This enumeration specifies highlight modes that can be used to visually identify the hotspot area.
Values:
| IG_ARTX_HIGHLIGHT_NONE | Do not highlight the area. |
| IG_ARTX_HIGHLIGHT_INVERT | Invert colors within the area. |
| IG_ARTX_HIGHLIGHT_OUTLINE | Draw an outline of the area. |
| IG_ARTX_HIGHLIGHT_PUSH | Display the area as if it were being pressed below the surface of the page. |