#include <math.h>

#include <gtk/gtk.h>

#include "src/giram.h"
#include "src/object.h"
#include "src/camera.h"

gchar *module_icon_xpm[] =
{
  "20 20 32 1",
  " 	c None",
  ".	c #F88484",
  "+	c #F68181",
  "@	c #EF7878",
  "#	c #D15151",
  "$	c #B12828",
  "%	c #970606",
  "&	c #F78282",
  "*	c #E76D6D",
  "=	c #C74545",
  "-	c #A71B1B",
  ";	c #960404",
  ">	c #EC7575",
  ",	c #D65858",
  "'	c #B42D2D",
  ")	c #9E1010",
  "!	c #930202",
  "~	c #FB4242",
  "{	c #FA5252",
  "]	c #FA5858",
  "^	c #EE5858",
  "/	c #D74A4A",
  "(	c #FE1212",
  "_	c #FD2121",
  ":	c #FC2C2C",
  "<	c #E42C2C",
  "[	c #C11E1E",
  "}	c #FF0000",
  "|	c #DB0000",
  "1	c #B70101",
  "2	c #BB0101",
  "3	c #C10101",
  "      .........+@#$%",
  "     ..........&*=-;",
  "    ...........>,')!",
  "   ...........>,')!!",
  "  ...........>,')!!!",
  " ~{]]]]]]]]]^/')!!!!",
  "(_::::::::::<[)!!!!!",
  "}}}}}}}}}}}}|1!!!!!!",
  "}}}}}}}}}}}}|1!!!!!!",
  "}}}}}}}}}}}}|1!!!!!!",
  "}}}}}}}}}}}}|1!!!!!!",
  "}}}}}}}}}}}}|1!!!!!!",
  "}}}}}}}}}}}}|1!!!!!!",
  "}}}}}}}}}}}}|1!!!!!!",
  "}}}}}}}}}}}}|1!!!!! ",
  "}}}}}}}}}}}}|1!!!!  ",
  "}}}}}}}}}}}}|1!!!   ",
  "}}}}}}}}}}}}|1!!    ",
  "}}}}}}}}}}}}|2!     ",
  "}}}}}}}}}}}}|3      "
};

gchar *module_name = "The raytracing renderer module";

gint module_type = 1;

/*************************************************************************
*  rendering_func
**************************************************************************/

GdkPixmap *rendering_func(GtkWidget *area, gint width, gint height)
{
  GdkPixmap          *pixmap;
  FrameStruct        *frame;
  GSList             *tmp_list, *tmp_ls;
  ObjectStruct       *Tmp, *nearest_object;
  CameraStruct       *camera;
  gdouble             color[5];
  gdouble             color_result[5];
  gdouble             Norme, alpha;
  Vector              dx, dy; 
  LightSourceStruct  *Light;
  Vector              origin, dir, NormalLight, intersect, normal, I, N, dist;
  gint                i, j;
  guchar             *rgb_buf;
  gdouble nearest;
  gboolean render;
  
  pixmap = gdk_pixmap_new(area->window, width, height, -1);

  frame = g_object_get_data(G_OBJECT(area), "frame");
  camera = frame->all_cameras->data;
 
  /* Origin of the ray ( case of 1 camera) */
  V3Dcopy(origin, camera->Location);

  dx[0]=camera->Right[0]/width;
  dx[1]=camera->Right[1]/width;
  dx[2]=camera->Right[2]/width;
  dy[0]=camera->Up[0]/height;
  dy[1]=camera->Up[1]/height;
  dy[2]=camera->Up[2]/height;
  
  rgb_buf = g_malloc0(3*width*height);

  for (i=0 ; i<width; i++)
    for (j = 0 ; j<height ; j++)
    {
      dir[0]=camera->Direction[0]+0.5*camera->Up[0]-0.5*camera->Right[0]+dx[0]*i-dy[0]*j;
      dir[1]=camera->Direction[1]+0.5*camera->Up[1]-0.5*camera->Right[1]+dx[1]*i-dy[1]*j;
      dir[2]=camera->Direction[2]+0.5*camera->Up[2]-0.5*camera->Right[2]+dx[2]*i-dy[2]*j;
      nearest_object = NULL;
      nearest = 0.0;

      /* cast the primary rays */
      for (tmp_list = frame->all_objects ; tmp_list ; tmp_list = g_slist_next(tmp_list))
      {
        Tmp = tmp_list->data;
        if ((Tmp->visible) && (giram_object_find_intersection(Tmp, origin, dir, I, N)))
        {
          dist[0] = I[0]-origin[0];
          dist[1] = I[1]-origin[1];
          dist[2] = I[2]-origin[2];
          if (V3DLength(dist) < nearest || !nearest_object)
          {
            nearest = V3DLength(dist);
            V3Dcopy(intersect, I);
            V3Dcopy(normal, N);
            nearest_object = Tmp;
          }
        }
      }

      if (nearest_object)
      {	/* we found an object */
        if (nearest_object->Texture &&
            nearest_object->Texture->Pigment)
          giram_pigment_evaluate(color, nearest_object->Texture->Pigment, intersect);
        else
          color[0] = color[1] = color[2] = 1.0;

        /* ambient part of the light  */
        color_result[0] = color[0] * nearest_object->Texture->finish->ambient[0];
        color_result[1] = color[1] * nearest_object->Texture->finish->ambient[1];
        color_result[2] = color[2] * nearest_object->Texture->finish->ambient[2];
        for (tmp_ls = frame->all_light_sources ; tmp_ls ;   tmp_ls = g_slist_next(tmp_ls))
        { /* add diffuse for all lights */
          Light = tmp_ls->data;
          NormalLight[0] = Light->Location[0]-intersect[0];
          NormalLight[1] = Light->Location[1]-intersect[1];
          NormalLight[2] = Light->Location[2]-intersect[2];
          Norme = V3DLength(NormalLight);
          NormalLight[0] /= Norme;
          NormalLight[1] /= Norme;
          NormalLight[2] /= Norme;
          alpha = V3DDot(normal, NormalLight) * nearest_object->Texture->finish->diffuse;
          if (alpha>0.)
          {
            render = TRUE;
            for (tmp_list = frame->all_objects ; tmp_list ; tmp_list = g_slist_next(tmp_list))
            { /* now cast the shadow rays */
              Tmp = tmp_list->data;
              if (giram_object_is_intersection(Tmp,intersect,NormalLight))
              {
                render = FALSE;
                break;
              }
            }
            if (render)
            {
              color_result[0] += alpha*color[0]*Light->Color[0];
              color_result[1] += alpha*color[1]*Light->Color[1];
              color_result[2] += alpha*color[2]*Light->Color[2];
            }
          }   
        }
        rgb_buf[j*3*width+i*3+0]=255.*CLAMP(color_result[0], 0.0, 1.0);
        rgb_buf[j*3*width+i*3+1]=255.*CLAMP(color_result[1], 0.0, 1.0);
        rgb_buf[j*3*width+i*3+2]=255.*CLAMP(color_result[2], 0.0, 1.0);
      }	else
      {    
        rgb_buf[j*3*width+i*3+0] = 255.*frame->background_color[0];
        rgb_buf[j*3*width+i*3+1] = 255.*frame->background_color[1];
        rgb_buf[j*3*width+i*3+2] = 255.*frame->background_color[2];
      }
    }
  gdk_draw_rgb_image(pixmap, area->style->white_gc, 0,0, 
                     width, height,
                     GDK_RGB_DITHER_MAX,
                     rgb_buf, 3*width);

  /* Freeing ... */
  g_free(rgb_buf);

  return pixmap;
}