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249use crate::{
image::{Image, ImageFormat, ImageType, TextureError},
TextureReinterpretationError,
};
use bevy_asset::{io::Reader, AssetLoader, LoadContext, RenderAssetUsages};
use bevy_reflect::TypePath;
use thiserror::Error;
use super::{CompressedImageFormats, ImageSampler};
use serde::{Deserialize, Serialize};
/// Loader for images that can be read by the `image` crate.
#[derive(Clone, TypePath)]
pub struct ImageLoader {
supported_compressed_formats: CompressedImageFormats,
}
impl ImageLoader {
/// Full list of supported formats.
pub const SUPPORTED_FORMATS: &'static [ImageFormat] = &[
#[cfg(feature = "basis-universal")]
ImageFormat::Basis,
#[cfg(feature = "bmp")]
ImageFormat::Bmp,
#[cfg(feature = "dds")]
ImageFormat::Dds,
#[cfg(feature = "ff")]
ImageFormat::Farbfeld,
#[cfg(feature = "gif")]
ImageFormat::Gif,
#[cfg(feature = "ico")]
ImageFormat::Ico,
#[cfg(feature = "jpeg")]
ImageFormat::Jpeg,
#[cfg(feature = "ktx2")]
ImageFormat::Ktx2,
#[cfg(feature = "png")]
ImageFormat::Png,
#[cfg(feature = "pnm")]
ImageFormat::Pnm,
#[cfg(feature = "qoi")]
ImageFormat::Qoi,
#[cfg(feature = "tga")]
ImageFormat::Tga,
#[cfg(feature = "tiff")]
ImageFormat::Tiff,
#[cfg(feature = "webp")]
ImageFormat::WebP,
];
/// Total count of file extensions, for computing supported file extensions list.
const COUNT_FILE_EXTENSIONS: usize = {
let mut count = 0;
let mut idx = 0;
while idx < Self::SUPPORTED_FORMATS.len() {
count += Self::SUPPORTED_FORMATS[idx].to_file_extensions().len();
idx += 1;
}
count
};
/// Gets the list of file extensions for all formats.
pub const SUPPORTED_FILE_EXTENSIONS: &'static [&'static str] = &{
let mut exts = [""; Self::COUNT_FILE_EXTENSIONS];
let mut ext_idx = 0;
let mut fmt_idx = 0;
while fmt_idx < Self::SUPPORTED_FORMATS.len() {
let mut off = 0;
let fmt_exts = Self::SUPPORTED_FORMATS[fmt_idx].to_file_extensions();
while off < fmt_exts.len() {
exts[ext_idx] = fmt_exts[off];
off += 1;
ext_idx += 1;
}
fmt_idx += 1;
}
exts
};
/// Creates a new image loader that supports the provided formats.
pub fn new(supported_compressed_formats: CompressedImageFormats) -> Self {
Self {
supported_compressed_formats,
}
}
}
/// How to determine an image's format when loading.
#[derive(Serialize, Deserialize, Default, Debug, Clone)]
pub enum ImageFormatSetting {
/// Determine the image format from its file extension.
///
/// This is the default.
#[default]
FromExtension,
/// Declare the image format explicitly.
Format(ImageFormat),
/// Guess the image format by looking for magic bytes at the
/// beginning of its data.
Guess,
}
/// How to interpret the image as an array of textures.
#[derive(Serialize, Deserialize, Debug, Clone, Copy)]
pub enum ImageArrayLayout {
/// Interpret the image as a vertical stack of *n* images.
RowCount { rows: u32 },
/// Interpret the image as a vertical stack of images, each *n* pixels tall.
RowHeight { pixels: u32 },
}
/// Settings for loading an [`Image`] using an [`ImageLoader`].
#[derive(Serialize, Deserialize, Debug, Clone)]
pub struct ImageLoaderSettings {
/// How to determine the image's container format.
pub format: ImageFormatSetting,
/// Forcibly use a specific [`wgpu_types::TextureFormat`].
