8 files changed, 109 insertions, 3 deletions
diff --git a/include/cru/platform/native_window.hpp b/include/cru/platform/native_window.hpp
index 3a8e27ad..2daf4870 100644
--- a/include/cru/platform/native_window.hpp
+++ b/include/cru/platform/native_window.hpp
@@ -32,7 +32,7 @@ struct NativeWindow : public virtual Interface {
   // The lefttop of the rect is relative to screen lefttop.
   virtual void SetWindowRect(const ui::Rect& rect) = 0;
 
-  virtual Painter* BeginDraw() = 0;
+  virtual Painter* BeginPaint() = 0;
 
   virtual Event<>* DestroyEvent() = 0;
   virtual Event<ui::Size>* ResizeEvent() = 0;
diff --git a/include/cru/platform/painter.hpp b/include/cru/platform/painter.hpp
index 4ad09247..77ca5098 100644
--- a/include/cru/platform/painter.hpp
+++ b/include/cru/platform/painter.hpp
@@ -8,8 +8,10 @@ struct Brush;
 struct Geometry;
 
 struct Painter : virtual Interface {
-  virtual void StrokeGeometry(Geometry* geometry, Brush* brush, float width) = 0;
+  virtual void StrokeGeometry(Geometry* geometry, Brush* brush,
+                              float width) = 0;
   virtual void FillGeometry(Geometry* geometry, Brush* brush) = 0;
   virtual void EndDraw() = 0;
+  virtual bool IsDisposed() = 0;
 };
 }  // namespace cru::platform
diff --git a/include/cru/platform/win/win_brush.hpp b/include/cru/platform/win/win_brush.hpp
index 2668215d..d32f6bbc 100644
--- a/include/cru/platform/win/win_brush.hpp
+++ b/include/cru/platform/win/win_brush.hpp
@@ -4,7 +4,13 @@
 #include "../brush.hpp"
 
 namespace cru::platform::win {
-class WinSolidColorBrush : public Object, public virtual SolidColorBrush {
+struct WinBrush : virtual Brush {
+  virtual ID2D1Brush* GetD2DBrush() = 0;
+};
+
+class WinSolidColorBrush : public Object,
+                           public virtual SolidColorBrush,
+                           public virtual WinBrush {
  public:
   explicit WinSolidColorBrush(
       Microsoft::WRL::ComPtr<ID2D1SolidColorBrush> brush);
@@ -17,6 +23,8 @@ class WinSolidColorBrush : public Object, public virtual SolidColorBrush {
   ui::Color GetColor() override;
   void SetColor(const ui::Color& color) override;
 
+  ID2D1Brush* GetD2DBrush() override { return brush_.Get(); }
+
  private:
   Microsoft::WRL::ComPtr<ID2D1SolidColorBrush> brush_;
 };
diff --git a/include/cru/platform/win/win_native_window.hpp b/include/cru/platform/win/win_native_window.hpp
index 8b787485..ae19c9f3 100644
--- a/include/cru/platform/win/win_native_window.hpp
+++ b/include/cru/platform/win/win_native_window.hpp
@@ -44,6 +44,8 @@ class WinNativeWindow : public Object, public virtual NativeWindow {
   // The lefttop of the rect is relative to screen lefttop.
   void SetWindowRect(const ui::Rect& rect) override;
 
