS_CreateInstance(entityHandle, et.entityHandle);
-			ECS_UpdateInstance(entityHandle, comp.instPos);
+			ECS_UpdateInstance(entityHandle, comp.instPos, true);
 			break;
 		}
 		if (strstr(readLine, PKE_FILE_INSTANCE_ENTITY_HANDLE)) {
@@ -422,6 +422,7 @@ void Game_Tick(double delta) {
 		EntityHandle newEntity = ECS_CreateEntity();
 		ECS_CreateInstance(newEntity, createInfo.entityTypeEntityHandle);
 	}
+
 	PkeInput_Tick(delta);
 	PkeInputEventHolder holder = PkeInput_Query(dbgCtrl_UnlockCamera);
 	if (holder.type != InputEventHash{0}) {
@@ -573,6 +574,7 @@ void RecordImGuiEditorWrapper() {
 	}
 	if (ImGui::BeginMenu("Debug")) {
 		ImGui::Checkbox("Show Debug Hitboxes", &pkeSettings.isRenderingDebug);
+		ImGui::Checkbox("Pause Physics Simulation", &pkeSettings.isSimulationPaused);
 		if (ImGui::Checkbox("Uncap Framerate", &pkeSettings.graphicsSettings.isFramerateUnlocked)) {
 			shouldRecreateSwapchain = true;
 		}
@@ -815,7 +817,7 @@ void RecordImGui_CompInstPos(bool readonly, CompInstance *component) {
 	changed = ImGui::InputScalarN("scale", ImGuiDataType_Float, &component->instPos.scale, 3, nullptr, nullptr, nullptr, inputTextFlags) || changed;
 
 	if (changed) {
-		ECS_UpdateInstance(component->entHandle, component->instPos);
+		ECS_UpdateInstance(component->entHandle, component->instPos, true);
 	}
 
 	ImGui::Spacing();