/// Useful to control how data is handled when used
/// in a shader.
/// Ex: data that would be `R16Uint` that needs to
/// be sampled as a float using `R16Snorm`.
#[serde(skip)]
pub texture_format: Option<wgpu_types::TextureFormat>,
/// Specifies whether image data is linear
/// or in sRGB space when this is not determined by
/// the image format.
pub is_srgb: bool,
/// [`ImageSampler`] to use when rendering - this does
/// not affect the loading of the image data.
pub sampler: ImageSampler,
/// Where the asset will be used - see the docs on
/// [`RenderAssetUsages`] for details.
pub asset_usage: RenderAssetUsages,
/// Interpret the image as an array of images. This is
/// primarily for use with the `texture2DArray` shader
/// uniform type.
#[serde(default)]
pub array_layout: Option<ImageArrayLayout>,
}
impl Default for ImageLoaderSettings {
fn default() -> Self {
Self {
format: ImageFormatSetting::default(),
texture_format: None,
is_srgb: true,
sampler: ImageSampler::Default,
asset_usage: RenderAssetUsages::default(),
array_layout: None,
}
}
}
/// An error when loading an image using [`ImageLoader`].
#[non_exhaustive]
#[derive(Debug, Error)]
pub enum ImageLoaderError {
/// An error occurred while trying to load the image bytes.
#[error("Failed to load image bytes: {0}")]
Io(#[from] std::io::Error),
/// An error occurred while trying to decode the image bytes.
#[error("Could not load texture file: {0}")]
FileTexture(#[from] FileTextureError),
/// An error occurred while trying to interpret the image bytes as an array texture.
#[error("Invalid array layout: {0}")]
ArrayLayout(#[from] TextureReinterpretationError),
}
impl AssetLoader for ImageLoader {
type Asset = Image;
type Settings = ImageLoaderSettings;
type Error = ImageLoaderError;
async fn load(
&self,
reader: &mut dyn Reader,
settings: &ImageLoaderSettings,
load_context: &mut LoadContext<'_>,
) -> Result<Image, Self::Error> {
let mut bytes = Vec::new();
reader.read_to_end(&mut bytes).await?;
let image_type = match settings.format {
ImageFormatSetting::FromExtension => {
// use the file extension for the image type
let ext = load_context
.path()
.path()
.extension()
.unwrap()
.to_str()
.unwrap();
ImageType::Extension(ext)
}
ImageFormatSetting::Format(format) => ImageType::Format(format),
ImageFormatSetting::Guess => {
let format = image::guess_format(&bytes).map_err(|err| FileTextureError {
error: err.into(),
path: format!("{}", load_context.path().path().display()),
})?;
ImageType::Format(ImageFormat::from_image_crate_format(format).ok_or_else(
|| FileTextureError {
error: TextureError::UnsupportedTextureFormat(format!("{format:?}")),
path: format!("{}", load_context.path().path().display()),
},
)?)
}
};
let mut image = Image::from_buffer(
&bytes,
image_type,
self.supported_compressed_formats,
settings.is_srgb,
settings.sampler.clone(),
settings.asset_usage,
)
.map_err(|err| FileTextureError {
error: err,
path: format!("{}", load_context.path().path().display()),
})?;
if let Some(format) = settings.texture_format {
image.texture_descriptor.format = format;
}
if let Some(array_layout) = settings.array_layout {
let layers = match array_layout {
ImageArrayLayout::RowCount { rows } => rows,
ImageArrayLayout::RowHeight { pixels } => image.height() / pixels,
};
image.reinterpret_stacked_2d_as_array(layers)?;
}
Ok(image)
}
fn extensions(&self) -> &[&str] {
Self::SUPPORTED_FILE_EXTENSIONS
}
}
/// An error that occurs when loading a texture from a file.
#[derive(Error, Debug)]
#[error("Error reading image file {path}: {error}.")]
pub struct FileTextureError {
error: TextureError,
path: String,
}