feather-ui 0.4.0

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: 2025 Fundament Research Institute <https://fundament.institute>

use std::any::Any;
use std::sync::Arc;

#[cfg(feature = "jxl")]
use jxl_oxide::{EnumColourEncoding, JxlImage};
#[cfg(feature = "svg")]
use resvg::{tiny_skia, usvg};

use crate::render::atlas;
use crate::{Error, Pixel, PxDim};
use guillotiere::euclid::Size2D;
use std::hash::Hash;

pub(crate) const MIN_AREA: i32 = 64 * 64;
pub(crate) const MAX_VARIANCE: f32 = 0.1;

pub(crate) fn within_variance(l: i32, r: i32, range: f32) -> bool {
    let diff = l as f32 / r as f32;
    diff > (1.0 - range) && diff < (1.0 + range)
}

/// An empty size request equates to requesting the native size of the image.
/// One axis being zero equates to requesting the equivalent aspect ratio from
/// the native aspect ratio.
#[inline]
pub fn fill_size(size: atlas::Size, native: atlas::Size) -> atlas::Size {
    match (size.width, size.height) {
        (0, 0) => native,
        (x, 0) => atlas::Size::new(
            x,
            (native.height as f32 * (x as f32 / native.width as f32)).round() as i32,
        ),
        (0, y) => atlas::Size::new(
            (native.width as f32 * (y as f32 / native.height as f32)).round() as i32,
            y,
        ),
        _ => size,
    }
}

#[inline]
pub fn fill_dim(size: PxDim, native: PxDim) -> PxDim {
    match (size.width, size.height) {
        (0.0, 0.0) => native,
        (x, 0.0) => PxDim::new(x, native.height * (x / native.width)),
        (0.0, y) => PxDim::new(native.width * (y / native.height), y),
        _ => size,
    }
}

pub trait Location: crate::DynHashEq + Any + Send + Sync {
    fn fetch(&self) -> Result<Box<dyn Loader>, Error>;
}

dyn_clone::clone_trait_object!(Location);

pub trait Loader: std::fmt::Debug + Send + Sync {
    /// The preload function does most of the work, loading the image into a
    /// byte buffer of a given width and height
    fn preload(&self, size: atlas::Size, dpi: f32) -> Result<(Vec<u8>, Size2D<u32, Pixel>), Error>;

    /// The load function simply consumes the byte buffer and loads it into the
    /// atlas.
    fn load(
        &self,
        driver: &crate::graphics::Driver,
        data: (Vec<u8>, Size2D<u32, Pixel>),
        resize: bool,
    ) -> Result<(atlas::Region, atlas::Size), Error>;
}

impl Hash for dyn Location {
    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
        self.dyn_hash(state);
    }
}

impl PartialEq for dyn Location {
    fn eq(&self, other: &Self) -> bool {
        self.dyn_eq(other as &dyn Any)
    }
}

impl Eq for dyn Location {}

#[cfg(feature = "svg")]
#[derive(Debug)]
// resvg requires the DPI when it parses the XML, and we can't store the XML
// tree directly, so we store the string instead.
struct SvgXml(String);

impl Location for std::path::PathBuf {
    fn fetch(&self) -> Result<Box<dyn Loader>, Error> {
        #[cfg(feature = "svg")]
        if let Some(extension) = self.extension() {
            use std::fs::File;
            use std::io::Read;

            let ext = extension.to_str().unwrap().to_ascii_lowercase();
            if &ext == "svgz" {
                let mut buf = Vec::new();
                {
                    let mut f = File::open(self)?;
                    f.read_to_end(&mut buf)?;
                }

                if buf.starts_with(&[0x1f, 0x8b]) {
                    buf = usvg::decompress_svgz(&buf)
                        .map_err(|e| Error::ResourceError(Box::new(e)))?;
                }

                return Ok(Box::new(SvgXml(
                    String::from_utf8(buf).map_err(|e| Error::ResourceError(Box::new(e)))?,
                )));
            } else if &ext == "svg" {
                let mut buf = String::new();
                File::open(self)?.read_to_string(&mut buf)?;
                return Ok(Box::new(SvgXml(buf)));
            }
        }

        #[cfg(feature = "svg")]
        {
            use std::fs::File;
            use std::io::Read;

            let mut f = File::open(self)?;
            let mut header = [0_u8; 2];
            if f.read(&mut header)? == 2 && header == [0x1f_u8, 0x8b_u8] {
                let mut buf: Vec<u8> = header.into();
                f.read_to_end(&mut buf)?;
                buf = usvg::decompress_svgz(&buf).map_err(|e| Error::ResourceError(Box::new(e)))?;

                return Ok(Box::new(SvgXml(
                    String::from_utf8(buf).map_err(|e| Error::ResourceError(Box::new(e)))?,
                )));
            }
        }

