feat: calculate model collision tree with leafs

2026-05-25 02:51:43 +00:00 · 2026-05-21 18:24:51 +02:00
parent a128fbeb5e
commit 5cf0ce37c1
7 changed files with 268 additions and 9 deletions
@@ -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