use crate::{
pipeline::constants::{OUTPUT_BUFFER_SIZE, PREVIEW_INDICES_BUFFER_SIZE, PREVIEW_TEXTURE_SIZE},
wgpu_render_state, OUTPUT_BUFFER,
};
use egui::TextureId;
use once_cell::unsync::OnceCell;
use std::{cell::RefCell, num::NonZeroU64};
use wgpu::*;
use super::preview_indices::PreviewIndices;
thread_local! {
static PREVIEW: OnceCell<Preview> = const { OnceCell::new() };
}
#[derive(Debug)]
pub struct Preview {
pipeline: RenderPipeline,
bind_group_layout: BindGroupLayout,
bind_group: RefCell<Option<BindGroup>>,
view: TextureView,
texture_id: TextureId,
}
impl Preview {
fn init() -> Self {
let texture_desc = TextureDescriptor {
size: Extent3d {
width: PREVIEW_TEXTURE_SIZE as u32,
height: PREVIEW_TEXTURE_SIZE as u32,
depth_or_array_layers: 1,
},
mip_level_count: 1,
sample_count: 1,
dimension: TextureDimension::D2,
format: TextureFormat::Bgra8Unorm,
usage: TextureUsages::COPY_SRC
| TextureUsages::RENDER_ATTACHMENT
| TextureUsages::TEXTURE_BINDING,
label: None,
view_formats: &[TextureFormat::Bgra8Unorm],
};
let wgpu_render_state = wgpu_render_state();
let device = wgpu_render_state.device;
let texture = device.create_texture(&texture_desc);
let view = texture.create_view(&TextureViewDescriptor::default());
let vertex_shader = device.create_shader_module(ShaderModuleDescriptor {
label: Some("preview vertex shader"),
source: ShaderSource::Wgsl(include_str!("../shaders/vertex.wgsl").into()),
});
let fragment_shader = device.create_shader_module(ShaderModuleDescriptor {
label: Some("preview fragment shader"),
source: ShaderSource::Wgsl(include_str!("../shaders/preview.wgsl").into()),
});
let bind_group_layout = device.create_bind_group_layout(&BindGroupLayoutDescriptor {
label: Some("preview bind group layout"),
entries: &[
BindGroupLayoutEntry {
binding: 0,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Buffer {
ty: BufferBindingType::Storage { read_only: true },
has_dynamic_offset: false,
min_binding_size: NonZeroU64::new(PREVIEW_INDICES_BUFFER_SIZE),
},
count: None,
},
BindGroupLayoutEntry {
binding: 1,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Buffer {
ty: BufferBindingType::Storage { read_only: true },
has_dynamic_offset: false,
min_binding_size: NonZeroU64::new(OUTPUT_BUFFER_SIZE),
},
count: None,
},
],
});
let pipeline_layout = device.create_pipeline_layout(&PipelineLayoutDescriptor {
label: Some("preview pipeline layout"),
bind_group_layouts: &[&bind_group_layout],
push_constant_ranges: &[],
});
let pipeline = device.create_render_pipeline(&RenderPipelineDescriptor {
cache: None,
label: Some("preview pipeline"),
layout: Some(&pipeline_layout),
vertex: VertexState {
module: &vertex_shader,
entry_point: Some("vs_main"),
buffers: &[],
compilation_options: Default::default(),
},
fragment: Some(FragmentState {
module: &fragment_shader,
entry_point: Some("fs_main"),
targets: &[Some(TextureFormat::Bgra8Unorm.into())],
compilation_options: Default::default(),
}),
primitive: PrimitiveState::default(),
depth_stencil: None,
multisample: MultisampleState::default(),
multiview: None,
});
let texture_id = wgpu_render_state.renderer.write().register_native_texture(
&device,
&view,
wgpu::FilterMode::Nearest,
);
Self {
pipeline,
bind_group_layout,
bind_group: RefCell::new(None),
view,
texture_id,
}
}
pub fn set_buffers() {
PREVIEW.with(|preview| {
let preview = preview.get_or_init(Self::init);
let device = wgpu_render_state().device;
preview
.bind_group
.replace(Some(device.create_bind_group(&BindGroupDescriptor {
label: Some("Preview bind group"),
layout: &preview.bind_group_layout,
entries: &[
BindGroupEntry {
binding: 0,
resource: PreviewIndices::get().indices().as_entire_binding(),
},
BindGroupEntry {
binding: 1,
resource: OUTPUT_BUFFER.as_entire_binding(),
},
],
})));
});
}
pub fn run(encoder: &mut CommandEncoder) {
PREVIEW.with(|preview| {
let preview = preview.get_or_init(Self::init);
if let Some(bind_group) = &*preview.bind_group.borrow() {
let mut render_pass = encoder.begin_render_pass(&RenderPassDescriptor {
label: Some("Renderer Pass"),
color_attachments: &[Some(RenderPassColorAttachment {
view: &preview.view,
resolve_target: None,
ops: Operations {
load: LoadOp::Clear(wgpu::Color {
r: 0.0,
g: 0.0,
b: 0.0,
a: 1.0,
}),
store: StoreOp::Store,
},
})],
depth_stencil_attachment: None,
timestamp_writes: None,
occlusion_query_set: None,
});
render_pass.set_pipeline(&preview.pipeline);
render_pass.set_bind_group(0, bind_group, &[]);
render_pass.draw(0..3, 0..1);
}
});
}
pub fn texture_id() -> TextureId {
PREVIEW.with(|preview| preview.get_or_init(Self::init).texture_id)
}
}