ff-render 0.15.0

//! Shared GPU pipeline helpers for composite nodes and the compositor.
//!
//! Bind-group layouts, render pipelines, samplers, texture uploads, and
//! render-pass submission shared by every GPU node implementation.

#[cfg(feature = "wgpu")]
pub(crate) fn linear_sampler(device: &wgpu::Device, label: &str) -> wgpu::Sampler {
    device.create_sampler(&wgpu::SamplerDescriptor {
        label: Some(&format!("{label} sampler")),
        address_mode_u: wgpu::AddressMode::ClampToEdge,
        address_mode_v: wgpu::AddressMode::ClampToEdge,
        mag_filter: wgpu::FilterMode::Linear,
        min_filter: wgpu::FilterMode::Linear,
        ..Default::default()
    })
}

/// Build a BGL with one texture + one sampler + one uniform buffer.
#[cfg(feature = "wgpu")]
pub(super) fn one_tex_sampler_uniform_bgl(
    device: &wgpu::Device,
    label: &str,
) -> wgpu::BindGroupLayout {
    device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
        label: Some(&format!("{label} BGL")),
        entries: &[
            wgpu::BindGroupLayoutEntry {
                binding: 0,
                visibility: wgpu::ShaderStages::FRAGMENT,
                ty: wgpu::BindingType::Texture {
                    sample_type: wgpu::TextureSampleType::Float { filterable: true },
                    view_dimension: wgpu::TextureViewDimension::D2,
                    multisampled: false,
                },
                count: None,
            },
            wgpu::BindGroupLayoutEntry {
                binding: 1,
                visibility: wgpu::ShaderStages::FRAGMENT,
                ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
                count: None,
            },
            wgpu::BindGroupLayoutEntry {
                binding: 2,
                visibility: wgpu::ShaderStages::FRAGMENT,
                ty: wgpu::BindingType::Buffer {
                    ty: wgpu::BufferBindingType::Uniform,
                    has_dynamic_offset: false,
                    min_binding_size: None,
                },
                count: None,
            },
        ],
    })
}

/// Build a BGL with two textures + one sampler + one uniform buffer.
#[cfg(feature = "wgpu")]
pub(crate) fn two_tex_sampler_uniform_bgl(
    device: &wgpu::Device,
    label: &str,
) -> wgpu::BindGroupLayout {
    device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
        label: Some(&format!("{label} BGL")),
        entries: &[
            wgpu::BindGroupLayoutEntry {
                binding: 0,
                visibility: wgpu::ShaderStages::FRAGMENT,
                ty: wgpu::BindingType::Texture {
                    sample_type: wgpu::TextureSampleType::Float { filterable: true },
                    view_dimension: wgpu::TextureViewDimension::D2,
                    multisampled: false,
                },
                count: None,
            },
            wgpu::BindGroupLayoutEntry {
                binding: 1,
                visibility: wgpu::ShaderStages::FRAGMENT,
                ty: wgpu::BindingType::Texture {
                    sample_type: wgpu::TextureSampleType::Float { filterable: true },
                    view_dimension: wgpu::TextureViewDimension::D2,
                    multisampled: false,
                },
                count: None,
            },
            wgpu::BindGroupLayoutEntry {
                binding: 2,
                visibility: wgpu::ShaderStages::FRAGMENT,
                ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
                count: None,
            },
            wgpu::BindGroupLayoutEntry {
                binding: 3,
                visibility: wgpu::ShaderStages::FRAGMENT,
                ty: wgpu::BindingType::Buffer {
                    ty: wgpu::BufferBindingType::Uniform,
                    has_dynamic_offset: false,
                    min_binding_size: None,
                },
                count: None,
            },
        ],
    })
}

#[cfg(feature = "wgpu")]
pub(crate) fn fullscreen_pipeline(
    device: &wgpu::Device,
    shader: &wgpu::ShaderModule,
    label: &str,
    bgl: &wgpu::BindGroupLayout,
) -> wgpu::RenderPipeline {
    let layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
        label: Some(&format!("{label} layout")),
        bind_group_layouts: &[Some(bgl)],
        immediate_size: 0,
    });
    device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
        label: Some(&format!("{label} pipeline")),
        layout: Some(&layout),
        vertex: wgpu::VertexState {
            module: shader,
            entry_point: Some("vs_main"),
            buffers: &[],
            compilation_options: wgpu::PipelineCompilationOptions::default(),
        },
        fragment: Some(wgpu::FragmentState {
            module: shader,
            entry_point: Some("fs_main"),
            targets: &[Some(wgpu::ColorTargetState {
                format: wgpu::TextureFormat::Rgba8Unorm,
                blend: None,
                write_mask: wgpu::ColorWrites::ALL,
            })],
            compilation_options: wgpu::PipelineCompilationOptions::default(),
        }),
        primitive: wgpu::PrimitiveState::default(),
        depth_stencil: None,
        multisample: wgpu::MultisampleState::default(),
        multiview_mask: None,
        cache: None,
    })
}

#[cfg(feature = "wgpu")]
pub(crate) fn upload_rgba_texture(
    ctx: &crate::context::RenderContext,
    data: &[u8],
    width: u32,
    height: u32,
    label: &str,
) -> wgpu::Texture {
    let tex = ctx.device.create_texture(&wgpu::TextureDescriptor {
        label: Some(label),
        size: wgpu::Extent3d {
            width,
            height,
            depth_or_array_layers: 1,
        },
        mip_level_count: 1,
        sample_count: 1,
        dimension: wgpu::TextureDimension::D2,
        format: wgpu::TextureFormat::Rgba8Unorm,
        usage: wgpu::TextureUsages::COPY_DST | wgpu::TextureUsages::TEXTURE_BINDING,
        view_formats: &[],
    });
    ctx.queue.write_texture(
        wgpu::TexelCopyTextureInfo {
            texture: &tex,
            mip_level: 0,
            origin: wgpu::Origin3d::ZERO,
            aspect: wgpu::TextureAspect::All,
        },
        data,
        wgpu::TexelCopyBufferLayout {
            offset: 0,
            bytes_per_row: Some(width * 4),
            rows_per_image: None,
        },
        wgpu::Extent3d {
            width,
            height,
            depth_or_array_layers: 1,
        },
    );
    tex
}

#[cfg(feature = "wgpu")]
pub(crate) fn submit_render_pass(
    ctx: &crate::context::RenderContext,
    pipeline: &wgpu::RenderPipeline,
    bind_group: &wgpu::BindGroup,
    out_view: &wgpu::TextureView,
    label: &str,
) {
    let mut encoder = ctx
        .device
        .create_command_encoder(&wgpu::CommandEncoderDescriptor {
            label: Some(&format!("{label} encoder")),
        });
    {
        let mut pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
            label: Some(&format!("{label} pass")),
            color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                view: out_view,
                resolve_target: None,
                depth_slice: None,
                ops: wgpu::Operations {
                    load: wgpu::LoadOp::Clear(wgpu::Color::TRANSPARENT),
                    store: wgpu::StoreOp::Store,
                },
            })],
            depth_stencil_attachment: None,
            timestamp_writes: None,
            occlusion_query_set: None,
            multiview_mask: None,
        });
        pass.set_pipeline(pipeline);
        pass.set_bind_group(0, bind_group, &[]);
        pass.draw(0..6, 0..1);
    }
    ctx.queue.submit(std::iter::once(encoder.finish()));
}

#[cfg(feature = "wgpu")]
pub(super) fn pack_f32(values: &[f32]) -> Vec<u8> {
    values.iter().flat_map(|f| f.to_le_bytes()).collect()
}