#![warn(missing_docs)]

//! This crate creates texture atlases from an asset tree.
//! The main interface for this crate is ... TODO

use std::{
	collections::HashMap,
	path::{Path, PathBuf},
};

use serde::{Deserialize, Serialize};

/// The location of a single image in a sprite atlas
#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct SpriteAtlasImage {
	/// The index of the atlas this image is in
	pub atlas: usize,

	/// x-position of this image
	/// (between 0 and 1, using wgpu texture coordinates)
	pub x: f32,

	/// y-position of this image
	/// (between 0 and 1, using wgpu texture coordinates)
	pub y: f32,

	/// Width of this image
	/// (between 0 and 1, using wgpu texture coordinates)
	pub w: f32,

	/// Height of this image
	/// (between 0 and 1, using wgpu texture coordinates)
	pub h: f32,
}

/// A map between file paths (relative to the root asset dir)
/// and [`AtlasTexture`]s.
#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct SpriteAtlasIndex {
	pub(crate) index: HashMap<PathBuf, SpriteAtlasImage>,
}

impl SpriteAtlasIndex {
	/// Make an empty [`SpriteAtlasIndex`]
	pub fn new() -> Self {
		Self {
			index: HashMap::new(),
		}
	}

	/// Make an empty [`SpriteAtlasIndex`]
	pub fn insert(&mut self, path: PathBuf, atlasimage: SpriteAtlasImage) {
		self.index.insert(path, atlasimage);
	}

	/// Get an [`AtlasImage`] for a file `p`.
	/// Paths must be relative to the root of the asset directory.
	pub fn get(&self, p: &Path) -> Option<&SpriteAtlasImage> {
		self.index.get(p)
	}
}