Function DrawSky

Descent3/terrainrender.cpp:2027–2178

Draw the suns,moons,stars, horizon, etc

}
// Draw the suns,moons,stars, horizon, etc
void DrawSky(vector *veye, matrix *vorient) {
  int i, t;

  vector tempvec;

  rend_SetLighting(LS_GOURAUD);
  rend_SetZBufferState(0);
  rend_SetZBufferWriteMask(0);

  // If the sky is rotating, update the horizon vectors accordingly
  if (Rendering_main_view && Terrain_sky.flags & TF_ROTATE_SKY && Terrain_sky.rotate_rate > 0) {
    matrix mat;
    vm_AnglesToMatrix(&mat, 0, Terrain_sky.rotate_rate * Frametime * (65536.0 / 360.0), 0);
    vm_Orthogonalize(&mat);
    for (i = 0; i < 6; i++) {
      for (t = 0; t < MAX_HORIZON_PIECES; t++) {
        vector rot_vec;
        tempvec = Terrain_sky.horizon_vectors[t][i];
        vm_MatrixMulVector(&rot_vec, &tempvec, &mat);
        Terrain_sky.horizon_vectors[t][i] = rot_vec;
      }
    }
  }

  for (i = 0; i < 6; i++) {
    for (t = 0; t < MAX_HORIZON_PIECES; t++) {
      tempvec = Terrain_sky.horizon_vectors[t][i];
      tempvec.y -= veye->y * 0.5f;
      vm_MatrixMulVector(&Temp_sky_vectors[t][i], &tempvec, vorient);

      tempvec = Terrain_sky.horizon_vectors[t][i];
      tempvec.x += veye->x;
      tempvec.z += veye->z;
      tempvec.y += veye->y * 0.5f;
      Temp_sky_vectors_unrotated[t][i] = tempvec;
    }
  }
  float sr = (float)GR_COLOR_RED(Terrain_sky.sky_color) / 255.0;
  float sg = (float)GR_COLOR_GREEN(Terrain_sky.sky_color) / 255.0;
  float sb = (float)GR_COLOR_BLUE(Terrain_sky.sky_color) / 255.0;
  if (!Terrain_sky.textured) {
    DrawGouraudSky();
  } else {
    DrawTexturedSky();
  }

  if (Terrain_sky.flags & TF_STARS) {
    DrawStars(vorient);
  }

  if (Terrain_sky.flags & TF_SATELLITES) {
    rend_SetWrapType(WT_CLAMP);
    rend_SetColorModel(CM_MONO);

    // do satellites
    for (i = 0; i < Terrain_sky.num_satellites; i++) {
      int bm_handle = GetTextureBitmap(Terrain_sky.satellite_texture[i], 0);
      vector subvec = Terrain_sky.satellite_vectors[i] - *veye;