Clump together wgpu options in a struct

crates/eframe/src/native/wgpu_integration.rs

@@ -186,13 +186,15 @@ impl<'app> WgpuWinitApp<'app> {
         let mut painter = pollster::block_on(egui_wgpu::winit::Painter::new(
             egui_ctx.clone(),
             self.native_options.wgpu_options.clone(),
-            self.native_options.multisampling.max(1) as _,
             egui_wgpu::depth_format_from_bits(
                 self.native_options.depth_buffer,
                 self.native_options.stencil_buffer,
             ),
             self.native_options.viewport.transparent.unwrap_or(false),
-            self.native_options.dithering,
+            egui_wgpu::RendererOptions {
+                msaa_samples: self.native_options.multisampling.max(1) as _,
+                dithering: self.native_options.dithering,
+            },
         ));
 
         let window = Arc::new(window);

crates/egui-wgpu/src/lib.rs

@@ -174,8 +174,7 @@ impl RenderState {
         instance: &wgpu::Instance,
         compatible_surface: Option<&wgpu::Surface<'static>>,
         depth_format: Option<wgpu::TextureFormat>,
-        msaa_samples: u32,
+        options: RendererOptions,
-        dithering: bool,
     ) -> Result<Self, WgpuError> {
         profiling::scope!("RenderState::create"); // async yield give bad names using `profile_function`
 
@@ -244,13 +243,7 @@ impl RenderState {
         };
         let target_format = crate::preferred_framebuffer_format(&surface_formats)?;
 
-        let renderer = Renderer::new(
+        let renderer = Renderer::new(&device, target_format, depth_format, options);
-            &device,
-            target_format,
-            depth_format,
-            msaa_samples,
-            dithering,
-        );
 
         // On wasm, depending on feature flags, wgpu objects may or may not implement sync.
         // It doesn't make sense to switch to Rc for that special usecase, so simply disable the lint.

crates/egui-wgpu/src/renderer.rs

@@ -3,6 +3,7 @@
 use std::{borrow::Cow, num::NonZeroU64, ops::Range};
 
 use ahash::HashMap;
+use bytemuck::Zeroable as _;
 use epaint::{PaintCallbackInfo, Primitive, Vertex, emath::NumExt as _};
 
 use wgpu::util::DeviceExt as _;
@@ -175,6 +176,39 @@ pub struct Texture {
     pub options: Option<epaint::textures::TextureOptions>,
 }
 
+/// Ways to configure [`Renderer`] during creation.
+#[derive(Clone, Copy, Debug)]
+pub struct RendererOptions {
+    /// Set the level of the multisampling anti-aliasing (MSAA).
+    ///
+    /// Must be a power-of-two. Higher = more smooth 3D.
+    ///
+    /// A value of `0` turns it off (default).
+    ///
+    /// `egui` already performs anti-aliasing via "feathering"
+    /// (controlled by [`egui::epaint::TessellationOptions`]),
+    /// but if you are embedding 3D in egui you may want to turn on multisampling.
+    pub msaa_samples: u32,
+
+    /// Controls whether to apply dithering to minimize banding artifacts.
+    ///
+    /// Dithering assumes an sRGB output and thus will apply noise to any input value that lies between
+    /// two 8bit values after applying the sRGB OETF function, i.e. if it's not a whole 8bit value in "gamma space".
+    /// This means that only inputs from texture interpolation and vertex colors should be affected in practice.
+    ///
+    /// Defaults to true.
+    pub dithering: bool,
+}
+
+impl Default for RendererOptions {
+    fn default() -> Self {
+        Self {
+            msaa_samples: 0,
+            dithering: true,
+        }
+    }
+}
+
 /// Renderer for a egui based GUI.
 pub struct Renderer {
     pipeline: wgpu::RenderPipeline,
@@ -194,7 +228,7 @@ pub struct Renderer {
     next_user_texture_id: u64,
     samplers: HashMap<epaint::textures::TextureOptions, wgpu::Sampler>,
 
-    dithering: bool,
+    options: RendererOptions,
 
     /// Storage for resources shared with all invocations of [`CallbackTrait`]'s methods.
     ///
@@ -211,8 +245,7 @@ impl Renderer {
         device: &wgpu::Device,
         output_color_format: wgpu::TextureFormat,
         output_depth_format: Option<wgpu::TextureFormat>,
-        msaa_samples: u32,
+        options: RendererOptions,
-        dithering: bool,
     ) -> Self {
         profiling::function_scope!();
 
@@ -229,7 +262,7 @@ impl Renderer {
             label: Some("egui_uniform_buffer"),
             contents: bytemuck::cast_slice(&[UniformBuffer {
                 screen_size_in_points: [0.0, 0.0],
-                dithering: u32::from(dithering),
+                dithering: u32::from(options.dithering),
                 _padding: Default::default(),
             }]),
             usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
@@ -337,7 +370,7 @@ impl Renderer {
                 depth_stencil,
                 multisample: wgpu::MultisampleState {
                     alpha_to_coverage_enabled: false,
-                    count: msaa_samples,
+                    count: options.msaa_samples,
                     mask: !0,
                 },
 
