feat: calculate model collision tree with leafs

src/Common/Game/IW3/IW3_Assets.h

@@ -327,8 +327,8 @@ namespace IW3
 
     struct XSurfaceCollisionTree
     {
-        float trans[3];
+        vec3_t trans;
-        float scale[3];
+        vec3_t scale;
         unsigned int nodeCount;
         XSurfaceCollisionNode* nodes;
         unsigned int leafCount;

src/Common/Game/IW4/IW4_Assets.h

@@ -468,8 +468,8 @@ namespace IW4
 
     struct XSurfaceCollisionTree
     {
-        float trans[3];
+        vec3_t trans;
-        float scale[3];
+        vec3_t scale;
         unsigned int nodeCount;
         XSurfaceCollisionNode* nodes;
         unsigned int leafCount;

src/Common/Game/IW5/IW5_Assets.h

@@ -492,8 +492,8 @@ namespace IW5
 
     struct XSurfaceCollisionTree
     {
-        float trans[3];
+        vec3_t trans;
-        float scale[3];
+        vec3_t scale;
         unsigned int nodeCount;
         XSurfaceCollisionNode* nodes;
         unsigned int leafCount;

src/Common/Game/T5/T5_Assets.h

@@ -488,8 +488,8 @@ namespace T5
 
     struct XSurfaceCollisionTree
     {
-        float trans[3];
+        vec3_t trans;
-        float scale[3];
+        vec3_t scale;
         unsigned int nodeCount;
         XSurfaceCollisionNode* nodes;
         unsigned int leafCount;

src/ObjLoading/XModel/CollisionTreeCreator.cpp

@@ -0,0 +1,116 @@
+#include "CollisionTreeCreator.h"
+
+#include <cassert>
+
+namespace
+{
+    class Bounds
+    {
+    public:
+        Bounds()
+            : m_mins(std::numeric_limits<float>::max(), std::numeric_limits<float>::max(), std::numeric_limits<float>::max()),
+              m_maxs(std::numeric_limits<float>::min(), std::numeric_limits<float>::min(), std::numeric_limits<float>::min())
+        {
+        }
+
+        void ExpandFromTri(const std::array<Eigen::Vector3f, 3>& triCoordinates)
+        {
+            for (const auto& vert : triCoordinates)
+            {
+                m_mins[0] = std::min(m_mins[0], vert.x());
+                m_mins[1] = std::min(m_mins[1], vert.y());
+                m_mins[2] = std::min(m_mins[2], vert.z());
+                m_maxs[0] = std::max(m_maxs[0], vert.x());
+                m_maxs[1] = std::max(m_maxs[1], vert.y());
+                m_maxs[2] = std::max(m_maxs[2], vert.z());
+            }
+        }
+
+        void ExpandFromBounds(const Bounds& otherBounds)
+        {
+            m_mins[0] = std::min(m_mins[0], otherBounds.m_mins[0]);
+            m_mins[1] = std::min(m_mins[1], otherBounds.m_mins[1]);
+            m_mins[2] = std::min(m_mins[2], otherBounds.m_mins[2]);
+            m_maxs[0] = std::min(m_maxs[0], otherBounds.m_maxs[0]);
+            m_maxs[1] = std::min(m_maxs[1], otherBounds.m_maxs[1]);
+            m_maxs[2] = std::min(m_maxs[2], otherBounds.m_maxs[2]);
+        }
+
+        [[nodiscard]] Eigen::Vector3f GetDelta() const
+        {
+            return m_maxs - m_mins;
+        }
+
+        [[nodiscard]] float GetVolume() const
+        {
+            return GetDelta().prod();
+        }
+
+        Eigen::Vector3f m_mins;
+        Eigen::Vector3f m_maxs;
+    };
+} // namespace
+
+namespace xmodel
+{
+    std::unique_ptr<CommonCollisionTree> CreateCollisionTree(const IRigidVertListAccessor& vertList)
+    {
+        auto tree = std::make_unique<CommonCollisionTree>();
+
+        Bounds globalBounds;
+
+        const auto triOffset = vertList.GetTriOffset();
+        const auto triCount = vertList.GetTriCount();
+        std::vector<Bounds> leafBounds;
+        auto lastMergeable = false;
+
+        Bounds prevBounds;
+        for (size_t triNumber = 0; triNumber < triCount; triNumber++)
+        {
+            const auto triIndex = triOffset + triNumber;
+            Bounds triBounds;
+
+            triBounds.ExpandFromTri(vertList.GetCoordinatesForTri(triIndex));
+            globalBounds.ExpandFromBounds(triBounds);
+
+            auto shouldMerge = false;
+            if (lastMergeable)
+            {
+                const auto prevVolume = prevBounds.GetVolume();
+                const auto thisVolume = triBounds.GetVolume();
+
+                prevBounds.ExpandFromBounds(triBounds);
+                const auto combinedVolume = prevBounds.GetVolume();
+                if (combinedVolume <= prevVolume + thisVolume)
+                    shouldMerge = true;
+            }
+
+            if (shouldMerge)
+            {
+                leafBounds.back() = prevBounds;
+                assert(!tree->leafs.back().twoTriangles);
+                tree->leafs.back().twoTriangles = 1;
+                lastMergeable = false;
+            }
+            else
+            {
+                tree->leafs.emplace_back(CommonCollisionLeaf{
+                    .triangleBeginIndex = static_cast<decltype(CommonCollisionLeaf::triangleBeginIndex)>(triIndex),
+                    .twoTriangles = 0,
+                });
+                leafBounds.emplace_back(triBounds);
+                lastMergeable = true;
+                prevBounds = triBounds;
+            }
+        }
+
+        tree->trans = -globalBounds.m_mins;
+        const auto globalDelta = globalBounds.GetDelta();
+        tree->scale = Eigen::Vector3f(std::numeric_limits<uint16_t>::max(), std::numeric_limits<uint16_t>::max(), std::numeric_limits<uint16_t>::max())
+                          .cwiseQuotient(globalDelta);
+
+        // TODO: Calculate nodes
+
+        return std::move(tree);
+    }
+} // namespace xmodel

