Merge pull request #85 from teamfisk/FrustumCulling

Frustum culling

include/Engine/Collision/Collision.h

@@ -78,8 +78,6 @@ bool AABBVsAABB(const AABB& a, const AABB& b);
 //Also outputs the minimum translation that box [a] would need in order to resolve collision.
 bool AABBVsAABB(const AABB& a, const AABB& b, glm::vec3& minimumTranslation);
 
-//Attaches an AABB which contains all vertices in the entitys Model.
-bool AttachAABBComponentFromModel(EntityWrapper entity);
 // Calculates an absolute AABB from an entity AABB component
 boost::optional<EntityAABB> EntityAbsoluteAABB(EntityWrapper& entity);
 

include/Engine/Collision/FillFrustumOctreeSystem.h

@@ -0,0 +1,25 @@
+#ifndef FillFrustumOctreeSystem_h__
+#define FillFrustumOctreeSystem_h__
+
+#include "../Core/System.h"
+#include "../Core/Octree.h"
+#include "Collision.h"
+#include "EntityAABB.h"
+
+class FillFrustumOctreeSystem : public ImpureSystem, public PureSystem
+{
+public:
+    FillFrustumOctreeSystem(World* world, EventBroker* eventBroker, Octree<EntityAABB>* octree)
+        : System(world, eventBroker)
+        , PureSystem("Model")
+        , m_Octree(octree)
+    { }
+
+    virtual void Update(double dt) override;
+    virtual void UpdateComponent(EntityWrapper& entity, ComponentWrapper& component, double dt) override;
+
+private:
+    Octree<EntityAABB>* m_Octree;
+};
+
+#endif

include/Engine/Collision/FillOctreeSystem.h

@@ -1,5 +1,5 @@
-#ifndef CollidableOctreeSystem_h__
+#ifndef FillOctreeSystem_h__
-#define CollidableOctreeSystem_h__
+#define FillOctreeSystem_h__
 
 #include "../Core/System.h"
 #include "../Core/Octree.h"

include/Engine/Core/Frustum.h

@@ -0,0 +1,77 @@
+#ifndef Frustum_h__
+#define Frustum_h__
+
+#include "../GLM.h"
+#include "AABB.h"
+#include <bitset>
+
+//A frustum defined by 6 planes.
+struct Frustum
+{
+    //Contains points P in: dot(normal, P) + d = 0
+    struct Plane
+    {
+        glm::vec3 Normal;
+        float Distance;
+    };
+
+    enum class Output
+    {
+        Inside,
+        Outside,
+        Intersects
+    };
+    Plane Planes[6];
+
+    Frustum() = default;
+    Frustum(glm::mat4x4 viewProjMatrix)
+    {
+        //Order: Right, left, top, bottom, far, near.
+        int sign = 1;
+        for (int i = 0; i < 6; ++i) {
+            sign = -sign;
+            int index = i / 2;
+            Plane& plane = Planes[i];
+            plane.Normal.x = viewProjMatrix[0].w + sign * viewProjMatrix[0][index];
+            plane.Normal.y = viewProjMatrix[1].w + sign * viewProjMatrix[1][index];
+            plane.Normal.z = viewProjMatrix[2].w + sign * viewProjMatrix[2][index];
+            plane.Distance = viewProjMatrix[3].w + sign * viewProjMatrix[3][index];
+            float divByNormalLength = 1.0f / glm::length(plane.Normal);
+            plane.Normal *= divByNormalLength;
+            plane.Distance *= divByNormalLength;
+        }
+    }
+
+    Output VsAABB(const AABB& box) const
+    {
+        const glm::vec3& maxCorner = box.MaxCorner();
+        const glm::vec3& minCorner = box.MinCorner();
+        bool completelyInside = true;
+        for (const Plane& p : Planes) {
+            bool anyWasInside = false;
+            bool anyWasOutside = false;
+            //If points are on both sides of the plane, we can stop.
+            for (int i = 0; i < 8 && (!anyWasInside || !anyWasOutside); ++i) {
+                std::bitset<3> bits(i);
+                glm::vec3 corner;
+                corner.x = bits.test(0) ? maxCorner.x : minCorner.x;
+                corner.y = bits.test(1) ? maxCorner.y : minCorner.y;
+                corner.z = bits.test(2) ? maxCorner.z : minCorner.z;
+                if (glm::dot(p.Normal, corner) > -p.Distance) {
+                    anyWasInside = true;
+                } else {
+                    anyWasOutside = true;
+                }
+            }
+            if (!anyWasInside) {
+                return Output::Outside;
+            }
+            if (anyWasOutside) {
+                completelyInside = false;
+            }
+        }
+        return completelyInside ? Output::Inside : Output::Intersects;
+    }
+};
+
+#endif

include/Engine/Core/Octree.h

@@ -5,6 +5,7 @@
 
 #include "../Common.h"
 #include "AABB.h"
+#include "Frustum.h"
 
