add Font/Context

CMakeLists.txt

@@ -142,6 +142,7 @@ target_sources(nf7
 
     file/audio_context.cc
     file/audio_device.cc
+    file/font_context.cc
     file/gl_obj.cc
     file/luajit_context.cc
     file/luajit_node.cc

file/font_context.cc

@@ -0,0 +1,121 @@
+#include <atomic>
+#include <typeinfo>
+#include <memory>
+
+#include <ft2build.h>
+#include FT_FREETYPE_H
+
+#include <imgui.h>
+
+#include "nf7.hh"
+
+#include "common/dir_item.hh"
+#include "common/font_queue.hh"
+#include "common/generic_type_info.hh"
+#include "common/ptr_selector.hh"
+#include "common/thread.hh"
+
+
+namespace nf7 {
+namespace {
+
+class FontContext final : public nf7::File, public nf7::DirItem {
+ public:
+  static inline const nf7::GenericTypeInfo<FontContext> kType = {
+    "Font/Context", {"nf7::DirItem",}};
+  static void UpdateTypeTooltip() noexcept {
+    ImGui::TextUnformatted("Drives freetype context.");
+    ImGui::Bullet(); ImGui::TextUnformatted("implements nf7::font::Queue");
+    ImGui::Bullet(); ImGui::TextUnformatted(
+        "there's few merit to use multiple contexts");
+    ImGui::Bullet(); ImGui::TextUnformatted(
+        "the context remains alive after file deletion until unused");
+  }
+
+  class Queue;
+
+  FontContext(nf7::Env& env) noexcept :
+      nf7::File(kType, env),
+      nf7::DirItem(nf7::DirItem::kTooltip),
+      q_(std::make_shared<Queue>(*this)) {
+  }
+
+  FontContext(nf7::Deserializer& ar) : FontContext(ar.env()) {
+  }
+  void Serialize(nf7::Serializer&) const noexcept override {
+  }
+  std::unique_ptr<nf7::File> Clone(nf7::Env& env) const noexcept override {
+    return std::make_unique<FontContext>(env);
+  }
+
+  void UpdateTooltip() noexcept override;
+
+  nf7::File::Interface* interface(const std::type_info& t) noexcept {
+    return nf7::InterfaceSelector<
+        nf7::DirItem, nf7::font::Queue>(t).Select(this, q_.get());
+  }
+
+ private:
+  std::shared_ptr<Queue> q_;
+};
+
+class FontContext::Queue final : public nf7::font::Queue,
+    public std::enable_shared_from_this<FontContext::Queue> {
+ public:
+  struct SharedData final {
+   public:
+    std::atomic<bool> broken = false;
+    FT_Library        ft;
+  };
+  struct Runner final {
+   public:
+    Runner(const std::shared_ptr<SharedData>& d) noexcept : data_(d) {
+    }
+    void operator()(Task&& t) noexcept {
+      if (!data_->broken) {
+        t(data_->ft);
+      }
+    }
+   private:
+    std::shared_ptr<SharedData> data_;
+  };
+  using Thread = nf7::Thread<Runner, Task>;
+
+  Queue(FontContext& f) noexcept :
+      data_(std::make_shared<SharedData>()),
+      th_(std::make_shared<Thread>(f, Runner {data_})) {
+    th_->Push(th_, [data = data_](auto) {
+      if (const auto err = FT_Init_FreeType(&data->ft)) {
+        data->broken = true;
+      }
+    });
+  }
+  ~Queue() noexcept {
+    th_->Push(th_, [](auto ft) {
+      FT_Done_FreeType(ft);
+    });
+  }
+
+  void Push(const std::shared_ptr<nf7::Context>& ctx, Task&& task) noexcept override {
+    th_->Push(ctx, std::move(task));
+  }
+  std::shared_ptr<nf7::font::Queue> self() noexcept override {
+    return shared_from_this();
+  }
+
+  bool broken() const noexcept { return data_->broken; }
+  size_t tasksDone() const noexcept { return th_->tasksDone(); }
+
+ private:
+  std::shared_ptr<SharedData> data_;
+  std::shared_ptr<Thread>     th_;
+};
+
+
+void FontContext::UpdateTooltip() noexcept {
+  ImGui::Text("status    : %s", q_->broken()? "broken": "running");
+  ImGui::Text("tasks done: %zu", q_->tasksDone());
+}
+
+}  // namespace
+}  // namespace nf7