default assets

bevy_asset/src/lib.rs

@@ -11,6 +11,7 @@ use std::{any::TypeId, collections::HashMap, marker::PhantomData};
 
 // TODO: move these types to their own files
 pub type HandleId = usize;
+pub const DEFAULT_HANDLE_ID: HandleId = 0;
 
 pub struct Handle<T> {
     pub id: HandleId,
@@ -58,11 +59,10 @@ impl<T> Debug for Handle<T> {
     }
 }
 
-// TODO: somehow handle this gracefully in asset managers. or alternatively remove Default
 impl<T> Default for Handle<T> {
     fn default() -> Self {
         Handle {
-            id: std::usize::MAX,
+            id: DEFAULT_HANDLE_ID,
             marker: PhantomData,
         }
     }
@@ -121,7 +121,7 @@ impl<T> AssetStorage<T> {
         AssetStorage {
             assets: HashMap::new(),
             names: HashMap::new(),
-            current_index: 0,
+            current_index: 1,
         }
     }
 
@@ -139,6 +139,11 @@ impl<T> AssetStorage<T> {
         }
     }
 
+    pub fn add_default(&mut self, asset: T) -> Handle<T> {
+        self.assets.insert(DEFAULT_HANDLE_ID, asset);
+        Handle::default()
+    }
+
     pub fn set_name(&mut self, name: &str, handle: Handle<T>) {
         self.names.insert(name.to_string(), handle);
     }

bevy_render/src/pipeline/pipelines/forward/mod.rs

@@ -15,7 +15,7 @@ pub trait ForwardPipelineBuilder {
 
 impl<'a, 'b, 'c> ForwardPipelineBuilder for RenderGraphBuilder<'a, 'b, 'c> {
     fn add_forward_pipeline(&mut self) -> &mut Self {
-        self.add_pipeline(resource_name::pipeline::FORWARD, |builder| {
+        self.add_default_pipeline(resource_name::pipeline::FORWARD, |builder| {
             builder
                 .with_vertex_shader(Shader::from_glsl(
                     ShaderStage::Vertex,

bevy_render/src/render_graph/render_graph_builder.rs

@@ -40,6 +40,20 @@ impl<'a, 'b, 'c> RenderGraphBuilder<'a, 'b, 'c> {
         self
     }
 
+    pub fn add_default_pipeline(&mut self, name: &str, build: impl Fn(&mut PipelineBuilder)) -> &mut Self {
+        if let Some(ref pass) = self.current_pass {
+            let mut builder = PipelineBuilder::new(name, &mut self.shaders);
+            build(&mut builder);
+            let pipeline = builder.finish();
+            let pipeline_descriptor_handle = self.pipelines.add_default(pipeline);
+            self.pipelines.set_name(name, pipeline_descriptor_handle);
+            self.render_graph
+                .add_pipeline(&pass, pipeline_descriptor_handle);
+        }
+
+        self
+    }
+
     pub fn add_pipeline_to_pass(
         &mut self,
         pass: &str,
@@ -59,6 +73,25 @@ impl<'a, 'b, 'c> RenderGraphBuilder<'a, 'b, 'c> {
         self
     }
 
+    pub fn add_default_pipeline_to_pass(
+        &mut self,
+        pass: &str,
+        name: &str,
+        build: impl Fn(&mut PipelineBuilder),
+    ) -> &mut Self {
+        {
+            let mut builder = PipelineBuilder::new(name, &mut self.shaders);
+            build(&mut builder);
+            let pipeline = builder.finish();
+            let pipeline_descriptor_handle = self.pipelines.add_default(pipeline);
+            self.pipelines.set_name(name, pipeline_descriptor_handle);
+            self.render_graph
+                .add_pipeline(pass, pipeline_descriptor_handle);
+        }
+
+        self
+    }
+
     pub fn add_resource_provider<T>(&mut self, resource_provider: T) -> &mut Self
     where
         T: ResourceProvider + Send + Sync + 'static,

bevy_render/src/renderable.rs

@@ -24,7 +24,7 @@ impl Default for Renderable {
         Renderable {
             is_visible: true,
             pipelines: vec![
-                Handle::new(0), // TODO: this could be better
+                Handle::default(),
             ],
             render_resource_assignments: RenderResourceAssignments::default(),
             is_instanced: false,