3 files changed, 83 insertions, 3 deletions
diff --git a/engine/src/lighting.rs b/engine/src/lighting.rs
index e0608ef..6944ee5 100644
--- a/engine/src/lighting.rs
+++ b/engine/src/lighting.rs
@@ -1,6 +1,7 @@
-use ecs::Component;
+use ecs::{Component, Sole};
 
 use crate::color::Color;
+use crate::util::builder;
 
 #[derive(Debug, Clone, Component)]
 pub struct LightSource
@@ -21,3 +22,22 @@ impl Default for LightSource
         }
     }
 }
+
+builder! {
+/// Global light properties.
+#[builder(name = GlobalLightBuilder, derives = (Debug, Clone, Default))]
+#[derive(Debug, Clone, Default, Sole)]
+#[non_exhaustive]
+pub struct GlobalLight
+{
+    pub ambient_offset: Color<f32>,
+}
+}
+
+impl GlobalLight
+{
+    pub fn builder() -> GlobalLightBuilder
+    {
+        GlobalLightBuilder::default()
+    }
+}
diff --git a/engine/src/renderer/mod.rs b/engine/src/renderer/mod.rs
index e2a567a..f9082fc 100644
--- a/engine/src/renderer/mod.rs
+++ b/engine/src/renderer/mod.rs
@@ -12,7 +12,7 @@ use crate::camera::Camera;
 use crate::color::Color;
 use crate::data_types::dimens::Dimens;
 use crate::event::{Present as PresentEvent, Start as StartEvent};
-use crate::lighting::LightSource;
+use crate::lighting::{GlobalLight, LightSource};
 use crate::material::Material;
 use crate::matrix::Matrix;
 use crate::mesh::Mesh;
@@ -95,6 +95,7 @@ fn render(
     light_source_query: Query<(LightSource, Transform)>,
     camera_query: Query<(Camera,)>,
     window: Single<Window>,
+    global_light: Single<GlobalLight>,
     mut gl_objects: Local<GlObjects>,
 )
 {
@@ -138,6 +139,7 @@ fn render(
 
         apply_light(
             &material,
+            &global_light,
             shader_program,
             light_source
                 .as_ref()
@@ -344,6 +346,7 @@ fn apply_transformation_matrices(
 
 fn apply_light(
     material: &Material,
+    global_light: &GlobalLight,
     gl_shader_program: &mut GlShaderProgram,
     light_source: Option<(&LightSource, &Transform)>,
     camera: &Camera,
@@ -385,7 +388,7 @@ fn apply_light(
 
     gl_shader_program.set_uniform_vec_3fv(
         cstr!("material.ambient"),
-        &material.ambient().clone().into(),
+        &(material.ambient().clone() + global_light.ambient_offset.clone()).into(),
     );
 
     gl_shader_program.set_uniform_vec_3fv(
diff --git a/engine/src/util.rs b/engine/src/util.rs
index b1a98ca..a7d5794 100644
--- a/engine/src/util.rs
+++ b/engine/src/util.rs
@@ -22,3 +22,60 @@ macro_rules! or {
 }
 
 pub(crate) use or;
+
+macro_rules! builder {
+    (
+        $(#[doc = $doc: literal])*
+        #[builder(
+            name = $builder_name: ident
+            $(, derives = ($($builder_derive: ident),+))?
+        )]
+        $(#[$attr: meta])*
+        $visibility: vis struct $name: ident
+        {
+            $(
+                $(#[$field_attr: meta])*
+                $field_visibility: vis $field: ident: $field_type: ty,
+            )*
+        }
+    ) => {
+        $(#[doc = $doc])*
+        $(#[$attr])*
+        $visibility struct $name
+        {
+            $(
+                $(#[$field_attr])*
+                $field_visibility $field: $field_type,
+            )*
+        }
+
+        $(#[derive($($builder_derive),+)])?
+        $visibility struct $builder_name
+        {
+            $(
+                $field: $field_type,
+            )*
+        }
+
+        impl $builder_name
+        {
+            $(
+                $visibility fn $field(mut self, $field: $field_type) -> Self
+                {
+                    self.$field = $field;
+                    self
+                }
+            )*
+
+            $visibility fn build(self) -> $name {
+                $name {
+                    $(
+                        $field: self.$field,
+                    )*
+                }
+            }
+        }
+    };
+}
+
+pub(crate) use builder;