Function ApplyLightingToExternalRoom

Descent3/lighting.cpp:262–551

Does lighting for the passed in external room

// Does lighting for the passed in external room
void ApplyLightingToExternalRoom(vector *pos, int roomnum, float light_dist, float red_scale, float green_scale,
                                 float blue_scale, vector *light_direction, float dot_range) {
  int i, lm_handle, t;
  uint16_t *dest_data;
  vector rad;
  room *rp = &Rooms[roomnum];
  vector Light_min_xyz;
  vector Light_max_xyz;
  uint16_t lmilist[MAX_DYNAMIC_FACES];
  int num_spoken_for = 0;

  int red_limit = 31;
  int green_limit = 31;
  int blue_limit = 31;

  rad.x = light_dist;
  rad.y = light_dist;
  rad.z = light_dist;

  Light_min_xyz = *pos - rad;
  Light_max_xyz = *pos + rad;

  // Now the Light_position is in the submodels frame of reference
  for (i = 0; i < rp->num_faces; i++) {
    face *fp = &rp->faces[i];

    // check to see if this face is within reach
    if (Light_max_xyz.y < fp->min_xyz.y || fp->max_xyz.y < Light_min_xyz.y || Light_max_xyz.x < fp->min_xyz.x ||
        fp->max_xyz.x < Light_min_xyz.x || Light_max_xyz.z < fp->min_xyz.z || fp->max_xyz.z < Light_min_xyz.z)
      continue;

    // Make sure face was rendered
    if (fp->renderframe != ((FrameCount - 1) % 256))
      continue;

    if (Num_dynamic_faces >= MAX_DYNAMIC_FACES) {
      mprintf(0, "Too many dynamic faces!\n");
      return;
    }

    // Make sure there already is a lightmap for this face
    if (!(fp->flags & FF_LIGHTMAP))
      continue;

    if (Lmi_spoken_for[fp->lmi_handle / 8] & (1 << (fp->lmi_handle % 8)))
      continue;

    int xres = lmi_w(fp->lmi_handle);
    int yres = lmi_h(fp->lmi_handle);

    lightmap_info *lmi_ptr = &LightmapInfo[fp->lmi_handle];
    // Lightmap width and height
    int lmw = lm_w(lmi_ptr->lm_handle);

    // Check for backfaces
    vector subvec = *pos - lmi_ptr->upper_left;
    float dist_from_plane = fabs(vm_DotProduct(&subvec, &lmi_ptr->normal));