4 files changed, 22 insertions, 13 deletions

diff --git a/lib/nes/app/application.cc b/lib/nes/app/application.cc
index 4498f98..bb2f1e4 100644
--- a/lib/nes/app/application.cc
+++ b/lib/nes/app/application.cc
@@ -7,6 +7,16 @@
 
 namespace nes::app
 {
+	auto application::display_proxy::get_front() const -> span<rgb, display::width * display::height>
+	{
+		return buffer_front_;
+	}
+
+	auto application::display_proxy::set(u32 const x, u32 const y, rgb const value) -> void {
+		buffer_back_[y * display::width + x] = value;
+		base.set(x, y, value);
+	}
+	
 	auto application::display_proxy::switch_buffers() -> void
 	{
 		auto r = renderer{ base };
@@ -30,6 +40,7 @@ namespace nes::app
 			r.render_text_format(32, 29, color::fixed_white, attrs, "{}", fps_counter.get_fps());
 		}
 
+		swap(buffer_front_, buffer_back_);
 		base.switch_buffers();
 	}
 
@@ -74,7 +85,7 @@ namespace nes::app
 			{
 				if (event == input_event::key_down(key::escape))
 				{
-					screen_freeze_.freeze(display_);
+					screen_freeze_.freeze(display_.get_front());
 					screen_confirm_quit_.set_confirm(false);
 					display_.screen = &screen_freeze_;
 					display_.popup = &screen_confirm_quit_;
@@ -93,7 +104,7 @@ namespace nes::app
 
 			if (console_->get_status() != status::success)
 			{
-				screen_freeze_.freeze(display_);
+				screen_freeze_.freeze(display_.get_front());
 				display_.screen = &screen_freeze_;
 				show_error("Runtime error", console_->get_status(), action::go_to_browser());
 				console_.clear();
diff --git a/lib/nes/app/application.hh b/lib/nes/app/application.hh
index f0117b1..d0973e8 100644
--- a/lib/nes/app/application.hh
+++ b/lib/nes/app/application.hh
@@ -31,6 +31,9 @@ namespace nes::app
 		class display_proxy final : public display
 		{
 			preferences& preferences_;
+			rgb buffers_[2][display::width * display::height]{};
+			span<rgb, display::width * display::height> buffer_front_ = buffers_[0];
+			span<rgb, display::width * display::height> buffer_back_ = buffers_[1];
 
 		public:
 			fps_counter fps_counter;
@@ -44,8 +47,9 @@ namespace nes::app
 			{
 			}
 
-			auto get(u32 const x, u32 const y) const -> rgb override { return base.get(x, y); }
-			auto set(u32 const x, u32 const y, rgb const value) -> void override { base.set(x, y, value); }
+			auto set(u32 const x, u32 const y, rgb const value) -> void override;
+			auto get_front() const -> span<rgb, display::width * display::height>;
+
 			auto switch_buffers() -> void override;
 		};
 
diff --git a/lib/nes/app/ui/screen-freeze.cc b/lib/nes/app/ui/screen-freeze.cc
index 60410dd..68507db 100644
--- a/lib/nes/app/ui/screen-freeze.cc
+++ b/lib/nes/app/ui/screen-freeze.cc
@@ -3,15 +3,9 @@
 
 namespace nes::app
 {
-	auto screen_freeze::freeze(display const& disp) -> void
+	auto screen_freeze::freeze(span<rgb, display::width * display::height> front_buffer) -> void
 	{
-		for (auto y = u32{ 0 }; y < display::height; ++y)
-		{
-			for (auto x = u32{ 0 }; x < display::width; ++x)
-			{
-				frozen_data_[y * display::width + x] = disp.get(x, y);
-			}
-		}
+		copy(front_buffer.get_data(), frozen_data_, front_buffer.get_length());
 	}
 
 	auto screen_freeze::render(renderer& renderer) -> void
diff --git a/lib/nes/app/ui/screen-freeze.hh b/lib/nes/app/ui/screen-freeze.hh
index fe67aad..2ae1eb2 100644
--- a/lib/nes/app/ui/screen-freeze.hh
+++ b/lib/nes/app/ui/screen-freeze.hh
@@ -20,6 +20,6 @@ namespace nes::app
 		auto process_events() -> action override;
 
 		/// Update the image shown to the back buffer of the given display.
-		auto freeze(display const&) -> void;
+		auto freeze(span<rgb, display::width * display::height> front_buffer) -> void;
 	};
 } // namespace nes::app
\ No newline at end of file