library: render: add LightAggregate implementation

src/render/light_aggregate.rs

@@ -0,0 +1,60 @@
+use crate::light;
+
+#[derive(Debug, PartialEq)]
+pub struct LightAggregate {
+    ambient_lights: Vec<light::AmbientLight>,
+    directional_lights: Vec<light::DirectionalLight>,
+    point_lights: Vec<light::PointLight>,
+    spot_lights: Vec<light::SpotLight>,
+}
+
+impl LightAggregate {
+    pub fn empty() -> Self {
+        LightAggregate::new(vec![], vec![], vec![], vec![])
+    }
+
+    pub fn new(
+        ambient_lights: Vec<light::AmbientLight>,
+        directional_lights: Vec<light::DirectionalLight>,
+        point_lights: Vec<light::PointLight>,
+        spot_lights: Vec<light::SpotLight>,
+    ) -> Self {
+        LightAggregate {
+            ambient_lights,
+            directional_lights,
+            point_lights,
+            spot_lights,
+        }
+    }
+}
+
+impl Default for LightAggregate {
+    fn default() -> Self {
+        LightAggregate::empty()
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn empty_works() {
+        let lights = LightAggregate::empty();
+        assert_eq!(
+            lights,
+            LightAggregate {
+                ambient_lights: vec![],
+                directional_lights: vec![],
+                point_lights: vec![],
+                spot_lights: vec![],
+            }
+        )
+    }
+
+    #[test]
+    fn default_is_empty() {
+        let lights = <LightAggregate as Default>::default();
+        assert_eq!(lights, LightAggregate::empty())
+    }
+}

src/render/mod.rs

@@ -1,2 +1,5 @@
+pub mod light_aggregate;
+pub use light_aggregate::*;
+
 pub mod object;
 pub use object::*;