Configure the focus regions on the camera.
camera_error_t camera_set_focus_regions(camera_handle_t handle, int numregions, camera_region_t *regions)
The handle returned by a call to the camera_open() function.
The number of regions to apply, which is the number of elements in the regions array.
A pointer to an array of focus regions to apply.
This function can be called if the CAMERA_FEATURE_REGIONFOCUS feature is available. You can determine whether the feature is available by calling the camera_can_feature() function.
You can configure as many regions as you want as long as it is less than the number of regions specified by the numsupported argument in the camera_get_focus_regions() function.
After setting the regions, the changes will be committed only after a call to camera_set_focus_mode() .
CAMERA_OK when the function successfully completes, otherwise another camera_error_t value that provides the reason that the call failed.