How to get Firemonkey to use the DirectX 9 context in Delphi XE3?

Question

In the main TForm3D window of the Firemonkey application in Delphi X3 there is Context:TContext3D , which gives me access to the currently used device.
In my case with Windows7 64, it always shows the TDX10Context object from FMX.Context.DX10.pas .

I have no visibility to create a new instance from the TDX9Context class from FMX.Context.DX9.pas to see the TCustomDX9Context ancestor.

I found the TContextManager class that collects register 3D contexts in a strict personal TList :(, this is the only class that can call the constructor ...

 { Don't call contructor directly from TContext - only using TContextManager class } constructor CreateFromWindow(const AParent: TFmxHandle; const AWidth, AHeight: Integer;` 

They call TContextManager to get context when creating new forms, then the readonly property TContextManager.DefaultContextClass .

Unable to find access to contexts other than DefaultContextClass .

Answer 1

For the record:

Put the following line in the project file:

 GlobalUseDX10 := False; <<-- add this. Application.Initialize; <<-- just before this line.