Scan Line Rendering System

Basic System


Image *img = NULL;
View *view = NULL;
Light *lights = NULL;
OBJECT *objs = NULL;
Matrix4 mclip, mdpy;
RContext *rc;


int main(int argc, char **argv)
{
  OBJECT *o;  Poly *p;  Color c;

  read_scene();
  init_render();

  for (o = objs; o != NULL; o = o->next) {
    for (p = o->shp; p != NULL; p = p->next) {
      if (is_backfacing(p, view->normal))
        continue;
      c = flat_shade(p, view->center, rc, lights, o->mat);
      if (poly_clip(view->front/view->back, poly_transform(p, mclip)))
        scan_obj(poly_round_xy(poly_homoxform(p, mdpy)), pix_paint, &c);
    }
  }
  img_write(img, "stdout", 0);
  exit(0);
}


void pix_paint(Vector3 v, int lv, Real lt, int rv, Real rt, Real st, Color *c)
{
  if (zbuf_store(v))
    img_puti(img, v.x, v.y, col_dpymap((*c)));
}


void init_render(void)
{
  if (view == NULL)
    view = initview();
  mclip = m4_m4prod(view->C, view->V);
  mdpy = m4_m4prod(view->S, view->P);

  if (img == NULL)
    img = img_init(view->sc_max.x, view->sc_max.y, 0);
  zbuf_init(img->w, img->h);
  if (lights == NULL)
    LIST_INSERT(lights, light_ambient(.5), Light);
  rc = NEWSTRUCT(RContext);
}

Input-Output

Input 
scene {
   camera = view {from = {0, 0, -3}, to = {0, 0, 0}, roll = 0, fov = 60},
   light = dist_light {direction = {0, 0, 1} },
   object = polyobj {
              material = metal { se = 2 },
              shape = trilist {
                 {{0.5, 0, 0.866025}, {2, 0, 0}, {2, 2, 0}},
                 {{0.5, 2, 0.866025}, {0.5, 0, 0.866025}, {2, 2, 0}},
                 {{0.5, 0, -0.866025}, {0.5, 0, 0.866025}, {0.5, 2, 0.866025}},
                 {{0.5, 2, -0.866025}, {0.5, 0,-0.866025}, {0.5, 2, 0.866025}},
                 {{2, 0, 0},  {0.5, 0, -0.866025},  {0.5, 2, -0.866025}},
                 {{2, 2, 0},  {2, 0, 0},  {0.5, 2, -0.866025}},
              }
   }
};
Output 
Image file (stdout)

Extension Options

Copyright © 1997 Luiz Velho