Avoid generating empty caches in iced_wgpu

wgpu/src/geometry.rs

@@ -38,8 +38,8 @@ pub enum Geometry {
 
 #[derive(Clone)]
 pub struct Cache {
-    pub meshes: triangle::Cache,
-    pub text: text::Cache,
+    pub meshes: Option<triangle::Cache>,
+    pub text: Option<text::Cache>,
 }
 
 impl Cached for Geometry {
@@ -53,8 +53,17 @@ impl Cached for Geometry {
         match self {
             Self::Live { meshes, text } => {
                 if let Some(mut previous) = previous {
-                    previous.meshes.update(meshes);
-                    previous.text.update(text);
+                    if let Some(cache) = &mut previous.meshes {
+                        cache.update(meshes);
+                    } else {
+                        previous.meshes = triangle::Cache::new(meshes);
+                    }
+
+                    if let Some(cache) = &mut previous.text {
+                        cache.update(text);
+                    } else {
+                        previous.text = text::Cache::new(text);
+                    }
 
                     previous
                 } else {

wgpu/src/lib.rs

@@ -517,8 +517,13 @@ impl graphics::geometry::Renderer for Renderer {
                 self.layers.draw_text_group(text);
             }
             Geometry::Cached(cache) => {
-                self.layers.draw_mesh_cache(cache.meshes);
-                self.layers.draw_text_cache(cache.text);
+                if let Some(meshes) = cache.meshes {
+                    self.layers.draw_mesh_cache(meshes);
+                }
+
+                if let Some(text) = cache.text {
+                    self.layers.draw_text_cache(text);
+                }
             }
         }
     }

wgpu/src/text.rs

@@ -43,14 +43,18 @@ pub struct Cache {
 pub struct Id(u64);
 
 impl Cache {
-    pub fn new(text: Vec<Text>) -> Self {
+    pub fn new(text: Vec<Text>) -> Option<Self> {
         static NEXT_ID: AtomicU64 = AtomicU64::new(0);
 
-        Self {
+        if text.is_empty() {
+            return None;
+        }
+
+        Some(Self {
             id: Id(NEXT_ID.fetch_add(1, atomic::Ordering::Relaxed)),
             text: Rc::from(text),
             version: 0,
-        }
+        })
     }
 
     pub fn update(&mut self, text: Vec<Text>) {
@@ -78,8 +82,12 @@ impl Storage {
         Self::default()
     }
 
-    fn get(&self, id: Id) -> Option<&Upload> {
-        self.uploads.get(&id)
+    fn get(&self, cache: &Cache) -> Option<&Upload> {
+        if cache.text.is_empty() {
+            return None;
+        }
+
+        self.uploads.get(&cache.id)
     }
 
     fn prepare(
@@ -97,8 +105,9 @@ impl Storage {
             hash_map::Entry::Occupied(entry) => {
                 let upload = entry.into_mut();
 
-                if upload.version != cache.version
-                    || upload.transformation != new_transformation
+                if !cache.text.is_empty()
+                    && (upload.version != cache.version
+                        || upload.transformation != new_transformation)
                 {
                     let _ = prepare(
                         device,
@@ -154,6 +163,12 @@ impl Storage {
                     transformation: new_transformation,
                     version: 0,
                 });
+
+                log::info!(
+                    "New text upload: {} (total: {})",
+                    cache.id.0,
+                    self.uploads.len()
+                );
             }
         }
 
@@ -291,7 +306,7 @@ impl Pipeline {
                     layer_count += 1;
                 }
                 Item::Cached { cache, .. } => {
-                    if let Some(upload) = storage.get(cache.id) {
+                    if let Some(upload) = storage.get(cache) {
                         upload
                             .renderer
                             .render(&upload.atlas, render_pass)

wgpu/src/triangle.rs

@@ -38,14 +38,18 @@ pub struct Cache {
 pub struct Id(u64);
 
 impl Cache {
-    pub fn new(meshes: Vec<Mesh>) -> Self {
+    pub fn new(meshes: Vec<Mesh>) -> Option<Self> {
         static NEXT_ID: AtomicU64 = AtomicU64::new(0);
 
-        Self {
+        if meshes.is_empty() {
+            return None;
+        }
+
+        Some(Self {
             id: Id(NEXT_ID.fetch_add(1, atomic::Ordering::Relaxed)),
             batch: Rc::from(meshes),
             version: 0,
-        }
+        })
     }
 
     pub fn update(&mut self, meshes: Vec<Mesh>) {
@@ -72,8 +76,12 @@ impl Storage {
         Self::default()
     }
 
-    fn get(&self, id: Id) -> Option<&Upload> {
-        self.uploads.get(&id)
+    fn get(&self, cache: &Cache) -> Option<&Upload> {
+        if cache.batch.is_empty() {
+            return None;
+        }
+
+        self.uploads.get(&cache.id)
     }
 
     fn prepare(
@@ -90,8 +98,9 @@ impl Storage {
             hash_map::Entry::Occupied(entry) => {
                 let upload = entry.into_mut();
 
-                if upload.version != cache.version
-                    || upload.transformation != new_transformation
+                if !cache.batch.is_empty()
+                    && (upload.version != cache.version
+                        || upload.transformation != new_transformation)
                 {
                     upload.layer.prepare(
                         device,
@@ -125,6 +134,12 @@ impl Storage {
                     transformation: new_transformation,
                     version: 0,
                 });
+
+                log::info!(
+                    "New mesh upload: {} (total: {})",
+                    cache.id.0,
+                    self.uploads.len()
+                );
             }
         }
 
@@ -247,7 +262,7 @@ impl Pipeline {
                 transformation,
                 cache,
             } => {
-                let upload = storage.get(cache.id)?;
+                let upload = storage.get(cache)?;
 
                 Some((
                     &upload.layer,