use egui::{epaint::Primitive, PaintCallbackInfo};
use fxhash::FxHashMap;
use std::{borrow::Cow, num::NonZeroU32};
use type_map::concurrent::TypeMap;
use wgpu::util::DeviceExt as _;
use wgpu::{self, TextureViewDescriptor};
const EGUI_WGSL: &str = r#"
// Vertex shader bindings
struct VertexOutput {
@location(0) tex_coord: vec2<f32>,
@location(1) color: vec4<f32>,
@builtin(position) position: vec4<f32>,
};
struct Locals {
screen_size: vec2<f32>,
// Uniform buffers need to be at least 16 bytes in WebGL.
// See https://github.com/gfx-rs/wgpu/issues/2072
_padding: vec2<u32>,
};
@group(0) @binding(0) var<uniform> r_locals: Locals;
// 0-1 from 0-255
fn linear_from_srgb(srgb: vec3<f32>) -> vec3<f32> {
let cutoff = srgb < vec3<f32>(10.31475);
let lower = srgb / vec3<f32>(3294.6);
let higher = pow((srgb + vec3<f32>(14.025)) / vec3<f32>(269.025), vec3<f32>(2.4));
return select(higher, lower, cutoff);
}
// [u8; 4] SRGB as u32 -> [r, g, b, a]
fn unpack_color(color: u32) -> vec4<f32> {
return vec4<f32>(
f32(color & 255u),
f32((color >> 8u) & 255u),
f32((color >> 16u) & 255u),
f32((color >> 24u) & 255u),
);
}
fn position_from_screen(screen_pos: vec2<f32>) -> vec4<f32> {
return vec4<f32>(
2.0 * screen_pos.x / r_locals.screen_size.x - 1.0,
1.0 - 2.0 * screen_pos.y / r_locals.screen_size.y,
0.0,
1.0,
);
}
@vertex
fn vs_main(
@location(0) a_pos: vec2<f32>,
@location(1) a_tex_coord: vec2<f32>,
@location(2) a_color: u32,
) -> VertexOutput {
var out: VertexOutput;
out.tex_coord = a_tex_coord;
let color = unpack_color(a_color);
out.color = vec4<f32>(linear_from_srgb(color.rgb), color.a / 255.0);
out.position = position_from_screen(a_pos);
return out;
}
@vertex
fn vs_conv_main(
@location(0) a_pos: vec2<f32>,
@location(1) a_tex_coord: vec2<f32>,
@location(2) a_color: u32,
) -> VertexOutput {
var out: VertexOutput;
out.tex_coord = a_tex_coord;
let color = unpack_color(a_color);
out.color = vec4<f32>(color.rgba / 255.0);
out.position = position_from_screen(a_pos);
return out;
}
// Fragment shader bindings
@group(1) @binding(0) var r_tex_color: texture_2d<f32>;
@group(1) @binding(1) var r_tex_sampler: sampler;
@fragment
fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
return in.color * textureSample(r_tex_color, r_tex_sampler, in.tex_coord);
}
"#;
const IDX_BUF: &str = "egui_index_buffer";
const VTX_BUF: &str = "egui_vertex_buffer";
const UNI_BUF: &str = "egui_uniform_buffer";
const WG_RPAS: &str = "wgpu render pass";
const GRP_LAB: &str = "egui_pass";
pub struct CallbackFn {
prepare: Box<PrepareCallback>,
paint: Box<PaintCallback>,
}
type PrepareCallback = dyn Fn(&wgpu::Device, &wgpu::Queue, &mut TypeMap) + Sync + Send;
type PaintCallback =
dyn for<'a, 'b> Fn(PaintCallbackInfo, &'a mut wgpu::RenderPass<'b>, &'b TypeMap) + Sync + Send;
impl Default for CallbackFn {
fn default() -> Self {
CallbackFn {
prepare: Box::new(|_, _, _| ()),
paint: Box::new(|_, _, _| ()),
}
}
}
#[allow(dead_code)]
impl CallbackFn {
pub fn new() -> Self {
Self::default()
}
pub fn prepare<F>(mut self, prepare: F) -> Self
where
F: Fn(&wgpu::Device, &wgpu::Queue, &mut TypeMap) + Sync + Send + 'static,
