Function ClipLine

renderer/HardwareClipper.cpp:257–285

clips a line to the viewing pyramid.

// clips a line to the viewing pyramid.
void ClipLine(g3Point **p0, g3Point **p1, uint8_t codes_or) {
  int plane_flag;
  g3Point *old_p1;

  // might have these left over
  //(*p0)->p3_flags &= ~(PF_UV|PF_L|PF_RGBA|PF_UV2);
  //(*p1)->p3_flags &= ~(PF_UV|PF_L|PF_RGBA|PF_UV2);

  for (plane_flag = 1; plane_flag <= 32; plane_flag <<= 1) {
    if (codes_or & plane_flag) {
      if ((*p0)->p3_codes & plane_flag) {
        // swap!
        g3Point *t = *p0;
        *p0 = *p1;
        *p1 = t;
      }

      old_p1 = *p1;

      *p1 = ClipEdge(plane_flag, *p0, *p1);

      codes_or = (*p0)->p3_codes | (*p1)->p3_codes; // get new codes

      if (old_p1->p3_flags & PF_TEMP_POINT) {
        FreeTempPoint(old_p1);
      }
    }
  }
}

int ClipPlane(int plane_flag, g3Point **src, g3Point **dest, int *nv, g3Codes *cc) {
  int i, prev, next;