SNAPMODE

SNAPMODE_POINT	Snap to a vertex on a mesh.
SNAPMODE_EDGE	Snap to any point along an edge.
SNAPMODE_POLYGON	Snap to the surface of a polygon.
SNAPMODE_SPLINE	Snap to any point along a spline.
SNAPMODE_AXIS	Snap to the axis of an object.
SNAPMODE_INTERSECTION	Snap to the intersections of objects and guides.
SNAPMODE_MIDPOINT	Snap to midpoint. Allows sub-snapping.
SNAPMODE_EDGEMID	Snap to middle of an edge.
SNAPMODE_POLYGONCENTER	Snap to the center of individual polygons.
SNAPMODE_SPLINEMID	Snap to the middle of a spline segment.
SNAPMODE_WORKPLANE	Snap to the surface of the workplane.
SNAPMODE_GRIDPOINT	Snap to the intersection points of the grid on the workplane.
SNAPMODE_GRIDLINE	Snap to the grid lines on the workplane.
SNAPMODE_GUIDEMID	Snap to the mid point in between of static guides intersections.
SNAPMODE_GUIDE	Snap to guide obejcts.
SNAPMODE_DYNAMICGUIDE	Snap using dynamic or inferred guides.
SNAPMODE_ORTHO	Snap perpendicular to guides edges and splines.
SNAPMODE_PIXEL	Snap to the texture’s pixels in the UV viewport.