{
self.prepare = Box::new(prepare) as _;
self
}
pub fn paint<F>(mut self, paint: F) -> Self
where
F: for<'a, 'b> Fn(PaintCallbackInfo, &'a mut wgpu::RenderPass<'b>, &'b TypeMap)
+ Sync
+ Send
+ 'static,
{
self.paint = Box::new(paint) as _;
self
}
}
#[derive(Debug)]
enum BufferType {
Uniform,
Index,
Vertex,
}
pub struct ScreenDescriptor {
pub size_in_pixels: [u32; 2],
pub pixels_per_point: f32,
}
impl ScreenDescriptor {
pub fn screen_size_in_points(&self) -> [f32; 2] {
[
self.size_in_pixels[0] as f32 / self.pixels_per_point,
self.size_in_pixels[1] as f32 / self.pixels_per_point,
]
}
}
#[derive(Clone, Copy, Debug, bytemuck::Pod, bytemuck::Zeroable)]
#[repr(C)]
struct UniformBuffer {
screen_size_in_points: [f32; 2],
_padding: [u32; 2],
}
#[derive(Debug)]
struct SizedBuffer {
buffer: wgpu::Buffer,
size: usize,
}
pub struct RenderPass<'a> {
render_pipeline: wgpu::RenderPipeline,
index_buffers: Vec<SizedBuffer>,
vertex_buffers: Vec<SizedBuffer>,
uniform_buffer: SizedBuffer,
uniform_bind_group: wgpu::BindGroup,
texture_bind_group_layout: wgpu::BindGroupLayout,
textures: FxHashMap<egui::TextureId, (Option<wgpu::Texture>, wgpu::BindGroup)>,
next_user_texture_id: u64,
pub paint_callback_resources: TypeMap,
sampler: wgpu::Sampler,
texture_size: wgpu::Extent3d,
pub tex_view_desc: TextureViewDescriptor<'a>,
}
impl<'a> RenderPass<'a> {
pub fn new(
device: &wgpu::Device,
texture_format: wgpu::TextureFormat,
msaa_samples: u32,
) -> Self {
let shader = wgpu::ShaderModuleDescriptor {
label: Some("egui_shader"),
source: wgpu::ShaderSource::Wgsl(Cow::Borrowed(EGUI_WGSL)),
};
let module = device.create_shader_module(shader);
let uniform_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some(UNI_BUF),
contents: bytemuck::cast_slice(&[UniformBuffer {
screen_size_in_points: [0.0, 0.0],
_padding: Default::default(),
}]),
usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
});
let uniform_buffer = SizedBuffer {
buffer: uniform_buffer,
size: std::mem::size_of::<UniformBuffer>(),
};
let uniform_bind_group_layout =
device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
label: Some("egui_uniform_bind_group_layout"),
entries: &[wgpu::BindGroupLayoutEntry {
binding: 0,
visibility: wgpu::ShaderStages::VERTEX,
ty: wgpu::BindingType::Buffer {
has_dynamic_offset: false,
min_binding_size: None,
ty: wgpu::BufferBindingType::Uniform,
},
count: None,
}],
});
let uniform_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
label: Some("egui_uniform_bind_group"),
layout: &uniform_bind_group_layout,
entries: &[wgpu::BindGroupEntry {
binding: 0,
resource: wgpu::BindingResource::Buffer(wgpu::BufferBinding {
buffer: &uniform_buffer.buffer,
offset: 0,
size: None,
}),
}],
});
let texture_bind_group_layout =
device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
label: Some("egui_texture_bind_group_layout"),
entries: &[
wgpu::BindGroupLayoutEntry {
binding: 0,
visibility: wgpu::ShaderStages::FRAGMENT,
ty: wgpu::BindingType::Texture {
multisampled: false,
sample_type: wgpu::TextureSampleType::Float { filterable: true },
view_dimension: wgpu::TextureViewDimension::D2,
},
