replace overlay render target when viewport resizes

thermion_dart/lib/src/filament/src/implementation/ffi_view.dart

@@ -61,10 +61,25 @@ class FFIView extends View<Pointer<TView>> {
     await FilamentApp.instance!.updateRenderOrder();
   }
 
+  Timer? _overlayResize;
+
   @override
   Future setViewport(int width, int height) async {
     View_setViewport(view, width, height);
-    // await overlayView?.setViewport(width, height);
+
+    if (overlayManager != null) {
+      _overlayResize?.cancel();
+      _overlayResize = Timer(Duration(milliseconds: 33), () async {
+        var oldRenderTarget = overlayRenderTarget;
+        overlayRenderTarget =
+            await FilamentApp.instance!.createRenderTarget(width, height);
+        OverlayManager_setRenderTarget(
+            overlayManager!, overlayRenderTarget!.getNativeHandle());
+        await oldRenderTarget!.destroy();
+        print("Resized render target to ${width}x${height}");
+        print(StackTrace.current);
+      });
+    }
   }
 
   Future<RenderTarget?> getRenderTarget() async {

thermion_dart/native/include/c_api/TOverlayManager.h

@@ -28,6 +28,10 @@ EMSCRIPTEN_KEEPALIVE void OverlayManager_removeComponent(
     EntityId entityId
 );
 
+EMSCRIPTEN_KEEPALIVE void OverlayManager_setRenderTarget(
+    TOverlayManager *tOverlayManager,
+    TRenderTarget *tRenderTarget
+);
 
 #ifdef __cplusplus
 }

thermion_dart/native/include/components/OverlayComponentManager.hpp

@@ -1,8 +1,11 @@
 #pragma once
 
 #include <map>
+#include <mutex>
 #include <vector>
+
 #include <math/mat4.h>
+
 #include <filament/Engine.h>
 #include <filament/Material.h>
 #include <filament/MaterialInstance.h>
@@ -44,8 +47,24 @@ namespace thermion
             mEngine->destroy(mDepthMaterial);
         }
 
+        void setRenderTarget(filament::RenderTarget *renderTarget) {
+            std::lock_guard lock(mMutex);
+            mRenderTarget = renderTarget;
+            auto *color = mRenderTarget->getTexture(filament::RenderTarget::AttachmentPoint::COLOR);
+            for (auto it = begin(); it < end(); it++)
+            {
+                const auto &entity = getEntity(it);
+                auto componentInstance = getInstance(entity);
+                auto &materialInstance = elementAt<0>(componentInstance);    
+                materialInstance->setParameter("depth", color, mDepthSampler);
+            }
+
+        }
+
         void addOverlayComponent(utils::Entity target, filament::MaterialInstance *materialInstance)
         {
+            std::lock_guard lock(mMutex);
+
             auto *color = mRenderTarget->getTexture(filament::RenderTarget::AttachmentPoint::COLOR);
             materialInstance->setParameter("depth", color, mDepthSampler);
             if (!hasComponent(target))
@@ -58,6 +77,8 @@ namespace thermion
 
         void removeOverlayComponent(utils::Entity target)
         {
+            std::lock_guard lock(mMutex);
+
             if (hasComponent(target))
             {
                 removeComponent(target);
@@ -67,10 +88,12 @@ namespace thermion
 
         void update()
         {
-            if (!mView || !mScene || getComponentCount() == 0)
+            if (!mView || !mScene || !mRenderTarget || getComponentCount() == 0)
             {
                 return;
             }
+
+            std::lock_guard lock(mMutex);
             auto &rm = mEngine->getRenderableManager();
             std::map<utils::Entity, std::vector<filament::MaterialInstance *>> materials;
             auto *scene = mView->getScene();
@@ -138,6 +161,7 @@ namespace thermion
         }
 
     private:
+        std::mutex mMutex;
         filament::Engine *mEngine = std::nullptr_t();
         filament::View *mView = std::nullptr_t();
         filament::Scene *mScene = std::nullptr_t();

thermion_dart/native/src/c_api/TOverlayManager.cpp

@@ -29,13 +29,18 @@ EMSCRIPTEN_KEEPALIVE TOverlayManager *OverlayManager_create(TEngine *tEngine, TR
     return reinterpret_cast<TOverlayManager *>(overlayManager);
 }
 
+EMSCRIPTEN_KEEPALIVE void OverlayManager_setRenderTarget(TOverlayManager *tOverlayManager, TRenderTarget *tRenderTarget) {
+    auto *overlayManager = reinterpret_cast<OverlayComponentManager *>(tOverlayManager);
+    auto *renderTarget = reinterpret_cast<filament::RenderTarget *>(tRenderTarget);
+    overlayManager->setRenderTarget(renderTarget);
+}
+
 EMSCRIPTEN_KEEPALIVE void OverlayManager_addComponent(TOverlayManager *tOverlayManager, EntityId entityId, TMaterialInstance *tMaterialInstance) {
     auto *overlayManager = reinterpret_cast<OverlayComponentManager *>(tOverlayManager);
     auto *materialInstance = reinterpret_cast<filament::MaterialInstance *>(tMaterialInstance);
     overlayManager->addOverlayComponent(utils::Entity::import(entityId), materialInstance);
 }
 
-
 EMSCRIPTEN_KEEPALIVE void OverlayManager_removeComponent(TOverlayManager *tOverlayManager, EntityId entityId) {
     auto *overlayManager = reinterpret_cast<OverlayComponentManager *>(tOverlayManager);
     overlayManager->removeOverlayComponent(utils::Entity::import(entityId));