| Offset | Contents |
|---|---|
| +0 | Window handle |
| +4 | Visible area minimum x (inclusive) |
| +8 | Visible area minimum y (inclusive) |
| +12 | Visible area maximum x (inclusive) |
| +16 | Visible area maximum y (inclusive) |
| +20 | Scroll x |
| +24 | Scroll y |
| +28 | Redraw rectangle minimum x (exclusive) |
| +32 | Redraw rectangle minimum y (exclusive) |
| +36 | Redraw rectangle maximum x (exclusive) |
| +40 | Redraw rectangle maximum y (exclusive) |