src/ObjLoading/XModel/CollisionTreeCreator.h

@@ -0,0 +1,55 @@
+#pragma once
+
+#include <Eigen>
+#include <array>
+#include <cstdint>
+#include <memory>
+#include <vector>
+
+namespace xmodel
+{
+    struct CommonCollisionAabb
+    {
+        std::array<uint16_t, 3> mins;
+        std::array<uint16_t, 3> maxs;
+    };
+
+    struct CommonCollisionNode
+    {
+        CommonCollisionAabb aabb;
+        uint16_t childBeginIndex;
+        uint16_t childCount : 15;
+        uint16_t childrenAreLeafs : 1;
+    };
+
+    struct CommonCollisionLeaf
+    {
+        uint16_t triangleBeginIndex : 15;
+        uint16_t twoTriangles : 1;
+    };
+
+    struct CommonCollisionTree
+    {
+        Eigen::Vector3f trans;
+        Eigen::Vector3f scale;
+        std::vector<CommonCollisionNode> nodes;
+        std::vector<CommonCollisionLeaf> leafs;
+    };
+
+    class IRigidVertListAccessor
+    {
+    public:
+        IRigidVertListAccessor() = default;
+        virtual ~IRigidVertListAccessor() = default;
+        IRigidVertListAccessor(const IRigidVertListAccessor& other) = default;
+        IRigidVertListAccessor(IRigidVertListAccessor&& other) noexcept = default;
+        IRigidVertListAccessor& operator=(const IRigidVertListAccessor& other) = default;
+        IRigidVertListAccessor& operator=(IRigidVertListAccessor&& other) noexcept = default;
+
+        [[nodiscard]] virtual size_t GetTriOffset() const = 0;
+        [[nodiscard]] virtual size_t GetTriCount() const = 0;
+        [[nodiscard]] virtual std::array<Eigen::Vector3f, 3> GetCoordinatesForTri(size_t triIndex) const = 0;
+    };
+
+    std::unique_ptr<CommonCollisionTree> CreateCollisionTree(const IRigidVertListAccessor& vertList);
+} // namespace xmodel

src/ObjLoading/XModel/LoaderXModel.cpp.template

@@ -44,6 +44,7 @@
 #include <nlohmann/json.hpp>
 #pragma warning(pop)
 
+#include "XModel/CollisionTreeCreator.h"
 #include "XModel/PartClassificationState.h"
 #include "XModel/TangentData.h"
 #include "XModel/Tangentspace.h"
@@ -59,6 +60,47 @@ using namespace GAME;
 
