From e984d8cf71b8652cc757c2241230342405e97f86 Mon Sep 17 00:00:00 2001
From: Nick Fisher <nick.fisher@avinium.com>
Date: Tue, 1 Jul 2025 13:01:39 +0800
Subject: [PATCH] don't pass View to readPixels (only width/height, x/y offsets
 needed, and optionally rendertarget)

---
 .../filament/src/implementation/ffi_filament_app.dart    | 3 ++-
 thermion_dart/native/include/c_api/TRenderer.h           | 2 +-
 .../native/include/c_api/ThermionDartRenderThreadApi.h   | 2 +-
 thermion_dart/native/src/c_api/TRenderer.cpp             | 9 +++------
 .../native/src/c_api/ThermionDartRenderThreadApi.cpp     | 4 ++--
 5 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart b/thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart
index 06c8f8ff..87535a37 100644
--- a/thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart
+++ b/thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart
@@ -800,10 +800,11 @@ class FFIFilamentApp extends FilamentApp<Pointer> {
         if (captureRenderTarget && view.renderTarget == null) {
           throw Exception();
         }
+
         await withVoidCallback((requestId, cb) {
           Renderer_readPixelsRenderThread(
               renderer,
-              view.view,
+              viewport.width, viewport.height, 0, 0,
               view.renderTarget == null
                   ? nullptr
                   : view.renderTarget!.getNativeHandle(),
diff --git a/thermion_dart/native/include/c_api/TRenderer.h b/thermion_dart/native/include/c_api/TRenderer.h
index 069ddca3..b491d876 100644
--- a/thermion_dart/native/include/c_api/TRenderer.h
+++ b/thermion_dart/native/include/c_api/TRenderer.h
@@ -17,7 +17,7 @@ EMSCRIPTEN_KEEPALIVE void Renderer_render(TRenderer *tRenderer, TView *tView);
 EMSCRIPTEN_KEEPALIVE void Renderer_renderStandaloneView(TRenderer *tRenderer, TView *tView);
 EMSCRIPTEN_KEEPALIVE void Renderer_readPixels(
     TRenderer *tRenderer,
-    TView *tView,
+    uint32_t width, uint32_t height, uint32_t xOffset, uint32_t yOffset,
     TRenderTarget *tRenderTarget,
     TPixelDataFormat tPixelBufferFormat,
     TPixelDataType tPixelDataType,
diff --git a/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h b/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
index 6a72ed3d..c31e52dd 100644
--- a/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
+++ b/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
@@ -79,7 +79,7 @@ namespace thermion
         void Renderer_renderStandaloneViewRenderThread(TRenderer *tRenderer, TView *tView, uint32_t requestId,  VoidCallback onComplete);
         void Renderer_readPixelsRenderThread(
             TRenderer *tRenderer,
-            TView *tView,
+            uint32_t width, uint32_t height, uint32_t xOffset, uint32_t yOffset,
             TRenderTarget *tRenderTarget,
             TPixelDataFormat tPixelBufferFormat,
             TPixelDataType tPixelDataType,
diff --git a/thermion_dart/native/src/c_api/TRenderer.cpp b/thermion_dart/native/src/c_api/TRenderer.cpp
index f04fb6ee..24796cdb 100644
--- a/thermion_dart/native/src/c_api/TRenderer.cpp
+++ b/thermion_dart/native/src/c_api/TRenderer.cpp
@@ -93,7 +93,7 @@ class CaptureCallbackHandler : public filament::backend::CallbackHandler
 
 EMSCRIPTEN_KEEPALIVE void Renderer_readPixels(
     TRenderer *tRenderer,
-    TView *tView,
+    uint32_t width, uint32_t height, uint32_t xOffset, uint32_t yOffset,
     TRenderTarget *tRenderTarget,
     TPixelDataFormat tPixelBufferFormat,
     TPixelDataType tPixelDataType,
@@ -102,9 +102,6 @@ EMSCRIPTEN_KEEPALIVE void Renderer_readPixels(
     
     auto *renderer = reinterpret_cast<filament::Renderer *>(tRenderer);
     auto *renderTarget = reinterpret_cast<filament::RenderTarget *>(tRenderTarget);
-    auto *view = reinterpret_cast<filament::View *>(tView);
-
-    filament::Viewport const &vp = view->getViewport();
 
     filament::backend::PixelDataFormat pixelBufferFormat = static_cast<filament::backend::PixelDataFormat>(tPixelBufferFormat);
     filament::backend::PixelDataType pixelDataType = static_cast<filament::backend::PixelDataType>(tPixelDataType);
@@ -126,9 +123,9 @@ EMSCRIPTEN_KEEPALIVE void Renderer_readPixels(
     );
 
     if(renderTarget) {
-        renderer->readPixels(renderTarget, 0, 0, vp.width, vp.height, std::move(pbd));
+        renderer->readPixels(renderTarget, xOffset, yOffset, width, height, std::move(pbd));
     } else {
-        renderer->readPixels(0, 0, vp.width, vp.height, std::move(pbd));
+        renderer->readPixels(xOffset, yOffset, width, height, std::move(pbd));
     }
 
 }
diff --git a/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp b/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
index 3ce0a01b..6f00a17e 100644
--- a/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
+++ b/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
@@ -474,7 +474,7 @@ extern "C"
 
   EMSCRIPTEN_KEEPALIVE void Renderer_readPixelsRenderThread(
       TRenderer *tRenderer,
-      TView *tView,
+      uint32_t width, uint32_t height, uint32_t xOffset, uint32_t yOffset,
       TRenderTarget *tRenderTarget,
       TPixelDataFormat tPixelBufferFormat,
       TPixelDataType tPixelDataType,
@@ -485,7 +485,7 @@ extern "C"
     std::packaged_task<void()> lambda(
         [=]() mutable
         {
-          Renderer_readPixels(tRenderer, tView, tRenderTarget, tPixelBufferFormat, tPixelDataType, out, outLength);
+          Renderer_readPixels(tRenderer, width, height, xOffset, yOffset, tRenderTarget, tPixelBufferFormat, tPixelDataType, out, outLength);
           PROXY(onComplete(requestId));
         });
     auto fut = _renderThread->add_task(lambda);