use crate::render::wgpu::rendergraph::{PassExecutionContext, PassNode};
use wgpu::{
BindGroup, BindGroupLayout, Operations, RenderPassColorAttachment, RenderPipeline, Sampler,
};
const FULLSCREEN_VERTEX_SHADER: &str = "
struct VertexOutput {
@builtin(position) position: vec4<f32>,
@location(0) uv: vec2<f32>,
};
@vertex
fn vertex_main(@builtin(vertex_index) vertex_index: u32) -> VertexOutput {
var out: VertexOutput;
let x = f32((vertex_index & 1u) << 1u);
let y = f32((vertex_index & 2u));
out.position = vec4<f32>(x * 2.0 - 1.0, y * 2.0 - 1.0, 0.0, 1.0);
out.uv = vec2<f32>(x, 1.0 - y);
return out;
}
";
const BLIT_FRAGMENT_SHADER: &str = "
@group(0) @binding(0)
var input_texture: texture_2d<f32>;
@group(0) @binding(1)
var input_sampler: sampler;
@fragment
fn fragment_main(in: VertexOutput) -> @location(0) vec4<f32> {
return textureSample(input_texture, input_sampler, in.uv);
}
";
pub struct BlitPass {
pub pipeline: RenderPipeline,
bind_group_layout: BindGroupLayout,
sampler: Sampler,
cached_bind_group: Option<BindGroup>,
name: String,
}
impl BlitPass {
pub fn create_pipeline(
device: &wgpu::Device,
surface_format: wgpu::TextureFormat,
) -> RenderPipeline {
let shader_source = format!("{}\n{}", FULLSCREEN_VERTEX_SHADER, BLIT_FRAGMENT_SHADER);
let shader_module = device.create_shader_module(wgpu::ShaderModuleDescriptor {
label: Some("Blit Shader"),
source: wgpu::ShaderSource::Wgsl(std::borrow::Cow::Owned(shader_source)),
});
let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
label: Some("Blit Bind Group Layout"),
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,
},
],
});
let pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
label: Some("Blit Pipeline Layout"),
bind_group_layouts: &[Some(&bind_group_layout)],
immediate_size: 0,
});
device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
label: Some("Blit Pipeline"),
layout: Some(&pipeline_layout),
vertex: wgpu::VertexState {
module: &shader_module,
entry_point: Some("vertex_main"),
buffers: &[],
compilation_options: Default::default(),
},
primitive: wgpu::PrimitiveState {
topology: wgpu::PrimitiveTopology::TriangleList,
strip_index_format: None,
front_face: wgpu::FrontFace::Ccw,
cull_mode: None,
unclipped_depth: false,
polygon_mode: wgpu::PolygonMode::Fill,
conservative: false,
},
depth_stencil: None,
multisample: wgpu::MultisampleState {
count: 1,
mask: !0,
alpha_to_coverage_enabled: false,
},
fragment: Some(wgpu::FragmentState {
module: &shader_module,
entry_point: Some("fragment_main"),
targets: &[Some(wgpu::ColorTargetState {
format: surface_format,
blend: None,
write_mask: wgpu::ColorWrites::ALL,
})],
compilation_options: Default::default(),
}),
multiview_mask: None,
cache: None,
})
}
pub fn new(device: &wgpu::Device, surface_format: wgpu::TextureFormat) -> Self {
let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
label: Some("Blit Bind Group Layout"),
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,
},
],
});
let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
label: Some("Blit Sampler"),
address_mode_u: wgpu::AddressMode::ClampToEdge,
address_mode_v: wgpu::AddressMode::ClampToEdge,
address_mode_w: wgpu::AddressMode::ClampToEdge,
mag_filter: wgpu::FilterMode::Linear,
min_filter: wgpu::FilterMode::Linear,
mipmap_filter: wgpu::MipmapFilterMode::Nearest,
..Default::default()
});
Self {
pipeline: Self::create_pipeline(device, surface_format),
bind_group_layout,
sampler,
cached_bind_group: None,
name: "blit_pass".to_string(),
}
}
pub fn with_name(mut self, name: &str) -> Self {
self.name = name.to_string();
self
}
}
impl PassNode<crate::ecs::world::World> for BlitPass {
fn name(&self) -> &str {
&self.name
}
fn reads(&self) -> Vec<&str> {
vec!["input"]
}
fn writes(&self) -> Vec<&str> {
vec!["output"]
}
fn invalidate_bind_groups(&mut self) {
self.cached_bind_group = None;
}
fn execute<'r, 'e>(
&mut self,
context: PassExecutionContext<'r, 'e, crate::ecs::world::World>,
) -> crate::render::wgpu::rendergraph::Result<
Vec<crate::render::wgpu::rendergraph::SubGraphRunCommand<'r>>,
> {
if !context.is_pass_enabled() {
return Ok(context.into_sub_graph_commands());
}
if self.cached_bind_group.is_none() {
let input_view = context.get_texture_view("input")?;
self.cached_bind_group = Some(context.device.create_bind_group(
&wgpu::BindGroupDescriptor {
label: Some("Blit Bind Group"),
layout: &self.bind_group_layout,
entries: &[
wgpu::BindGroupEntry {
binding: 0,
resource: wgpu::BindingResource::TextureView(input_view),
},
wgpu::BindGroupEntry {
binding: 1,
resource: wgpu::BindingResource::Sampler(&self.sampler),
},
],
},
));
}
let (color_view, color_load_op, color_store_op) = context.get_color_attachment("output")?;
let mut render_pass = context
.encoder
.begin_render_pass(&wgpu::RenderPassDescriptor {
label: Some("Blit Render Pass"),
color_attachments: &[Some(RenderPassColorAttachment {
view: color_view,
resolve_target: None,
ops: Operations {
load: color_load_op,
store: color_store_op,
},
depth_slice: None,
})],
depth_stencil_attachment: None,
timestamp_writes: None,
occlusion_query_set: None,
multiview_mask: None,
});
render_pass.set_pipeline(&self.pipeline);
render_pass.set_bind_group(0, self.cached_bind_group.as_ref().unwrap(), &[]);
render_pass.draw(0..3, 0..1);
drop(render_pass);
Ok(context.into_sub_graph_commands())
}
}