As I noted above, Windows uses the device context to store ”attributes“ that govern how the GDI functions operate on the display. For instance, when you display some text using the TextOut function, you don't have to specify the color of the text or the font. Windows uses the device context to obtain this information.
When a program obtains a handle to a device context, Windows creates a device context with default values for all the attributes. The device context attributes are shown in the following table. A program can change or obtain any of the attributes.
| Device Context Attribute | Default | Function(s) to Change | Function(s) to Get |
| Mapping mode | MM_TEXT | SetMapMode | GetMapMode |
| Window origin | (0, 0) | SetWindowOrg | GetWindowOrg
OffsetWindowOrg |
| Viewport origin | (0, 0) | SetViewportOrg | GetViewportOrg
OffsetViewportOrg |
| Window extents | (1, 1) | SetWindowExt | GetWindowExt
SetMapMode |
| Viewport extents | (1, 1) | SetViewportExt | GetViewportExt
SetMapMode |
| Pen | BLACK_PE | SelectObject | SelectObject |
| Brush | WHITE_BRUSH | SelectObject | SelectObject |
| Font | SYSTEM_FONT | SelectObject | SelectObject |
| Bitmap | None | SelectObject | SelectObject |
| Current pen position | (0, 0) | MoveTo
LineTo |
GetCurrentPosition |
| Background mode | OPAQUE | SetBkMode | GetBkMode |
| Background color | White | SetBkColor | GetBkColor |
| Text color | Black | SetTextColor | GetTextColor |
| Drawing mode | R2_COPYPEN | SetROP2 | GetROP2 |
| Stretching mode | BLACKONWHITE | SetPolyFillMode | GetPolyFillMode |
| Polygon filling mode | ALTERNATE | SetPolyFillMode | GetPolyFillMode |
| Intercharacter spacing | 0 | SetTextCharacterExtra | GetTextCharacterExtra |
| Brush origin | (0, 0) in screen coordinates | SetBrushOrg | GetBrushOrg |
| Clipping region | None | SelectObject | SelectObject |
| SelectClipRgn
IntersectClipRect OffsetClipRgn ExcludeClipRect |
GetClipBox |