        #[cfg(feature = "jxl")]
        if let Ok(mut img) = JxlImage::builder().open(self) {
            img.request_color_encoding(EnumColourEncoding::srgb(
                jxl_oxide::RenderingIntent::Relative,
            ));
            return Ok(Box::new(img));
        }

        // We start by guessing the format from ImageReader, because it only reads a
        // maximum of 16 bytes from the file.
        #[cfg(any(
            feature = "avif",
            feature = "bmp",
            feature = "dds",
            feature = "exr",
            feature = "ff",
            feature = "gif",
            feature = "hdr",
            feature = "ico",
            feature = "pnm",
            feature = "qoi",
            feature = "tga",
            feature = "tiff",
            feature = "webp"
        ))]
        {
            let image = image::ImageReader::open(self)?.with_guessed_format()?;

            match image.format() {
                Some(image::ImageFormat::Png) | Some(image::ImageFormat::Jpeg) => (),
                _ => {
                    return Ok(Box::new(
                        image
                            .decode()
                            .map_err(|e| Error::ResourceError(Box::new(e)))?,
                    ));
                }
            }
        }

        // If we get here, it's a PNG or JPEG, (or an unsupported format) so we drop the
        // image to close the file handle, then load it with load_image instead
        // to correctly convert it to sRGB color space using the embedded color profile.
        #[cfg(any(feature = "png", feature = "jpeg"))]
        return Ok(Box::new(load_image::load_path(self).map_err(
            |e| match e {
                load_image::Error::UnsupportedFileFormat => Error::UnknownResourceFormat,
                _ => Error::ResourceError(Box::new(e)),
            },
        )?));

        #[allow(unreachable_code)]
        Err(Error::UnknownResourceFormat)
    }
}

#[cfg(feature = "jxl")]
struct JxlFrameView<'a>(&'a jxl_oxide::FrameBuffer);

#[cfg(feature = "jxl")]
impl<'a> fast_image_resize::IntoImageView for JxlFrameView<'a> {
    fn pixel_type(&self) -> Option<fast_image_resize::PixelType> {
        use fast_image_resize::PixelType;
        match self.0.channels() {
            1 => Some(PixelType::F32),
            2 => Some(PixelType::F32x2),
            3 => Some(PixelType::F32x3),
            4 => Some(PixelType::F32x4),
            _ => None,
        }
    }

    fn width(&self) -> u32 {
        self.0.width() as u32
    }

    fn height(&self) -> u32 {
        self.0.height() as u32
    }

    fn image_view<P: fast_image_resize::PixelTrait>(
        &self,
    ) -> Option<impl fast_image_resize::ImageView<Pixel = P>> {
        if P::pixel_type() == self.pixel_type().unwrap() {
            return fast_image_resize::images::TypedImageRef::<P>::from_buffer(
                self.width(),
                self.height(),
                bytemuck::cast_slice(self.0.buf()),
            )
            .ok();
        }
        None
    }
}

#[cfg(feature = "jxl")]
fn gamma_into_linear(input: f32) -> f32 {
    input.powf(2.2)
}

#[cfg(feature = "jxl")]
fn linear_into_gamma(input: f32) -> f32 {
    input.powf(1.0 / 2.2)
}

#[cfg(feature = "jxl")]
fn in_place_map<const N: usize, const FORWARD: bool>(
    buf: &mut [[f32; N]],
) -> fast_image_resize::PixelType {
    let gamma: fn(f32) -> f32 = if FORWARD {
        gamma_into_linear
    } else {
        linear_into_gamma
    };
    let color = if FORWARD {
        crate::color::srgb_to_linear
    } else {
        crate::color::linear_to_srgb
    };

    match N {
        1 => {
            for p in buf {
                p[0] = gamma(p[0]);
            }
            fast_image_resize::PixelType::F32
        }
        2 => {
            for p in buf {
                p[0] = gamma(p[0]);
            }
            fast_image_resize::PixelType::F32x2
        }
        3 => {
            for p in buf {
                p[0] = color(p[0]);
                p[1] = color(p[1]);
                p[2] = color(p[2]);
            }
            fast_image_resize::PixelType::F32x3
        }
        4 => {
            for p in buf {
                p[0] = color(p[0]);
                p[1] = color(p[1]);
                p[2] = color(p[2]);
            }
            fast_image_resize::PixelType::F32x4
        }
        _ => unreachable!(),
    }
}

