Specifies sources of entity attributes.

Values:

IG_VECT_ATTR_SOURCE_ACTUAL	Use an actual value of attribute. Color is defined by its red, green, blue and alpha components, line type and fill type use they default values.
IG_VECT_ATTR_SOURCE_NONE	Same as IG_VECT_ATTR_SOURCE_ACTUAL.
IG_VECT_ATTR_SOURCE_BLOCK	Use an attribute attached to the current block.
IG_VECT_ATTR_SOURCE_LAYER	Use the layer attribute.

Remarks:

Attribute sources are applicable to draw color, fill color, line type, fill type and thickness.