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("egui_pipeline_layout"),
bind_group_layouts: &[&uniform_bind_group_layout, &texture_bind_group_layout],
push_constant_ranges: &[],
});
let mut multisample = wgpu::MultisampleState::default();
multisample.count = msaa_samples;
let render_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
label: Some("egui_pipeline"),
layout: Some(&pipeline_layout),
vertex: wgpu::VertexState {
entry_point: if texture_format.describe().srgb {
"vs_main"
} else {
"vs_conv_main"
},
module: &module,
buffers: &[wgpu::VertexBufferLayout {
array_stride: 5 * 4,
step_mode: wgpu::VertexStepMode::Vertex,
attributes: &wgpu::vertex_attr_array![0 => Float32x2, 1 => Float32x2, 2 => Uint32],
}],
},
primitive: wgpu::PrimitiveState {
topology: wgpu::PrimitiveTopology::TriangleList,
unclipped_depth: false,
conservative: false,
cull_mode: None,
front_face: wgpu::FrontFace::default(),
polygon_mode: wgpu::PolygonMode::default(),
strip_index_format: None,
},
depth_stencil: None,
multisample,
fragment: Some(wgpu::FragmentState {
module: &module,
entry_point: "fs_main",
targets: &[Some(wgpu::ColorTargetState {
format: texture_format,
blend: Some(wgpu::BlendState {
color: wgpu::BlendComponent {
src_factor: wgpu::BlendFactor::One,
dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
operation: wgpu::BlendOperation::Add,
},
alpha: wgpu::BlendComponent {
src_factor: wgpu::BlendFactor::OneMinusDstAlpha,
dst_factor: wgpu::BlendFactor::One,
operation: wgpu::BlendOperation::Add,
},
}),
write_mask: wgpu::ColorWrites::ALL,
})],
}),
multiview: None,
});
let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
label: None,
mag_filter: wgpu::FilterMode::Linear,
min_filter: wgpu::FilterMode::Nearest,
..Default::default()
});
let texture_size = wgpu::Extent3d {
width: 200,
height: 200,
depth_or_array_layers: 1,
};
Self {
render_pipeline,
vertex_buffers: Vec::with_capacity(64),
index_buffers: Vec::with_capacity(64),
uniform_buffer,
uniform_bind_group,
texture_bind_group_layout,
textures: FxHashMap::default(),
next_user_texture_id: 0,
paint_callback_resources: TypeMap::default(),
sampler,
texture_size,
tex_view_desc: TextureViewDescriptor::default(),
}
}
pub fn execute(
&self,
encoder: &mut wgpu::CommandEncoder,
color_attachment: &wgpu::TextureView,
paint_jobs: Vec<egui::epaint::ClippedPrimitive>,
screen_descriptor: &ScreenDescriptor,
clear_color: Option<wgpu::Color>,
) {
let load_operation = if let Some(color) = clear_color {
wgpu::LoadOp::Clear(color)
} else {
wgpu::LoadOp::Load
};
let mut rpass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
color_attachments: &[Some(wgpu::RenderPassColorAttachment {
view: color_attachment,
resolve_target: None,
ops: wgpu::Operations {
load: load_operation,
store: true,
},
})],
depth_stencil_attachment: None,
label: Some(WG_RPAS),
});
rpass.push_debug_group(GRP_LAB);
self.execute_with_renderpass(&mut rpass, paint_jobs, screen_descriptor);
rpass.pop_debug_group();
}
pub fn execute_with_renderpass<'rpass>(
&'rpass self,
rpass: &mut wgpu::RenderPass<'rpass>,
paint_jobs: Vec<egui::epaint::ClippedPrimitive>,
