Scaffold C++20 screencast project with Meson, agent workflow, and phase plan

include/screencast/render/renderer.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include "screencast/codec/decoder.h"
+
+#include <cstdint>
+#include <memory>
+#include <optional>
+#include <string_view>
+
+namespace sc {
+
+struct RendererConfig {
+    std::string_view window_title = "screencast receiver";
+    int initial_width = 1280;
+    int initial_height = 720;
+};
+
+class Renderer {
+  public:
+    virtual ~Renderer () = default;
+
+    // Present one decoded frame. Returns false if the window was closed.
+    virtual bool present ( const DecodedFrame &frame ) = 0;
+
+    // Pump events (window close, resize). Non-blocking.
+    virtual bool poll_events () = 0;
+
+    // Destroy the window and release GPU resources.
+    virtual void shutdown () = 0;
+};
+
+class RendererFactory {
+  public:
+    static std::unique_ptr<Renderer> create ( const RendererConfig &config );
+};
+
+}  // namespace sc