metaforce/Runtime/Collision/CAreaOctTree.hpp

#pragma once

#include <optional>

#include "Runtime/RetroTypes.hpp"
#include "Runtime/Collision/CCollisionEdge.hpp"
#include "Runtime/Collision/CCollisionSurface.hpp"

#include <zeus/CAABox.hpp>
#include <zeus/CLine.hpp>
#include <zeus/CPlane.hpp>
#include <zeus/CVector3f.hpp>

namespace urde {
class CMaterialFilter;
class CAreaOctTree {
  friend class CBooRenderer;

public:
  struct SRayResult {
    zeus::CPlane x0_plane;
    std::optional<CCollisionSurface> x10_surface;
    float x3c_t;
  };

  class TriListReference {
    const u16* m_ptr;

  public:
    explicit TriListReference(const u16* ptr) : m_ptr(ptr) {}
    u16 GetAt(int idx) const { return m_ptr[idx + 1]; }
    u16 GetSize() const { return m_ptr[0]; }
  };

  class Node {
  public:
    enum class ETreeType { Invalid, Branch, Leaf };

  private:
    zeus::CAABox x0_aabb;
    const u8* x18_ptr;
    const CAreaOctTree& x1c_owner;
    ETreeType x20_nodeType;

    bool LineTestInternal(const zeus::CLine& line, const CMaterialFilter& filter, float lT, float hT, float maxT,
                          const zeus::CVector3f& vec) const;
    void LineTestExInternal(const zeus::CLine& line, const CMaterialFilter& filter, SRayResult& res, float lT, float hT,
                            float maxT, const zeus::CVector3f& dirRecip) const;

  public:
    Node(const void* ptr, const zeus::CAABox& aabb, const CAreaOctTree& owner, ETreeType type)
    : x0_aabb(aabb), x18_ptr(reinterpret_cast<const u8*>(ptr)), x1c_owner(owner), x20_nodeType(type) {}

    bool LineTest(const zeus::CLine& line, const CMaterialFilter& filter, float length) const;
    void LineTestEx(const zeus::CLine& line, const CMaterialFilter& filter, SRayResult& res, float length) const;

    const CAreaOctTree& GetOwner() const { return x1c_owner; }

    const zeus::CAABox& GetBoundingBox() const { return x0_aabb; }

    u16 GetChildFlags() const { return *reinterpret_cast<const u16*>(x18_ptr); }

    Node GetChild(int idx) const;

    TriListReference GetTriangleArray() const { return TriListReference(reinterpret_cast<const u16*>(x18_ptr + 24)); }

    ETreeType GetChildType(int idx) const {
      u16 flags = *reinterpret_cast<const u16*>(x18_ptr);
      return ETreeType((flags >> (2 * idx)) & 0x3);
    }

    ETreeType GetTreeType() const { return x20_nodeType; }
  };

  zeus::CAABox x0_aabb;
  Node::ETreeType x18_treeType;
  const u8* x1c_buf;
  const u8* x20_treeBuf;
  u32 x24_matCount;
  const u32* x28_materials;
  const u8* x2c_vertMats;
  const u8* x30_edgeMats;
  const u8* x34_polyMats;
  u32 x38_edgeCount;
  const CCollisionEdge* x3c_edges;
  u32 x40_polyCount;
  const u16* x44_polyEdges;
  u32 x48_vertCount;
  const float* x4c_verts;

  void SwapTreeNode(u8* ptr, Node::ETreeType type);

public:
  CAreaOctTree(const zeus::CAABox& aabb, Node::ETreeType treeType, const u8* buf, const u8* treeBuf, u32 matCount,
               const u32* materials, const u8* vertMats, const u8* edgeMats, const u8* polyMats, u32 edgeCount,
               const CCollisionEdge* edges, u32 polyCount, const u16* polyEdges, u32 vertCount, const float* verts);

  const zeus::CAABox& GetAABB() const { return x0_aabb; }
  Node GetRootNode() const { return Node(x20_treeBuf, x0_aabb, *this, x18_treeType); }
  const u8* GetTreeMemory() const { return x20_treeBuf; }
  zeus::CVector3f GetVert(int idx) const {
    const float* vert = &x4c_verts[idx * 3];
    return zeus::CVector3f(vert[0], vert[1], vert[2]);
  }
  const CCollisionEdge& GetEdge(int idx) const { return x3c_edges[idx]; }
  u32 GetVertMaterial(int idx) const { return x28_materials[x2c_vertMats[idx]]; }
  u32 GetEdgeMaterial(int idx) const { return x28_materials[x30_edgeMats[idx]]; }
  u32 GetTriangleMaterial(int idx) const { return x28_materials[x34_polyMats[idx]]; }
  u32 GetNumEdges() const { return x38_edgeCount; }
  u32 GetNumVerts() const { return x48_vertCount; }
  u32 GetNumTriangles() const { return x40_polyCount; }
  CCollisionSurface GetMasterListTriangle(u16 idx) const;
  void GetTriangleVertexIndices(u16 idx, u16 indicesOut[3]) const;
  const u16* GetTriangleEdgeIndices(u16 idx) const { return &x44_polyEdges[idx * 3]; }

  static std::unique_ptr<CAreaOctTree> MakeFromMemory(const u8* buf, unsigned int size);
};

} // namespace urde