Resolve some remaining TODOs for ui image processing changes

* Explicitly assert that neither of the requested dimensions for an
  image are 0. (I think this used to fail later on anyway)
* Don't show the UI alpha premultiply pass in GPU timings in the HUD
  debug info display since it only very transiently appears (since this
  doesn't run every frame).

voxygen/src/hud/mod.rs

@@ -2769,11 +2769,13 @@ impl Hud {
                 }
 
                 for (i, timing) in gpu_timings.iter().enumerate() {
-                    let timings_text = &format!(
-                        "{:16}{:.3} ms",
-                        &format!("{}:", timing.1),
-                        timing.2 * 1000.0,
-                    );
+                    let label = timing.1;
+                    // We skip displaying these since they aren't present every frame.
+                    if label.starts_with(crate::render::UI_PREMULTIPLY_PASS) {
+                        continue;
+                    }
+                    let timings_text =
+                        &format!("{:16}{:.3} ms", &format!("{label}:"), timing.2 * 1000.0,);
                     let timings_widget = Text::new(timings_text)
                         .color(TEXT_COLOR)
                         .down(V_PAD)

voxygen/src/render/mod.rs

@@ -53,7 +53,7 @@ pub use self::{
             DebugDrawer, DebugShadowDrawer, Drawer, FigureDrawer, FigureShadowDrawer,
             FirstPassDrawer, ParticleDrawer, PreparedUiDrawer, ShadowPassDrawer, SpriteDrawer,
             TerrainDrawer, TerrainShadowDrawer, ThirdPassDrawer, TrailDrawer,
-            TransparentPassDrawer, UiDrawer, VolumetricPassDrawer,
+            TransparentPassDrawer, UiDrawer, VolumetricPassDrawer, UI_PREMULTIPLY_PASS,
         },
         AltIndices, ColLightInfo, CullingMode, Renderer,
     },

voxygen/src/render/renderer/drawer.rs

@@ -20,6 +20,9 @@ use wgpu_profiler::scope::{ManualOwningScope, OwningScope, Scope};
 #[cfg(feature = "egui-ui")]
 use {common_base::span, egui_wgpu_backend::ScreenDescriptor, egui_winit_platform::Platform};
 
+/// Gpu timing label prefix associated with the UI alpha premultiplication pass.
+pub const UI_PREMULTIPLY_PASS: &str = "ui_premultiply_pass";
+
 // Currently available pipelines
 enum Pipelines<'frame> {
     Interface(&'frame super::InterfacePipelines),
@@ -447,10 +450,8 @@ impl<'frame> Drawer<'frame> {
 
         for (i, (target_texture, uploads)) in targets.into_iter().enumerate() {
             prof_span!("ui premultiply pass");
-            let profile_name = format!("ui_premultiply_pass {}", i);
-            let label = format!("ui premultiply pass {}", i);
-            // S-TODO: a GPU profile scope on each of the passes here may be a bit too fine
-            // grained.
+            let profile_name = format!("{UI_PREMULTIPLY_PASS} {i}");
+            let label = format!("ui premultiply pass {i}");
             let mut render_pass =
                 encoder.scoped_render_pass(&profile_name, device, &wgpu::RenderPassDescriptor {
                     label: Some(&label),

voxygen/src/ui/graphic/mod.rs

@@ -214,8 +214,6 @@ impl TextureRequirements {
         }
     }
 
-    // TODO: what if requested size is 0? Do we currently panic on this case and
-    // expect caller not to ask for 0 size? (if so document that)
     fn to_key_and_tex_parameters(
         self,
         graphic_id: Id,
@@ -387,6 +385,10 @@ impl GraphicCache {
 
     /// Source rectangle should be from 0 to 1, and represents a bounding box
     /// for the source image of the graphic.
+    ///
+    /// # Panics
+    ///
+    /// Panics if one of the lengths in requested_dims is zero.
     pub fn cache_res(
         &mut self,
         renderer: &mut Renderer,
@@ -399,6 +401,7 @@ impl GraphicCache {
         source: Aabr<f64>,
         rotation: Rotation,
     ) -> Option<((Aabr<f64>, Vec2<f32>), TexId)> {
+        assert!(requested_dims.map(|e| e != 0).reduce_and());
         let requested_dims_upright = match rotation {
             // The image is stored on the GPU with no rotation, so we need to swap the dimensions
             // here to get the resolution that the image will be displayed at but re-oriented into
@@ -433,15 +436,13 @@ impl GraphicCache {
         };
         // Apply all transformations.
         // TODO: Verify rotation is being applied correctly.
-        let transformed_aabr = |aabr| {
+        let transformed_aabr_and_scale = |aabr| {
             let scaled = scaled_aabr(aabr);
             // Calculate how many displayed pixels there are for each pixel in the source
             // image. We need this to calculate where to sample in the shader to
             // retain crisp pixel borders when scaling the image.
-            // S-TODO: A bit hacky inserting this here, just to get things working initially
             let scale = requested_dims_upright.map2(
                 Vec2::from(scaled.size()),
-                // S-TODO div by zero potential? If so, is NaN an issue in that case?
                 |screen_pixels, sample_pixels: f64| screen_pixels as f32 / sample_pixels as f32,
             );
             let transformed = rotated_aabr(scaled);
@@ -500,7 +501,10 @@ impl GraphicCache {
                     details.set_valid();
                 }
 
-                return Some((transformed_aabr(aabr.map(|e| e as f64)), TexId(idx)));
+                return Some((
+                    transformed_aabr_and_scale(aabr.map(|e| e as f64)),
+                    TexId(idx),
+                ));
             },
             Entry::Vacant(details) => details,
         };
@@ -592,7 +596,10 @@ impl GraphicCache {
         // Insert into cached map
         details.insert(location);
 
-        Some((transformed_aabr(aabr.map(|e| e as f64)), TexId(idx)))
+        Some((
+            transformed_aabr_and_scale(aabr.map(|e| e as f64)),
+            TexId(idx),
+        ))
     }
 }