Line-output functions create simple and complex line output with the selected pen. The following list briefly describes each line-output function:
| Function | Description | |
| Arc | Draws an arc. | |
| LineDDA | Computes successive points on a line. | |
| LineTo | Draws a line with the selected pen. | |
| MoveTo | Moves the current position to the specified point. | |
| Polyline | Draws a set of line segments. |
Figure 2.7 shows an arc created by using the Arc function. The upper portion of the illustration shows the arc as it would appear on a display; the lower portion shows the arc suspended in its bounding rectangle, which GDI uses to determine the size and shape of the arc: