#ifndef __RT_H__
#define __RT_H__


/*

Lewpen's Realtime Raytracing library


Changelog
-

2003-08-24
  2151 - Added xc, xs, yc, ys to RT_SCENE to hold per-rotation constants

2003-08-25
  2015 - Added size, w2,w3,w4,wm4 to RT_VIEW

*/




#define RT_SCENE_MAXSPHERES 1000

#define RT_OBJ_NONE   0
#define RT_OBJ_SPHERE 1
#define RT_OBJ_PLANE  2
#define RT_OBJ_MESH   3




typedef struct
{
  float ax, ay, az;  //  Actual position
  float rad;         //  Radius
  int col;

  //  Data for render calculations

  float  x,  y,  z;  //  Transformed position

  float r2, c;       //  Per-frame constants

  int x1, y1, x2, y2;  //  Screen bounding box
}
RT_SPHERE;



typedef struct
{
  float ox, oy, oz;
  float dx, dy, dz;

  //- Precalculated values for rendering

  float dx2, dy2, dz2;  //  Squared values of ray direction
  float len2, leno22, len42;  //  Various lengths
}
RT_RAY;



typedef struct
{
  float rx, ry;          //  Current rotation
  float xc, xs, yc, ys;  //  Per-rotation constants

  int numSpheres;
  RT_SPHERE sphere[ RT_SCENE_MAXSPHERES ];

}
RT_SCENE;



typedef struct
{
  int w, h, size;

  //- The render buffer

  int *buf;

  //- Object, shadow, reflection buffer

  unsigned int *obj;

  //- View box (for calculating rays)

  float bx1, by1, bx2, by2;
  float bdx, bdy;

  //- Various precalculated values

  int w2;   //  Width times 2
  int w3;   //  Width times 3
  int w4;   //  Width times 4
  int wm4;  //  Width minus 4
}
RT_VIEW;



//---- FUNCTIONS -------------------------------------------------------------//



RT_VIEW*  rt_view_create( int w, int h );
void      rt_view_destroy( RT_VIEW *view );

RT_SCENE* rt_scene_create( );
void      rt_scene_destroy( RT_SCENE *scene );

int       rt_scene_sphere( RT_SCENE *scene, float x, float y, float z, float r, int col );

void      rt_scene_setRotation( RT_SCENE *scene, float rx, float ry );

bool rt_sphere_boundingRect( float x, float y, float z, float r, float *bounds );

void      rt_render_area( RT_SCENE *scene, int x1, int y1, int x2, int y2, RT_VIEW *view );
void      rt_render_area_4x4( RT_SCENE *scene, int x1, int y1, int x2, int y2, RT_VIEW *view );

void      rt_render( RT_SCENE *scene, RT_VIEW *view );


void      rt_setPixel( RT_VIEW *view, float x, float y, int col );
void      rt_setPixelAbs( RT_VIEW *view, int x, int y, int col );

void      rt_drawHUD( RT_SCENE *scene, RT_VIEW *view );

void      rt_drawFrameRate( RT_VIEW *view );






#endif