ArtX Curve mark.
Members:
| IG_ARTX_curve_bounds_get | Queries the bounding rectangle. |
| IG_ARTX_curve_create | Creates curve mark. |
| IG_ARTX_curve_line_get | Queries the annotation line attribute. |
| IG_ARTX_curve_line_set | Updates the annotation line attribute. |
| IG_ARTX_curve_opacity_get | Queries the Opacity attribute. |
| IG_ARTX_curve_opacity_set | Updates the Opacity attribute. |
| IG_ARTX_curve_point_count_get | Gets the number of curve points. |
| IG_ARTX_curve_points_get | Gets the curve points. |
| IG_ARTX_curve_points_set | Sets the curve points. |