Function DrawVisBlastRing

Descent3/viseffect.cpp:991–1080

Draws a blast ring vis effect

// Draws a blast ring vis effect
void DrawVisBlastRing(vis_effect *vis) {
  vector inner_vecs[30], outer_vecs[30];
  g3Point inner_points[30], outer_points[30];
  float lifenorm = (vis->lifetime - vis->lifeleft) / vis->lifetime;
  float cur_size = lifenorm * vis->size;
  int i;
  g3Point *pntlist[4];
  matrix orient;
  vector fvec;

  if (vis->flags & VF_REVERSE) {
    lifenorm = 1 - lifenorm;
    cur_size = lifenorm * vis->size;
  }

  if (vis->flags & VF_PLANAR)
    fvec = vis->end_pos;
  else {
    fvec = Viewer_object->pos - vis->pos;
    vm_NormalizeVectorFast(&fvec);
  }

  if (vm_GetMagnitudeFast(&fvec) < .5)
    return;
  vm_VectorToMatrix(&orient, &fvec, NULL, NULL);

  int num_segments = 20;

  int ring_increment = 65536 / num_segments;
  int ring_angle = 0;

  if (lifenorm > 1.0)
    lifenorm = 1.0;

  rend_SetAlphaType(AT_SATURATE_TEXTURE_VERTEX);
  rend_SetOverlayType(OT_NONE);
  rend_SetTextureType(TT_LINEAR);
  rend_SetLighting(LS_NONE);
  rend_SetZBias(-1.0);
  rend_SetZBufferWriteMask(0);

  ring_angle = 0;

  for (i = 0; i < num_segments; i++, ring_angle += ring_increment) {
    float ring_sin = FixSin(ring_angle);
    float ring_cos = FixCos(ring_angle);

    inner_vecs[i] = orient.rvec * (ring_cos * (cur_size / 2));
    inner_vecs[i] += orient.uvec * (ring_sin * (cur_size / 2));
    inner_vecs[i] += vis->pos;

    outer_vecs[i] = orient.rvec * (ring_cos * cur_size);
    outer_vecs[i] += orient.uvec * (ring_sin * cur_size);
    outer_vecs[i] += vis->pos;

    g3_RotatePoint(&inner_points[i], &inner_vecs[i]);
    g3_RotatePoint(&outer_points[i], &outer_vecs[i]);
    outer_points[i].p3_flags |= PF_UV | PF_RGBA;