#[cfg(feature = "jxl")]
impl Loader for JxlImage {
    fn preload(
        &self,
        mut size: atlas::Size,
        _: f32,
    ) -> Result<(Vec<u8>, Size2D<u32, Pixel>), Error> {
        use crate::color::sRGB;
        use wide::f32x4;

        if self.num_loaded_keyframes() == 0 {
            return Err(Error::ResourceError(Box::new(eyre::eyre!(
                "JpegXL had no keyframes to load???"
            ))));
        }

        size = fill_size(
            size,
            atlas::Size::new(self.width() as i32, self.height() as i32),
        );

        let render = self
            .render_frame(0)
            .map_err(|e| Error::ResourceError(Box::new(e)))?;
        let mut frame = render.image_all_channels();

        // If we're too close to the native size of the image, skip resizing it and
        // simply store the native size to the atlas.
        let force_native = within_variance(size.height, self.height() as i32, 0.05)
            && within_variance(size.width, self.width() as i32, 0.05);
        let (raw, w, h) = if !(force_native
            || size.width as u32 > self.width() && size.height as u32 > self.height())
        {
            use fast_image_resize::PixelType;

            let inner_format = match frame.channels() {
                1 => in_place_map::<1, true>(frame.buf_grouped_mut::<1>()),
                2 => in_place_map::<2, true>(frame.buf_grouped_mut::<2>()),
                3 => in_place_map::<3, true>(frame.buf_grouped_mut::<3>()),
                4 => in_place_map::<4, true>(frame.buf_grouped_mut::<4>()),
                _ => {
                    return Err(Error::ResourceError(Box::new(eyre::eyre!(
                        "Channel count not 1-4"
                    ))));
                }
            };

            let mut dst_image = fast_image_resize::images::Image::new(
                size.width as u32,
                size.height as u32,
                inner_format,
            );

            fast_image_resize::Resizer::new()
                .resize(
                    &JxlFrameView(&frame),
                    &mut dst_image,
                    &fast_image_resize::ResizeOptions::new()
                        .use_alpha(true)
                        .resize_alg(fast_image_resize::ResizeAlg::Convolution(
                            fast_image_resize::FilterType::CatmullRom,
                        )),
                )
                .map_err(|e| Error::ResourceError(Box::new(e)))?;

            let mut output = unsafe {
                vec![
                    std::mem::zeroed::<u8>();
                    (dst_image.width() * dst_image.height() * 4) as usize
                ]
            };

            use fast_image_resize::pixels;

            use crate::color::linear_to_srgb;
            match dst_image.pixel_type() {
                PixelType::F32 => process_load_pixels(
                    output.as_mut_slice(),
                    dst_image.typed_image::<pixels::F32>().unwrap().pixels(),
                    |p| sRGB {
                        rgba: f32x4::new([
                            linear_into_gamma(p.0),
                            linear_into_gamma(p.0),
                            linear_into_gamma(p.0),
                            1.0,
                        ]),
                    },
                ),
                PixelType::F32x2 => process_load_pixels(
                    output.as_mut_slice(),
                    dst_image.typed_image::<pixels::F32x2>().unwrap().pixels(),
                    |p| sRGB {
                        rgba: f32x4::new([
                            linear_into_gamma(p.0[0]),
                            linear_into_gamma(p.0[0]),
                            linear_into_gamma(p.0[0]),
                            p.0[1],
                        ]),
                    },
                ),
                PixelType::F32x3 => process_load_pixels(
                    output.as_mut_slice(),
                    dst_image.typed_image::<pixels::F32x3>().unwrap().pixels(),
                    |p| sRGB {
                        rgba: f32x4::new([
                            linear_to_srgb(p.0[0]),
                            linear_to_srgb(p.0[1]),
                            linear_to_srgb(p.0[2]),
                            1.0,
                        ]),
                    },
                ),
                PixelType::F32x4 => process_load_pixels(
                    output.as_mut_slice(),
                    dst_image.typed_image::<pixels::F32x4>().unwrap().pixels(),
                    |p| sRGB {
                        rgba: f32x4::new([
                            linear_to_srgb(p.0[0]),
                            linear_to_srgb(p.0[1]),
                            linear_to_srgb(p.0[2]),
                            p.0[3],
                        ]),
                    },
                ),
                _ => {
                    return Err(Error::ResourceError(Box::new(eyre::eyre!(
                        "Channel count not 1-4"
                    ))));
                }
            }