screen_descriptor: &ScreenDescriptor,
) {
let pixels_per_point = screen_descriptor.pixels_per_point;
let size_in_pixels = screen_descriptor.size_in_pixels;
let mut needs_reset = true;
let mut index_buffers = self.index_buffers.iter();
let mut vertex_buffers = self.vertex_buffers.iter();
for egui::ClippedPrimitive {
clip_rect,
primitive,
} in paint_jobs
{
if needs_reset {
rpass.set_viewport(
0.0,
0.0,
size_in_pixels[0] as f32,
size_in_pixels[1] as f32,
0.0,
1.0,
);
rpass.set_pipeline(&self.render_pipeline);
rpass.set_bind_group(0, &self.uniform_bind_group, &[]);
needs_reset = false;
}
{
let rect = ScissorRect::new(&clip_rect, pixels_per_point, size_in_pixels);
if rect.width == 0 || rect.height == 0 {
if let Primitive::Mesh(_) = primitive {
index_buffers.next().unwrap();
vertex_buffers.next().unwrap();
}
continue;
}
rpass.set_scissor_rect(rect.x, rect.y, rect.width, rect.height);
}
match primitive {
Primitive::Mesh(mesh) => {
let index_buffer = index_buffers.next().unwrap();
let vertex_buffer = vertex_buffers.next().unwrap();
if let Some((_texture, bind_group)) = self.textures.get(&mesh.texture_id) {
rpass.set_bind_group(1, bind_group, &[]);
rpass.set_index_buffer(
index_buffer.buffer.slice(..),
wgpu::IndexFormat::Uint32,
);
rpass.set_vertex_buffer(0, vertex_buffer.buffer.slice(..));
rpass.draw_indexed(0..mesh.indices.len() as u32, 0, 0..1);
} else {
eprintln!("Missing texture: {:?}", mesh.texture_id);
}
}
Primitive::Callback(callback) => {
let cbfn = if let Some(c) = callback.callback.downcast_ref::<CallbackFn>() {
c
} else {
continue;
};
if callback.rect.is_positive() {
needs_reset = true;
{
let rect_min_x = pixels_per_point * callback.rect.min.x;
let rect_min_y = pixels_per_point * callback.rect.min.y;
let rect_max_x = pixels_per_point * callback.rect.max.x;
let rect_max_y = pixels_per_point * callback.rect.max.y;
let rect_min_x = rect_min_x.round();
let rect_min_y = rect_min_y.round();
let rect_max_x = rect_max_x.round();
let rect_max_y = rect_max_y.round();
rpass.set_viewport(
rect_min_x,
rect_min_y,
rect_max_x - rect_min_x,
rect_max_y - rect_min_y,
0.0,
1.0,
);
}
(cbfn.paint)(
PaintCallbackInfo {
viewport: callback.rect,
clip_rect,
pixels_per_point,
screen_size_px: size_in_pixels,
},
rpass,
&self.paint_callback_resources,
);
}
}
}
}
rpass.set_scissor_rect(0, 0, size_in_pixels[0], size_in_pixels[1]);
}
pub fn update_texture(
&mut self,
device: &wgpu::Device,
queue: &wgpu::Queue,
id: egui::TextureId,
image_delta: &egui::epaint::ImageDelta,
) {
let width = image_delta.image.width() as u32;
let height = image_delta.image.height() as u32;
self.texture_size.width = width;
self.texture_size.height = height;
let data_color32 = match &image_delta.image {
egui::ImageData::Color(image) => {
assert_eq!(
width as usize * height as usize,
image.pixels.len(),
"Mismatch between texture size and texel count"
);
Cow::Borrowed(&image.pixels)
}
egui::ImageData::Font(image) => {
assert_eq!(
width as usize * height as usize,
image.pixels.len(),
"Mismatch between texture size and texel count"
);
Cow::Owned(image.srgba_pixels(1.0).collect::<Vec<_>>())
}
};
