engine: add optional labels to resource manager

engine/src/main.rs

@@ -103,13 +103,13 @@ impl Main {
                 20, 22, 21, 22, 20, 23,
 
             ]);
-            renderer.add_resource(Mesh::new(vertices, indices))
+            renderer.add_resource(Mesh::new(vertices, indices), Some("cube"))
         };
 
         let material = renderer.add_resource(PBRMaterialBuilder {
             diffuse: Texture::from_image(String::from("//assets/test-128px.png")),
             roughness: Texture::from_image(String::from("//assets/test-128px-roughness.png")),
-        }.build());
+        }.build(), Some("test-128px"));
 
         for x in -20..20 {
             for y in -20..20 {
@@ -122,7 +122,7 @@ impl Main {
             }
         }
 
-        let light = renderer.add_resource(Light::omni_test());
+        let light = renderer.add_resource(Light::omni_test(), Some("omni"));
 
         // The Sun (Sol) is 1AU from the Earth. We ignore the diameter of the Sun and the Earth, as
         // these are negligible at this scale.
@@ -135,7 +135,7 @@ impl Main {
         let sun_lumen: f32 = sun_luminous_emittance * (4.0 * 3.14159 * sun_distance * sun_distance);
 
         let sun_color = color::XYZ::new(sun_lumen/3.0, sun_lumen/3.0, sun_lumen/3.0);
-        let sun = renderer.add_resource(Light::omni_with_color(sun_color));
+        let sun = renderer.add_resource(Light::omni_with_color(sun_color), Some("sun"));
 
         // In our scene, the sun at a 30 degree zenith.
         let sun_angle: f32 = (3.14159 * 2.0) / (360.0 / 30.0);

engine/src/render/mod.rs

@@ -303,7 +303,7 @@ impl Renderer {
         return (close, events);
     }
 
-    pub fn add_resource<T: Resource>(&mut self, r: T) -> ResourceID<T> {
-        self.rm.add(r)
+    pub fn add_resource<T: Resource, S: ToString>(&mut self, r: T, label: Option<S>) -> ResourceID<T> {
+        self.rm.add(r, label)
     }
 }

engine/src/render/resource.rs

@@ -9,6 +9,8 @@ pub struct Manager {
     meshes: Map<Mesh>,
     materials: Map<Material>,
     lights: Map<Light>,
+
+    label_to_numeric: BTreeMap<String, u64>,
     counter: u64,
 }
 
@@ -19,6 +21,7 @@ impl Manager {
             materials: BTreeMap::new(),
             lights: BTreeMap::new(),
 
+            label_to_numeric: BTreeMap::new(),
             counter: 0,
         }
     }
@@ -27,15 +30,30 @@ impl Manager {
         T::map(&self)
     }
 
-    pub fn add<T: Resource>(&mut self, r: T) -> ResourceID<T> {
+    pub fn add<T: Resource, S: ToString>(&mut self, r: T, label: Option<S>) -> ResourceID<T> {
+        let numeric = self.counter;
+        if let Some(label) = label {
+            self.label_to_numeric.insert(label.to_string(), numeric);
+        }
         let id = ResourceID {
-            numerical: self.counter,
+            numeric,
             phantom: std::marker::PhantomData,
         };
+
         self.counter += 1;
         T::map_mut(self).insert(id, r);
         id
     }
+
+    pub fn by_label<T: Resource, S: ToString>(&self, label: S) -> Option<&T> {
+        let label = label.to_string();
+        let numeric = self.label_to_numeric.get(&label)?.clone();
+        let rid = ResourceID {
+            numeric,
+            phantom: std::marker::PhantomData,
+        };
+        T::map(self).get(&rid)
+    }
 }
 
 pub trait Resource: Sized {
@@ -58,14 +76,14 @@ impl Resource for Material {
 
 #[derive(Debug)]
 pub struct ResourceID<T: Resource> {
-    numerical: u64,
+    numeric: u64,
     phantom: std::marker::PhantomData<T>,
 }
 
 impl <T: Resource> Clone for  ResourceID<T> {
     fn clone(&self) -> ResourceID<T> {
         ResourceID {
-            numerical: self.numerical.clone(),
+            numeric: self.numeric.clone(),
             phantom: std::marker::PhantomData,
         }
     }
@@ -81,7 +99,7 @@ impl <T: Resource> ResourceID<T> {
 
 impl <T: Resource> Ord for ResourceID<T> {
     fn cmp(&self, other: &Self) -> Ordering {
-        self.numerical.cmp(&other.numerical)
+        self.numeric.cmp(&other.numeric)
     }
 }
 
@@ -93,7 +111,7 @@ impl <T: Resource> PartialOrd for ResourceID<T> {
 
 impl <T: Resource> PartialEq for ResourceID<T> {
     fn eq(&self, other: &Self) -> bool {
-        self.numerical == other.numerical
+        self.numeric == other.numeric
     }
 }