            (output, dst_image.width(), dst_image.height())
        } else {
            let mut output =
                unsafe { vec![std::mem::zeroed::<u8>(); frame.width() * frame.height() * 4] };

            match frame.channels() {
                1 => process_load_pixels(output.as_mut_slice(), frame.buf(), |p| sRGB {
                    rgba: f32x4::new([*p, *p, *p, 1.0]),
                }),
                2 => {
                    process_load_pixels(output.as_mut_slice(), frame.buf_grouped::<2>(), |p| sRGB {
                        rgba: f32x4::new([p[0], p[0], p[0], p[1]]),
                    })
                }
                3 => {
                    process_load_pixels(output.as_mut_slice(), frame.buf_grouped::<3>(), |p| sRGB {
                        rgba: f32x4::new([p[0], p[1], p[2], 1.0]),
                    })
                }
                4 => {
                    process_load_pixels(output.as_mut_slice(), frame.buf_grouped::<4>(), |p| sRGB {
                        rgba: f32x4::new(*p),
                    })
                }
                _ => {
                    return Err(Error::ResourceError(Box::new(eyre::eyre!(
                        "Channel count not 1-4"
                    ))));
                }
            }

            (output, self.width() as u32, self.height() as u32)
        };

        Ok((raw, Size2D::new(w, h)))
    }
    fn load(
        &self,
        driver: &crate::graphics::Driver,
        data: (Vec<u8>, Size2D<u32, Pixel>),
        resize: bool,
    ) -> Result<(atlas::Region, atlas::Size), Error> {
        let region = driver.atlas.write().reserve(
            &driver.device,
            atlas::Size::new(data.1.width as i32, data.1.height as i32),
            if resize { Some(&driver.queue) } else { None },
        )?;

        queue_atlas_data(
            &data.0,
            &region,
            &driver.queue,
            data.1.width,
            data.1.height,
            &driver.atlas.read(),
        );

        let native = atlas::Size::new(self.width() as i32, self.height() as i32);
        Ok((region, native))
    }
}

#[cfg(feature = "svg")]
impl Loader for SvgXml {
    fn preload(&self, size: atlas::Size, dpi: f32) -> Result<(Vec<u8>, Size2D<u32, Pixel>), Error> {
        let xml_opt = usvg::roxmltree::ParsingOptions {
            allow_dtd: true,
            ..Default::default()
        };
        let xml_tree = usvg::roxmltree::Document::parse_with_options(&self.0, xml_opt)
            .map_err(|e| Error::ResourceError(Box::new(e)))?;

        let mut svg_opt = usvg::Options {
            dpi,
            font_size: 12.0, // TODO: change this based on system text-scaling property.
            ..Default::default()
        };

        if let Some(sz) = tiny_skia::Size::from_wh(size.width as f32, size.height as f32) {
            svg_opt.default_size = sz;
        }

        let svg = usvg::Tree::from_xmltree(&xml_tree, &svg_opt)
            .map_err(|e| Error::ResourceError(Box::new(e)))
            .map(Box::new)?;

        // TODO: This rounds, which might not give accurate results. It might instead
        // need to use ceiling.
        let svg_size = svg.size();
        let native_size = PxDim::new(svg_size.width(), svg_size.height());
        let sizevec = fill_dim(
            PxDim::new(size.height as f32, size.width as f32),
            native_size,
        );

        let t = if sizevec == native_size {
            tiny_skia::Transform::identity()
        } else {
            tiny_skia::Transform::from_scale(
                sizevec.width / native_size.width,
                sizevec.height / native_size.height,
            )
        };

        let mut pixmap =
            tiny_skia::Pixmap::new(sizevec.width.ceil() as u32, sizevec.height.ceil() as u32)
                .unwrap();

        resvg::render(&svg, t, &mut pixmap.as_mut());

        // The pixels are already premultiplied for us, we just have to flip the order.
        for c in pixmap.data_mut().as_chunks_mut::<4>().0 {
            c.swap(0, 2);
        }

        let sz = Size2D::new(pixmap.width(), pixmap.height());
        Ok((pixmap.take(), sz))
    }

    fn load(
        &self,
        driver: &crate::graphics::Driver,
        data: (Vec<u8>, Size2D<u32, Pixel>),
        resize: bool,
    ) -> Result<(atlas::Region, atlas::Size), Error> {
        let size = atlas::Size::new(data.1.width as i32, data.1.height as i32);
        let region = driver.atlas.write().reserve(
            &driver.device,
            size,
            if resize { Some(&driver.queue) } else { None },
            None,
        )?;

        driver.atlas.read().queue_data(
            &data.0,
            &region,
            &driver.queue,
            data.1.width,
            data.1.height,
        );

        Ok((region, size))
    }
}

#[cfg(any(feature = "png", feature = "jpeg"))]
struct LoadImageView<'a>(&'a load_image::Image);

