renderer: add zoom with detached camera (#12548)

src/helpers/MonitorZoomController.hpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include "./math/Math.hpp"
+
+struct SCurrentRenderData;
+
+class CMonitorZoomController {
+  public:
+    bool m_resetCameraState = true;
+
+    void applyZoomTransform(CBox& monbox, const SCurrentRenderData& m_renderData);
+
+  private:
+    void  zoomWithDetachedCamera(CBox& result, const SCurrentRenderData& m_renderData);
+
+    CBox  m_camera;
+    float m_lastZoomLevel = 1.0f;
+    bool  m_padCamEdges   = true;
+};