 //Fwd declarations.
 class Ray;
@@ -40,6 +41,8 @@ public:
     //The type Box must be AABB, or inherit from AABB.
     template<typename Box>
     void ObjectsInSameRegion(const Box& box, std::vector<T>& outObjects);
+    //Get the objects that are inside the frustum, the objects are put in outObjects.
+    void ObjectsInFrustum(const Frustum& frustum, std::vector<T>& outObjects);
     //Empty the tree of all objects, static and dynamic.
     void ClearObjects();
     //Empty the tree of all dynamic objects. Static objects remain in the tree.
@@ -97,6 +100,8 @@ struct Child
     void AddStaticObject(const AABB& box);
     template<typename T, typename Box>
     void ObjectsInSameRegion(const Box& box, std::vector<T>& outObjects) const;
+    template<typename T>
+    void ObjectsInFrustum(const Frustum& frustum, std::vector<T>& outObjects, bool takeAllDontTest) const;
     void ClearObjects();
     void ClearDynamicObjects();
     bool RayCollides(const Ray& ray, Output& data) const;
@@ -154,6 +159,13 @@ void Octree<T>::ObjectsInSameRegion(const Box& box, std::vector<T>& outObjects)
     m_Root->ObjectsInSameRegion(box, outObjects);
 }
 
+template<typename T>
+void Octree<T>::ObjectsInFrustum(const Frustum& frustum, std::vector<T>& outObjects)
+{
+    falsifyObjectChecks();
+    m_Root->ObjectsInFrustum(frustum, outObjects, false);
+}
+
 template<typename T>
 void Octree<T>::ClearObjects()
 {
@@ -230,4 +242,46 @@ void OctSpace::Child::ObjectsInSameRegion(const Box& box, std::vector<T>& outObj
     }
 }
 
+template<typename T>
+void OctSpace::Child::ObjectsInFrustum(const Frustum& frustum, std::vector<T>& outObjects, bool takeAllDontTest) const
+{
+    if (hasChildren()) {
+        for (const Child* c : m_Children) {
+            Frustum::Output out = Frustum::Output::Inside;
+            if (!takeAllDontTest) {
+                out = frustum.VsAABB(c->m_Box);
+                if (out == Frustum::Output::Outside) {
+                    continue;
+                }
+            }
+            c->ObjectsInFrustum(frustum, outObjects, out == Frustum::Output::Inside);
+        }
+    } else {
+        size_t startIndex = outObjects.size();
+        int numDuplicates = 0;
+        outObjects.resize(outObjects.size() + m_StaticObjIndices.size() + m_DynamicObjIndices.size());
+        for (size_t i = 0; i < m_StaticObjIndices.size(); ++i) {
+            ContainedObject& obj = m_StaticObjectsRef[m_StaticObjIndices[i]];
+            if (obj.Checked || frustum.VsAABB(*obj.Box) == Frustum::Output::Outside) {
+                ++numDuplicates;
+            } else {
+                obj.Checked = true;
+                outObjects[startIndex + i - numDuplicates] = *static_cast<T*>(obj.Box.get());
+            }
+        }
+        for (size_t i = 0; i < m_DynamicObjIndices.size(); ++i) {
+            ContainedObject& obj = m_DynamicObjectsRef[m_DynamicObjIndices[i]];
+            if (obj.Checked || frustum.VsAABB(*obj.Box) == Frustum::Output::Outside) {
+                ++numDuplicates;
+            } else {
+                obj.Checked = true;
+                outObjects[startIndex + i - numDuplicates] = *static_cast<T*>(obj.Box.get());
+            }
+        }
+        for (size_t i = 0; i < numDuplicates; ++i) {
+            outObjects.pop_back();
+        }
+    }
+}
+
 #endif

include/Engine/Rendering/Model.h

@@ -4,6 +4,7 @@
 #include "Rendering/RawModelCustom.h"
 //#include "Rendering/RawModelAssimp.h"
 #include "../OpenGL.h"
+#include "Core/AABB.h"
 
 class Model : public ThreadUnsafeResource
 {
@@ -17,12 +18,14 @@ public:
     const std::vector<RawModel::MaterialGroup>& MaterialGroups() const { return m_RawModel->MaterialGroups; }
     const glm::mat4& Matrix() const { return m_RawModel->m_Matrix; }
     const std::vector<RawModel::Vertex>& Vertices() const { return m_RawModel->m_Vertices; }
+    const AABB& Box() const { return m_Box; }
 
