.. _program_listing_file_Src_GraphicsEngineOpenGL_scene_ViewFrustumCulling.ixx:

Program Listing for File ViewFrustumCulling.ixx
===============================================

|exhale_lsh| :ref:`Return to documentation for file <file_Src_GraphicsEngineOpenGL_scene_ViewFrustumCulling.ixx>` (``Src/GraphicsEngineOpenGL/scene/ViewFrustumCulling.ixx``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   module;
   
   #include <glad/glad.h>
   
   #include <glm/glm.hpp>
   #include <glm/gtc/matrix_transform.hpp>
   #include <glm/gtc/type_ptr.hpp>
   #include <memory>
   #include <vector>
   
   #include "hostDevice/GlobalValues.hpp"
   
   export module kataglyphis.opengl.view_frustum_culling;
   
   import kataglyphis.opengl.camera;
   import kataglyphis.opengl.aabb;
   import kataglyphis.opengl.texture;
   
   export class ViewFrustumCulling
   {
     public:
       ViewFrustumCulling();
   
       bool is_inside(GLfloat ratio,
         const std::shared_ptr<Camera> &main_camera,
         const std::shared_ptr<AABB> &bounding_box,
         glm::mat4 model);
   
       void render_view_frustum() const;
   
       ~ViewFrustumCulling();
   
     private:
       // render view frustum
       unsigned int VBO, VAO, EBO;
   
       unsigned int m_drawCount;
   
       // we get that as input
       GLfloat near_plane, far_plane, fov, ratio;
   
       // calculate as soon as we become params
       GLfloat tan, near_height, near_width, far_height, far_width;
   
       std::shared_ptr<Camera> main_camera;
   
       glm::vec3 dir, near_center, far_center;
   
       // all corners of the frustum
       // near plane
       glm::vec3 near_top_left, near_top_right, near_bottom_left, near_bottom_right;
       // far plane
       glm::vec3 far_top_left, far_top_right, far_bottom_left, far_bottom_right;
   
       // planes in Hesse normal form
       // layout: [0]: near plane, [1] far plane, [2] front, [3] bottom, [4]: left,
       // [5]: right
       struct frustum_plane
       {
           glm::vec3 normal;
           glm::vec3 position;
       };
   
       frustum_plane frustum_planes[NUM_FRUSTUM_PLANES];
   
       void init(std::vector<glm::vec3> frustum_corner);
   
       bool corners_outside_plane(std::vector<glm::vec3> aabb_corners, frustum_plane plane, GLuint outcode_pattern);
   
       static GLfloat plane_point_distance(frustum_plane plane, glm::vec3 corner);
   
       void update_frustum_param(GLfloat near_plane,
         GLfloat far_plane,
         GLfloat fov,
         GLfloat ratio,
         const std::shared_ptr<Camera> &main_camera);
   };