text: /*
   * Copyright (C) 2015 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #ifndef TNT_FILAMENT_DETAILS_CULLER_H
  #define TNT_FILAMENT_DETAILS_CULLER_H
  
  #include <filament/Frustum.h>
  
  #include <utils/compiler.h>
  #include <utils/Slice.h>
  
  #include <math/vec4.h>
  #include <math/vec2.h>
  
  namespace filament {
  namespace details {
  
  /*
   * This is where culling is implemented.
   *
   * The implementation assumes 'count' below is multiple of 8
   *
   */
  
  class Culler {
  public:
      // Culler can only process buffers with a size multiple of MODULO
      static constexpr size_t MODULO = 8;
      static inline size_t round(size_t count) noexcept {
          return (count + (MODULO - 1)) & ~(MODULO - 1);
      }
  
      // A good loop value to use to amortize the loop overhead
      static constexpr size_t MIN_LOOP_COUNT_HINT = 8;
  
      using result_type = uint8_t;
  
      /*
       * returns whether each AABB in an array intersects with the furstum
       */
      static void intersects(result_type* results,
              Frustum const& frustum,
              math::float3 const* center,
              math::float3 const* extent,
              size_t count, size_t bit) noexcept;
  
      /*
       * returns whether each shpere in an array intersects with the furstum
       */
      static void intersects(
              result_type* results,
              Frustum const& frustum,
              math::float4 const* b,
              size_t count) noexcept;
  
      /*
       * returns whether an AABB intersects with the frustum
       */
      static bool intersects(
              Frustum const& frustum,
              Box const& box) noexcept;
  
      /*
       * returns whether an sphere intersects with the frustum
       */
      static bool intersects(
              Frustum const& frustum,
              math::float4 const& sphere) noexcept;
  
  
      struct UTILS_PUBLIC Test {
          static void intersects(result_type* results,
                  Frustum const& frustum,
                  math::float3 const* c,
                  math::float3 const* e,
                  size_t count) noexcept;
  
          static void intersects(result_type* results,
                  Frustum const& frustum,
                  math::float4 const* b,
                  size_t count) noexcept;
      };
  };
  
  } // namespace details
  } // namespace filament
  
  #endif // TNT_FILAMENT_DETAILS_CULLER_H
  