 	GLuint VAO;
 	GLuint ElementBuffer;
     RawModel* m_RawModel;
 
 private:
+    AABB m_Box;
 
 	GLuint VertexBuffer;
 	GLuint NormalBuffer;

include/Engine/Rendering/RenderSystem.h

@@ -16,11 +16,13 @@
 #include "PointLightJob.h"
 #include "../Core/Transform.h"
 #include "../Core/EPlayerSpawned.h"
+#include "../Core/Octree.h"
+#include "../Collision/EntityAABB.h"
 
 class RenderSystem : public ImpureSystem
 {
 public:
-    RenderSystem(World* world, EventBroker* eventBrokerer, const IRenderer* renderer, RenderFrame* renderFrame);
+    RenderSystem(World* world, EventBroker* eventBrokerer, const IRenderer* renderer, RenderFrame* renderFrame, Octree<EntityAABB>* frustumCullOctree);
     ~RenderSystem();
 
     virtual void Update(double dt) override;
@@ -32,6 +34,7 @@ private:
     World* m_World;
     EntityWrapper m_CurrentCamera = EntityWrapper::Invalid;
     EntityWrapper m_LocalPlayer = EntityWrapper::Invalid;
+    Octree<EntityAABB>* m_Octree;
 
     EventRelay<RenderSystem, Events::SetCamera> m_ESetCamera;
     bool OnSetCamera(Events::SetCamera &event);

src/Engine/Collision/Collision.cpp

@@ -1,4 +1,5 @@
 #include <algorithm>
+#include <bitset>
 
 #include "Collision/Collision.h"
 #include "Engine/GLM.h"
@@ -564,47 +565,50 @@ bool AABBvsTriangles(const AABB& box,
     return hit;
 }
 
-bool AttachAABBComponentFromModel(EntityWrapper entity)
-{
-    if (!entity.HasComponent("Model")) {
-        return false;
-    }
-    //Derive AABB from model
-    RawModel* model;
-    try {
-        model = ResourceManager::Load<RawModel, true>(entity["Model"]["Resource"]);
-    } catch (const std::exception&) {
-        return false;
-    }
-
-    glm::vec3 mini(INFINITY);
-    glm::vec3 maxi(-INFINITY);
-    for (const auto& v : model->m_Vertices) {
-        mini = glm::min(mini, v.Position);
-        maxi = glm::max(maxi, v.Position);
-    }
-
-    entity.AttachComponent("AABB");
-    entity["AABB"]["Origin"] = 0.5f * (maxi + mini);
-    entity["AABB"]["Size"] = maxi - mini;
-    return true;
-}
-
 boost::optional<EntityAABB> EntityAbsoluteAABB(EntityWrapper& entity)
 {
-    if (!entity.HasComponent("AABB")) {
+    AABB modelSpaceBox;
+    if (entity.HasComponent("AABB")) {
+        ComponentWrapper& cAABB = entity["AABB"];
+        modelSpaceBox = EntityAABB::FromOriginSize((glm::vec3)cAABB["Origin"], (glm::vec3)cAABB["Size"]);
+    } else if (entity.HasComponent("Model")) {
+        Model* model;
+        std::string res = entity["Model"]["Resource"];
+        if (res.empty()) {
+            return boost::none;
+        }
+        try {
+            model = ResourceManager::Load<::Model, true>(res);
+        } catch (const Resource::StillLoadingException&) {
+            return boost::none;
+        } catch (const std::exception&) {
+            return boost::none;
+        }
+        modelSpaceBox = model->Box();
+    } else {
         return boost::none;
     }
 