#[cfg(any(feature = "png", feature = "jpeg"))]
fn image_data_as_bytes(data: &load_image::ImageData) -> &[u8] {
    match data {
        load_image::ImageData::RGB8(rgbs) => bytemuck::cast_slice(rgbs.as_slice()),
        load_image::ImageData::RGBA8(rgbas) => bytemuck::cast_slice(rgbas.as_slice()),
        load_image::ImageData::RGB16(rgbs) => bytemuck::cast_slice(rgbs.as_slice()),
        load_image::ImageData::RGBA16(rgbas) => bytemuck::cast_slice(rgbas.as_slice()),
        load_image::ImageData::GRAY8(gray_v08s) => bytemuck::cast_slice(gray_v08s.as_slice()),
        load_image::ImageData::GRAY16(gray_v08s) => bytemuck::cast_slice(gray_v08s.as_slice()),
        load_image::ImageData::GRAYA8(gray_alpha_v08s) => {
            bytemuck::cast_slice(gray_alpha_v08s.as_slice())
        }
        load_image::ImageData::GRAYA16(gray_alpha_v08s) => {
            bytemuck::cast_slice(gray_alpha_v08s.as_slice())
        }
    }
}

#[cfg(any(feature = "png", feature = "jpeg"))]
impl<'a> fast_image_resize::IntoImageView for LoadImageView<'a> {
    fn pixel_type(&self) -> Option<fast_image_resize::PixelType> {
        use fast_image_resize::PixelType;
        use load_image::ImageData;
        Some(match self.0.bitmap {
            ImageData::RGB8(_) => PixelType::U8x3,
            ImageData::RGBA8(_) => PixelType::U8x4,
            ImageData::GRAY8(_) => PixelType::U8,
            ImageData::GRAYA8(_) => PixelType::U8x2,
            ImageData::RGB16(_) => PixelType::U16x3,
            ImageData::RGBA16(_) => PixelType::U16x4,
            ImageData::GRAY16(_) => PixelType::U16,
            ImageData::GRAYA16(_) => PixelType::U16x2,
        })
    }

    fn width(&self) -> u32 {
        self.0.width as u32
    }

    fn height(&self) -> u32 {
        self.0.height as u32
    }

    fn image_view<P: fast_image_resize::PixelTrait>(
        &self,
    ) -> Option<impl fast_image_resize::ImageView<Pixel = P>> {
        if P::pixel_type() == self.pixel_type().unwrap() {
            return fast_image_resize::images::TypedImageRef::<P>::from_buffer(
                self.width(),
                self.height(),
                image_data_as_bytes(&self.0.bitmap),
            )
            .ok();
        }
        None
    }
}

#[cfg(any(
    feature = "avif",
    feature = "bmp",
    feature = "dds",
    feature = "exr",
    feature = "ff",
    feature = "gif",
    feature = "hdr",
    feature = "ico",
    feature = "pnm",
    feature = "png",
    feature = "jpeg",
    feature = "qoi",
    feature = "tga",
    feature = "tiff",
    feature = "webp"
))]
fn process_pixels<P: fast_image_resize::pixels::InnerPixel>(
    output: &mut [u8],
    dst_image: &fast_image_resize::images::Image<'_>,
    convert: fn(p: &P) -> crate::color::sRGB,
) {
    use crate::color::Premultiplied;
    for (p, c) in dst_image
        .typed_image::<P>()
        .unwrap()
        .pixels()
        .iter()
        .zip(output.chunks_exact_mut(4))
    {
        c.copy_from_slice(&convert(p).srgb_pre().as_bgra())
    }
}

fn process_load_pixels<T>(
    output: &mut [u8],
    source: &[T],
    convert: fn(p: &T) -> crate::color::sRGB,
) {
    use crate::color::Premultiplied;
    for (p, c) in source.iter().zip(output.chunks_exact_mut(4)) {
        // Pre-multiply color, then extract in BGRA form.
        c.copy_from_slice(&convert(p).srgb_pre().as_bgra());
    }
}

#[cfg(any(
    feature = "avif",
    feature = "bmp",
    feature = "dds",
    feature = "exr",
    feature = "ff",
    feature = "gif",
    feature = "hdr",
    feature = "ico",
    feature = "pnm",
    feature = "png",
    feature = "jpeg",
    feature = "qoi",
    feature = "tga",
    feature = "tiff",
    feature = "webp"
))]
fn image_resize_loader(
    inner_format: fast_image_resize::PixelType,
    srgb_map: fast_image_resize::PixelComponentMapper,
    source: &impl fast_image_resize::IntoImageView,
    size: atlas::Size,
) -> Result<(Vec<u8>, u32, u32), Error> {
    use crate::color::sRGB64;
    use fast_image_resize::PixelType;

    let mut inner_src_image =
        fast_image_resize::images::Image::new(source.width(), source.height(), inner_format);

