Add GPU_ENABLE_PRELOADING_RESOURCES and use it on Web/Android/iOS to reduce engine resources preloading

Source/Engine/Graphics/Config.h

@@ -64,6 +64,11 @@
 #define GPU_ENABLE_ASYNC_RESOURCES_CREATION 1
 #endif
 
+// Enable/disable preloading GPU resources (eg. shaders, default assets)
+#ifndef GPU_ENABLE_PRELOADING_RESOURCES
+#define GPU_ENABLE_PRELOADING_RESOURCES 1
+#endif
+
 // Enable/disable force shaders recompilation
 #define GPU_FORCE_RECOMPILE_SHADERS 0
 

Source/Engine/Platform/Android/AndroidDefines.h

@@ -38,5 +38,6 @@
 
 #define GPU_ALLOW_TESSELLATION_SHADERS 0 // Tess on mobile is not well supported
 #define GPU_ALLOW_GEOMETRY_SHADERS 0 // Don't even try GS on mobile
+#define GPU_ENABLE_PRELOADING_RESOURCES 0 // Don't preload things unless needed
 
 #endif

Source/Engine/Platform/Web/WebDefines.h

@@ -18,6 +18,7 @@
 #define GPU_ALLOW_TESSELLATION_SHADERS 0
 #define GPU_ALLOW_GEOMETRY_SHADERS 0
 #define GPU_ALLOW_PROFILE_EVENTS 0
+#define GPU_ENABLE_PRELOADING_RESOURCES 0 // Don't preload things unless needed
 
 // Threading is optional
 #ifdef __EMSCRIPTEN_PTHREADS__

Source/Engine/Platform/iOS/iOSDefines.h

@@ -21,5 +21,6 @@
 
 #define GPU_ALLOW_TESSELLATION_SHADERS 0 // MoltenVK has artifacts when using tess so disable it
 #define GPU_ALLOW_GEOMETRY_SHADERS 0 // Don't even try GS on mobile
+#define GPU_ENABLE_PRELOADING_RESOURCES 0 // Don't preload things unless needed
 
 #endif

Source/Engine/Renderer/Renderer.cpp

@@ -105,6 +105,7 @@ bool RendererService::Init()
         return false;
     }
 
+#if GPU_ENABLE_PRELOADING_RESOURCES
     // Init child services
     for (int32 i = 0; i < PassList.Count(); i++)
     {
@@ -114,6 +115,7 @@ bool RendererService::Init()
             return true;
         }
     }
+#endif
 
     return false;
 }

Source/Engine/Renderer/RendererPass.h

@@ -21,7 +21,9 @@
 class FLAXENGINE_API RendererPassBase : public Object
 {
 protected:
-
+#if !GPU_ENABLE_PRELOADING_RESOURCES
+    bool _lazyInit = true;
+#endif
     bool _hasValidResources;
 
     /// <summary>
@@ -66,7 +68,13 @@ protected:
     {
         if (_hasValidResources)
             return false;
-
+#if !GPU_ENABLE_PRELOADING_RESOURCES
+        if (_lazyInit)
+        {
+            _lazyInit = false;
+            Init();
+        }
+#endif
         const bool setupFailed = setupResources();
         _hasValidResources = !setupFailed;
         return setupFailed;

Source/Engine/Terrain/TerrainManager.cpp

@@ -68,6 +68,15 @@ TerrainManagerService TerrainManagerServiceInstance;
 
 MaterialBase* TerrainManager::GetDefaultTerrainMaterial()
 {
+    if (!DefaultTerrainMaterial)
+    {
+        // Load default terrain material as fallback
+        DefaultTerrainMaterial = Content::LoadAsyncInternal<MaterialBase>(TEXT("Engine/DefaultTerrainMaterial"));
+        if (DefaultTerrainMaterial == nullptr)
+        {
+            LOG(Warning, "Default terrain material is missing.");
+        }
+    }
     return DefaultTerrainMaterial.Get();
 }
 
@@ -221,13 +230,9 @@ bool TerrainManager::GetChunkGeometry(DrawCall& drawCall, int32 chunkSize, int32
 
 bool TerrainManagerService::Init()
 {
-    // Load default terrain material as fallback
-    DefaultTerrainMaterial = Content::LoadAsyncInternal<MaterialBase>(TEXT("Engine/DefaultTerrainMaterial"));
-    if (DefaultTerrainMaterial == nullptr)
-    {
-        LOG(Warning, "Default terrain material is missing.");
-    }
-
+#if GPU_ENABLE_PRELOADING_RESOURCES
+    TerrainManager::GetDefaultTerrainMaterial();
+#endif
     return false;
 }