-    ComponentWrapper& cAABB = entity["AABB"];
+    glm::mat4 modelMat = Transform::AbsoluteTransformation(entity);
-    glm::vec3 absPosition = Transform::AbsolutePosition(entity.World, entity.ID);
+    glm::vec3 mini(INFINITY);
-    glm::vec3 absScale = Transform::AbsoluteScale(entity.World, entity.ID);
+    glm::vec3 maxi(-INFINITY);
-    glm::vec3 origin = absPosition + (glm::vec3)cAABB["Origin"];
+    glm::vec3 maxCorner = modelSpaceBox.MaxCorner();
-    glm::vec3 size = (glm::vec3)cAABB["Size"] * absScale;
+    glm::vec3 minCorner = modelSpaceBox.MinCorner();
+    for (int i = 0; i < 8; ++i) {
+        std::bitset<3> bits(i);
+        glm::vec3 corner;
+        corner.x = bits.test(0) ? maxCorner.x : minCorner.x;
+        corner.y = bits.test(1) ? maxCorner.y : minCorner.y;
+        corner.z = bits.test(2) ? maxCorner.z : minCorner.z;
+        corner = Transform::TransformPoint(corner, modelMat);
+        mini = glm::min(mini, corner);
+        maxi = glm::max(maxi, corner);
+    }
+
+    EntityAABB aabb;
+    aabb = AABB(mini, maxi);
 
-    EntityAABB aabb = EntityAABB::FromOriginSize(origin, size);
     aabb.Entity = entity;
-
     return aabb;
 }
 

src/Engine/Collision/FillFrustumOctreeSystem.cpp

@@ -0,0 +1,21 @@
+#include "Collision/FillFrustumOctreeSystem.h"
+
+void FillFrustumOctreeSystem::Update(double dt)
+{
+    m_Octree->ClearDynamicObjects();
+}
+
+void FillFrustumOctreeSystem::UpdateComponent(EntityWrapper& entity, ComponentWrapper& component, double dt)
+{
+    if (entity.HasComponent("ExplosionEffect")) {
+        //TODO: Fix hack, get real box by using shader equation.
+        EntityAABB aabb = AABB(glm::vec3(-300), glm::vec3(300));
+        aabb.Entity = entity;
+        m_Octree->AddDynamicObject(aabb);
+    } else {
+        boost::optional<EntityAABB> absoluteAABB = Collision::EntityAbsoluteAABB(entity);
+        if (absoluteAABB) {
+            m_Octree->AddDynamicObject(*absoluteAABB);
+        }
+    }
+}

src/Engine/Collision/FillOctreeSystem.cpp

@@ -7,12 +7,6 @@ void FillOctreeSystem::Update(double dt)
 
 void FillOctreeSystem::UpdateComponent(EntityWrapper& entity, ComponentWrapper& component, double dt)
 {
-    if (!entity.HasComponent("AABB")) {
-        //Derive AABB from model.
-        if (!Collision::AttachAABBComponentFromModel(entity)) {
-            return;
-        }
-    }
     boost::optional<EntityAABB> absoluteAABB = Collision::EntityAbsoluteAABB(entity);
     if (absoluteAABB) {
         m_Octree->AddDynamicObject(*absoluteAABB);

src/Engine/Collision/TriggerSystem.cpp

@@ -5,11 +5,6 @@
 
 void TriggerSystem::UpdateComponent(EntityWrapper& triggerEntity, ComponentWrapper& cTrigger, double dt)
 {
-    // The trigger *should* have a bounding box, or something, to test against so it can be triggered.
-    // If it doesn't, add one as big as the model for now, then size can be modified in editor if necessary.
-    if (!triggerEntity.HasComponent("AABB")) {
-        Collision::AttachAABBComponentFromModel(triggerEntity);
-    }
     boost::optional<EntityAABB> triggerBox = Collision::EntityAbsoluteAABB(triggerEntity);
     if (!triggerBox) {
         return;

src/Engine/Rendering/Model.cpp

@@ -64,6 +64,15 @@ Model::Model(std::string fileName)
     GLERROR("GLEW: BufferFail5");
 
     //CreateBuffers();
+
+    glm::vec3 mini(INFINITY);
+    glm::vec3 maxi(-INFINITY);
+    for (const auto& v : m_RawModel->m_Vertices) {
+        mini = glm::min(mini, v.Position);
+        maxi = glm::max(maxi, v.Position);
+    }
+
+    m_Box = AABB(maxi, mini);
 }
 
 Model::~Model()

src/Engine/Rendering/RenderSystem.cpp

@@ -1,10 +1,13 @@
 #include "Rendering/RenderSystem.h"
+#include "Collision/Collision.h"
+#include "Core/Frustum.h"
 