    srgb_map
        .forward_map(source, &mut inner_src_image)
        .map_err(|e| Error::ResourceError(Box::new(e)))?;

    let mut dst_image =
        fast_image_resize::images::Image::new(size.width as u32, size.height as u32, inner_format);

    fast_image_resize::Resizer::new()
        .resize(
            &inner_src_image,
            &mut dst_image,
            &fast_image_resize::ResizeOptions::new()
                .use_alpha(true)
                .resize_alg(fast_image_resize::ResizeAlg::Convolution(
                    fast_image_resize::FilterType::CatmullRom,
                )),
        )
        .map_err(|e| Error::ResourceError(Box::new(e)))?;

    srgb_map
        .backward_map_inplace(&mut dst_image)
        .map_err(|e| Error::ResourceError(Box::new(e)))?;

    let mut output = unsafe {
        vec![std::mem::zeroed::<u8>(); (dst_image.width() * dst_image.height() * 4) as usize]
    };

    match inner_format {
        PixelType::U16 => process_pixels::<fast_image_resize::pixels::U16>(
            output.as_mut_slice(),
            &dst_image,
            |p| sRGB64::new(p.0, p.0, p.0, u16::MAX).as_f32(),
        ),
        PixelType::U16x2 => process_pixels::<fast_image_resize::pixels::U16x2>(
            output.as_mut_slice(),
            &dst_image,
            |p| sRGB64::new(p.0[0], p.0[0], p.0[0], p.0[1]).as_f32(),
        ),
        PixelType::U16x3 => process_pixels::<fast_image_resize::pixels::U16x3>(
            output.as_mut_slice(),
            &dst_image,
            |p| sRGB64::new(p.0[0], p.0[1], p.0[2], u16::MAX).as_f32(),
        ),
        PixelType::U16x4 => process_pixels::<fast_image_resize::pixels::U16x4>(
            output.as_mut_slice(),
            &dst_image,
            |p| sRGB64::new(p.0[0], p.0[1], p.0[2], p.0[3]).as_f32(),
        ),
        _ => return Err(Error::InternalFailure),
    }

    Ok((output, dst_image.width(), dst_image.height()))
}

/*
fn gen_test_image() {
    let mut imgbuf = image::ImageBuffer::new(128, 128);

    for (x, y, pixel) in imgbuf.enumerate_pixels_mut() {
        let v = match ((x / 4) % 2, (y / 4) % 2) {
            (0, 0) => [255, 0, 0, 0],
            (1, 0) => [0, 255, 0, 0],
            (0, 1) => [0, 0, 255, 0],
            (1, 1) => [0, 0, 0, 255],
            _ => panic!("math stopped working!"),
        };
        *pixel = image::Rgba::<u8>(v);
    }

    imgbuf
        .save_with_format("premul_test.png", image::ImageFormat::Png)
        .unwrap();
}
*/

#[cfg(any(feature = "png", feature = "jpeg"))]
impl Loader for load_image::Image {
    fn preload(
        &self,
        mut size: atlas::Size,
        _: f32,
    ) -> Result<(Vec<u8>, Size2D<u32, Pixel>), Error> {
        use crate::color::{sRGB32, sRGB64};

        size = fill_size(
            size,
            atlas::Size::new(self.width as i32, self.height as i32),
        );

        // If we're too close to the native size of the image, skip resizing it and
        // simply store the native size to the atlas.
        let force_native = within_variance(size.height, self.height as i32, 0.05)
            && within_variance(size.width, self.width as i32, 0.05);
        let (raw, w, h) = if !(force_native
            || size.width as usize > self.width && size.height as usize > self.height)
        {
            use load_image::ImageData;

            let srgb_map = match self.bitmap {
                ImageData::RGB8(_)
                | ImageData::RGBA8(_)
                | ImageData::RGB16(_)
                | ImageData::RGBA16(_) => fast_image_resize::create_srgb_mapper(),
                ImageData::GRAY8(_)
                | ImageData::GRAY16(_)
                | ImageData::GRAYA8(_)
                | ImageData::GRAYA16(_) => fast_image_resize::create_gamma_22_mapper(),
            };

            let inner_format = match self.bitmap {
                ImageData::RGB8(_) | ImageData::RGB16(_) => fast_image_resize::PixelType::U16x3,
                ImageData::RGBA8(_) | ImageData::RGBA16(_) => fast_image_resize::PixelType::U16x4,
                ImageData::GRAY8(_) | ImageData::GRAY16(_) => fast_image_resize::PixelType::U16,
                ImageData::GRAYA8(_) | ImageData::GRAYA16(_) => fast_image_resize::PixelType::U16x2,
            };

