Function gvr_sys::gvr_buffer_viewport_set_source_fov

pub unsafe extern "C" fn gvr_buffer_viewport_set_source_fov(
    viewport: *mut gvr_buffer_viewport, 
    fov: gvr_rectf
)

Sets the field of view for the viewport contents.

This is a helper that sets the projection matrix in such a way that the viewport's contents fill the specified FOV around the eye's optical axis.

@param viewport The buffer viewport. @param fov The field of view to use when compositing the rendered image, in degrees.