let queue_write_data_to_texture = |texture, origin| {
queue.write_texture(
wgpu::ImageCopyTexture {
texture,
mip_level: 0,
origin,
aspect: wgpu::TextureAspect::All,
},
bytemuck::cast_slice(data_color32.as_slice()),
wgpu::ImageDataLayout {
offset: 0,
bytes_per_row: NonZeroU32::new(4 * width),
rows_per_image: NonZeroU32::new(height),
},
self.texture_size,
);
};
if let Some(pos) = image_delta.pos {
let (texture, _bind_group) = self
.textures
.get(&id)
.expect("Tried to update a texture that has not been allocated yet.");
let origin = wgpu::Origin3d {
x: pos[0] as u32,
y: pos[1] as u32,
z: 0,
};
queue_write_data_to_texture(
texture.as_ref().expect("Tried to update user texture."),
origin,
);
} else {
let texture = device.create_texture(&wgpu::TextureDescriptor {
label: None,
size: self.texture_size,
mip_level_count: 1,
sample_count: 1,
dimension: wgpu::TextureDimension::D2,
format: wgpu::TextureFormat::Rgba8UnormSrgb,
usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::COPY_DST,
});
let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
label: None,
layout: &self.texture_bind_group_layout,
entries: &[
wgpu::BindGroupEntry {
binding: 0,
resource: wgpu::BindingResource::TextureView(
&texture.create_view(&self.tex_view_desc),
),
},
wgpu::BindGroupEntry {
binding: 1,
resource: wgpu::BindingResource::Sampler(&self.sampler),
},
],
});
let origin = wgpu::Origin3d::ZERO;
queue_write_data_to_texture(&texture, origin);
self.textures.insert(id, (Some(texture), bind_group));
};
}
pub fn free_texture(&mut self, id: &egui::TextureId) {
self.textures.remove(id);
}
pub fn texture(
&self,
id: &egui::TextureId,
) -> Option<&(Option<wgpu::Texture>, wgpu::BindGroup)> {
self.textures.get(id)
}
pub fn register_native_texture(
&mut self,
device: &wgpu::Device,
texture: &wgpu::TextureView,
texture_filter: wgpu::FilterMode,
) -> egui::TextureId {
self.register_native_texture_with_sampler_options(
device,
texture,
wgpu::SamplerDescriptor {
label: Some(
format!(
"egui_user_image_{}_texture_sampler",
self.next_user_texture_id
)
.as_str(),
),
mag_filter: texture_filter,
min_filter: texture_filter,
..Default::default()
},
)
}
#[allow(clippy::needless_pass_by_value)] pub fn register_native_texture_with_sampler_options(
&mut self,
device: &wgpu::Device,
texture: &wgpu::TextureView,
sampler_descriptor: wgpu::SamplerDescriptor<'_>,
) -> egui::TextureId {
let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
compare: None,
..sampler_descriptor
});
let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
label: Some(
format!(
"egui_user_image_{}_texture_bind_group",
self.next_user_texture_id
)
.as_str(),
),
layout: &self.texture_bind_group_layout,
entries: &[
wgpu::BindGroupEntry {
binding: 0,
resource: wgpu::BindingResource::TextureView(texture),
},
wgpu::BindGroupEntry {
binding: 1,
resource: wgpu::BindingResource::Sampler(&sampler),
},
],
});
let id = egui::TextureId::User(self.next_user_texture_id);
self.textures.insert(id, (None, bind_group));
self.next_user_texture_id += 1;
id
}
pub fn update_buffers(
&mut self,
device: &wgpu::Device,
queue: &wgpu::Queue,
paint_jobs: &[egui::epaint::ClippedPrimitive],
