Function ShootRayFromPoint

editor/rad_cast.cpp:328–419

Returns 1 if a src vector can hit dest vector unobstructed, else 0

// Returns 1 if a src vector can hit dest vector unobstructed, else 0
int ShootRayFromPoint(vector *src, vector *dest, rad_surface *src_surf, rad_surface *dest_surf) {
  float dist;
  bool do_backface = 0;
  fvi_info hit_info;
  fvi_query fq;
  vector temp_src = *src;
  vector temp_dest = *dest;
  int from_satellite = 0;

  // Trivially reject all rooms
  if (dest_surf->surface_type == ST_ROOM || dest_surf->surface_type == ST_ROOM_OBJECT) {
    if (src_surf->surface_type == ST_ROOM || src_surf->surface_type == ST_ROOM_OBJECT) {
      if (!BOA_IsVisible(dest_surf->roomnum, src_surf->roomnum))
        return 0;
    }
  }

  if (UseBSP) {
    if (dest_surf->surface_type == ST_ROOM || dest_surf->surface_type == ST_ROOM_OBJECT) {
      if (src_surf->surface_type == ST_ROOM || src_surf->surface_type == ST_ROOM_OBJECT) {
        int fate = BSPRayOccluded(src, dest, MineBSP.root);
        if (!fate)
          return 1;
        return 0;
      }
    }
  }

  // If this ray is too high, clip it to the ceiling
  if (src_surf->surface_type == ST_SATELLITE) {
    if (1 || dest->y >= MAX_TERRAIN_HEIGHT) {
      from_satellite = 1;
      // swap the src/dest the variables because we now want to shoot from the ground to the satellite
      rad_surface *temp_surf;
      vector *temp_vec;

      temp_surf = src_surf;
      src_surf = dest_surf;
      dest_surf = temp_surf;

      temp_vec = src;
      src = dest;
      dest = temp_vec;

      temp_dest = *dest;
      temp_src = *src;

      ClipSatelliteToTerrain(&temp_src, src, &temp_dest);
    } else {
      ClipSatelliteToTerrain(&temp_src, src, &temp_dest);
      int src_cell = GetTerrainCellFromPos(&temp_src);

      if (src_cell < 0) {
        src_cell = 0;
        Int3(); // Get Jason, satellite clipped off terrain?
      }

      src_surf->roomnum = MAKE_ROOMNUM(src_cell);