bevy_render/texture/
hdr_texture_loader.rs

1use crate::{
2    render_asset::RenderAssetUsages,
3    texture::{Image, TextureFormatPixelInfo},
4};
5use bevy_asset::{io::Reader, AssetLoader, AsyncReadExt, LoadContext};
6use image::DynamicImage;
7use serde::{Deserialize, Serialize};
8use thiserror::Error;
9use wgpu::{Extent3d, TextureDimension, TextureFormat};
10
11/// Loads HDR textures as Texture assets
12#[derive(Clone, Default)]
13pub struct HdrTextureLoader;
14
15#[derive(Serialize, Deserialize, Default, Debug)]
16pub struct HdrTextureLoaderSettings {
17    pub asset_usage: RenderAssetUsages,
18}
19
20#[non_exhaustive]
21#[derive(Debug, Error)]
22pub enum HdrTextureLoaderError {
23    #[error("Could load texture: {0}")]
24    Io(#[from] std::io::Error),
25    #[error("Could not extract image: {0}")]
26    Image(#[from] image::ImageError),
27}
28
29impl AssetLoader for HdrTextureLoader {
30    type Asset = Image;
31    type Settings = HdrTextureLoaderSettings;
32    type Error = HdrTextureLoaderError;
33    async fn load<'a>(
34        &'a self,
35        reader: &'a mut Reader<'_>,
36        settings: &'a Self::Settings,
37        _load_context: &'a mut LoadContext<'_>,
38    ) -> Result<Image, Self::Error> {
39        let format = TextureFormat::Rgba32Float;
40        debug_assert_eq!(
41            format.pixel_size(),
42            4 * 4,
43            "Format should have 32bit x 4 size"
44        );
45
46        let mut bytes = Vec::new();
47        reader.read_to_end(&mut bytes).await?;
48        let decoder = image::codecs::hdr::HdrDecoder::new(bytes.as_slice())?;
49        let info = decoder.metadata();
50        let dynamic_image = DynamicImage::from_decoder(decoder)?;
51        let image_buffer = dynamic_image
52            .as_rgb32f()
53            .expect("HDR Image format should be Rgb32F");
54        let mut rgba_data = Vec::with_capacity(image_buffer.pixels().len() * format.pixel_size());
55
56        for rgb in image_buffer.pixels() {
57            let alpha = 1.0f32;
58
59            rgba_data.extend_from_slice(&rgb.0[0].to_ne_bytes());
60            rgba_data.extend_from_slice(&rgb.0[1].to_ne_bytes());
61            rgba_data.extend_from_slice(&rgb.0[2].to_ne_bytes());
62            rgba_data.extend_from_slice(&alpha.to_ne_bytes());
63        }
64
65        Ok(Image::new(
66            Extent3d {
67                width: info.width,
68                height: info.height,
69                depth_or_array_layers: 1,
70            },
71            TextureDimension::D2,
72            rgba_data,
73            format,
74            settings.asset_usage,
75        ))
76    }
77
78    fn extensions(&self) -> &[&str] {
79        &["hdr"]
80    }
81}
bevy_render/texture/hdr_texture_loader.rs

bevy_render/texture/
hdr_texture_loader.rs