screen_descriptor: &ScreenDescriptor,
) {
let screen_size_in_points = screen_descriptor.screen_size_in_points();
self.update_buffer(
device,
queue,
&BufferType::Uniform,
0,
bytemuck::cast_slice(&[UniformBuffer {
screen_size_in_points,
_padding: Default::default(),
}]),
);
let mut mesh_idx = 0;
for egui::ClippedPrimitive { primitive, .. } in paint_jobs.iter() {
match primitive {
Primitive::Mesh(mesh) => {
{
let data: &[u8] = bytemuck::cast_slice(&mesh.indices);
if mesh_idx < self.index_buffers.len() {
self.update_buffer(device, queue, &BufferType::Index, mesh_idx, data);
} else {
let buffer =
device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some(IDX_BUF),
contents: data,
usage: wgpu::BufferUsages::INDEX | wgpu::BufferUsages::COPY_DST,
});
self.index_buffers.push(SizedBuffer {
buffer,
size: data.len(),
});
}
}
let data: &[u8] = bytemuck::cast_slice(&mesh.vertices);
if mesh_idx < self.vertex_buffers.len() {
self.update_buffer(device, queue, &BufferType::Vertex, mesh_idx, data);
} else {
let buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some(VTX_BUF),
contents: data,
usage: wgpu::BufferUsages::VERTEX | wgpu::BufferUsages::COPY_DST,
});
self.vertex_buffers.push(SizedBuffer {
buffer,
size: data.len(),
});
}
mesh_idx += 1;
}
Primitive::Callback(callback) => {
let cbfn = if let Some(c) = callback.callback.downcast_ref::<CallbackFn>() {
c
} else {
eprintln!("Unknown paint callback: expected `egui_gpu::CallbackFn`");
continue;
};
(cbfn.prepare)(device, queue, &mut self.paint_callback_resources);
}
}
}
}
fn update_buffer(
&mut self,
device: &wgpu::Device,
queue: &wgpu::Queue,
buffer_type: &BufferType,
index: usize,
data: &[u8],
) {
let (buffer, storage, label) = match buffer_type {
BufferType::Index => (
&mut self.index_buffers[index],
wgpu::BufferUsages::INDEX,
IDX_BUF,
),
BufferType::Vertex => (
&mut self.vertex_buffers[index],
wgpu::BufferUsages::VERTEX,
VTX_BUF,
),
BufferType::Uniform => (
&mut self.uniform_buffer,
wgpu::BufferUsages::UNIFORM,
UNI_BUF,
),
};
if data.len() > buffer.size {
buffer.size = data.len();
buffer.buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some(label),
contents: bytemuck::cast_slice(data),
usage: storage | wgpu::BufferUsages::COPY_DST,
});
} else {
queue.write_buffer(&buffer.buffer, 0, data);
}
}
}
struct ScissorRect {
x: u32,
y: u32,
width: u32,
height: u32,
}
impl ScissorRect {
fn new(clip_rect: &egui::Rect, pixels_per_point: f32, target_size: [u32; 2]) -> Self {
let clip_min_x = (pixels_per_point * clip_rect.min.x).round() as u32;
let clip_min_y = (pixels_per_point * clip_rect.min.y).round() as u32;
let clip_max_x = (pixels_per_point * clip_rect.max.x).round() as u32;
let clip_max_y = (pixels_per_point * clip_rect.max.y).round() as u32;
let clip_min_x = clip_min_x.clamp(0, target_size[0]);
let clip_min_y = clip_min_y.clamp(0, target_size[1]);
let clip_max_x = clip_max_x.clamp(clip_min_x, target_size[0]);
let clip_max_y = clip_max_y.clamp(clip_min_y, target_size[1]);
ScissorRect {
x: clip_min_x,
y: clip_min_y,
width: clip_max_x - clip_min_x,
height: clip_max_y - clip_min_y,
}
}
}