Refactor editor windowing and update renderer regression

editor/app/Windowing/EditorWindowShared.h

@@ -13,6 +13,26 @@ struct EditorWindowScreenPoint {
     std::int32_t y = 0;
 };
 
+struct EditorWindowScreenRect {
+    std::int32_t left = 0;
+    std::int32_t top = 0;
+    std::int32_t right = 0;
+    std::int32_t bottom = 0;
+
+    [[nodiscard]] std::int32_t Width() const {
+        return right - left;
+    }
+
+    [[nodiscard]] std::int32_t Height() const {
+        return bottom - top;
+    }
+
+    [[nodiscard]] bool Contains(const EditorWindowScreenPoint& point) const {
+        return point.x >= left && point.x < right &&
+            point.y >= top && point.y < bottom;
+    }
+};
+
 inline constexpr float kBorderlessTitleBarHeightDips = 28.0f;
 
 inline const ::XCEngine::UI::UIColor kShellSurfaceColor(0.10f, 0.10f, 0.10f, 1.0f);