 namespace
 {
+    constexpr uint16_t XSURFACE_COLLISION_NODE_HAS_LEAFS = 0x8000;
+    constexpr uint16_t XSURFACE_COLLISION_LEAF_TWO_TRIANGLES = 0x8000;
+    
+    Eigen::Vector3f ToEigen(const vec3_t& vec)
+    {
+        return Eigen::Vector3f(vec.x, vec.y, vec.z);
+    }
+
+    class RigidVertListAccessor : public xmodel::IRigidVertListAccessor
+    {
+    public:
+        RigidVertListAccessor(const XSurface& surface, const XRigidVertList& rigidVertList)
+            : m_surface(surface), 
+              m_rigid_vert_list(rigidVertList)
+        {
+        }
+        
+        [[nodiscard]] size_t GetTriOffset() const override
+        {
+            return m_rigid_vert_list.triOffset;
+        }
+        
+        [[nodiscard]] size_t GetTriCount() const override
+        {
+            return m_rigid_vert_list.triCount;
+        }
+        
+        [[nodiscard]] std::array<Eigen::Vector3f, 3> GetCoordinatesForTri(const size_t triIndex) const override
+        {
+            return std::array<Eigen::Vector3f, 3>({
+                ToEigen(m_surface.verts0[m_surface.triIndices[triIndex].i[0]].xyz),
+                ToEigen(m_surface.verts0[m_surface.triIndices[triIndex].i[1]].xyz),
+                ToEigen(m_surface.verts0[m_surface.triIndices[triIndex].i[2]].xyz),
+            });
+        }
+        
+    private:
+        const XSurface& m_surface;
+        const XRigidVertList& m_rigid_vert_list;
+    };
+    
     class XModelLoader final : public AssetCreator<AssetXModel>
     {
     public:
@@ -506,6 +548,49 @@ namespace
             surface.partBits[partBitsIndex] |= 1 << shiftValue;
         }
         
+        [[nodiscard]] XSurfaceCollisionTree* ConvertCollisionTree(const xmodel::CommonCollisionTree& commonTree) const
+        {
+            auto* tree = m_memory.Alloc<XSurfaceCollisionTree>();
+            tree->trans.x = commonTree.trans.x();
+            tree->trans.y = commonTree.trans.y();
+            tree->trans.z = commonTree.trans.z();
+            tree->scale.x = commonTree.scale.x();
+            tree->scale.y = commonTree.scale.y();
+            tree->scale.z = commonTree.scale.z();
+            tree->nodeCount = static_cast<decltype(XSurfaceCollisionTree::nodeCount)>(commonTree.nodes.size());
+            tree->nodes = m_memory.Alloc<XSurfaceCollisionNode>(tree->nodeCount);
+            for (auto nodeIndex = 0u; nodeIndex < tree->nodeCount; nodeIndex++)
+            {
+                auto& node = tree->nodes[nodeIndex];
+                const auto& commonNode = commonTree.nodes[nodeIndex];
+                
+                node.aabb.mins[0] = commonNode.aabb.mins[0];
+                node.aabb.mins[1] = commonNode.aabb.mins[1];
+                node.aabb.mins[2] = commonNode.aabb.mins[2];
+                node.aabb.maxs[0] = commonNode.aabb.maxs[0];
+                node.aabb.maxs[1] = commonNode.aabb.maxs[1];
+                node.aabb.maxs[2] = commonNode.aabb.maxs[2];
+                node.childBeginIndex = commonNode.childBeginIndex;
+                node.childCount = commonNode.childCount;
+                if (commonNode.childrenAreLeafs)
+                    node.childCount |= XSURFACE_COLLISION_NODE_HAS_LEAFS;
+            }
+            
+            tree->leafCount = commonTree.leafs.size();
+            tree->leafs = m_memory.Alloc<XSurfaceCollisionLeaf>(tree->leafCount);
+            for (auto leafIndex = 0u; leafIndex < tree->leafCount; leafIndex++)
+            {
+                auto& leaf = tree->leafs[leafIndex];
+                const auto& commonLeaf = commonTree.leafs[leafIndex];
+                
+                leaf.triangleBeginIndex = commonLeaf.triangleBeginIndex;
+                if (commonLeaf.twoTriangles)
+                    leaf.triangleBeginIndex |= XSURFACE_COLLISION_LEAF_TWO_TRIANGLES;
+            }
+            
+            return tree;
+        }
+
         void CreateVertListData(XSurface& surface, const std::vector<size_t>& xmodelToCommonVertexIndexLookup, const XModelCommon& common) const
         {
             ReorderRigidTrisByBoneIndex(xmodelToCommonVertexIndexLookup, surface, common);
@@ -538,7 +623,10 @@ namespace
 
                 if (boneVertList.triCount > 0 || boneVertList.vertCount > 0)
                 {
-                    boneVertList.collisionTree = nullptr; // TODO
+                    RigidVertListAccessor vertListAccessor(surface, boneVertList);
+                    const auto commonCollisionTree = xmodel::CreateCollisionTree(vertListAccessor);
+                    boneVertList.collisionTree = ConvertCollisionTree(*commonCollisionTree);
+                    
                     vertLists.emplace_back(boneVertList);
 
                     currentVertexTail = currentVertexHead;