texture_packer 0.23.1

use crate::{
    texture::{Pixel, Texture},
    texture_packer::{PackResult, TexturePacker},
    texture_packer_config::TexturePackerConfig,
};
use std::hash::Hash;

/// Texture packer supporting multiple atlases.
///
/// Will create a new page for textures that do not fit. Textures packed after a new page is added
/// will still attempt to check each page for available space.
pub struct MultiTexturePacker<'a, T: 'a + Clone, K: Clone + Eq + Hash> {
    config: TexturePackerConfig,
    pages: Vec<TexturePacker<'a, T, K>>,
}

impl<'a, Pix: Pixel, T: Clone + Texture<Pixel = Pix>, K: Clone + Eq + Hash>
    MultiTexturePacker<'a, T, K>
{
    /// Get an array of all underlying single-atlas texture packers.
    pub fn get_pages(&self) -> &[TexturePacker<'a, T, K>] {
        &self.pages
    }
}

impl<'a, Pix: Pixel, T: 'a + Clone + Texture<Pixel = Pix>, K: Clone + Eq + Hash>
    MultiTexturePacker<'a, T, K>
{
    /// Create a new packer using the skyline packing algorithm.
    pub fn new_skyline(config: TexturePackerConfig) -> Self {
        Self {
            config,
            pages: vec![],
        }
    }
}

impl<'a, Pix: Pixel, T: 'a + Clone + Texture<Pixel = Pix>, K: Clone + Eq + Hash>
    MultiTexturePacker<'a, T, K>
{
    /// Pack the `texture` into this packer, taking a reference of the texture object.
    pub fn pack_ref(&mut self, key: K, texture: &'a T) -> PackResult<()> {
        for packer in &mut self.pages {
            if packer.can_pack(texture) {
                return packer.pack_ref(key, texture);
            }
        }
        let mut packer = TexturePacker::new_skyline(self.config);
        packer.pack_ref(key, texture)?;
        self.pages.push(packer);
        Ok(())
    }

    /// Pack the `texture` into this packer, taking ownership of the texture object.
    pub fn pack_own(&mut self, key: K, texture: T) -> PackResult<()> {
        for packer in &mut self.pages {
            if packer.can_pack(&texture) {
                return packer.pack_own(key, texture);
            }
        }
        let mut packer = TexturePacker::new_skyline(self.config);
        packer.pack_own(key, texture)?;
        self.pages.push(packer);
        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{texture::memory_rgba8_texture as mrt, texture_packer::PackError};

    #[test]
    fn texture_too_small() {
        let config = TexturePackerConfig {
            max_width: 1,
            max_height: 1,
            allow_rotation: false,
            border_padding: 0,
            texture_padding: 0,
            texture_extrusion: 0,
            trim: false,
            texture_outlines: false,
        };
        let mut mtp = MultiTexturePacker::new_skyline(config);
        let texture = mrt::MemoryRGBA8Texture::from_memory(&[0, 0, 0, 0, 0, 0, 0, 0], 2, 1);
        assert_eq!(
            Err(PackError::TextureTooLargeToFitIntoAtlas),
            mtp.pack_own(String::from(""), texture)
        );
    }
}