@@ -392,17 +425,13 @@ impl Renderer {
             },
             uniform_buffer,
             // Buffers on wgpu are zero initialized, so this is indeed its current state!
-            previous_uniform_buffer_content: UniformBuffer {
+            previous_uniform_buffer_content: UniformBuffer::zeroed(),
-                screen_size_in_points: [0.0, 0.0],
-                dithering: 0,
-                _padding: 0,
-            },
             uniform_bind_group,
             texture_bind_group_layout,
             textures: HashMap::default(),
             next_user_texture_id: 0,
             samplers: HashMap::default(),
-            dithering,
+            options,
             callback_resources: CallbackResources::default(),
         }
     }
@@ -846,7 +875,7 @@ impl Renderer {
 
         let uniform_buffer_content = UniformBuffer {
             screen_size_in_points,
-            dithering: u32::from(self.dithering),
+            dithering: u32::from(self.options.dithering),
             _padding: Default::default(),
         };
         if uniform_buffer_content != self.previous_uniform_buffer_content {

crates/egui-wgpu/src/winit.rs

@@ -1,8 +1,11 @@
 #![allow(clippy::missing_errors_doc)]
 #![allow(clippy::undocumented_unsafe_blocks)]
 
-use crate::capture::{CaptureReceiver, CaptureSender, CaptureState, capture_channel};
 use crate::{RenderState, SurfaceErrorAction, WgpuConfiguration, renderer};
+use crate::{
+    RendererOptions,
+    capture::{CaptureReceiver, CaptureSender, CaptureState, capture_channel},
+};
 use egui::{Context, Event, UserData, ViewportId, ViewportIdMap, ViewportIdSet};
 use std::{num::NonZeroU32, sync::Arc};
 
@@ -21,9 +24,8 @@ struct SurfaceState {
 pub struct Painter {
     context: Context,
     configuration: WgpuConfiguration,
-    msaa_samples: u32,
+    options: RendererOptions,
     support_transparent_backbuffer: bool,
-    dithering: bool,
     depth_format: Option<wgpu::TextureFormat>,
     screen_capture_state: Option<CaptureState>,
 
@@ -54,10 +56,9 @@ impl Painter {
     pub async fn new(
         context: Context,
         configuration: WgpuConfiguration,
-        msaa_samples: u32,
         depth_format: Option<wgpu::TextureFormat>,
         support_transparent_backbuffer: bool,
-        dithering: bool,
+        options: RendererOptions,
     ) -> Self {
         let (capture_tx, capture_rx) = capture_channel();
         let instance = configuration.wgpu_setup.new_instance().await;
@@ -65,9 +66,8 @@ impl Painter {
         Self {
             context,
             configuration,
-            msaa_samples,
+            options,
             support_transparent_backbuffer,
-            dithering,
             depth_format,
             screen_capture_state: None,
 
@@ -205,8 +205,7 @@ impl Painter {
                 &self.instance,
                 Some(&surface),
                 self.depth_format,
-                self.msaa_samples,
+                self.options,
-                self.dithering,
             )
             .await?;
             self.render_state.get_or_insert(render_state)
@@ -292,7 +291,7 @@ impl Painter {
                             depth_or_array_layers: 1,
                         },
                         mip_level_count: 1,
-                        sample_count: self.msaa_samples,
+                        sample_count: self.options.msaa_samples,
                         dimension: wgpu::TextureDimension::D2,
                         format: depth_format,
                         usage: wgpu::TextureUsages::RENDER_ATTACHMENT
@@ -303,7 +302,7 @@ impl Painter {
             );
         }
 
-        if let Some(render_state) = (self.msaa_samples > 1)
+        if let Some(render_state) = (self.options.msaa_samples > 1)
             .then_some(self.render_state.as_ref())
             .flatten()
         {
@@ -320,7 +319,7 @@ impl Painter {
                             depth_or_array_layers: 1,
                         },
                         mip_level_count: 1,
-                        sample_count: self.msaa_samples,
+                        sample_count: self.options.msaa_samples,
                         dimension: wgpu::TextureDimension::D2,
                         format: texture_format,
                         usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
@@ -450,7 +449,7 @@ impl Painter {
             };
             let target_view = target_texture.create_view(&wgpu::TextureViewDescriptor::default());
 
-            let (view, resolve_target) = (self.msaa_samples > 1)
+            let (view, resolve_target) = (self.options.msaa_samples > 1)
                 .then_some(self.msaa_texture_view.get(&viewport_id))
                 .flatten()
                 .map_or((&target_view, None), |texture_view| {