            image_resize_loader(inner_format, srgb_map, &LoadImageView(self), size)?
        } else {
            let mut output =
                unsafe { vec![std::mem::zeroed::<u8>(); self.width * self.height * 4] };

            match &self.bitmap {
                load_image::ImageData::RGB8(rgbs) => {
                    process_load_pixels(output.as_mut_slice(), rgbs, |p| {
                        sRGB32::new(p.r, p.g, p.b, u8::MAX).as_f32()
                    })
                }
                load_image::ImageData::RGBA8(rgbas) => {
                    process_load_pixels(output.as_mut_slice(), rgbas, |p| {
                        sRGB32::new(p.r, p.g, p.b, p.a).as_f32()
                    })
                }
                load_image::ImageData::RGB16(rgbs) => {
                    process_load_pixels(output.as_mut_slice(), rgbs, |p| {
                        sRGB64::new(p.r, p.g, p.b, u16::MAX).as_f32()
                    })
                }
                load_image::ImageData::RGBA16(rgbas) => {
                    process_load_pixels(output.as_mut_slice(), rgbas, |p| {
                        sRGB64::new(p.r, p.g, p.b, p.a).as_f32()
                    })
                }
                load_image::ImageData::GRAY8(gray_v08s) => {
                    process_load_pixels(output.as_mut_slice(), gray_v08s, |p| {
                        sRGB32::new(p.value(), p.value(), p.value(), u8::MAX).as_f32()
                    })
                }
                load_image::ImageData::GRAY16(gray_v08s) => {
                    process_load_pixels(output.as_mut_slice(), gray_v08s, |p| {
                        sRGB64::new(p.value(), p.value(), p.value(), u16::MAX).as_f32()
                    })
                }
                load_image::ImageData::GRAYA8(gray_alpha_v08s) => {
                    process_load_pixels(output.as_mut_slice(), gray_alpha_v08s, |p| {
                        sRGB32::new(p.v, p.v, p.v, p.a).as_f32()
                    })
                }
                load_image::ImageData::GRAYA16(gray_alpha_v08s) => {
                    process_load_pixels(output.as_mut_slice(), gray_alpha_v08s, |p| {
                        sRGB64::new(p.v, p.v, p.v, p.a).as_f32()
                    })
                }
            };

            (output, self.width as u32, self.height as u32)
        };

        Ok((raw, Size2D::new(w, h)))
    }
    fn load(
        &self,
        driver: &crate::graphics::Driver,
        data: (Vec<u8>, Size2D<u32, Pixel>),
        resize: bool,
    ) -> Result<(atlas::Region, atlas::Size), Error> {
        let region = driver.atlas.write().reserve(
            &driver.device,
            atlas::Size::new(data.1.width as i32, data.1.height as i32),
            if resize { Some(&driver.queue) } else { None },
            None,
        )?;

        driver.atlas.read().queue_data(
            &data.0,
            &region,
            &driver.queue,
            data.1.width,
            data.1.height,
        );

        let native = atlas::Size::new(self.width as i32, self.height as i32);

        Ok((region, native))
    }
}

#[cfg(any(
    feature = "avif",
    feature = "bmp",
    feature = "dds",
    feature = "exr",
    feature = "ff",
    feature = "gif",
    feature = "hdr",
    feature = "ico",
    feature = "pnm",
    feature = "qoi",
    feature = "tga",
    feature = "tiff",
    feature = "webp"
))]
impl Loader for image::DynamicImage {
    fn preload(
        &self,
        mut size: atlas::Size,
        _: f32,
    ) -> Result<(Vec<u8>, Size2D<u32, Pixel>), Error> {
        use crate::color::{Premultiplied, sRGB32};

        let native = atlas::Size::new(self.width() as i32, self.height() as i32);
        size = fill_size(size, native);

        // If we're too close to the native size of the image, skip resizing it and
        // simply store the native size to the atlas.
        let force_native = within_variance(size.height, self.height() as i32, 0.05)
            && within_variance(size.width, self.width() as i32, 0.05);

        let (raw, w, h) = if !(force_native
            || size.width as u32 > self.width() && size.height as u32 > self.height())
        {
            let srgb_map = if self.color().has_color() {
                fast_image_resize::create_srgb_mapper()
            } else {
                fast_image_resize::create_gamma_22_mapper()
            };

            let inner_format = match self.color().channel_count() {
                4 => fast_image_resize::PixelType::U16x4,
                3 => fast_image_resize::PixelType::U16x3,
                2 => fast_image_resize::PixelType::U16x2,
                1 => fast_image_resize::PixelType::U16,
                _ => return Err(Error::InternalFailure),
            };

            image_resize_loader(inner_format, srgb_map, self, size)?
        } else {
            let mut raw = self.to_rgba8().into_vec();

