From 25ada92574f32ad9309992bef56ba82cfe965b71 Mon Sep 17 00:00:00 2001
From: Nick Fisher <nick.fisher@avinium.com>
Date: Tue, 13 May 2025 22:36:17 +0800
Subject: [PATCH] add View_pickRenderThread method (only used in WASM builds so
 we can proxy the callback to the main thread

---
 .../filament/src/implementation/ffi_view.dart | 40 +++++++++----------
 .../c_api/ThermionDartRenderThreadApi.h       |  1 +
 .../src/c_api/ThermionDartRenderThreadApi.cpp |  7 ++++
 3 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/thermion_dart/lib/src/filament/src/implementation/ffi_view.dart b/thermion_dart/lib/src/filament/src/implementation/ffi_view.dart
index 9bbce28a..7c4dcbb6 100644
--- a/thermion_dart/lib/src/filament/src/implementation/ffi_view.dart
+++ b/thermion_dart/lib/src/filament/src/implementation/ffi_view.dart
@@ -1,7 +1,6 @@
 import 'dart:async';
-import 'dart:math';
-
 import 'package:logging/logging.dart';
+import 'package:thermion_dart/src/bindings/src/js_interop.dart';
 import 'package:thermion_dart/src/filament/src/interface/scene.dart';
 import 'package:thermion_dart/src/filament/src/implementation/ffi_filament_app.dart';
 import 'package:thermion_dart/src/filament/src/implementation/ffi_render_target.dart';
@@ -11,7 +10,6 @@ import 'package:thermion_dart/thermion_dart.dart';
 import 'ffi_camera.dart';
 
 class FFIView extends View {
-
   late final _logger = Logger(this.runtimeType.toString());
   int _renderOrder = 0;
   int get renderOrder => _renderOrder;
@@ -26,15 +24,13 @@ class FFIView extends View {
 
   late CallbackHolder<PickCallbackFunction> _onPickResultHolder;
 
-
   FFIView(this.view, this.app) {
     final renderTargetPtr = View_getRenderTarget(view);
     if (renderTargetPtr != nullptr) {
       renderTarget = FFIRenderTarget(renderTargetPtr, app);
     }
-    
-    _onPickResultHolder =
-        _onPickResult.asCallback();
+
+    _onPickResultHolder = _onPickResult.asCallback();
   }
 
   ///
@@ -113,8 +109,8 @@ class FFIView extends View {
 
   @override
   Future setBloom(bool enabled, double strength) async {
-    await withVoidCallback((requestId,cb) {
-      View_setBloomRenderThread(view, enabled, strength, requestId,cb);
+    await withVoidCallback((requestId, cb) {
+      View_setBloomRenderThread(view, enabled, strength, requestId, cb);
     });
   }
 
@@ -174,27 +170,30 @@ class FFIView extends View {
   }
 
   int _pickRequestId = -1;
-  
+
   static int kMaxPickRequests = 1024;
-  final _pickRequests = List<({void Function(PickResult) handler, int x, int y})?>.generate(kMaxPickRequests, (idx) => null);
-  
-  
+  final _pickRequests =
+      List<({void Function(PickResult) handler, int x, int y})?>.generate(
+          kMaxPickRequests, (idx) => null);
+
   ///
   ///
   ///
   @override
   Future pick(int x, int y, void Function(PickResult) resultHandler) async {
-    _pickRequestId = max(_pickRequestId + 1, kMaxPickRequests);
-    
+    _pickRequestId++;
+    var pickRequestId = _pickRequestId;
+
     _pickRequests[_pickRequestId % kMaxPickRequests] =
         (handler: resultHandler, x: x, y: y);
-    var pickRequestId = _pickRequestId;
+
     var viewport = await getViewport();
     y = viewport.height - y;
-
-    View_pick(
-        view, pickRequestId, x, y, _onPickResultHolder.pointer);
-
+    if (FILAMENT_WASM) {
+      View_pickRenderThread(view, pickRequestId, x, y, _onPickResultHolder.pointer);
+    } else {
+      View_pick(view, pickRequestId, x, y, _onPickResultHolder.pointer);
+    }
   }
 
   void _onPickResult(int requestId, ThermionEntity entityId, double depth,
@@ -220,5 +219,4 @@ class FFIView extends View {
       fragZ: fragZ,
     ));
   }
-
 }
diff --git a/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h b/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
index 34cac45c..fb8799bc 100644
--- a/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
+++ b/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
@@ -87,6 +87,7 @@ namespace thermion
         void Material_createGizmoMaterialRenderThread(TEngine *tEngine, void (*onComplete)(TMaterial *));
 
         void ColorGrading_createRenderThread(TEngine *tEngine, TToneMapping toneMapping, void (*callback)(TColorGrading *));  
+        void View_pickRenderThread(TView *tView, uint32_t requestId, uint32_t x, uint32_t y, PickCallback callback);
         void View_setColorGradingRenderThread(TView *tView, TColorGrading *tColorGrading, uint32_t requestId,  VoidCallback onComplete);
         void View_setBloomRenderThread(TView *tView, bool enabled, double strength, uint32_t requestId,  VoidCallback onComplete);
         void View_setCameraRenderThread(TView *tView, TCamera *tCamera, uint32_t requestId,  VoidCallback onComplete);
diff --git a/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp b/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
index 1ab23cc6..fce6a651 100644
--- a/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
+++ b/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
@@ -554,6 +554,13 @@ EMSCRIPTEN_KEEPALIVE void SceneAsset_createFromFilamentAssetRenderThread(
     auto fut = _renderThread->add_task(lambda);
   }
 
+  EMSCRIPTEN_KEEPALIVE void View_pickRenderThread(TView *tView, uint32_t requestId, uint32_t x, uint32_t y, PickCallback callback) {
+    auto *view = reinterpret_cast<View *>(tView);
+    view->pick(x, y, [=](filament::View::PickingQueryResult const &result) {       
+      PROXY(callback(requestId, utils::Entity::smuggle(result.renderable), result.depth, result.fragCoords.x, result.fragCoords.y, result.fragCoords.z));
+    });
+  }
+
   EMSCRIPTEN_KEEPALIVE void View_setColorGradingRenderThread(TView *tView, TColorGrading *tColorGrading, uint32_t requestId, VoidCallback onComplete)
   {
     std::packaged_task<void()> lambda(