globalmapper.SpatialDifference
==============================

.. currentmodule:: globalmapper
.. py:function:: SpatialDifference (GM_LayerHandle_t32 aLayer1, GM_LayerHandle_t32 aLayer2, GM_SpatialOps_Params_t aParams) -> GM_Error_t32

	The **Difference** operation is akin to the subtraction of layer 2 from layer 1. This operation will output the parts in
	layer 1 that are not covered by layer 2. Attributes for the new features are copied from their source features in
	the first input layer.
	
	:param GM_LayerHandle_t32 aLayer1: First layer in operation
	:param GM_LayerHandle_t32 aLayer2: Second layer in operation
	:param GM_SpatialOps_Params_t aParams: Parameters
	:returns: Error Code
	:rtype: GM_Error_t32