-RenderSystem::RenderSystem(World* world, EventBroker* eventBroker, const IRenderer* renderer, RenderFrame* renderFrame) 
+RenderSystem::RenderSystem(World* world, EventBroker* eventBroker, const IRenderer* renderer, RenderFrame* renderFrame, Octree<EntityAABB>* frustumCullOctree)
     : System(world, eventBroker)
     , m_Renderer(renderer)
     , m_RenderFrame(renderFrame)
     , m_World(world)
+    , m_Octree(frustumCullOctree)
 {
     EVENT_SUBSCRIBE_MEMBER(m_ESetCamera, &RenderSystem::OnSetCamera);
     EVENT_SUBSCRIBE_MEMBER(m_EInputCommand, &RenderSystem::OnInputCommand);
@@ -42,12 +45,13 @@ bool RenderSystem::isChildOfCurrentCamera(EntityWrapper entity)
 
 void RenderSystem::fillModels(RenderScene::Queues &Jobs)
 {
-    auto models = m_World->GetComponents("Model");
+    Frustum frustum(m_Camera->ProjectionMatrix() * m_Camera->ViewMatrix());
-    if (models == nullptr) {
+    std::vector<EntityAABB> seenEntities;
-        return;
+    m_Octree->ObjectsInFrustum(frustum, seenEntities);
-    }
 
-    for (auto& cModel : *models) {
+    for (auto& seenEntity : seenEntities) {
+        EntityWrapper entity = seenEntity.Entity;
+        ComponentWrapper cModel = entity["Model"];
         bool visible = cModel["Visible"];
         if (!visible) {
             continue;
@@ -57,8 +61,6 @@ void RenderSystem::fillModels(RenderScene::Queues &Jobs)
             continue;
         }
 
-        EntityWrapper entity(m_World, cModel.EntityID);
-
         // Only render children of a camera if that camera is currently active
         if (isChildOfACamera(entity) && !isChildOfCurrentCamera(entity)) {
             continue;

src/Game/Game.cpp

@@ -1,5 +1,6 @@
 #include "Game.h"
 #include "Collision/FillOctreeSystem.h"
+#include "Collision/FillFrustumOctreeSystem.h"
 #include "Collision/EntityAABB.h"
 #include "Collision/TriggerSystem.h"
 #include "Collision/CollisionSystem.h"
@@ -77,9 +78,11 @@ Game::Game(int argc, char* argv[])
     m_SoundManager = new SoundManager(m_World, m_EventBroker);
 
     // Create Octrees
-    m_OctreeCollision = new Octree<EntityAABB>(AABB(glm::vec3(-100), glm::vec3(100)), 4);
+    // TODO: Perhaps the world bounds should be set in some non-arbitrary way instead of this.
-    m_OctreeTrigger = new Octree<EntityAABB>(AABB(glm::vec3(-100), glm::vec3(100)), 4);
+    AABB boxContainingTheWorld(glm::vec3(-300), glm::vec3(300));
-    m_OctreeFrustrumCulling = new Octree<EntityAABB>(AABB(glm::vec3(-100), glm::vec3(100)), 4);
+    m_OctreeCollision = new Octree<EntityAABB>(boxContainingTheWorld, 4);
+    m_OctreeTrigger = new Octree<EntityAABB>(boxContainingTheWorld, 4);
+    m_OctreeFrustrumCulling = new Octree<EntityAABB>(boxContainingTheWorld, 4);
     // Create system pipeline
     m_SystemPipeline = new SystemPipeline(m_World, m_EventBroker);
 
@@ -102,6 +105,7 @@ Game::Game(int argc, char* argv[])
     ++updateOrderLevel;
     m_SystemPipeline->AddSystem<FillOctreeSystem>(updateOrderLevel, m_OctreeCollision, "Collidable");
     m_SystemPipeline->AddSystem<FillOctreeSystem>(updateOrderLevel, m_OctreeTrigger, "Player");
+    m_SystemPipeline->AddSystem<FillFrustumOctreeSystem>(updateOrderLevel, m_OctreeFrustrumCulling);
     m_SystemPipeline->AddSystem<PlayerHUD>(updateOrderLevel);
     m_SystemPipeline->AddSystem<AnimationSystem>(updateOrderLevel);
 
@@ -110,7 +114,7 @@ Game::Game(int argc, char* argv[])
     m_SystemPipeline->AddSystem<CollisionSystem>(updateOrderLevel, m_OctreeCollision);
     m_SystemPipeline->AddSystem<TriggerSystem>(updateOrderLevel, m_OctreeTrigger);
     ++updateOrderLevel;
-    m_SystemPipeline->AddSystem<RenderSystem>(updateOrderLevel, m_Renderer, m_RenderFrame);
+    m_SystemPipeline->AddSystem<RenderSystem>(updateOrderLevel, m_Renderer, m_RenderFrame, m_OctreeFrustrumCulling);
     ++updateOrderLevel;
     m_SystemPipeline->AddSystem<EditorSystem>(updateOrderLevel, m_Renderer, m_RenderFrame);