#pragma once



typedef struct ViewportF32 ViewportF32;
struct ViewportF32 
{
  F32 width;
  F32 height;
  F32 aspect_ratio;
  Vec3F32 u; // along horizontal edge, right from top left corner
  Vec3F32 v; // along vertical edge, down from top left corner
  Vec3F32 upper_left;
  Vec3F32 pixel_origin;
  Vec3F32 pixel_delta_u;
  Vec3F32 pixel_delta_v;
};

typedef struct CameraF32 CameraF32;
struct CameraF32 
{
  Vec3F32 center;
  Vec3F32 up;
  F32 focal_length;
  F32 pixel_sample_scale;
};

typedef struct ImageF32 ImageF32;
struct ImageF32 
{
  U32 width;
  U32 height;
  F32 aspect_ratio;
  U32 total_num_pixels;
};

enum EntityKind 
{
  EntityKind_Nil,
  EntityKind_Sphere,
  EntityKind_Tri,
  Num_EntityKinds
};

typedef struct HitRecord HitRecord;
struct HitRecord 
{
  Vec3F32 point;
  Vec3F32 normal;
  F32 t; // Root parameter for hit sphere
  F32 hit; // Hit true or false
  F32 front_face;
};

typedef struct Entity Entity;
struct Entity
{
  EntityKind kind;
  Vec3F32 center;
  Vec3F32 vertex0;
  Vec3F32 vertex1;
  Vec3F32 vertex2;
  F32 radius;
};



__host__ function void write_buffer_to_ppm(Vec3F32 *buffer, U32 image_width, 
                                           U32 image_height, const char *filename);

__device__ function RayF32 ray_get_F32(F32 x, F32 y, Vec3F32 cam_center, 
                                       curandState *local_rand_state);

__host__ __device__ inline function void
triangle_intersection_common(RayF32 *ray, HitRecord *rec, Vec3F32 edge1, Vec3F32 edge2, 
                             Entity* triangle);
__device__ function HitRecord hit_triangle(RayF32 *ray, Entity *triangle, 
                                           F32 closest_so_far);
__host__ function void hit_triangle_host(RayF32 *ray, HitRecord *rec, Entity *triangle);

__global__ void cuda_init_state(curandState *rand_state);
__host__ void cuda_free(void *device_ptr);