Extract bounded additional scene lights

engine/src/Rendering/RenderSceneUtility.cpp

@@ -2,6 +2,7 @@
 
 #include "Components/CameraComponent.h"
 #include "Components/GameObject.h"
+#include "Components/LightComponent.h"
 #include "Components/MeshFilterComponent.h"
 #include "Components/MeshRendererComponent.h"
 #include "Components/TransformComponent.h"
@@ -139,5 +140,57 @@ std::vector<VisibleRenderItem> CollectRenderItemsForEntityIds(
     return visibleItems;
 }
 
+bool IsUsableLight(const Components::LightComponent* light) {
+    return light != nullptr &&
+           light->IsEnabled() &&
+           light->GetGameObject() != nullptr &&
+           light->GetGameObject()->IsActiveInHierarchy();
+}
+
+bool IsLightVisibleForCullingMask(
+    const Components::LightComponent& light,
+    uint32_t cullingMask) {
+    if (!IsUsableLight(&light)) {
+        return false;
+    }
+
+    const Components::GameObject* gameObject = light.GetGameObject();
+    const uint32_t gameObjectLayerMask = 1u << gameObject->GetLayer();
+    return (cullingMask & gameObjectLayerMask) != 0u;
+}
+
+Math::Vector3 BuildRenderLightDirection(
+    const Components::LightComponent& light) {
+    Math::Vector3 direction = light.transform().GetForward() * -1.0f;
+    if (direction.SqrMagnitude() <= Math::EPSILON) {
+        return Math::Vector3::Back();
+    }
+
+    return direction.Normalized();
+}
+
+Components::LightComponent* FindMainDirectionalLight(
+    const Components::Scene& scene,
+    uint32_t cullingMask) {
+    const std::vector<Components::LightComponent*> lights =
+        scene.FindObjectsOfType<Components::LightComponent>();
+
+    Components::LightComponent* mainDirectionalLight = nullptr;
+    for (Components::LightComponent* light : lights) {
+        if (light == nullptr ||
+            !IsLightVisibleForCullingMask(*light, cullingMask) ||
+            light->GetLightType() != Components::LightType::Directional) {
+            continue;
+        }
+
+        if (mainDirectionalLight == nullptr ||
+            light->GetIntensity() > mainDirectionalLight->GetIntensity()) {
+            mainDirectionalLight = light;
+        }
+    }
+
+    return mainDirectionalLight;
+}
+
 } // namespace Rendering
 } // namespace XCEngine