            // Raw is in sRGB RGBA but our atlas is in pre-multiplied BGRA format
            for c in raw.as_mut_slice().chunks_exact_mut(4) {
                // Pre-multiply color, then extract in BGRA form.
                c.copy_from_slice(
                    &sRGB32::new(c[0], c[1], c[2], c[3])
                        .as_f32()
                        .srgb_pre()
                        .as_bgra(),
                );
            }

            (raw, self.width(), self.height())
        };

        Ok((raw, Size2D::new(w, h)))
    }

    fn load(
        &self,
        driver: &crate::graphics::Driver,
        data: (Vec<u8>, Size2D<u32, Pixel>),
        resize: bool,
    ) -> Result<(atlas::Region, atlas::Size), Error> {
        let region = driver.atlas.write().reserve(
            &driver.device,
            atlas::Size::new(data.1.width as i32, data.1.height as i32),
            if resize { Some(&driver.queue) } else { None },
            None,
        )?;

        driver.atlas.read().queue_data(
            &data.0,
            &region,
            &driver.queue,
            data.1.width,
            data.1.height,
        );

        let native = atlas::Size::new(self.width() as i32, self.height() as i32);
        Ok((region, native))
    }
}

pub fn load_icon(location: &dyn Location) -> Result<winit::window::Icon, Error> {
    let loader = location.fetch()?;

    #[cfg(target_os = "windows")]
    use windows_sys::Win32::UI::WindowsAndMessaging::{GetSystemMetrics, SM_CXICON, SM_CYICON};

    #[cfg(target_os = "windows")]
    let sz = unsafe { atlas::Size::new(GetSystemMetrics(SM_CXICON), GetSystemMetrics(SM_CYICON)) };

    #[cfg(not(target_os = "windows"))]
    let sz = atlas::Size::new(128, 128);

    let (mut data, dim) = loader.preload(sz, crate::BASE_DPI.width)?;

    // This data is in BGRA format, but this wants RGBA, so we swap it (again). Not
    // very efficient, but icons shouldn't be very large anyway.
    for c in data.as_chunks_mut::<4>().0 {
        c.swap(0, 2);
    }

    winit::window::Icon::from_rgba(data, dim.width, dim.height)
        .map_err(|e| Error::ResourceError(Box::new(e)))
}

#[cfg(any(
    feature = "avif",
    feature = "bmp",
    feature = "dds",
    feature = "exr",
    feature = "ff",
    feature = "gif",
    feature = "hdr",
    feature = "ico",
    feature = "pnm",
    feature = "qoi",
    feature = "tga",
    feature = "tiff",
    feature = "webp"
))]
#[derive(Debug, Clone)]
pub struct ImageRef(pub Arc<image::DynamicImage>);

#[cfg(any(
    feature = "avif",
    feature = "bmp",
    feature = "dds",
    feature = "exr",
    feature = "ff",
    feature = "gif",
    feature = "hdr",
    feature = "ico",
    feature = "pnm",
    feature = "qoi",
    feature = "tga",
    feature = "tiff",
    feature = "webp"
))]
impl std::hash::Hash for ImageRef {
    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
        Arc::as_ptr(&self.0).hash(state);
    }
}

#[cfg(any(
    feature = "avif",
    feature = "bmp",
    feature = "dds",
    feature = "exr",
    feature = "ff",
    feature = "gif",
    feature = "hdr",
    feature = "ico",
    feature = "pnm",
    feature = "qoi",
    feature = "tga",
    feature = "tiff",
    feature = "webp"
))]
impl PartialEq for ImageRef {
    fn eq(&self, other: &Self) -> bool {
        Arc::ptr_eq(&self.0, &other.0)
    }
}

#[cfg(any(
    feature = "avif",
    feature = "bmp",
    feature = "dds",
    feature = "exr",
    feature = "ff",
    feature = "gif",
    feature = "hdr",
    feature = "ico",
    feature = "pnm",
    feature = "qoi",
    feature = "tga",
    feature = "tiff",
    feature = "webp"
))]
impl Eq for ImageRef {}

#[cfg(any(
    feature = "avif",
    feature = "bmp",
    feature = "dds",
    feature = "exr",
    feature = "ff",
    feature = "gif",
    feature = "hdr",
    feature = "ico",
    feature = "pnm",
    feature = "qoi",
    feature = "tga",
    feature = "tiff",
    feature = "webp"
))]
impl Location for ImageRef {
    fn fetch(&self) -> Result<Box<dyn Loader>, Error> {
        Ok(Box::new(image::DynamicImage::clone(&self.0)))
    }
}