docs: private void DrawPrimitive( DrawCuboid c, World w ) throws Exception
      {
          XMLBlockState blockType = new XMLBlockState(c.getType(), c.getColour(), c.getFace(), c.getVariant());
          if (!blockType.isValid())
              throw new Exception("Unrecogised item type: "+c.getType().value());
  
          int x1 = Math.min(c.getX1(), c.getX2());
          int x2 = Math.max(c.getX1(), c.getX2());
          int y1 = Math.min(c.getY1(), c.getY2());
          int y2 = Math.max(c.getY1(), c.getY2());
          int z1 = Math.min(c.getZ1(), c.getZ2());
          int z2 = Math.max(c.getZ1(), c.getZ2());
  
          clearEntities(w, x1, y1, z1, x2 + 1, y2 + 1, z2 + 1);
  
          for( int x = x1; x <= x2; x++ ) {
              for( int y = y1; y <= y2; y++ ) {
                  for( int z = z1; z <= z2; z++ ) {
                      BlockPos pos = new BlockPos(x, y, z);
                      setBlockState(w, pos, blockType);
                  }
              }
          }
      }