/*
 * Copyright (C) Oscar Shrimpton 2020
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

//! Parses the BSP tree into a usable format

use super::{HasBrushes, HasFaces, HasVisData};
use crate::coords::CoordSystem;
use na::Vector3;

/// A node in a BSP tree.
/// Either has two children *or* a leaf entry.
#[derive(Debug, Clone)]
pub struct BSPNode {
    pub plane_idx: u32,
    pub min: Vector3<i32>,
    pub max: Vector3<i32>,
    pub value: BSPNodeValue,
}

#[derive(Debug, Clone)]
pub enum BSPNodeValue {
    Leaf(BSPLeaf),
    Children(Box<BSPNode>, Box<BSPNode>),
}

/// A leaf in a BSP tree.
/// Will be under a `BSPNode`, min and max values are stored there.
#[derive(Debug, Clone)]
pub struct BSPLeaf {
    pub cluster_id: u32,
    pub area: i32,
    pub faces_idx: Box<[u32]>,
    pub brushes_idx: Box<[u32]>,
}

pub trait HasBSPTree<S: CoordSystem>: HasFaces<S> + HasBrushes<S> + HasVisData {
    fn get_bsp_root(&self) -> &BSPNode;
}