fix(engine): use ambient light from GlobalLight

3 files changed, 53 insertions, 12 deletions

diff --git a/engine/src/lighting.rs b/engine/src/lighting.rs
index d08276e..f41437a 100644
--- a/engine/src/lighting.rs
+++ b/engine/src/lighting.rs
@@ -6,7 +6,6 @@ use crate::util::builder;
 #[derive(Debug, Clone, Component)]
 pub struct LightSource
 {
-    pub ambient: Color<f32>,
     pub diffuse: Color<f32>,
     pub specular: Color<f32>,
 }
@@ -16,7 +15,6 @@ impl Default for LightSource
     fn default() -> Self
     {
         Self {
-            ambient: Color { red: 0.2, green: 0.2, blue: 0.2 },
             diffuse: Color { red: 0.5, green: 0.5, blue: 0.5 },
             specular: Color { red: 1.0, green: 1.0, blue: 1.0 },
         }
@@ -30,7 +28,7 @@ builder! {
 #[non_exhaustive]
 pub struct GlobalLight
 {
-    pub ambient_offset: Color<f32>,
+    pub ambient: Color<f32>,
 }
 }
 
diff --git a/engine/src/material.rs b/engine/src/material.rs
index 5e360cd..5c59a9a 100644
--- a/engine/src/material.rs
+++ b/engine/src/material.rs
@@ -3,6 +3,7 @@ use ecs::Component;
 use crate::color::Color;
 use crate::data_types::dimens::Dimens;
 use crate::texture::{Id as TextureId, Texture};
+use crate::util::builder;
 
 #[derive(Debug, Clone, Component)]
 #[non_exhaustive]
@@ -176,6 +177,27 @@ impl Default for Builder
     }
 }
 
+builder! {
+/// Material flags.
+#[builder(name = FlagsBuilder, derives = (Debug, Default, Clone))]
+#[derive(Debug, Default, Clone, Component)]
+#[non_exhaustive]
+pub struct Flags
+{
+    /// Whether to use material's ambient color instead of the global ambient color.
+    /// Default is `false`
+    pub use_ambient_color: bool,
+}
+}
+
+impl Flags
+{
+    pub fn builder() -> FlagsBuilder
+    {
+        FlagsBuilder::default()
+    }
+}
+
 fn create_1x1_white_texture() -> Texture
 {
     Texture::new_from_color(&Dimens { width: 1, height: 1 }, &Color::WHITE_U8)
diff --git a/engine/src/renderer/mod.rs b/engine/src/renderer/mod.rs
index 2035a3c..4f9d7e6 100644
--- a/engine/src/renderer/mod.rs
+++ b/engine/src/renderer/mod.rs
@@ -13,7 +13,7 @@ use crate::color::Color;
 use crate::data_types::dimens::Dimens;
 use crate::event::{Present as PresentEvent, Start as StartEvent};
 use crate::lighting::{GlobalLight, LightSource};
-use crate::material::Material;
+use crate::material::{Flags as MaterialFlags, Material};
 use crate::matrix::Matrix;
 use crate::mesh::Mesh;
 use crate::opengl::buffer::{Buffer, Usage as BufferUsage};
@@ -91,7 +91,13 @@ fn initialize(window: Single<Window>)
 }
 
 fn render(
-    query: Query<(Mesh, ShaderProgram, Material, Transform)>,
+    query: Query<(
+        Mesh,
+        ShaderProgram,
+        Material,
+        Option<MaterialFlags>,
+        Transform,
+    )>,
     light_source_query: Query<(LightSource, Transform)>,
     camera_query: Query<(Camera,)>,
     window: Single<Window>,
@@ -125,7 +131,11 @@ fn render(
 
     clear_buffers(BufferClearMask::COLOR | BufferClearMask::DEPTH);
 
-    for (mesh, shader_program, material, transform) in &query {
+    for (mesh, shader_program, material, material_flags, transform) in &query {
+        let material_flags = material_flags
+            .map(|material_flags| material_flags.clone())
+            .unwrap_or_default();
+
         let shader_program = gl_shader_programs
             .entry(shader_program.u64_hash())
             .or_insert_with(|| create_gl_shader_program(&shader_program).unwrap());
@@ -139,6 +149,7 @@ fn render(
 
         apply_light(
             &material,
+            &material_flags,
             &global_light,
             shader_program,
             light_source
@@ -346,6 +357,7 @@ fn apply_transformation_matrices(
 
 fn apply_light(
     material: &Material,
+    material_flags: &MaterialFlags,
     global_light: &GlobalLight,
     gl_shader_program: &mut GlShaderProgram,
     light_source: Option<(&LightSource, &Transform)>,
@@ -361,11 +373,12 @@ fn apply_light(
 
     gl_shader_program.set_uniform_vec_3fv(
         cstr!("light.ambient"),
-        &light_source
-            .map_or(Color::WHITE_F32, |(light_source, _)| {
-                light_source.ambient.clone()
-            })
-            .into(),
+        // There cannot be both a material ambient color and a global ambient color
+        &if material_flags.use_ambient_color {
+            Color::WHITE_F32.into()
+        } else {
+            global_light.ambient.clone().into()
+        },
     );
 
     gl_shader_program.set_uniform_vec_3fv(
@@ -388,7 +401,15 @@ fn apply_light(
 
     gl_shader_program.set_uniform_vec_3fv(
         cstr!("material.ambient"),
-        &(material.ambient.clone() + global_light.ambient_offset.clone()).into(),
+        // When using the material ambient color is disabled, the ambient color has to be
+        // white and not black since the material's ambient color is multiplied
+        // with the global ambient light in the shader
+        &if material_flags.use_ambient_color {
+            material.ambient.clone()
+        } else {
+            Color::WHITE_F32
+        }
+        .into(),
     );
 
     gl_shader_program