MeshUtils.h

#pragma once
#include "Engine/Core/Types.h"
#include <array>
#include <memory>
#include <span>
#include <vector>
 
namespace enzo::geo {
class Mesh;
}
 
namespace enzo::utils {
 
struct TriangulatedMesh
{
    std::shared_ptr<geo::Mesh> mesh;
    std::vector<Offset> faceToOriginal;
};
 
TriangulatedMesh triangulateMesh(const geo::Mesh& src);
 
Vector3 polygonNormal(std::span<const Vector3> positions, std::span<const intT> polygonPoints);
 
std::vector<std::array<Offset, 3>> earClipTriangleIndices(const geo::Mesh& mesh);
 
std::vector<std::array<Offset, 3>>
earClipTriangleIndices(const geo::Mesh& mesh, std::span<const Offset> faceOffsets);
 
enum class TangentMode
{
    // Direction from each point to the next.
    FirstPoint,
    // Average of the incoming and outgoing segment directions.
    TwoPoint
};
 
class FaceTangents
{
  public:
    FaceTangents(const geo::Mesh& mesh, TangentMode mode = TangentMode::FirstPoint)
        : mesh_(mesh), mode_(mode)
    {
    }
 
    std::span<const Vector3> operator()(Offset faceOffset);
 
  private:
    const geo::Mesh& mesh_;
    TangentMode mode_;
    std::vector<Vector3> tangents_;
};
 
} // namespace enzo::utils