librashader/librashader-runtime-wgpu/src/luts.rs

use crate::texture::{Handle, InputImage};
use librashader_presets::TextureConfig;
use librashader_runtime::image::{Image, BGRA8};
use librashader_runtime::scaling::MipmapSize;
use std::sync::Arc;
use wgpu::util::DeviceExt;
use wgpu::{ImageDataLayout, Label, TextureDescriptor};

pub(crate) struct LutTexture(InputImage);
impl AsRef<InputImage> for LutTexture {
    fn as_ref(&self) -> &InputImage {
        &self.0
    }
}

impl LutTexture {
    pub fn new(
        device: &wgpu::Device,
        queue: &wgpu::Queue,
        _cmd: &mut wgpu::CommandEncoder,
        image: Image,
        config: &TextureConfig,
    ) -> LutTexture {
        let texture = device.create_texture(&TextureDescriptor {
            label: Some(&config.name),
            size: image.size.into(),
            mip_level_count: if config.mipmap {
                image.size.calculate_miplevels()
            } else {
                1
            },
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format: wgpu::TextureFormat::Rgba8Unorm,
            usage: wgpu::TextureUsages::TEXTURE_BINDING
                | wgpu::TextureUsages::COPY_DST
                // need render attachment for mipmaps...
                | wgpu::TextureUsages::RENDER_ATTACHMENT,
            view_formats: &[wgpu::TextureFormat::Rgba8Unorm],
        });

        queue.write_texture(
            wgpu::ImageCopyTexture {
                texture: &texture,
                mip_level: 0,
                origin: wgpu::Origin3d::ZERO,
                aspect: wgpu::TextureAspect::All,
            },
            &image.bytes,
            wgpu::ImageDataLayout {
                offset: 0,
                bytes_per_row: Some(4 * image.size.width),
                rows_per_image: None,
            },
            image.size.into(),
        );

        // todo: mipmaps

        // todo: fix this
        let view = texture.create_view(&wgpu::TextureViewDescriptor {
            label: Some("lut view"),
            format: None,
            dimension: None,
            aspect: Default::default(),
            base_mip_level: 0,
            mip_level_count: None,
            base_array_layer: 0,
            array_layer_count: None,
        });

        let image = InputImage {
            image: Arc::new(texture),
            view: Arc::new(view),
            wrap_mode: config.wrap_mode,
            filter_mode: config.filter_mode,
            mip_filter: config.filter_mode,
        };

        Self(image)
    }
}