Own grid workers and thin Apple platform bridge

src/legacy_grid_ui_services.cpp

@@ -7,9 +7,89 @@
 #include "image.h"
 #include "node_panel_grid.h"
 
+#include <condition_variable>
+#include <deque>
+#include <functional>
+#include <mutex>
+#include <stop_token>
+#include <thread>
+
 namespace pp::panopainter {
 namespace {
 
+class LegacyGridWorker final {
+public:
+    LegacyGridWorker()
+        : worker_([this](std::stop_token stop_token) {
+            run(stop_token);
+        })
+    {
+    }
+
+    ~LegacyGridWorker()
+    {
+        shutdown();
+    }
+
+    void post(std::function<void()> task)
+    {
+        {
+            std::lock_guard<std::mutex> lock(mutex_);
+            if (stopping_)
+                return;
+            tasks_.push_back(std::move(task));
+        }
+        cv_.notify_one();
+    }
+
+private:
+    void shutdown()
+    {
+        {
+            std::lock_guard<std::mutex> lock(mutex_);
+            stopping_ = true;
+        }
+        cv_.notify_all();
+    }
+
+    void run(std::stop_token stop_token)
+    {
+        for (;;) {
+            std::function<void()> task;
+            {
+                std::unique_lock<std::mutex> lock(mutex_);
+                cv_.wait(lock, [&] {
+                    return stopping_ || stop_token.stop_requested() || !tasks_.empty();
+                });
+                if ((stopping_ || stop_token.stop_requested()) && tasks_.empty())
+                    break;
+                task = std::move(tasks_.front());
+                tasks_.pop_front();
+            }
+
+            if (task) {
+                try {
+                    task();
+                } catch (...) {
+                    LOG("grid worker task failed");
+                }
+            }
+        }
+    }
+
+    std::mutex mutex_;
+    std::condition_variable cv_;
+    std::deque<std::function<void()>> tasks_;
+    bool stopping_ = false;
+    std::jthread worker_;
+};
+
+LegacyGridWorker& grid_worker()
+{
+    static LegacyGridWorker worker;
+    return worker;
+}
+
 class LegacyGridUiServices final : public pp::app::GridUiServices {
 public:
     explicit LegacyGridUiServices(NodePanelGrid& panel) noexcept
@@ -66,13 +146,17 @@ public:
         if (!renders_lightmap)
             return;
 
-        auto* panel = &panel_;
-        std::thread([panel] {
+        auto panel = std::static_pointer_cast<NodePanelGrid>(panel_.shared_from_this());
+        grid_worker().post([panel] {
             BT_SetTerminate();
             panel->bake_uvs();
-            panel->m_hm_shading->set_index(3);
-            panel->m_shade_mode = NodePanelGrid::ShadeMode::Textured;
-        }).detach();
+            if (App::I) {
+                App::I->ui_task([panel] {
+                    panel->m_hm_shading->set_index(3);
+                    panel->m_shade_mode = NodePanelGrid::ShadeMode::Textured;
+                });
+            }
+        });
     }
 
     void commit_heightmap(bool updates_ground_opacity) override