Function ApplyLightingToSubmodel

Descent3/lighting.cpp:600–903

Applies lighting to a submodel and all its children

// Applies lighting to a submodel and all its children
void ApplyLightingToSubmodel(object *obj, poly_model *pm, bsp_info *sm, float light_dist, float red_scale,
                             float green_scale, float blue_scale, float dot_range) {
  matrix mat;
  vector Light_min_xyz;
  vector Light_max_xyz;
  vector rad;
  int i, t;
  int subnum = sm - pm->submodel;
  int lm_handle;
  uint16_t *dest_data;
  uint16_t lmilist[MAX_DYNAMIC_FACES];
  int num_spoken_for = 0;

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

  if (IsNonRenderableSubmodel(pm, subnum))
    return; // Don't do shells, frontfaces, etc

  // Start instance stuff
  vector temp_vec = sm->mod_pos + sm->offset;
  vm_AnglesToMatrix(&mat, sm->angs.p, sm->angs.h, sm->angs.b);
  StartLightingInstance(&temp_vec, &mat);

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

  vector light_pos = Light_position;
  vector light_dir = Light_direction;

  Light_min_xyz = light_pos - rad;
  Light_max_xyz = light_pos + rad;

  // Now the Light_position is in the submodels frame of reference
  for (i = 0; i < sm->num_faces; i++) {
    // check to see if this face is within reach
    if (Light_max_xyz.y < sm->face_min[i].y || sm->face_max[i].y < Light_min_xyz.y ||
        Light_max_xyz.x < sm->face_min[i].x || sm->face_max[i].x < Light_min_xyz.x ||
        Light_max_xyz.z < sm->face_min[i].z || sm->face_max[i].z < Light_min_xyz.z)
      continue;

    // Ok, now we know that this light touches this face
    if (Num_dynamic_faces >= MAX_DYNAMIC_FACES) {
      mprintf(0, "Too many dynamic faces!\n");
      DoneLightingInstance();
      return;
    }

    lightmap_object_face *fp = &obj->lm_object.lightmap_faces[subnum][i];

    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);