lgr_material_set.hpp

#pragma once

#include <lgr_mesh_indices.hpp>

namespace lgr {

HPC_ALWAYS_INLINE HPC_HOST_DEVICE int
popcount(unsigned x) noexcept
{
#ifdef __CUDA_ARCH__
  return __popc(x);
#else
  return __builtin_popcount(x);
#endif
}

HPC_ALWAYS_INLINE HPC_HOST_DEVICE int
popcount(unsigned long x) noexcept
{
#ifdef __CUDA_ARCH__
  return __popcll(x);
#else
  return __builtin_popcountl(x);
#endif
}

HPC_ALWAYS_INLINE HPC_HOST_DEVICE int
popcount(unsigned long long x) noexcept
{
#ifdef __CUDA_ARCH__
  return __popcll(x);
#else
  return __builtin_popcountll(x);
#endif
}

class material_set
{
  std::uint64_t     bits{0};
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE explicit constexpr material_set(std::uint64_t const bits_in) noexcept
      : bits(bits_in)
  {
  }

 public:
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE explicit constexpr material_set(material_index const material) noexcept
      : bits(std::uint64_t(1) << hpc::weaken(material))
  {
  }
  HPC_ALWAYS_INLINE
  material_set() noexcept = default;
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE constexpr material_set
  operator|(material_set const other) const noexcept
  {
    return material_set(bits | other.bits);
  }
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE constexpr bool
  contains(material_set const other) const noexcept
  {
    return (bits | other.bits) == bits;
  }
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE constexpr explicit operator std::uint64_t() const noexcept
  {
    return bits;
  }
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE int
  size() const noexcept
  {
    return popcount(bits);
  }
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE constexpr material_set
  operator-(material_set const other) const noexcept
  {
    return material_set(bits & (~other.bits));
  }
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE constexpr static material_set
  none() noexcept
  {
    return material_set(std::uint64_t(0));
  }
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE constexpr static material_set
  all(material_index const size) noexcept
  {
    return material_set((std::uint64_t(1) << hpc::weaken(size)) - 1);
  }
  HPC_ALWAYS_INLINE HPC_HOST_DEVICE constexpr bool
  operator==(material_set const other) const noexcept
  {
    return bits == other.bits;
  }
};

}  // namespace lgr