1 files changed, 61 insertions, 0 deletions
diff --git a/src/tests/common/offscreen_render_target.h b/src/tests/common/offscreen_render_target.h
new file mode 100644
index 0000000..10c12aa
--- /dev/null
+++ b/src/tests/common/offscreen_render_target.h
@@ -0,0 +1,61 @@
+// This file is part of the 64k demo project.
+// It provides offscreen rendering without windows (headless testing).
+// Enables pixel readback for frame validation in tests.
+
+#pragma once
+
+#include "platform/platform.h"
+#include <cstdint>
+#include <vector>
+
+// Offscreen render target for headless GPU testing
+// Creates a texture that can be rendered to and read back
+class OffscreenRenderTarget {
+ public:
+  // Create an offscreen render target with specified dimensions
+  OffscreenRenderTarget(
+      WGPUInstance instance, WGPUDevice device, int width, int height,
+      WGPUTextureFormat format = WGPUTextureFormat_BGRA8Unorm);
+  ~OffscreenRenderTarget();
+
+  // Accessors
+  WGPUTexture texture() const {
+    return texture_;
+  }
+  WGPUTextureView view() const {
+    return view_;
+  }
+  int width() const {
+    return width_;
+  }
+  int height() const {
+    return height_;
+  }
+  WGPUTextureFormat format() const {
+    return format_;
+  }
+
+  // Read pixels from the render target
+  // Returns BGRA8 pixel data (width * height * 4 bytes)
+  std::vector<uint8_t> read_pixels();
+
+ private:
+  WGPUInstance instance_;
+  WGPUDevice device_;
+  WGPUTexture texture_;
+  WGPUTextureView view_;
+  int width_;
+  int height_;
+  WGPUTextureFormat format_;
+
+  // Helper: Create staging buffer for readback
+  WGPUBuffer create_staging_buffer();
+
+  // Callback state for async buffer mapping
+  struct MapState {
+    bool done = false;
+    WGPUMapAsyncStatus status = WGPUMapAsyncStatus_Unknown;
+  };
+
+  static void map_callback(WGPUMapAsyncStatus status, void* userdata);
+};