+  Painter* BeginPaint() override;
+
   Event<>* DestroyEvent() override { return &destroy_event_; }
   Event<ui::Size>* ResizeEvent() override { return &resize_event_; }
   Event<>* PaintEvent() override { return &paint_event_; }
diff --git a/include/cru/platform/win/win_painter.hpp b/include/cru/platform/win/win_painter.hpp
new file mode 100644
index 00000000..7b71ccbd
--- /dev/null
+++ b/include/cru/platform/win/win_painter.hpp
@@ -0,0 +1,34 @@
+#pragma once
+#include "win_pre_config.hpp"
+
+#include "../painter.hpp"
+
+namespace cru::platform::win {
+class WinNativeWindow;
+
+class WinPainter : public Object, public virtual Painter {
+ public:
+  explicit WinPainter(WinNativeWindow* window);
+  WinPainter(const WinPainter& other) = delete;
+  WinPainter(WinPainter&& other) = delete;
+  WinPainter& operator=(const WinPainter& other) = delete;
+  WinPainter& operator=(WinPainter&& other) = delete;
+  ~WinPainter() override;
+
+  void StrokeGeometry(Geometry* geometry, Brush* brush, float width) override;
+  void FillGeometry(Geometry* geometry, Brush* brush) override;
+  void EndDraw() override;
+  bool IsDisposed() override { return is_disposed; }
+
+  void EndDrawAndDeleteThis() {
+    EndDraw();
+    delete this;
+  }
+
+ private:
+  WinNativeWindow* window_;
+  ID2D1RenderTarget* render_target_;
+
+  bool is_disposed = false;
+};
+}  // namespace cru::platform::win
diff --git a/src/platform_win/CMakeLists.txt b/src/platform_win/CMakeLists.txt
index 40c9d85a..c8a5840e 100644
--- a/src/platform_win/CMakeLists.txt
+++ b/src/platform_win/CMakeLists.txt
@@ -9,6 +9,7 @@ add_library(cru_platform_win STATIC
 	win_geometry.cpp
 	win_graph_factory.cpp
 	win_native_window.cpp
+	win_painter.cpp
 	window_class.cpp
 	window_manager.cpp
 	window_render_target.cpp)
diff --git a/src/platform_win/win_native_window.cpp b/src/platform_win/win_native_window.cpp
index 5c159290..ae740205 100644
--- a/src/platform_win/win_native_window.cpp
+++ b/src/platform_win/win_native_window.cpp
@@ -2,6 +2,7 @@
 
 #include "cru/platform/win/exception.hpp"
 #include "cru/platform/win/win_application.hpp"
+#include "cru/platform/win/win_painter.hpp"
 #include "cru/platform/win/window_class.hpp"
 #include "dpi_util.hpp"
 #include "window_manager.hpp"
@@ -111,6 +112,8 @@ void WinNativeWindow::SetWindowRect(const ui::Rect& rect) {
   }
 }
 
+Painter* WinNativeWindow::BeginPaint() { return new WinPainter(this); }
+
 bool WinNativeWindow::HandleNativeWindowMessage(HWND hwnd, UINT msg,
                                                 WPARAM w_param, LPARAM l_param,
                                                 LRESULT* result) {
diff --git a/src/platform_win/win_painter.cpp b/src/platform_win/win_painter.cpp
new file mode 100644
index 00000000..29777669
--- /dev/null
+++ b/src/platform_win/win_painter.cpp
@@ -0,0 +1,56 @@
+#include "cru/platform/win/win_painter.hpp"
+
+#include "cru/platform/win/exception.hpp"
+#include "cru/platform/win/graph_manager.hpp"
+#include "cru/platform/win/win_brush.hpp"
+#include "cru/platform/win/win_geometry.hpp"
+#include "cru/platform/win/win_native_window.hpp"
+#include "cru/platform/win/window_render_target.hpp"
+
+#include <cassert>
+
+namespace cru::platform::win {
+WinPainter::WinPainter(WinNativeWindow* window) {
+  assert(window);
+  window_ = window;
+  const auto window_render_target = window_->GetWindowRenderTarget();
+  render_target_ =
+      window_render_target->GetGraphManager()->GetD2D1DeviceContext();
+  window_render_target->SetAsTarget();
+  render_target_->BeginDraw();
+}
+
+WinPainter::~WinPainter() {
+  if (!IsDisposed()) {
+    ThrowIfFailed(render_target_->EndDraw());
+  }
+}
+
+void WinPainter::StrokeGeometry(Geometry* geometry, Brush* brush, float width) {
+  assert(!IsDisposed());
+  const auto g = dynamic_cast<WinGeometry*>(geometry);
+  assert(g);
+  const auto b = dynamic_cast<WinBrush*>(brush);
+  assert(b);
+
+  render_target_->DrawGeometry(g->GetNative(), b->GetD2DBrush(), width);
+}
+
+void WinPainter::FillGeometry(Geometry* geometry, Brush* brush) {
+  assert(!IsDisposed());
+  const auto g = dynamic_cast<WinGeometry*>(geometry);
+  assert(g);
+  const auto b = dynamic_cast<WinBrush*>(brush);
+  assert(b);
+
+  render_target_->FillGeometry(g->GetNative(), b->GetD2DBrush());
+}
+
+void WinPainter::EndDraw() {
+  if (!IsDisposed()) {
+    ThrowIfFailed(render_target_->EndDraw());
+    render_target_ = nullptr;
+    is_disposed = true;
+  }
+}
+}  // namespace cru::platform::win